A111D2 fiDfifl3b

NAFL INST OF STANDARDS & TECH R.I.C.

All 102808836

Mathey, Robert G/Revlew of nondestructlv QC100 .U5753 N0.1247 1988 V198 C.I NBS-P

NBS

PUBLICATIONS

OF COMMERCE

Itandards

NBS Technical Note 1247

Review of Nondestructive Evaluation Methods

Applicable to Construction Materials and Structures

Robert G. Mathey and James R. Clifton

\'BS NBS NBS NBS NBS NBS NBS NBS NBS NBS

iS NBS NBS NBS NBS NBS NBS NBS NBS NBS Ni

NBS NBS NBS NB:^ BS NBS NBS NBS

IS NBS NBS NBS NBS NBS NBS NBS NBS NBS N

\o.> ,voS NBS NBS NBS /v/>o ,%/>.> \/j.> SBS l\l}^>

iS NBS NBS NBS NBS NBS NBS NBS NBS NBS N

NBS NBS NBS NBS NBS NBS NBS NBS NBS NBS

iS NBS NBS NBS NBS NBS NBS NBS NBS NBS N.

\BS NBS NBS NBS NBS NBS NBS NBS NBS

iS NBS NBS NBS NBS NBS NBS NBS NBS NBS N

NBS ,\/>:> viio National Bureau ofStandards .\BS " '"

iS NBS NBS NBS NBS NBS NBS NBS NBS NBS TV I NBS NBS NBS NBS NBS NBS NBS NB'

S NBS NBS NBS NBS NBS NBS NBS NBS N

^BS NBS NB HS NB

S NBS NBS NBS NBS NBS NBS NBS NBS N.
Tm he National Bureau of Standards' was established by an act of Congress on March 3, 1901. The Bureau's overall J^^ goal is to strengthen and advance the nation's science and technology and facilitate their effective appUcation for public benefit. To this end, the Bureau conducts research to assure international competitiveness and leadership of U.S.

industry, science arid technology. NBS work involves development and transfer of measurements, standards and related science and technology, in support of continually improving U.S. productivity, product quality and reliability, innovation

and underlying science and engineering. The Bureau's technical work is performed by the National Measurement

Laboratory, the National Engineering Laboratory, the Institute for Computer Sciences and Technology, and the Institute for Materials Science and Engineering.

The National Measurement Laboratory

Provides the national system of physical and chemical measurement;

coordinates the system with measurement systems of other nations and

furnishes essential services leading to accurate and uniform physical and

chemical measurement throughout the Nation's scientific community,

industry, and commerce; provides advisory and research services to other Government agencies; conducts physical and chemical research; develops,

produces, and distributes Standard Reference Materials; provides

calibration services; and manages the National Standard Reference Data

System. The Laboratory consists of the following centers:

• Basic Standards^

• Radiation Research

• Chemical Physics

• Analytical Chemistry

The National Engineering Laboratory

Provides technology and technical services to the public and private sectors

to address national needs and to solve national problems; conducts research

in engineering and applied science in support of these efforts; builds and

maintains competence in the necessary disciplines required to carry out this research and technical service; develops engineering data and measurement

capabilities; provides engineering measurement traceabiUty services; develops test methods and proposes engineering standards and code

changes; develops and proposes new engineering practices; and develops

and improves mechanisms to transfer results of its research to the ultimate

user. TTie Laboratory consists of the following centers:

• Applied Mathematics

• Electronics and Electrical Engineering^

• Manufacturing Engineering

• Building Technology

• Fire Research

• Chemical Engineering^

The Institute for Computer Sciences and Technology

Conducts research and provides scientific and technical services to aid Federal agencies in the selection, acquisition, application, and use of

computer technology to improve effectiveness and economy in Government

operations in accordance with Public Law 89-306 (40 U.S. C. 759),

relevant Executive Orders, and other directives; carries out this mission by

managing the Federal Information Processing Standards Program,

developing Federal ADP standards guidelines, and managing Federal

paiticipation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal agencies; and

provides the technical foundation for computer-related policies of the Federal Government. The Institute consists of the following divisions:

Information Systems Engineering

Systems and Softwju-e

Technology

Computer Security

Systems and Network

Architecture

Advanced Computer Systems

The Institute for Materials Science and Engineering

Conducts research and provides measurements, data, standards, reference

materials, quantitative understanding and other technical information

fundamental to the processing, structure, properties and performance of

materials; addresses the scientific basis for new advanced materials technologies; plans research around cross-cutting scientific themes such as nondestructive evaluation and phase diagram development; oversees Bureau-wide technical programs in nuclear reactor radiation research and

nondestructive evaluation; and broadly disseminates generic technical information resulting from its programs. The Institute consists of the following Divisions:

• Ceramics

• Fracture and Deformation^

• Polymers

• Metallurgy

• Reactor Radiation

'Headquarters and Laboratories at Gaithersburg, MD, unless otherwise noted; mailing address

Gaithersburg, MD 20899. 'Some divisions within the center are located at Boulder, CO 80303.

^Located at Boulder, CO, with some elements at Gaithersburg, ^D
JElesearch luformation Center

iNalioaal t>ureau of Standards

Gaithersburg, IVIaryknd 20899

QCfOo

NBS Technical Note 1247 ^f ^/

Review of Nondestructive Evaluation Methods

Applicable to Construction Materials and Structures

Robert G. Mathey and James R. Clifton

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Gaithersburg, MD 20899

Prepared for:

Naval Civil Engineering Laboratory

Port Hueneme, CA 93043-5003

June 1988

U.S. Department of Commerce

C. Waiiam Verity, Secretary

National Bureau of Standards

Ernest Ambler, Director
National Bureau of Standards U.S. Government Printing Office For sale by the Superintendent

Technical Note 1247 Washington: 1988 of Documents,

Natl. Bur. Stand. (U.S.), U.S. Government Printing Office,

Tech. Note 1247 Washington, DC 20402

203 pages (June 1988)

CODEN: NBTNAE
PREFACE

This is the second compilation of nondestructive evaluation (NDE) methods for

construction materials and structures prepared by the Center for Building

Technology. Significant advances in NDE methods for construction materials and

structures have been made since the first report was published in 1982 [1].

Readers, undoubtedly, are aware of NDE methods not included in the present

compilation, which should be included in a future version. The authors welcome

suggestions regarding additions to the compilation of NDE methods.

An extensive effort was required in the preparation of this report and if the

anticipated growth in NDE occurs then preparation of a future version, in the same format, may become unwieldy. It is recommended, therefore, that starting

with the present report the compilation be coded in an expert system form.

This would facilitate the identification of appropriate NDE methods for specific

materials and problems. Also, additions to the compilation could be easily

introduced into the expert system program, thereby, reflecting the current

state-of-the-art

.

During the preparation of this report, it became obvious to the authors that an

improved bases needs to be developed for interpreting the results of NDE

inspections. At present, interpretation is frequently based on intuition and

past experiences which are generally not recorded and, thus, are not of help to

new inspectors. Without an adequate bases for interpretation, incorrect

decisions could be made regarding the condition of building materials, components,

or structures. Therefore, it is recommended that a standard practice, guide,

or methodology be developed for interpreting the results of NDE tests.

iii
ABSTRACT

Nondestructive evaluation (NDE) methods for evaluating in situ construction

materials and for condition assessment of building components and systems were identified and are described. This report is intended to help inspectors and

those involved in condition assessment choose appropriate NDE methods for

specific building materials, components, and systems. Important properties of

building materials along with important performance requirements for building

components are listed, and appropriate NDE methods for determining these

properties are recommended. In many cases the advantages and limitations of

the NDE methods are presented. Potential NDE methods which may or may not

require further research and development before they are ready for routine use were also identified and are briefly described. In addition, ASTM standards

for NDE methods for concrete and other building materials and components were identified.

In a related aspect of the study, current Navy practices relative to the use

of NDE methods in the construction and service cycle of buildings and other

structures were reviewed. This review was based on Navy reports and documents

provided by NCEL and NAVFAC, and on discussions with NAVFAC personnel involved

with buildings and structures problems where NDE methods are used for diagnostic

purposes. Navy Guide Specifications were examined for required tests, both

NDE and destructive, of in situ building materials and components.

Key Words: Building components; building diagnostics; building materials;

condition assessment; construction materials; in situ evaluation;

nondestructive evaluation.

iv
TABLE OF CONTENTS

Page

Abstract Iv

1 . INTRODUCTION 1

1 .

Background 1 1.2 Objective 2

1 .

Scope 2

2 . REV lEW OF CURRENT NDE NAVY PRACT ICES 4

2.1 Guide Specifications 4

2.2 Summary of NDE Practices Obtained from Brief Discussions with

NAVFAC Personnel 4

2.3 Review of Needed and Presently Used Methods Based on the

Results of Responses to NCEL Questionnaires 5

2.3.1 List of Reported Needed NDE Methods 6

2.3.2 List of Reported Presently Used NDE Methods 7

2 .4 Navy NDE Publications 8

3NDE METHODS 11

4. NDE TABLES 13

4.1 Building Materials, Components, and Systems 13

4.2 Survey of NDE Methods 14

5. DESCRIPTION OF NDE METHODS 37

5.1 Acoustic Emission Method 37

5.2 Acoustic Impact Method 39

5.3 Air Flow 41

5.3.1 Pltot Traverse 41

5.4 Air Infiltration Measurements 42

5.4.1 Tracer-Gas Decay Method 42

5.4.2 Fan Pressurlzatlon Technique 43

5.4.3 Acoustic Method 44

5.4.4 Smoke Tracer 45

5.5 Air Permeability 46

5.6 Break-Off Method 46

5.7 Cast-ln-Place Pullout 47
TABLE OF CONTENTS (Continued)

Page

5.8 Electrical Potential Measurements 49

5.9 Electromagnetic Methods 51

5.9.1 Eddy Current Inspection 51

5.9.2 Magneto- Inductive Methods (Magnetic Field Testing) ... 54

5.9.3 Cover Meters 55

5.9.4 Magnetic Particle Inspection 57

5.9.5 Steel Fiber Content 60

5.10 Holography 60

5.11 Leak Testing Method 61

5.12 Longitudinal Stress Waves 62

5.13 Maturity Concept 63

5.14 Microwave Inspection 65

5.15 Middle Ordinate Method 66

5.16 Moisture Detection Methods 67

5.16.1 Electrical Resistance Probe 67

5.16.2 Capacitance Instruments 69

5.16.3 Nuclear Meter 70

5.16.4 Infrared Thermography 72

5.17 Nuclear Density Meter 72

5.18 Paint Inspection Gages 73

5.18.1 Tooke Gage 73

5.18.2 Pencil Test 73

5.18.3 Magnetic Thickness Gages 74

5.18.3.1 Magnetic Pull-Off Gage 74

5.18.3.2 Magnetic Flux Gage 74

5.18.4 Wet Film Thickness 75

5.18.4.1 Interchemical Wet Film Thickness Gage 75

5.18.4.2 Pfung Gage 76

5.18.4.3 Notch Gage 76

5.19 Pin Hole Detector 77

5 . 20 Point-Load Test 78

5.21 Probe Penetration Method 79

5.22 Proof Load Testing 82

5.23 Pull-Off Test 82

5.24 Radar 84

5.25 Radioactive Methods 85

vi
TABLE OF CONTENTS (Continued)

Page

5.25.1 Radiography 86

5.25.2 X-ray Radiography 86

5.25.3 Gamma Radiography 87

5.25.4 X-ray Fluorescence Analyzer 90

5.26 Seismic Testing 91

5 .27 Soil Exploration 92

5.27.1 Cone Penetration Test 92

5.27.2 Helical Probes 92

5.27.3 Standard Penetration Test 93

5.28 Surface Hardness Testing 94

5.28.1 Static Indentation Tests 94

5.28.2 Rebound Hammer Method 96

5.29 Thermal Inspection Methods 99

5.29.1 Infrared Thermography 101

5.29.2 Envelope Thermal Testing Unit 104

5.29.3 Heat Flow Meter 105

5.29.4 Portable Calorimeter 106

5.29.5 Spot Radiometer 107

5 .30 Ultrasonic Pulse Methods 109

5.30.1 Ultrasonic Pulse Velocity 110

5.30.2 Ultrasonic Pulse Echo 113

5.31 Uplift Resistance 115

5.32 Visual Inspection 116

5.32.1 Optical Magnification 116

5.32.2 Fiberscope 117

5.32.3 Liquid Penetrant Inspection 118

5.33 Water Permeability of Masonry Walls 120

5.34 Combinations of Nondestructive Evaluation Methods 121

6. SUMMARY 124

7. ACKNOWLEDGMENTS 125

8. REFERENCES 126

vii
TABLE OF CONTENTS (Continued)

Page

APPENDIX A. REVIEW OF NAVY GUIDE SPECIFICATIONS A-1

APPENDIX B. REVIEWED NAVY GUIDE SPECIFICATIONS THAT CONTAIN REQUIRED

NDE TESTS B-1

APPENDIX C. LISTS OF REVIEWED NCEL TECHDATA SHEETS AND NCEL TECHNICAL

AND RESEARCH REPORTS THAT CONTAIN NDE METHODS C-1

APPENDIX D. ASTM STANDARDS FOR NDE METHODS FOR CONSTRUCTION MATERIALS

AND BUILDING COMPONENTS D-I

vlil
tiST OF TABLES

Page

Table 1. NDE Methods for Inspecting Hardened Concrete 15

Table 2. NDE Methods for Inspecting Masonry and Masonry Materials ... 16

Table 3. NDE Methods for Inspecting Wood and Lumber 16

Table 4. NDE Method for Inspecting Metals 17

Table 5. NDE Methods for Inspecting Roofing Systems 18

Table 6. NDE Methods for Inspecting Paints and Coatings 19

Table 7. NDE Methods for Inspecting Soils 20

Table 8 . NDE Methods for Inspecting Sealants 20

Table 9, NDE Methods for Inspecting Thermal Insulation 21

Table 10. NDE Methods for Inspecting the Building Envelope 22

Table 11. NDE Methods for Inspecting Pipe and Drainage Systems 23

Table 12. NDE Methods for Inspecting, Heating, Ventilation, and

Air Conditioning Systems 23

Table 13. Operation, Principles, and Applications of Commonly Used and

Potential NDE Methods for Inspection of Building Materials

and Systems 24

Table 14 . Gamma Ray Sources 88

Table 15. Pulse Velocities in Concrete Ill

Table A. Review of Navy Guide Specifications A-2

Table B. Reviewed Navy Guide Specifications that Contain Required

NDE Tests B-2

Table CI. List of Reviewed NCEL Techdata Sheets that Contain NDE

Methods C-2

Table C2. List of Reviewed NCEL Technical and Research Reports that

Contain NDE Methods * C-3

Table Dl . ASTM Standards for NDE Methods for Concrete D-2

Table D2. ASTM Standards for NDE Methods for Construction Materials

and Building Components D-3

~^ ix

1. INTRODUCTION

1 . 1 Background

Nondestructive evaluation (NDE) methods offer significant advantages over

traditional laboratory and field methods for determining the properties of

construction materials, especially in the making of in situ measurements of

these materials. There are many NDE methods and they may be used in all phases

of the construction and service cycle of buildings and other structures,

beginning with the construction phase and continuing through the maintenance,

repair, and rehabilitation phases. Currently used NDE methods and other

methods based on emerging and advanced technology may be used in the maintenance, repair, and condition assessment of buildings and facilities. In

addition, NDE methods may serve as an Important tool in building diagnostics

to assist in assessment of their condition because of construction deficiences

and changes in occupancy or mission or materials properties.

The National Bureau of Standards (NBS) completed a study in 1982 for the

U.S. Army Construction Engineering Research Laboratory (CERL) entitled,

" In-Place Nondestructive Evaluation Methods for Quality Assurance of Building

Materials" [1]^. Since then, advances in the state-of-the-art of some NDE

methods have taken place. The Naval Civil Engineering Laboratory (NCEL) and

the Naval Facilities Engineering Command (NAVFAC) asked NBS to review current

Navy NDE practices and to update the 1982 study [1]. This report is a revision

of the earlier study and includes additions to the tables of NDE methods

and to the text which describes the NDE methods. The list of ASTM standards for

•• Figures in brackets indicate references listed in Section 8.

1
isuti. methods applicable to building materials is revised and updated. Based on

reports and documents provided by NCEL and NAVFAC, a review of current Navy

NDE practices is presented along with a brief summary of NDE studies.

1.2 Objective

The objectives of this study are: (1) to update the 1982 NBS study,

" In-Place Nondestructive Evaluation Methods for Quality Assurance of Building

Materials" [1] by identifying new NDE methods which can be used for condition

assessment and to help to assure the quality and uniformity of in-place

construction materials; and (2) to review current Navy practices relative to

the use of NDE methods in the construction and service cycle of buildings and

other structures.

1.3 Scope

Since completion of the 1982 NBS study [1], there have been advances in

the state-of-the-art of some NDE methods. These advances in NDE methods for

construction materials and condition assessment of buildings and structures

have been included in this report. The information presented in this report

was obtained from the literature and from those knowledgeable in the field.

The 1982 NBS study [1] was the source for a considerable portion of the

information. No laboratory research was performed during the course of this

study. Discussions were held with members of technical committees which cover

the selection and use of NDE methods and with researchers who have evaluated

some NDE methods. ASTM standards were reviewed to identify those applicable

for NDE methods which may be used for the in situ evaluation of construction

materials and condition assessment of building components and structures.
Emerging NDE methods that have application to the diagnostic needs

of the Navy were identified. These are considered to be methods which recently

have been demonstrated to be sufficiently reliable to either be used in the

field without further development or which need minimal further development.

Promising advanced NDE methods which require further research and development

before they are ready for routine use were also identified. Needed research

in the area of NDE methods for construction applications of the Navy was

addressed.

Current Navy practices relative to the use of NDE methods in the

construction and condition assessment of buildings and other structures were

reviewed. Information for this review was obtained from Navy reports and

documents provided by NAVFAC and NCEL. The review of Navy practices regarding

NDE methods included information from reports dealing with their use, evaluation,

and research.

Over 200 Navy Guide Specifications were examined for required tests, both

NDE and destructive, of in situ building materials and components. A list of

the required NDE tests included in the Navy Guide Specifications was compiled.
2. REVIEW OF CURRENT NDE NAVY PRACTICES

2.1 Guide Specifications

NAVFAC provided NBS with 239 Guide Specifications for review with regard

to NDE in situ tests (field tests) of building materials and components. The

list of Guide Specifications and the corresponding required field tests, both

NDE and destructive, are given in Appendix A. NDE tests were required in 29

of the reviewed Navy Guide Specifications. A list of these 29 Guide

Specifications along with the in situ NDE tests are presented in Appendix B.

2.2 Summary of NDE Practices Obtained from Brief Discussions with NAVFAC

Personnel

Discussions with NAVFAC personnel indicated that the Engineering and

Design staff are involved with limited and special problems with buildings and

structures where NDE methods are used. As an example, with regard to condition

assessment of concrete, cover meters are used to determine rebar location and

thickness of concrete cover. The penetration probe and rebound hammer are

also used to assess concrete properties. Load tests of buildings and structures

are conducted. In these tests American Concrete Institute (ACI) recommendations

are followed for concrete structures. Strain gages and deflection gages are

used for making measurements. It was reported that NCEL has equipment to detect

vibrations in buildings that have been subjected to earthquakes and contain

cracks in order to assist in the assessment of the condition of these buildings.

In addition, NCEL has instrumented new buildings in order to obtain base line

data of the properties of these buildings.

Leak detectors are used to detect leaks in pipe lines, including joints.

Methods used have included ultrasonics and detection of gas. Welds are
inspected by different methods including liquid penetrant inspection. It is

desirable to determine the condition of underground pipe lines and to predict

their service life. Included in the condition of underground pipes is the

number of leaks (water, gas, steam, etc.) and the size and wall thickness

of the pipes. It was reported that the Naval Research Laboratory (NRL) has

developed methods for determining delamination of honeycomb panels using ultrasonic and acoustic emission techniques. It was also reported that NCEL has a

device for determining locations where corrosion is occuring in precast and

prestressed concrete piles. Underwater piles are difficult to inspect. The

Navy's Chesapeake Division is involved in the evaluation of underwater

structures.

NAVFAC has a program aimed at development of condition assessment

Standards for buildings, structures and utilities, such as PAVER (pavements)

and ROOFER (roofs) in order to provide consistency in inspections. It is

difficult to make usable technology available for condition assessment of

these facilities. Pavement inspections are mostly visual but ultrasonic and

radar techniques are used. These NDE methods are generally applicable at

specific locations. Skid resistance measurements are made on runways,

2,3 Review of NDE Needed and Presently Used Methods Based on the Results

of Responses to NCEL Questionnaires

In the fall of 1985 the NCEL sent questionnaires to Navy Public Works

Centers regarding their needs and practices to assess nondestructively the

quality of new construction and the condition of existing shore facilities.

Eight of the responses that were received from Navy Public Works Centers were

reviewed and a brief summary of the reported needs for Inspections and

assessment of the quality of new construction and the condition of existing

facilities are presented along with presently used NDE methods.
2.3.1 List of Reported Needed NDE Methods

• early Identification of problems with water front structures

• under-pler construction, methods for condition assessment and maintaining

existing systems

• underwater inspection of wharves, piers, and underwater structures

(currently divers must visually Inspect pilings and sheet piles)

• underwater TV camera for Inspection of piling underneath piers

• assessment of condition of underground heat distribution systems

• leak location detector for heating distribution systems

• extent of corrosion in piping, pumps and reservoirs

• location of underground piping

• detection of underground piping leaks

• remote monitoring of systems performance and condition of components

of facilities

• condition of underground utility systems including leak detection

(steam, electrical, natural gas, water, fuel)

• portable metering of utilities performance as a diagnostic tool in

utilities management and maintenance

• moisture detection device for inspection of built-up roofs

• condition of cast iron piping and earthen dams

• inspection of underground storm drain and sewer lines

• methods for determining condition of underground storage tanks and for

leak detection

• device to check for faults in power line insulation

• device to identify faults in pipe walls

• means for checking energy efficiency of building insulation (possible solution

Is the use of an infrared camera)

• infrared scanner to Inspect insulated heating pipe

• early detection of minor trouble with large pieces of dynamic equipment
pavement analysis equipment for early defect detection

detection of worn or thin Insulation on steam, chill water, and other

pipelines

determination of condition of transformers

development of an exterior painting condition assessment computer program

monitor condition of major transformers

condition assessment for wood buildings including termite damage of

wood components

training program in diagnostics and condition assessment technology

3.2 List of Reported Presently Used NDE Methods

location of underground piping leaks (methods used include Injection

of helium and SF5 into compressed air systems to pinpoint leaks)

leak location detector for heating distribution systems

infrared scanning of polelines , switchgear, electrical equipment,

electrical panels, and steam traps to Identify anomalous sources of heat

infrared scanning of building exteriors to identify heat leakage

nuclear meter for detection of moisture in roof surveys

electrical resistance probe for detecting moisture in walls, roofs, and

slabs of buildings

ultrasonic testing to determine the wall thickness of condensate pipe

lines and their condition while the line is still in service

ultrasonic testing to measure the wall thickness of metal pipes and

l:hickness of fuel storage tank siding and floor

examination of sewer lines with a TV camera to determine their

condition (visual inspection with remote monitor)

transformer condition can be judged from an analysis of its insulating

fluid

extent of wood decay and deterioration by puncturing with an ice pick

and tapping with a hammer

extent of termite damage using an audio scope.
2.4 Navy NDE Publications

Some Navy publications dealing with the inspection of buildings, design

criteria, research, and relevant NDE methods which were provided by NCEL

and NAVFAC were reviewed with regard to current Navy practices, evaluation

methods, and recent research. The manual, "Inspection of Shore Facilities,"

Volume 2, NAVFAC MO-322 , May 1978, provides maintenance inspection/service

checklists for buildings, grounds, utility plants, utility and distribution

systems, and components of Navy shore facilities. It provides a guide for

developing and implementing an effective and efficient preventive inspection

system. Only visual inspections are listed in this manual. Another Navy

manual "Engineering and Design Criteria for Navy Facilities", NAVFAC F-34

,

August 1985, lists specifications and standards relative to Navy facilities

which are issued by government agencies (public sector) and private sector

organizations. This design manual refers to nondestructive evaluation of butt

welds in crane and railroad rails.

Some NCEL Techdata Sheets containing information about NDE inspections or

the use of NDE equipment which were provided by NCEL were reviewed. Techdata

Sheets usually give a brief explanation of an NDE method or a brief description

of NDE equipment and its use. In many cases the Techdata Sheets are based on

a technical or research report which gives background data, research results,

and details pertinent to the NDE methods or equipment. A list of the NCEL

Techdata Sheets that were reviewed is given in Appendix C. The following

examples are given regarding NDE methods contained in the Techdata Sheets

:
• Inspection of painting

• Measuring water permeability of masonry walls

• Leak detection in pipelines

• Infrared thermometers for roofing inspections

• Use of penetration probe test system for strength evaluation

of concrete in Naval construction

• Problems with underwater ultrasonic inspection

• Inspection methods for wood fender and bearing piles

• Locating and tracing buried metallic pipeline

Many different NDE methods are included in the Techdata Sheets. Most of

the NDE methods are listed in the tables in Section 4 of this report and

described in Section 5.

Some NCEL technical and research reports provided by NCEL and NAVFAC were

reviewed with regard to NDE methods and equipment. These reviewed reports are

also listed in Appendix C. They contain information about many types of NDE

methods and in many cases research results, assessments of NDE methods,

comparisons of NDE methods, the significance of the methods, their accuracy

and reliability, and their use in the field are presented. Examples of the

information regarding NDE methods in the technical and research reports include

the following:

• Pulse echo ultrasonic testing has been investigated for measuring the

corroded metal thickness of steel piles. Results of ultrasonic

evaluations have been compared to resistance probing and coring for

condition assessment of wooden waterftont structures.

• Information is available about instructions for inspection and

testing of railroad and ground level trackage. NDE methods used are ultrasonic inspection, optical instrument surveying, electromechanical

relative displacement measurements, inertial displacement measuring

transducer, proximity sensors, and laser-based level devices.

• Assessment of cables and wire rope is carried out using alternating

current to produce an electromagnetic field to detect loss of

metallic areas in the wire rope. For smaller wire rope, a portable

NDE device that employs an audible signal detected by a head set can indicate flaws.

• Moisture can be detected in roofing systems based on surveys using

nuclear moisture meters, infrared thermography, and capacitance

meters.
With regard to underground utility lines, an NCEL state-of-the-art

survey found no existing techniques capable of nondestructive

condition assessment. Utility companies and water distribution

agencies use sonic detectors for leak detection. It was reported

that none of the six techniques investigated, acoustic emission,

radiography, sonic , ultrasonic , eddy current, and magnetic flux, were suitable for Navy use on buried pipelines. Ground penetrating radar was investigated as a method for detecting underground utility

lines

.

Extensive internal damage can be detected in underwater timber

piles by an impact hammer sounding technique. The pile is struck

with a hammer and damage is assessed from the acoustic response.

Small portable infrared specti'ophotometers that were introduced

commercially for field analysis of gases and liquids were modified

in order that organic solid materials could be identified and analyzed,

This modified portable instrument showed promise that organic

construction materials (paints, plastics, insulations, etc.) could

be identified in the field. This could help provide for proper

maintenance. It also could help ensure that specified materials

were used by the contractor, and deterioration of protective

coatings could be detected.

10
3. NDE METHODS

The NDE methods are listed in Tables 1 through 13 in Section 4 and

descriptions of the NDE methods are given in Section 5. The tables and

descriptions of the NDE methods have been updated from the previously

mentioned 1982 NBS study [1]. A considerable portion of the information in

the present report was taken from the previous study. It is noted that

some in situ NDE tests may or may not cause minor damage to materials or

buildings components. An example of an instrument that may cause minor

damage is an electrical resistance probe to determine the moisture content

of insulation.

The NDE tables in Section A list key properties of commonly used building

materials and NDE methods for estimating the level of these properties or

characterizing the materials. Operation, principles, and applications of the

NDE methods are outlined in Table 13, These tables are intended to familiarize

those personnel involved with quality assurance and condition assessment of

building materials and components with NDE methods, and to help in the selection

of appropriate methods. More detailed information about the NDE methods or

descriptions of the methods are provided in Section 5. Appendix D lists

standard test procedures which the American Society for Testing and Materials

(ASTM) has issued for some NDE methods covered in this report.

To use the information in this report most effectively, begin with

Tables 1 through 12. If, for example, the quality and uniformity of in-place

concrete seem questionable, further inspection could be justified. The options

for inspection of hardened concrete are given in Table 1. Concrete properties

are given in the first column and appropriate NDE methods for each property

are found in the second column. For the example given, four methods are listed

11
for determining the general quality and uniformity of hardened concrete:

(1) penetration probe, (2) rebound hammer, (3) ultrasonic pulse velocity, and

(4) radiography (gamma). The methods are not ranked; the table simply provides

a list of applicable methods. To help decide which of these methods would be

appropriate for a specific application (considering factors such as equipment

availability, cost, and information obtained), consult Table 13. For more

information before selecting any of the four methods, refer to Section 5 which

gives detailed information about the NDE methods.

The cross reference features of the tables can be used in the same way for

information about other recommended NDE methods.

Note that the information in this report is not intended to supersede

existing guide specifications. In cases of conflict, the guide specifications

are to be followed.

12
4. NDE TABLES

4.1 Building Materials, Components, and Systems

Major building materials, their important properties, and NDE methods for

estimating the value of these properties or for characterizing the materials

are given in Tables 1 through 9. Materials considered are:

Table No. Building Material

1 Concrete

2 Masonry materials

3 Wood and lumber

4 Metals

5 Roofing

6 Paints and coatings

7 Soils

8 Sealants

9 Thermal insulation

The following building components and systems are covered in Tables 10 through

12:

Table No. Components and Systems

10 Building envelope

11 Pipe and drainage systems

12 Heating, ventilation, and

air conditioning systems

In Tables 10-12, the main performance requirements are listed, and NDE

methods intended for determining if these requirements are being met are

also listed.

The selection of the building materials, components, and systems addressed

in this report was largely based on considerations of: (1) the amount of

their use; (2) the frequency and severity of problems caused by deficiencies

in their quality, uniformity, or performance; and (3) the value of using NDE

methods to inspect the material, component, or system. As an obvious example,

NDE inspection is not necessary to determine that a glass window is broken,

13
while locating reinforcing steel in concrete is more readily done by NDE

inspection than by coring. Researchers from the NBS Center for Building

Technology and from the NBS Office of Nondestructive Evaluation of the National

Bureau of Standards, and personnel of the U.S. Army Corps of Engineers

collaborated in the selection process in the earlier NBS study [1],

In Tables 1 through 12, the column headed "Currently Recommended NDE

Methods" lists ways of testing various material properties. These tests are

commonly used, and their limitations are well known. The column headed

"Potential NDE Methods" lists NDE methods that may prove useful, but are

still being assessed. In some cases, suitable NDE methods are not available,

as an example, for the inspection of the bond between a sealant and its

substrate (Table 8).

4.2 Survey of NDE Methods

The operation, principles, and applications of recommended NDE methods

for inspecting building materials are outlined in Table 13. Self-explanatory

NDE methods such as the use of rulers and visual inspection methods are not

included in Tables 1 through 12.

Once construction inspectors and those involved in condition assessment

become familiar with the advantages of using NDE, they may wish either to train

people in their own organizations, or to obtain help from persons knowledgeable

about NDE inspections. Comments on the expertise the user needs, equipment

costs, and safety requirements are intended to help potential users decide

which path to follow.

14
Table 1

NDE Methods for Inspecting Hardened Concrete

Property

Strength

Currently Reconmended NDE Methods

Method

Penetration Probe Rebound Hammer Cast-ln-place pullout

Maturity concept

Location

in Report ^

5.21 5.28.

5.7 5.13

Potential NDE Methods

Location

in Report ^

5.30. 5.20

5.23

5.6

Method

Ultrasonic pulse velocity

Point-load test Pull-off test Break-off method

General quality

and uniformity Penetration Probe 5.21 Rebound Hammer 5.26.2 Ultrasonic pulse velocity 5.30.1 Radiography 5.25.1

5.30.2

5.1A 5.24

5.5

Ultrasonic pulse echo Microwaves

Radar

Air permeability

Thickness

Density Radiography

Ultrasonic pulse velocity

5.25.3

5.30.1

5.1A 5.25.3

5.30

5.9.1 5.25.1

5.17

Microwaves (radar) Gamma radiography

Ultrasonic pulse,

velocity and echo Eddy current Radiography

Air content 5.17 Neutron density gage

Stiffness Ultrasonic pulse velocity 5.30.1

Surface texture Visual 5.32 5.14 Microwaves

Neutron density gage

Rebar depth

and position

Cover meter Radiography5.9.3 5.25.3

5.14

5.30. 5.24

Microwaves (radar) Ultrasonic pulse echo Radar

Corrosion state Visual

of reinforcing Electrical potential

steel measurement

5.32

5.8

Presence of Acoustic impact 5.2 subsurface voids Ultrasonic pulse echo 5.30.2

or delamlnatlons Radiography 5.25.3 Ultrasonic pulse velocity 5.30.1

5.29.1

5.24 Infrared thermography Radar

Moisture content

and moisture

penetration

5.14 5.16.3 Microwaves

Nuclear

Cement content 5.16.3 Nuclear

Durability Visual 5.32

Steel fiber content

5.9.5 Electromagnetic method

Critical and rupture loads (crackabillty

factor)

5.1 5.30.1 Acoustic emission

Ultrasonic pulse velocity

^ Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

15
Table 2

NDE Methods for Inspecclog Masonry and Masonry Materials

Property

Integrity of masonry

Qirrently Reco—ended NDE Methods

Mathod Location

Id Report *

4cou«tic lapact 5.2 Radiography J.25.3 Probe holes with 5.32.2 fiberscope

Dltraaonlc pulse velocity 5.30.1

Potential NDE Methods

Location

In Report *

5.30.2

5.14

5.24

NDEHethod

Ultrasonic pulie echo Microwaves

Radar

Thickness of asonry

Probe holes 5.32 5.9.1 5.30.2

5.25.1

Eddy current Ultrasonic pulse echo Radiography

Reinforcing steel (location and size)

Cover aeter Radiography

5.9.3

5.25.3

5.30.1

5.14

5.25.1

Ultrasonic pulse echo Microwaves Radiography

Presence of Probe holes 5.32 inner grout Radiography 5.25.3

Acoustic iapact 5.2 Ultrasonic pulse velocity 5.30.1

5.30.2 Ultrasonic pulse echo

Moisture content

and moisture

penetrstion

Moisture aeter- electrical resistance

5.16.1 5.14 5.16.3 Microwaves

Moisture aeter- nuclear

Presence of Acoustic iapact 5.2 delaninations Radiography 5.25.3 Ultrasonic pulse velocity 5.30.1

5.30.2

5.29.1

5.25.2

Ultrasonic pulse echo

Theraal inspection

(theraography) Radiography

Water perneablllty of coated masonry

5.33 Water peraeability

* Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

Table 3

NDE Methods for Inspecting Wood and Lumber

Property

Currently Reconaended NDE Methods

Method

Integrity and general quality

(including grade, aechanlcal

properties, and assessment of insect, mechanical

and decay damage*

Visual grading by certified grader*

Proof loading

Location

in Report *

5.22

Potential NDE Methods

Location

in Report*

5.1 5.30

5.25.1

5.15

5.12

Method

Acoustic emission

Ultrasonic pulse velocity

and echo Radiography Penetration hammer

Middle ordinate method

Longitudinal stress waves

Density Ultasonlc pulse velocity 5.30.1 5.25.1

5.12

Penetration hammer Radiography

Nuclear density aeter

Moisture content Electric resistance 5.16.1 probe Capacitance Instrument 5.16.2

5.16.3 Nuclear aoisture aeter

Surface hygrometers Microwaves absorption meter

Adhesive bond

for laminated

wood

5.2 5.29.1

5.25.1

Acoustic aethods

Theraal inspection

(theraography) Radiography

Dimensions Rulers, calipers, electronic measuring

devices**

• Numbers in this column refere to NDE Method Nos. described in Section 5 and listed in Table 13.

• Perform on luaber before use; this method not described in Table 13. ** Because of their simplicity, methods not described in Table 13. 16
Table A

NDE Methods for Inspecting Metals

Currently Recommended NDE Methods

Property Method Location

In Report"

Potential NDE Methods

Location

In Report ' Method

A. Structural Metals

Presence and location In other materials

Radiography 5.25.3

Magnetic devices

Cover meter 5.9.3 Eddy current devices 5.9.1 Probe holes with 5.32.2 fiberscope

5.30.2 Ultrasonic pulse echo

Type of metal Magnetic devices

Chemical spot testing*

Spark testing*

Color* X-ray fluorescence analyzer

Electromagnetic methods

5.25.4

5.9

Cracks, flaws Radiography 5.25.3 Ultrasonic pulse echo 5.30.2 Magnetic particle 5.9.4 Liquid penetrant 5.32.3 Eddy current 5.9.1

5.10

5.14

5.29.1

Holography Microwave

Thermal inspection

Corrosion condition Electrical potential measurement5.8 5.9.1 5.30.2 Eddy current Ultrasonic pulse echo

Loose bolts

rivets and screws Visual 5.32 5.2 Acoustic Impact

B. Weld Defects

Cracks Ultrasonic pulse echo 5.30.2 Radiography 5.25.3 Magnetic particle 5.9.4 Liquid penetrant 5.32.3

Lack of fusion Ultrasonic pulse echo Radiography

5.30.2

5.25.3

5.9.4 Magnetic particle

Slag inclusion Radiography

Magnetic particle

5.25.3

5.9.4 5.30.2 Ultrasonic pulse echo

Porosity Radiography 5.25.3 5.32.3

5.30.2

Liquid penetrant Ultrasonic pulse echo

Incomplete

penetration

Radiography

Ultrasonic pulse echo 5.25.3

5.30.2

C. Pipes and Tanks

Type of metal See Structural Metals, above

Wall thickness Eddy current 5.9.1 Ultrasonic pulse echo 5.30.2

Leaks and continuity

Leak testing 5.11

Corrosion condition

Electrical potential 5.8 measurements

5.9.1 5.30.2 Eddy current Ultrasonic pulse echo

a Numbers In this Column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

* For more Information on these methods see Reference [2). 17
Table 5

NDE Methods for Inspecting Roofing Systems

Property

Composition

Currently Recommended NDE Methods

Method Locationin Report ^

Potential NDE Methods

Location

in Report^ Method

Cores* — laboratory analysis,

specific gravity, solvent,

odor, and chemical tests to distinguish between asphalt

and coal tar pitch

Moisture content

of insulation

Thermal inspection 5 16 .It (thermography) Nuclear moisture 5 16 3 meter Capacitance 5 16 ,2 Electrical resistance 5 16 1 probe

5.14 Microwaves

Permeability of roofing systemFlood or pond water on roof followed by using methods to measure moisture content of Insulation

Seam integrity

(single-ply)

5,29.1 5.30.2Infrared thermography Ultrasonic pulse echo

Slope and drains Flood or pond water on roof

Self supporting

under design loads Proof loading 5.22 Wind uplift test (can 5.31 be destructive)

Uplift resistance Negative pressure 5.31

a Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13. Destructive method

18
Table 6

NDE Methods for Inspecting Paints and Coatings

Currently Recommended NDE Methods

Property Method Location

In Report^

Number and type of layers Tooke Gage 5.18.1

Dry film thickness

Metal

1

Magnetic pull-off gage

2. Magnetic flux gage

3. Eddy current

4. Tooke Gage

5.18.3.1 5.18.3.2

5.9.1 5.18.1

Potential NDE Methods

Location

In Report " Method

Wood: Tooke Gage 5.18.1

Wet film thickness 1. Interchemlcal gage

2. Pfund gage

3. Notch gage

5.18.4.1 5.18.4.2

5.18.4.3

Hardness Pencil test 5.18.2

Integrity

(Pin holes)

Metal:

Wood:

Pin hole (holiday) detector

Field microscope

5.19

5.32.1

Bond to subsurface

5.29.1

Adhesion tester Scratch adhesion test Thermal inspection

(thermography)

Surface preparation

5.18.1

5.32.1 Tooke gageField microscope

General quality

color, reflectance,

blistering, etc. 5.29.1

Photography — comparison

with standard Measurement of reflectivity

Thermal inspection

(thermography)

8 Numbers in this column refer to NDE Method Nos. described In Section 5 and listed in Table 13.

19
Table 7

NDE Methods for Incpectlng Soils

Property

Adequate drainage

Currently Recoanended NDE Methdos

Method

Visual check of grade

and topography*

Location

In Report*

Potential WDE Methods

Location

In Report •_ Method

Adequacy of backfill

5.14 Microwave to detect cavities In backfill

Density and compaction

Seismic testing (wave propagation) Nuclear density meter

5.26

5.17

5.27.2 Helical probes

Moisture contents

Detect cavities

Nuclear moisture meter 5.16.3 5.16.1

S.16.4

5.14

5.26

5.29.1

Electrical resistance

probe

btfrared thermography

Stiffness 5.26 Seismic testing (wave propagation)

Permeability 5.16.4 Infrared thermography

Strength Standard penetration test

Cone penetration test 5.27.3

5.27.1 5.27.2 Helical probes

Microwave

Seismic testing (wave propagation)

bifrared thermography

° Numbers in this column refer to NDE Method Nos. described In Section 5 and listed In Table 13.

* Because of its simplicity, method not described in Table 13.

Table 8

NDE Methods for Inspecting Sealants

Property

Currently Recoanended NDE Methods

Method Location

In Report*

Potential NDE Methods

Location

In Report* Method

Water permeability

(infiltration) Electrical resistance meter

Capacitance Instrument

5.16.1

5.16.2

General quality and workmanship

Move water Jet up the building wall (from bottom

to top) and observe water

infiltration — use methods given for testing for water permeability

5.16.1 5.16.2

Bond to substrate*

B Numbers in this column refer to NDE Methods Nos. described In Section 5 and listed In Table 13.

* Destructive laboratory tests are available.

20
Table 9

NDE Methods for Inspecting Thermal Insulation

Property

Currently Recommended NDE Methods Potential NDE Methods

Method In Report * in Report " Method

Performance Thermal Inspection

(Infrared thermography)

5.29.1 5.29.5 5.29,3

5.29.4

5.29.2

Spot radiometer

Beat flow meter Portable calorimeter Envelope thermal testing

unit

Location Thermal Inspection 5.29.1 (Infrared thermography)

Fiberscope 5.32.2

5.29.5

5.29.3

Spot radiometer

Heat flow meter

Moisture contents 5.16.2

5.16.1

5.29

Capacitance instrument Electrical resistance meter

Thermal inspection

Corroslveness Measure electrical potential

of metals In contact with insulation

5.8

B Numbers in this column refer to NDE Method Nos. described in Section 5 and listed in Table 13.

21
Table 10

NDE Methods for Inspecting the Building Envelope

Cjrrently Recommended NDE Methods Potential NDE Methods

Component Main Performance Location Location

or System Requirements Method in Report" in Report" Method

Walls and No penetration 5.16.2 Capacitance

Ceilings by rain water

5.32.2

5.16.3

5.16.1

instrumentation

Fiber scope Nuclear meter

Resistance probe

Retard heat Thermal 5.29 5.29.1 Thermal inspection

transmission Inspection

5.29.5 5.29.3

5.29.4 5.29.2

(thermography)

Spot radiometer

Heat flow meter

Portable calorimeter

Envelope thermal testing

unit

Building envelope Air Infiltration 5.

A

5.4.1 Tracer gas tightness measurement 5.4.4 Smoke tracer

Infrared thermography 5.29.1 5.4.3 Acoustic method

Foundation Supports building

and Basement Prevents settlement Visual crack survey

Level readings —

change with

elapsed time* Strain gage buttons on cracks* Photographic

recording of cracks with elapsed time*

Prevents upward Moslture meter 5.16 movement of moisture

Prevents Visual and/or 5.32 basement slab level readings - movement change with

elapsed time*

Roof No penetration

by rain water

Nuclear moisture meter

Thermal inspection

(thermography)

5.16.3

5.16.4

5.16.2 Capacitance instrument

Self-supporting Proof loading 5.22 under design loads

Retard heat Thermal inspection 5.16.4 transmitting (thermography)

Floor Levelness Level readings —

change with

elapsed time* Carpenter's level* Supports design Proof loading 5.22 service loads Joining details 5.25.3 Radiography

and construction 5.32.2 Fiberscope

practices and materials

" Numbers in this column refer to NDE Methods Nos. described in Section 5 and listed in Table 13.

* Self-explanatory; not described in Table 13.

12
Performance Requirements

Does not leak

Table 11

NDE Methods for Inspecting Pipe and Drainage Systems

Currently Reconmiended NDE Methods

Method

Leak testing

Location

In Report ^

5.11

Potential NDE Methods

Location

In Report ^ Method

Proper flow rate Measure volume of water flowing during

time Interval*

Flow meter connected

to outlet

Proper flow pressure Hydrostatic

pressure gage

Dielectric joints

between dissimilar

metals

Measurement of electrical resistance

across joint*

5.32.2 Inspection by

fiberscope

Prevention of back

flow of gases

Direct measurement

of water in trap* Determination

of pressure of proper component

^ Numbers in this column refer to NDE Methods Nob. described in Section 5 and listed in Table 13.

* Self-explanatory; not described in Table 13.

Performance

Requirements

Table 12

NDE Methods for Inspecting Heating, Ventilation, and Air Conditioning Systems

Currently Recommended NDE Methods Potential NDE Methods

Proper air flow level (ventilation)

Method Locationin Report^

Air flow measurement

(tracer gas)

5.4.1

Location

in Report ^

5.3.1

Method

Pltot traverse

Air ducts properly sealed Leak detection*

5.4.3 Sound Amplification

5.32.2 Fiberscope

5.4.4 Smoke tracer

8 Numbers in this column refer to NDE Methods Nos. described in Section 5 and listed in Table 13.

* Self-explanatory; not described in Table 13.

23
o k- c a- o

s o V a

CD 4-) l-i k4 14-1 c u u u

a 3 u CD 3

c; u 0] *-< to m oj 4-* o

m c 4J ' V be X V

u c V B 00 M H a. a •H 3 tj D. •^ V 3

cr « E 3 u cr

«> o o o- o 01

<u •O bO

(J 0) c

c lu •H u •H 4J

kJ 3 OD

d) cr OJ

u-t 0) i-> C 4^ O 01 l-i 0) (J Q- Ui

Ui X> 00 C l-i O

jj O <- O CO f-< i-J •»-( TS J-J

a: .-H u 0) « w

e 4-1 3 4J d V o go CO (0 HJ d) 01 V OJ c 4J o 4-i k^ vH tn V

1-1 o

3 -H O 4J

CO I T3 -H H 01 01 <0 I

C 4J ij -H j: BV 0) u •oa

CD s

ra

01 o> X JO

CD CO O

. 4J Q

O CD C C C

O -w

iH 4-t 0) 3 CO CJ O O C X O CO

CO rH ^

CO •H O • o; 3 3 o. o; ^ CD .C tic O T) CO o ot o c e

1-4 ^ 4J CO CO

go be c C CO

U u

u a

o e

l4-< OJ ^

c Lj T) o 4J .H 3

CD o 4-1 0) 01 Zl O

OJ a. oo a CO CO CO bo go c a

CO V 4J O. J3 o CO bc

4J u ^ a CO CJ c c •H CO a bO •r^ CO CO 3 CO c • • AJ > u J5 o o «H 01 CO •o o 1 tj 4-1 u o < 4J CO <•. CJ 3 O

(0 0) •T3 <U .-( ^

c 1-1 CO 4-1 o U-l 3 O 01 (0 U-. s: O 4-1

o

--H D 14-1 O

iH 4J t CO 01 V 0) 4-) C

•H go > bO T3 CO •(-1 • 4J T3 01 01 4-1 CD c t-t 4J go OJ u 4J o 0) 4J

01 m V t-i c •fi 4J Lj >h

4-> B CD 01 V 9 3 c a 3 o 01 » a 4-1 o cr CO o 1.1 CO

Bl. 4J M »< e 0> c 01 01 00 U u M u a CO U 1-1 •O >-. c to

CO c

e 0) -H e 4J X o. CO u 3 o

a a- a bl

o o o • o 01 ao I o. O .H 3 - T< 3

- bO O 4-1 J^ O C -O iH tl -I ^ D.-. 3 -rt </> CO 3 <« B a.

OD •* 01 3 4-1 CO 4-1 o or 'H

0) CO •H 3

V > i4 CO .- 4-1 01 O 01 01 -O "4-1 Ul ^ e ^ U U T3 01 CO O -w 0> >

4J 14-1 C "O -^ ^ U O 01 4-1 O 01 4-1 01 CO Du O. 4-1 C 4-1

01

CD O

bo

01 1-1 -H O O 4J o;u'C4jct4-ioi • > OJ 01 3 01 U (D

01 0.4-IXI-HT3 D.4-1 ^ X -W l-( 01 Ij ^

01 3 - 01 T) 01 3

^ O" 01 C^ 01 4J CD oc^a>cD><o>coi iJOt430IC-Hl-.

O X O -rt

01 Crt- 01 CO - CO CO Xl ^H CO 01 01 •H 10 01 e u

rH 3 3 -H

bO C cr u >

01 CO -H o 01 Z E C uj -O

b 0) 1 u 01 U 01 ^ o 01 rH

4-1 tH 4-1 o. ^ 4-1 o.

CO CO 01 B CO 01 w 01 e

•0 H > H •o H

>% « CO bO CO go 4J 01 c • M 01 r^ c •O CO 01 •H c £ CO u T-C CO ^ CO CO o c >^ 3 3 c >^ ^ 4J CO XI 4J 01 c CO £ • 01 c o •a bo H u •o > •H •a o 4J CO •D o 4-1 01 £ O u >, 4-1 01 £

l-l a. u c 4J 4-1 01 4J CJ c 4-1 H 3 •H 01 > 3 •H 01 < CO TI B e a < o T3 B B

OJ "O OJ M

X) 0) C 0) B -H C

•O l-l 0) c

•H O i4 o

3 VM i-l CO

OJ T) <U '-H .o o; c 0)

i-H o u o

3 Cl-l 4-1 CO O u bl j: 01 >. 01 tn

1 a

>< 4J o c o c C4-1 •

4-1 <0 >s to H B •a 4-> 4J a 01 •^ c

01 •o en u 01 ki «-. c 3 o e

CO O CO w 01

CD 01 (-( 01 CD CO U > 3 u B 01 01 CO

01 u ^ 4J u CO

go

01 4-1 ^ TJ CO c a.

4-1 c CO

CO 01 CJ T) be

go 01 CO ID be C Ji! • 01 C -H CO T) c -H e 01 OJ 4J TJ l-" ^H

01 CO bo -H 4J u u

•H 3 0) •rt O H ^ -O CO pH

.O 01 C 01 B -H C

•O t4 CO C

1-1 O fci o

O 3 01 -H 01

14-1 4J B CO E

CO • 4-1 to

a o

<! 4J

e T3 H o b 4J

bO > T3 Q. 3 cue T3

-H 01 01 bO

ki to O. C 01 O B -H Ui

4-1 be H u 3

•H C O 4-1 c >H 4-1 4J a • O tJ tl -H 3 bO e 3 01 c k c O 4-1 O 4J -H

3 3 O 01 O 4-1 C 4J 4-1 M

•H tJ 3 01 MJ

4J 3 01 iH O O

C 1-1 M-l .H C O

01 01 4J o -H

01 to •o •H 4-1 4J o C CO •H •H to o 3 T3 d •

to o 1-1 4J o to o > CO >> x: 4-1 o. H 01 M 4J 4-1 c

6 4J 1-1 3 c 01 CO 01

ej 01 KX o B d B

u 01 4J to H 01 4J to c 10 : 6 > a 01 E s: B bo to CO t5 u to a

c 01 01 u 01

to .*. iH 4-1 > o TJ 01 o to 4J d B CO 1-1 *J d 4-1 01 o 01 j; 01 o T-( o 1-1 ^ 4J u E 01 CO 01 o

00 CO CO E Cl-l £ 4J c

n i-i ce 3

a)M>>t-icoaJua>o

01 •o

01 bO

(» CO u

1-1 kJ 01 01 to > >

H Sn c

4-1 .o

tj

01 •u 01 & 01 4-1

1-1 fci £ bO 3 CO C u. •O tj O O d

4-1 d CO iH -rt d o to 01 lj 01 e o

4J 4-1 > b. -H

4-1 01 to C 01 4-1 d bo 1-1 bo 01 ^ to

01 10 d B ^ 01 1H

01 to bO to U 01 C 3 •-< 01 3

to M CI 1^ -H C 01

>< to 3 to ki

01 E CQ O O.

o u

1-1 o

4J Z

eg01 01 4-1 X 4J O 3

U O CO D.

j>! -a 01 bO

a 4-t -H 01 bO to C -H

> •t3 to 01 o

a 4J 4-1 o 4-1 01 -a to a 4-1 01 01 d 01 j: 4-> 3 T3 o

o to to to 01 4-1 ^ 4-1 M-l 10 o

o d

CO to 01

CO C 4-1 U tJ U

1-1 -H CO O (13 to 3 4-1 US Ui< 01 Ui O 03 C t-i 3 i-i x: iJ o f 4-) (0 (0 4J

a<4-i B o 01 10 tj ^

T3 COo

d

01 o T) tH c to d 4J 10 01 rH CO CO tj bla

CO >s Ui : 4J O 01 bO 41

01 c 4-1 C X • B 01 O bl to 3 10 bO 4J >s cr 1-1 C 01 tJ iH 01 to 4-1 01 f—

1

bl X i-i to (4-1 CO 14-1 u o 01 3 13

ID 0) bO 01 •o 3 e

d X d u-t

•'-^ •H bl H o

1^ (0 U 4-( OJ 01 o

> 0> U 3

»*-( 4J -H

T3 « > c a.

to B u B .. 01 01 to to (0 E 4-1 bl S'^ 4J > 4-1 be CD d o 01 4-1 01 to d ^ CO

t-( U-i to 4J •H E bl H CO O H 01 O o •H to t3 3 bl >^ d • a. •o O c 10 d to a- O •

4-1 3 d 10 o 01 01 4J o o 01 E 01 CI bl 01 u

o B H 4J > bl >4-( X 3

o O 4J o 3 01 vO O 4-1 T)

T3 O 01 01 d CO to 01 i-( 01 T) bO to CO bl bl to 01 > 01 CD CO to 01 01 4-1 01 to X

CO B bl 01 E > n 4J o 4J

4J k4 4-) CO

g^

to CO C bl CCO>30biO)010t4-i

I 4-1 d

1 CO -H

D T) CO C T-I bl

I CO bl tH

I 3 <

T3 CO

to X 01 • 4J bl 01

01 D. 3

. B a- d -H

>^ 10 C

to 3 E B

01 4Jto u

to T3

01

4-1 to ID d

>. to c Xi

•o bl

CO •H CO 4-1 4-> f-l U CO O

I x: 4J ex CJ U CO 3 4J CO

. 0) )-t O 0> kd 4J 4-> u-l e U

CI •H < COCO

• B m u

a:i

24
^ U -M U 9 >

i-t c bo (0

<-< 0) boC T3 (0 c n (0 01

•rt u 4) -H 4-t ^ u

•o -0 O -H fH B JD

T3 T3 >^ p 3 H > C u C >-. 3 -rt u a <u t4 09 XI -a o s: > VI o; a

•o .» C •H C C u OJ • n s (fl c

^^ c a o

M CD to o (U j! rH 3 Ui 4-1 n .o u

(U CO •D > o fU 3 <U c u 4-1 u (V & 01

4-i 4-1 to T3

CJ X >^ H)

(U bC 3 VI CO ^

4-1 -H 3 CO

01 HI C o IS 01 T3 3 c o

BO 0) c 4-( p

CO » -H CO S OJ M 3 -o a £

CO 01 4J U OJ -H c f-i • i-H > 3 OJ J3 01 01 •H Jl 0) to 4-> 4J T3 CO XI CO OJ V c c cH 3 Ui 4J 0) -H OJ CJ u 4-1 l-l CO c

11 X 0) c > o a o; J! to 0< u

a o 3 o e

C/5 rH to Z to

(Q CO O >4-i

J= 03 4J -^ ij

0) 0) C/^ ^ Z -c ^ -HO)

-H • t—4-i ^ OJ X) -<-t (0 4-1 <o c

OJ 4-1 Z) C l-l 09

-.H u a> oi c X

(0 O C 4J

i-i 01 O 03 w e « u

0) CQ CO O H TJ X u-(

•H 01 03 U •* > (0 XI bo 0) ,. •H Ui u •H OJ x: c a T3 l-l 01 o c 4-1 a

<: 4J o; O to x: c 01 U

C4-I u to o u x: a 4-1 to a 01 4J O CO c tj XI 3 4-1 a o OJ M-i •H

03 01 •T3 to 01 o to u >4-t »*4 4J w a • * u C to a o x: ac 3 OJ o

CO 1 OJ to o to 01 i-> c to l-l (U ^1 u a <4-l a 0) 4-1 rH -H to to 4-J 01 3 0) 4J y-i o 3 t3 01 CO 01 a O 10 4J T3 u a a. OJ a 01 l-l a CO to CO 11 u e u C -H 10 U OJ >s CO j: 01 H 3 C4-I CO t4-l (0 u a to 3 CO 4J trt o CO XI to o

U 01 C OJ

O U C 4-1 O -^ ^ CO

6 -O

•H C o

C/5 to 4-1

OJ T3 -H

-O ti OJ C

-I O C O

3 Mh •H CO Da o 14 to ui x: 01 >j u

c/^ o. 4-1 a.

01 T3 .H a ui OJ c

r-l o c o

3 t4-l nH CO O >-i to li x: OJ ki OJ cA a. 4-1 o.

3 T3 o o J a

o to u o

fj > x: c

•O •H u Ui

T3 1) 4-1 ij C W tJ CO xnojiioj'HiiJCj 4-1 4-i-u'4.itnociOC'a cDcr (D--Hy-IDOT3OC'4-ia)0t :£:coaiu4woiucoc3i-iu

4-1 to 4-1 CO OJ O OJ C CO 4-1 u

to (U ^ -H

a 13- <

I OJ U C CO CO OJ

« > CO OJ

-H CO CO (0 H OJ O N

U OJ 4J rH

OJ <4H to to

4J a

ts o

a ph

CO 00 C3 e 3 -H

c to 00 o t>0 c H c •H

4J H T3

CO c:0) H

Q a 3 3 o X!

l-« -H c to o

to to a OJ 01 OJ a U >

<4-l O to c

o

to

tj ^01 c be to bO o OJ c tJ d

tJO H o

4-1 (0 T3 -o

to ^ rH M

u to •H D H

o o; 3 C 3

iJ rH XI to XI

•o CO > 3 o to u

01 OJ •H V iH 1) OJ u o a U 4-1 4-1 b c

3 ki tJ bO to OJ a. o

i-H OJ 11 c c l-l a V

3 nj cj bO -H

CO 4-1 > TJ 1) X (0 01 c bC m •H CO CO X kl u X .^-^ o >> y-f u 4-1 >^W-l u O

(0 4-) 01 4J ^ ^-1 ^H (U

03 (13 rH o T-t <U X ^ o X (0 cd 4-J X 4-> (0 Ui

4J -H U-l C

0) O; 3 C

4J U to O U CO ql U

OJ >. OJ c

•o m z to 4J to c to to CO •H bo • bO CO OJ c 00 OJ B a

to •H c U a o •H iH tH OJ to -H 4J

ui to CJ C

OJ -H OJ O ^

U CO £ CO 03 4-> CO iH 14 O U 4J

4J 4-1 1.1 C C

CO 01 ^ x:

tJH >4H u

t4H < ^ U IH T3 H OJ

to 4J

• OJ x:

T3 u OJ 00

0) 3 £

to C t-< 03 4-1 4J •H (0 3 03 bO C CO I-i 01

to OJ a. 3

«4H a O o to OJ OJ u X 01 >, to H x: XI u t4H 4J

H C O C O ^ CO o

•H X CO ^

CO DO bO Q. M -H -H 3 C

•a o -H CO C l-l -a tH

C OO X l-> 3 CO 3 O (0 c o

o OJ ^ OJ ^H o

u OJ o Ui XJ a 4-1 to o. CO T3 OJ T3 j: CJ 01 a 1 tH C Ji OJ 1

c 00 CO u OJ •o o 3 T3 u o bO l-l U r^ c 4-1 O s OJ OJ Ui u CJ 3 u 3 a. OJ to CO CO > u x: H u CO >

OJ O 4-1 CO CO OJ c o. 3 CO to OJ —4 o c T3 Ui to >, OJ a •*H to u rH

-H OJ a CO U 4-1 CO CO CO Ui o

to CO c a CO •r^ -fH T5 >rC OJ CL u a

3 CO CO •H CO •o OJ u OJ u 01 o j: OJ T3 OJ a 1.1 OJ c T3

t4-l OJ CO • Ui J>! U 01 rH rH O to iH OJ o x: CO to 4-1 OJ O > 00 o a cu to a Li 4J 01 c CJ to a U CO CO U JI 3 11 u 3

OJ o Ui OJ l-l en OJ j! a o 3 OJ 1.1 OJ to •o u > CJ 3 T3 CO CO CO OJ O a o to -H c c OJ C ^*-i X3 OJ CO x: to -H c 01 OJ to o -H iH < m CO o O rH < H H > H tH a a

3 O 4J 4) ^

0)

^ 01

03 bC l-l -HO

OJ to C 0) Ix C

4-» 3 -w -^ -O O

Ot > C X O

Ui X O -^ X >x

CJ U E -H 0) X -O C -H 0> >N »- 0» U O O 3

0> 4J >^ u c

> .-I l-l X -H ^

03 -O ^H

V

C Olc^l-O-OtO-^OJX eC-^E CCJCQO)^ UirHCO-^a^tJOO

4->Cl. >-Hl.<O.C0C4^

G-y-i >* O rH O C < (OO O4-i<0 Q.O-»^

^ 0) O O"

4-1 t3 rO 01 O

• 3 X

25
eo 1-1 o "-t

^ £i J-) f—

t

• a

th 01 >^ u

Ui 4J f^

•C S CO0)

i. «J u 0> 01 o c u o

o o 01 OJ • j: o l1 c m

c o u

o c •c c

tH OJ o 4-t «

4-> c o 3 a

V D 0< O 01 3 01 a u-l u

tj 4-1 u o T3

j-i U « V u

(» 01 X 01 o

c 00 c c

o c c o 3 •«-( d. ^ o •w- T-) ^ (J> a e

•D U C m -H 4J O X (0 O 1-1 "O 0) x: .-H i-H o to OJ u

Sx a> w fc- -H ^ 4-1 2 e CO u bo jj a

bO o

iw m c

O 0) •v^ u

u 4-1 OJ •H u CJ

4-1 3 o 01 n o- U-i M

i-< 01 c (U a: 1-( c 01 01 o

, u

cs c c o e

o 4J

1-t o

4J 0) CO 4J

00 a 1-1 OJ 09 4-1 0^ U Ui U kj C 0(00 O U-i O (0 X) o

o; C «

e OJ OJ e

o. e > k4 -H v •H O

3 ^ OJ bo ^

o- 3 o c

OJ CD « O -H « B 4-P 01 OJ OJ iH e X CO .-1 X U f

<5 •o •H n CO 4J •o OJ -W

1^ 01 <0 a.H

O 01 a OJ

CL. M-l u 10 u

H ki O 01

.O 00 OJ f-f bO

(0 CO <4-l (J 4J

CO CO J= o. >

01 4-1 4-t a -rf u CO a to 4J H OJ 3 £ T) >^ to cr 4J ^ c

OJ <H o C OJ a: 3 OJ O to

OJ 1 .. > o f-(

1 to to u o b 4J

T-l u « OJ n ax e

c o

OJ c (4-( CO H T3c

o

>^ OJ 10 CO • ^ bo CJ OJ

01 c to •H iH B 10 OJ 4-1 X

OJ X H CO to u o 4-1 ft 4-1 4J Ui kl 14

»< o OJ OJ w 4J a 4j a

O O TJ to ^ to "O c o

c u to 1-< , o 4J 4J u CD 4J to 10 o c

OJ OJ Ui (4-1 o

l-l c OJ ^ •H J3 bo CJ •o 4-1 01 to c fH OJ to o B OJ to u o H o l-l o •H •H w l-l OJ 3 iH a u U-l •a o- a

a OJ OJ c 01 a

^ 44-1 U CO t-i CD

u I to •V -rf u-l C 1-1 •H ij •H O l-l O. >s OJ C OJ

to M C C 4-1 b ^ bo OJ c to

00 CO > -H B

.. CO B OJ

01 OJ T) U

l-l CO to OJ -H X •> 4.1 iJ 13 4J

to to CJ U T3 OJ

4-> 4-1 OJ OJ OJ C

M CO *J -t-l X bO o OJ OJ X e to Pu 4J t) O OJ B

01 01 OJ c X t4-l 4J ^

c OJ •V

to >. 4J c o X 01

Li CO r 73 CJ to » 41 c u

o m <3 OJ ^ 3 O 4J

OJ 00 N 00

4-1 3 tH E

to e 4J e OJ u bOiH

OJ u OJ O X

TJ OJ CJ o o CO X OJ u

z: 3 CO l-l a

O B

o

bo -rf 01 C 4J

4J •H CO o to a o

4J Ui C -H

OJ OJ -1 » o a a

o o

o o

o o o o

o o o

01> m

H o

a be e C

CO 01 c CJ l-l 4J

•r4 >M CO c 4.1 o

•H to OJ

CO U c s •H o ^ • •H CD OJ OJ 4J C 4J a CO 01 OJ < E u l-l

0) O -H

<H U 4J O O*

to u to OJ bO a c a c c

•H to Ji •H <4-l r-i CJ 4J

to » •H CO 4J GO •o X o t:

OJ •D c CJ o

B to •H

U-l O iJ >,

**-< > - O T^ o O

C CD CO C (0 0) (0

01 O CO 3 O W O

O. C CO C (0 L4

(0 U O <0 4J O.

C 00 •o OJ c tl

OJ CO •H o ^ H

c Ui OJ CO •o kl 4J

OJ OJ c 01 •H 3 OJ

OJ <M o kl £ CO c » u-l 1^ to bc

4J to kl bO OJ CO

OJ •o X c B E

e

CO6

c 4J o

bO c 4J to CO c •H c o c o 4-1 tkl -H •o •H OJ kl Uh j: OJ 4J e ^ a kl CO 00 T^ u o. o

•H CO 00 to .K 00 3 Xi o OJ CO o CO CO bo a kl 01 01 bO e to B 4J (0 4J c c

iH »H o 00 OJ J^ H 4J 01 o 4J 01 e (J 4J

01 OJ to kl bO •H 10 4J c 01 4-1 to X

D CO •H j: ID B 4J tj

u u U V

C (J > O Ui c Q} £ u a. to U rH 0*0 C 0) OD£U COCOX U-IO.U u-HUOJcn

*- C 3 O 0>O S*HOT3-a I-T3 QJ £4-t i-HOtO)OCA-' O4J^4JCU-l«0J

T3 O CO 3

OJ OJ u 10 a 01 •u 4J 01

kl k o CO kl 3 .-t 3 •H 1-4 • c (0 o •H

CO 3 OJ XI o X CO

to IT 01 to CO rH c

OJ 01 4-1 OJ OJ c 3 01 s kl CO X < X •H Oi 4J

(0 4J CO -H

c B c X

OJ OJ OJ CO

4-> o 4-i X

o kl o o a o

U-4 Ou a.

rH c •

CO 00 c O OJ •o OJ o H kl OJ 4-1 kl kl CO CO 4J ,-H 3 CJ o

CJ OJ CO H kl

OJ OJ CO T3 kl O 4J ^

C ^ 4J OJ c o H W 00 a •'< CJ

o 4J a OJ CJ kl T3 OJ C o Uh u N kl to 00 4J X CJ iH > 1 01 OJ kl T) •H O c •H X 4H Uh

kJ 3 OJ o 4-1 kl X 4J u OJ 4J to Uh bO bo c H T3 • o

OJ o •H CJ kl OJ 3 4-1 T? OJ OJ •V kl 3 < •H 01 TJ z >^ c Uh to 4J Uh O o to b c c O fH 01 OJ O TJ kl kl CD •o H bO a OJ X •tH 01 OJ bc kl c •H a OJ c kl TJ c to 10 OJ 4H u •o 1 O c a rH OJ >, o H 4J to 3 OJ o B O OJ X OJ 10 aT5 •H U i

01 o •H H o OJ T3 o UH fH B 4J T3 o •H c 4-1 tJ B C 4J 01 CD 4J 4-1 a T5 OJ >%T3 CO CO o OJ OJ >^ >s 00 O 3 * O 10 u UH OJ

OJ 01 3 4J C 4J .H OJ CO CJ kl c a c ^ 00 •H OJ TJ CJ kl OJ bc

bo c C iH OJ CO to iH to (0 4-1 •H B o •H 01 to fH •»-i C •H to a. CD to c •o bo bO O c to CO 4J 3 u tH -H O kl B to fH X o 00 o kl

01 to to c bO » UH O OJ c 01 to OJ X 4J CJ a O O •H o o •H 01 kl 4J w

» •o e B f-l to c o •H CJ to c p-4 I-l o 01 to c H O to U a o o

o 3 S o kl 3 bo u. OJ •H X 4J c 00 to kl O 4J H >s 01 c 01 >

iH »-( » /.^ •H c 4J •o TJ CO X 4J •H fH OJ 4J CO kl •^ 01 u

-H o 4J CD bo kl o 4-1 u c c B •V » CJ 4J kl O >> OJ OJ to 3 kl X TJ o c c a c 00 O -H c 01 to o • OJ IS X OJ CD o 01 M kJ bO-O 4J OJ 4J OJ U^ 01 o kl OJ 4J 01 ^ kl ,-H u TJ kl OJ bo CJ iH §

to c •H Uh OJ tJ

kl X 4-1 01 a to tJ OJ » 4J to 3 rH OJ c » 01 kl 4-1 o C 01 c 4J 3

01 01 kl kl 00 4-1 CO c c ^4 OJ 4J T) OJ 4-J 01 fl TJ CO •H to ,H o bO kl bo CO TJ X kl 3 01 OJ OJ c o 5

o OJ c •H iH X 5

C c U 01 o OJ to to 01 C P 10 CJ B B e o CJ UH OJ B UH to kl •H UH < a c > CD S 10 X kl •H

rH O

Ck -H

I H

U 10 C U 01 OO fH 4J

OJ CO

4-1 TJ

UJ 01 O

C X

ON bO kl

• CO OJ

u-l i: x: in S

CM OJ O O C TJ -H

• C 3 X bO -H 4J 9^ bO "O kl to OJ 1/1 • to C OJ £ -H OJ in s l-l r ^ "^ H

26
iJ u u

c u b <a H C O -H O «4-« O O C £

^ ^ ^ i«-l 01 tM 3 > » «

8 *M (H

M 0) -H U

•H -H V 0) CO

OJ 4) 4-1 DO T3 C ^ O (0 V

bO 01 S bi 8 O *«-i "O 3 o c .. «

U (4 to >> u

u u bC 4J bO V c H (U c

>*-l (-* •H > ^ •H

1 <0 •H 4J c u 9 U >% (a o a> O •H a V Z B y a a

bc U4 c 0) C <p4 N U 00 IS 1 1 CI ^ B u

0) u u .- o o b U (Q 01 CD U c U

« u bC M o. c ^ u u y M-i 00 « (0 O u g

«M 01 u CO c a • U O V •H «

(0 0) a o. 3 -1

OJ '4-» u V <Q u cr^

fH U CO y j: a « a ^ 3 <o to c ^

« CD >, y-i 01 •H a -H O. A « U TD c B pH a

O S j: 3 C o ^ > O (0 i-t la « a. cH a eg

X . «

0) "O U «<-i -H

rH C -H i-H T9 0) OJ 01 11 -H e "O l-" 01 )M O. 01 3 O )-• q)

0) ^ -rt C X U 3 4)

01 iJ > CT S • V 0) Ot O 73 ^ c *c? u y o U U 00 ^ u

O >N Of <H Of C ^ jC OS 0) 4-t :tf 4-> 00 > u ki M

<0 (0 O (0 C -TJ 41 3 o 01 c b

O 00 4-> o> u eo y

x: 3 o -o o

3 a u

o bl >. y 3

•H •o

4)

CO >% y

t-i o

U o h

c u o.

OJ (0 bo TJ o 4) •o ^ u

o (0 (0 £ yH

01 c iH X •H a

H fl V u 01 £

e v B 01 •o a

o CO JH <i

01 -H (0 o. u U >M £ »n

V U-i 00 ^ y

a. O ij <0

fl c (0 £ <u c 4> D

00 c c o u 01 o y 3 c H o. j-t tH

<o B s

c o CO 3 l-> « y 4J I.I V

(U s OJ i~t bO e C0 4> c •a eg •o « 4J T3 bO

OJ en 3 CO *^ Jii V

oj to c -*^ •^ at -^ u

o c > u u-i 0) CO o -o y

jC M 0) C C 0)

I 3 uj

I o p

4) ) _ bfl 1- 4J O V O C 4) (D

<e 4J u 00 -rH 4J u

kt (0 C C iH

41 >. t( •« ^ ^ 4J ^ CO OJ v « 4» CO O<Qa0Jk<OI^4)

4j o a o; o 4)

01 U 4J U 4-1

tfl -O C go 01 •H 4) O 4) 4J 0) S U U C 4J CO 00 u

u ^ u ^ O

4) 3 C Of 01 U ^

o. ?* <a c "o ui ui M Of •-* ^ O Of Of u ki a 4j £ a a

U C C bi u-t H .rt CO 4( O

3 O. W

a- O « c C bc c»

Of -^ e •H o c a

U Of Q -p^ .H Q

> U 0) 4-> Li 1-1 ^ Of bo x: (0 (0 bo

-H ^ o 4-1 4j a. o H M 0) a 'H

j^ c o c u o o

o o

o "^

00 —

bo bo e ceo o (0 -rJ ^ • O <- "O *-» "O o

c y o u^

Of Of Of X uv

•a a 4j «

•v^ 4) 4) 0) O 3 "o -o a *j

E»

u TJ u

CL C c e

<4-l « o

CB co

tou 3

c «

4J ^ o

M CO Of e

y kl •

CO o

c ^ tl^ at o 4J B V

ki Of X u

Of y 4J u

4J c a e

Of Of Of o a 00 o o

4) Of B TS kl «-« r-t 4J 3 c o. a y

«ki 00 01 CO a 3 o -H y 00 4

4J •H 00 c bo

4J «0 > 4J -H C

00 44-1 Im c U • -H gOf 4) 3 ^ i-t 4.> CD c *D o y

y c o u 4f a 4f -H & c 4^ a

4f C ^ -H C

41 j: w j: -o

ki u Of 4.) 4) £ C O ki c

a. y ki 4) y

O 4) 4J CD (D

4> B 4) 4) X C >4H bO B

4-» (0 -O O CO •^ C a k* C >M CO C <H

C C > U C ki o o k4 a o Of

4f T3 6

o w

y ki CO ^

<*4 O Of w u fl OXQOofkt^O

41 Mrf a. 4 y CB o

C 4J U

4» y TS 4f ^i (0 Of iH (D I 4) Uirf 4f O

U U-i ^ ^

Ql. CO >u U

41 4f W £ < CD kl

^ c ( o c k. O 1 Of Of ^ u 0) Of Of -rt y Of <ki CO tM s

u

•^ > £ c Of CO U-l "H > O T3 w

> 2i s bo y 4.* O 4) y C 3 3

c <4^ Of 00 •o Of CO y c y ^ 4) 10 >v 0) >^ c •O Of 01 J= 4-1 u K C

CO H 4.> 00 4-1 bo 4) £ B 4J 41 CD 4) 4) y 4

1^ tki ki 00 Of •H 4) CO -H H kl c H y c

u o 3 kl 3 Of >4^ bO 1-4 x: y Of kl X 41 01 C a C 3 a 4J >» 3

C > 4.4 3 kl 4J 4.1 4J bO ki H "3 ^ k> o. « 4J o 4) c y 9

Q a 4.i 4) >^ k. V H y •o J3 c 3 Of » ^ c H e

C X Of y Of d 3 kl y

<o "a o kJ o t4-( CO « e o e a bo b 01 CD y 4, ^

y Of y T3 Of ** •H y 3 c O o y 4f

4.* 00 Of « ^ u 4J Ul 4) 4.* >44 c o 00 4J b H

3

k) 4> y 3 4-( a C ^ CO kl CO u 01 «

Of 41 O o •o -0 y -o •H 00 3 y o 4f kt 3 00 y 4) c 00 ^ Of Of -H W O ^ y « « c y 3 kl bo 3 4) Of N 4f 4J > b Of •o CD 4) a. 9 w4 o 01 § y

3

4 Of X j: «H X 4f -rt « X c c •H £ a 01 o c

y U3 *-» *j 4J kl •D -O O. 4J (Q •H a H <9 a y 4.1 0) ^

*4-l ^ Of CO I "^

4> Of -H ^ > k. •H O C kl Of

(0 CO kl Of -H

c- 01 5 «*-

Of O C 4J

Of 00 U.I kl

00 3 Of O c Q.X bC a Q c B 4J «

> u 41 4) o B a > y -o -H

bC « 41 c a CD £ 01 X 1-1 -H

0) Of a a J3 CO «

> > c ^ u C

3 « 9 c o o -a ft) o

3 3 Of C -H

to Of U Of (0 y y

s

c X 3 bo C

01 X

3

a 4f Of bO c o c « u 3 X 9 Of *^ o <-• 9 w t) a « -a - 3

a -H

X O. 3 o

3 a CD O 41

Of « CD

4) U Of a. y

08 c c o u If Of 4) 00 M

o D Of a 9

Of •D C fl V

fr- CO 3 c 9

:8i

^ 4) <H «

• C u fi.

U-l 5 O. M

a> A a

in £ O kn £

27
I >H o

C 'M £ 8£ u

II a a

•M C • 9

<< -^ a o

c >. O w U 3

I ,0 u o 3 t^ w 4i v 0) « ^

bo (0 u u u a

c 2 •^ " " "

« B -a ^ a

b a e « w 01 O I Of ^

O > Z C 4-( tM o ^

o o H "O O B u >> 01 C

fi u a. o; o a

k< ^ O i-i 'H bi ^ b ^ 3 u O

•H 3 OJ o a a ^ u > (Q u c 5 g-S g2 S

bc O OD C -rt (0 no 'O 3 0^ « 0)

1*^ (0 (0 4

O C •^ k4 >, Of a

i-i l-i w C ^ O 4 Q

to > •^ c

(Q CO O 4>

0) 2 Of tM o s •o ^ •^ Ml o P B O C

£ CO k4 4J -H 0) to X ^ •F^ « 4J e u 3 X « bC rH u w c

U U ^ 4J

(9 10 DO U • 01 C 3 0^ 0) no o. u

OJ B «*-' « -H

i-i 0) o c «

•a ^

« O u o o

C *->»-» w -t-i O -H

>»-( "^ -H •« 01 4J 01 X o x:

•O 0) Q •>-)

n -H >^

1) u ^

V 0> ^

•-H O X 0)

CQ i-t qj • fH 0^ (0 -o

•-( U U 00 01 « 3 4-* C

Ui u 0) i-l -H

CD X 3 03 U T^ 09 W

O O O OJ X

Z B u k4 O

£ u -H 5 u « «

>s -O O -H 0) C CD

•>' £ £ a ki a. -M u 01 a a -c £

b CD ec a < §.5 S g

1 u a o a

c 3 13 -H >M 4J ^

eg 01 09 ^

00c

ki U -H CO (0 H C o (U b. ij rt o

«w a c i4J 00^ • a 01 c C w to

CO 01 • a 01 •^ y »H u u >> 01 <M JJ iJ 3 m

c u u b CJ 1^ 3 « 3 01 a 01 u u O u 10 o. a CD 01 u a 09 a (0 09 C 4J o »^ -H « o s

c o CO •< a £ e u rt (J a

bO 0)

(0 o» e <M C J= -H Of

(0 jj 0) u -o

0) X 3

B c ij -o y-t •^ 0) o

« >. u • bO u I ^ M

03 c O X (0 OJ 0) ^ U 4J •H X

T3 0) (Q bo u B

<H QO U C C 3

> o; o 01 0) ^

O CO X b u

U CO fl) 4J O C

« a

1 rH c

c a-o a H 5§ u

CO 09 09 V H 4J «

- V

4J a u s§ c > 10 B

OJ H u OJ >> B CO 0) U pH a c a 3 T) H 01 CO -rf 3 a CO a

o- X o OJ CO U 01 u B U

CO "^ p a

>>£ £

O. u u CD *J U O •H be c

U -ri ^ u C O

01 3 01 3 0> -H

Ci. 7 > 4J Ui 4J X 01 01 CO •-> 10 U ki -o

01 u u

CD C

a u

-1 B u

X O. CD £38

a o- 5-"

4J CJ T3

kl u C O 1 3 OJ 3 O P u u 1 a OJ u £ B CO </>

o o

o o

0) -1 o IS OJ

00 bO 4 00 c o OJ 4J 1 B -H ^ .^ o kj C U OJ C -o -a kl o a ki 01 OJ O TJ C CO o a u H £ £ kl b CO a Q OJ -o u c kl u kl OJ • a u £ • u B a y O OJ -O OJ OJ DO O -O a a m o o 2

a a kl k) > ot o 00 bO a OJ £ U 3 OJ o u a o c •^ kl u £ 4J CO a kl kl £ 0) » a U C eo u o CO >ki 03 U

ID £ DO a c CM u 00 01 OJ c OJ 09 •H C u OJ <J o «4-l £ u 3 -O O

CD 3 -< > K o kJ CJ to £ OJ a CJ

0) -I CJ OJ C OJ <M bO k> a

> U CO > o c e OJ 00 0) iki g -o -1 OJ a 01 o OJ £ 01 -rH £ O

» •- -O -1 3 c c c u kl > U OJ kl a OJ ij 1 OJ -H o § u u CO OJ > kl

00 « u u 00 i E u CD bO • 3 kl OJ bO c

OD ki O. u CD w

§

c OJ o IS "O C OJ

OJ a OJ OJ CD o OJ 00 u 3 -< u

u u T3 O u CD u O OJ > u a <J ID C C w O C u U (0 V <kl u W 3 £ >, CO -H en lu a a m £ -O r^ o a. 09 V a X £ 3 a o

bO >>

•H kl a c

00 kl -H OJ C CJ bO OJ

H 00 kJ a u 3 c

> CO £ 01 kl £

a kl bO kJ

09 OJ e

OJ £ OJ 09 c B CD 3 01

«k4 r^ kl tH 01 kJ C > »kl cn T-t O

^ U -H 3

O Qi O U

CO •^(0 0)

OJ 4J (D O <6 b c 1-t u a

a> o fl) w -H (8

CO >s C u

•H c 6. 1

bo u o a

O « 4-> u CO a 3 o OJ 09 bO CM . 01

<a 01 o a 3 iJ OJ o O 8

u

j= u o i-i G - -o Sfk,k* u CD u kl 3 >s o OJ c a CJ •H o £ c u u a o c O OJ kl 09 o c 3 >> OJ OJ CM OJ V o OJ kt kl -H a kJ <M 13 >

«) • OJ a kl a >, a u a. CD OJ C a c f-H kl u 3 U U u CD O a s

en *c 01 U o kJ It c 01 -H OJ -D o > OJ k> CD 01 OJ b OJ OJ u

ot 3 « o a a OJ > c kl u e

kJ u «kl «

i

01 u u £ 01 CO -H 3 ^ u « 1*4 k> 00 o H T3 M £ kl £

a kl £ OJ u OJ a b CO o CJ « CJ kl o kl b -1 OJ a

kl CJ ig c B CD OJ £ ( ss kJ b OJ CO a OJ b a £ 09 a OJ OD CM kl OJ u O CO a 3 kl -H u u IM c 01 >M « b 09 C^ kl >^.H o -. o bo > »< B 3 b gi kl o u

§

CO -a CO T3 IS OJ CM

OJ o IM OJ 3 T3 CD r* TJ CO O b b £ en 00 CO o o - • b OJ b a c OJ b 3 e 3 b b T3 T3 B CO CO CJ OJ 09 O IM

09 -o •M CD CO kl CJ OJ 01 fi kl £

a U b

rH OJ B > 00

OJ C T3 £ O CJ OJ 3 £ T3 a C OJ -o

-^ CO C kl OJ 01 B CJ M b u H B OJ 01 O o bo n OJ TJ OJ v4 09 M b IS zs a e OJ • ^ CO •o a o C £ CO >M CO 3

(0 OJ OJ >M £ H 3 c OJ U o

3 Z OJ -1 • b b OJ CO a b OJ OJ kl 01 B

U" b 01 B

b > B

•^^ 3 b kl a 3 CO 00 B a b 01

OJ o OJ kl "O OJ 09 b kJ o OJ M

b O O CO £ a 01 c

c A a £ a OJ 01 IM t

rf o £ >M CM n CJ 3 -> u H a£ o kl kJ H O

I 0) o.

CD o ^ CJ (D £

(0 (4-1 j: u U D O. g

O 4J c C CO

OJ U CO g

01 b

to B 0) 0) bO o 0) H Xi 3

• O a u 0) O b IS B

>. li b b

4J 4J o; Q. « OJ 01 o 09 -o B £

01 U 4J 3 Of OJ M a X c O a 9 iJ 0) O c 01 •o C B c <0 U b OJ H 3 JJ B CO b

a U o CO OJ CO 0) tJ 4J •Q nH 3aiCcD0lU3C

(Q (0 W 3 CJ <H

*J Of 00 CO V O

S X 0> (Q "D B

O C •H Q (Q ^ 3 -H iJ 0) •o c iH y

V 0) 03 c

iJ c Of

I-I o kl

0) a £

01 a If u

c S >

rg ttf 4j — B b

w^ ^ CO — u B

• a Q ./I X o

> -H

to u

3 U

in ^ £

_( TJ kJ

• b OJ in O X 28

H O

o •H CO X

tJ-§

vO OJ £

U kl

01 OJ

u-i Q X

. U 00 Of -H 01 CO O
Co).. Qi ^ O O "O t3 *-> U-t I <*-! ^ 4-t

M

T-t t-i

O CO

111

U

a u- o a <o rt -u 4J

go .. klu bo

a s •H •• -H to

U T3

a ^ £ •H O u iH -^ -O B u <o » u 3 V l-> 00 00 a <o

k< § b

O JJ

u

a CT «4-l tic

u

V

u <o c (w c u 01 U-i 00 o k> o n a -H O 1 41 T3 ki a CO ij • 3 u^ O (0 B o >. a lO 3 C 6CT3 01 1 (U -o C SI eo <o o <u u ^ O (V C V gg 1 I' u u c <u <0 e a u U -rl k. O 1 5 u •H kl 01 ^ (V O TJ 3 £

(0 T^u 3 **-! >^ 3 >. 4-1 4J bou ^ n 4^

a e aa o c u c a. c t3 -H rt

U .H

b 4) o to <J

g o it

a >> 3 0) £ -H Xi u u B o u -a -a X ^ a 4J

0) 4-) 0)b

•<-( 0) QD

O

u 3 (Q (0

01

O a> VM

U

w

B 1^ XI <v 3

-^ &0 >^ CO •H C ^

cd <o c U-)

«H

U

(J

a

a Xi a c 3 « -tH m

.-(

U U-( c

01 ••

U 0) •HO) b

J3 4J CO 3 u u u ta

iJ <0 01 01 u u •o u

•H

00 i § B uc 01 01

<•> £ u V •H ^ 0) >s > ^ CO -M

CO

O T5 60 c c u CO *J -H •o 4-1 3 at 01 C £ A • • 0) X u u aw -H

0) -rt ac CO

XU 3 C -1 •o

CO 3 -H Ui o; u 00 0> ^ 0) 4J

k4 CO -O

m iJ 00

4J kl OJ C4.t CO 3 -O O o 01 CO 3 a o> a V a o a 01 J3 , o 01 u OJ C >^ 4J ^ O c CO

01X CJ 10

U ^ CO 4-1 a 4J 4J X m a u c U .a

•H 01 •H 3 W a a 3 CO

01 -HU

U

00 Ui t3 4J 3 01 01 a 01 c O »< B CO

01 o. 4.1 Ui -H 0) 00 CO 0) CO u u

a c c o

4J

U -H a> 0)

01 a> CO o u 3 O. U ^ 41 X o 4J ^ a S4IU 4-> CO c a 01 •H a 4-» X a CO U 3 O a cT a u

•< o o o o o o -3- O o o o o o o

v> coL> OJ

u c

01 £ O 41

a jta Tj

*4-l •H

C c o c • 41 O D a CO -H ^

41 4J 4J (0 b e « -^ 3 4) -H 14

01 4J 3 V

CO e 00 4j

OJ o c a

<0 ^ iH 4J

H

41 3 CO 00 a 00 •^ 00 e U c u •r^ o; u c 4-1 01

41 « a 4-1 4J rH a CO u CO c •r^ a CO ^ O 00 a ^ o 00 c o CO •H c 3

41 U-i *4-l o u o "O •H >> 3 4J 4J u

4J

m t-t CD CO c O OJ C OJ -H

C

Q bO

01

O c • B rt 0)

OJU 4J

CO -H

U

C

41O CO

O

B e

41 Ji a o

-H 00 bO a 41 B

Ui c

41 o 4J

4J

u 10

OJ

a

a SI

u • 4J T3 ,-i j:

U 00 00 £ 41u 00 4J

B CO rH 4J CO •^

OJ

a CO •H 3 41 41 3

Jl 4-1 ^ OJ

U ki

C

U

V tu ^

(0

O ^ uO ^ o a >% <u

OJ c^ CJ yn t-( OJ

U-i

u rH

10u 41 CJ

u 4J o

OJ rH u 41 41 a iH £ a •o 4J

41 I l-< 41 £ O 4J 0) ^1 4-1 ki ^ 4J ^ CO C TJ 00 B

OJ 3 £ £ O

4J CO a. -H 4J -H

CJ CO

O 4J

q OJ

u 00 ^M TC Q. a

B CO 3 m o 4J 4J , s O a o CO CO ^^ o OJ £ o « o 4-> 4J en a 3 4-1 B u O CO OJ u w HI •o 01 <4H bo OJ 3 u E 41 u O CO 4J

41 4) 41 l-i CO

B i-i IS

B 4J bo 41u o TJ

a

B 4J CO OJ >-

4J

H

u 4-1

B £ 4-> £ a

00 T)

aO

a

u

," >> >> o U 3 o *4H

B

CX4 £ £ CO

u

B o.O

H P o. iH 41 o CO 01 o X o « CO 00 •o 41 CO 00 1 3

4J CO CO rH >. OJ

B

Uu CJ 00 ki E 41 (0 >% ^ (0 Li CO bO-C3 CO B 41 •rt 3 4J 41 3 o GC .—t

'4-1 •o t-t .§ V u CO B B -rt 4J £ £ 4-1 -5 3

0) 1-t a»U bO CO 00 CO u-i OJ 00

a

uB

u

u O. CJ CQ (S £. >» §

41 00 4-1 tH

U

H 3 M

a 0!

u 3 c u CO <U £ B >> OJ 3 •O B E IM 41 £ 4J o 4-1 a> u f 4J M s O B bO o 41 o U-l 00 c 4) (U -a iJ OJ -H -o ^ CO « U 41 3 a ji: C b O M £ £ 4J <J 00 a £ CO £ 00 u a; bc

CO QD i o 4J

O

U t-i •H CO 4J ^^ 4J CO CO OJ c

00 CO

B 4J 01 o £ 4J 60 -O a. 41a

b £ bc §

00 (0 00

Q IM £ aiu 4J

B 4JB 41 3 4) OJ

B COa i~i CO

X

a o bO^O 3 a TJ > r4 4-1 >^

U J^ 41 41

a T3 4 ^ (0 B T) e U o U 10 TJ 41 3 O ^ a E o C M (U -a c >-.£ rl 41 r-i « 10 B OJ CO -H 03 4J CO u >. V o 4J bo ID rt £ u -H a. OJ s) £ 41 E u "O 3 ttf *J -H 3 4-1 3 C4-I bO CJ a a£ OJ 4J O B a> 3 cc CO n CD t^ U *J CD O 00 B a 1 3 4J a a o a 0) c f-t V 4) CO 4) •H li B u a tH OJ 4-1 -H > 01 rH 3 T3 E u u QC O 00 bO

eg 0) c e o 41 £ CO g)

u 41 £ '^ a- E O E ^ OJa 4) CO c CO (0

O

a 0) 4)

a TS 4Ja Bu

a 3 14^ < 4J -rH OJ

n 4-1 <» 1*^ 0. £ •o ac •^ bo bC

f! 8 • O M

^O (0 *-t —« a. CO • (0 c m o •-» S 1 3

Hf ui

g >. • CO a £ Z

sD k4u o. r^

— It! 41 CO in *^ H bO u-l

00

C <J 41

— t£ *-* bO • CO ^ (0

u-i

X P O

29
CO 4J u -w

h 4J

H

a 3 3

a* 00

m c a o

0) t-( u u

CO CO o

•o o

HI

u

a

B so o

-^

C CO

w ^ a)

M-i

u e a

u

O ^ V O CO

kl

4) • -rt u 'O 4 •

03 a; o. 00 a c <u c H T-l iJ O x a -H O ^ CO t-( M OJ 'Q (0 a u 01 u a oj Of o ^ o ^ ^ c u

0}3 03 *M

a* ^ o

0) 01 0) 3 . u (1) CO bO ^

00 CD It CO 0} • £ c o 01 a iH £ o 1i U L< CO O 4-1 u £ 01 o OJ bo

IB 4-) 3 c o CO

u c

01 0)

a o>

CO (U >M 01 01 BO b4 01 4-1 o 4J u CO 0} 4-t u CO 01 01 e > CO u >^ l-l £ CO -1 4-> U o » -a bOU-i n CO •H c o c c 1-^ o >^ 4-1 o CJ 0) iH O B

J=

uu

CO

4J (U c £ H •o 09 u CO V eo CO 4J •o CO CO a J! •H 01 CJ •o o <a 01 01 a < u^ 4-1 4.4 C« Q -O c > C X > ) CO -H CO ^ -H 1 QQ 01 0) 1 XI C • T3 > C . 1 •H QJ T3 •H -H QJ T3 1 a a a jj a. 1 CO X £ CO CO X £

k4 OJ

U

U ^ 01 J^ < u. .H B

•o c •o c

•H 60 o •H 00

.c s c £ B c

4J ^4 (0 4J I.' 01 01 4-1 CO 01 0) 4-1 a 4-1 (0 01 a 4J CO

0) o c 01

O

t3 T3 CJ Ji TJ TJ o

CJ •H

a 4-1 •Ha 4.4 o O 0) £ « O 01 ps t4-l 3 4-1 a: cu 3

0) 00 jC -H

4J OJ

U

H c e -H

a

•H -H x:

-»

X 4J «4-l 13 -O O O a> rH

J-> -r^ OJ

u a. .H <U

U -U

at O. •H CD 0} -H

-a cQ i4_( 3 g

a

a

u

-HO

ena

.* OJ >< 3 B.13 01 4J TS ^ 4J a li

CO 01 c .H CO .H o M

O

01

a o CO

u CO 00 c c

4JU CO CO .H •o 01 a CO > c o

TJ 01 <4H o. .H 0> -H c > U 0) T3 CO 4J ,C C

M-i CO ^ 01 .r.4 c o

COa CO 01 c CO o;

J>! c OJ Ul 4-4 >»

CJ 01 OJ 0) 01 J3

a 3 o> 4-1 a.o £ M CO a -o t) .H 3 K a 4J .H tr o; c B 3 -O U CO C CO c .H o- C O 3 < .H o .H CO a [d CO >M cr

GO bc CD -a

M Cfl T>

Ui •H T3 bc a> -o tio at 1 (y .JJ OJ C I-i a; c )-< 1 (0 U f-K ^ ^ 1 =D cu 3 i-j 3 3 w 3 1 a* O to CT o (0 cr t q o a>

60 CO 13 00 CO -o 00 CO -a

•a OO 01

O 60 0) T3 00 a)

OJ

C l- 0)

C 1-1 01

C

M

-< -H rH .H "H ^^ T^ T* 3 4-> 3 3 4J 3 9 " =

01 >,-H

JQ Si CM ^ C •o >. OJ

CO OJu c

CJ 4J CO c

CO c:

L4 .H 0) 3 OJ -o u o a. u 3!

a OJ .H a 4J X Q. CO -1

u, 3 8

o. cr a csj o o o oCO- </v

OJ o CO >, QC m .H >^

4J

u

C

a

U 11 c

CO

O -H XI CO o o C 4-t c

IM CO CO .H <*4 00

B

O 3 a o c u CJ u .H

01 COu OJ COu OJ

to CJ

M 4-J 00 CO 00

OJ OJ -1 OJ 01 01 o CO o c o x>

t4-t 4J o m o S

01 CD 4J a

01 «

ca e

00 OJ c -< M o c .c

OJ O. 4J CO

U £ 01 01

OOUC CJ •H CO 0} C

4J -H OJ

U

O. 4J OJ 4-1 00 a .tH 4.4 CO OJ o B OJ a -H Ukiki.HU O CJ 4J kl

•kC 144

C CO Of

O .HO OJ O.

>NT3

a CO 4J OJ OJ kl r^ 00 (0 CO ^ 3 4J

CO OJ kl 3 01 j: trx 4J §

4^ CO CO

U 03 00 CO 4J CO 4J o OJ

a

U JS 0) (Q

O OJ c u o BH 4J •a o

4-t 3 C OJ OJ c .rt 00 0) 3 • 3 3 01 o c 4J ts bO S c j<: C u 4J CO O 00 O kl 00 -^ o 0) § o M CJ 0) 3 B a O OJ -1 4.1 -H o u .H T3 ^J . OJ >< OJ u E 00 o OJ

CO a>w

u £ 3 PL, CD CJ J3 OJa CD 10

u

m

u 3 c e c J= 4J -1 OJ j: B J= CO 00

a; o •H T3 4J CJ - 00 CJ 13 3 OJ

a ^ u CD

CJ !U OJ

aC -H 10 .H OJ rH vH 3 U

O 00

u c CO cn 00 -H T< CO 00

u 4J

O 01 00 COO

so 0) bo (L 3 c: .HU 4J

U .H

X XI >.

B -H -a kl c > 0) ^« 4-( 0) -1 X B O k. OJ 3 rH q) 3 OJ CJ • Q 4J OJ a CJ OJ a. 4j > u OJ OJ k4 CJ -B 10 a u (0 3 CO U 00 OJ u o a B B 01 .o U kl 00 iH

Q. o u^

U M^

O (U CO x: o o 3 OJ 5 B 3 OJ .H 3 kl .f-l W) u u 3 00 CJ c u CD U .H «kl 4.4 o: CJ o. O 14-1

•OO 00 o ^ o > at -H

^^ OJ

B OJ •

01 > g E 3 x: kl ho o T^ u •H B CO a. O 3 O ><rH B CO CJ a CO CO OJ OJ M

CO 4.1 kl •^ u 5 B CO 01 CJ

OJ 01 OJ .H ^

kl kl £ O. r-i 3 3 a CO 4J t) • >^ o U B 00 13 Q CJ .H T3 E 01 tj U 1

OJ C3 x: 4J

IS

B CJ CJ

ID CO 3 O .H 01

CO CO

OO x: x: ^ a CJ OO 3 OJ o B 1 B tj o kl ^

CJ CO .H r-l CJ 4J OJ IS H O a CO B CO CJ

ID 3 •rs a.

u 10 00 3 4-1 :> CJ <kl CD o CO OJ CO u OJ kl 01

kl OJ x:

B 3 E

XI 4-1 E H •o CJ 4-1 OJ cn •o

.H CD

OJ

OJ OJ , E aU

CO 4J TJ • ^ B kl 14-1 x: a o. 4-1 01 o •o o OJ o OO o. 4J OJ OJ 01 u 01 CO OJ x: u o E a 4J O a 4J 3 CO o 4-1 CO CO Ikl a CO 01 CO 00 B f-t .H X 01 CO kl kl rH OJ a 4J XI OJ "0 OJ 3 3 a O u o 00 XI a CO CD

01

a

u CO

B ID o •o x>O

kl OJ o OJ 4-1 kl E n 3 01 u CO a ^ f-l .H Ot eg .H 00 a > '^ 4-1 ^

CJ «.« US ^ U DO

-4 01

a CD rH OJ -; cn u CJ .* .H E -» 1 CJ • 0! 1 • OJ I- Ji 00 kl iH IS CO E ^ 01 CO B X 00 CJ 01 00 OJ a 01 OOM 00 00 3 00 u OJ 00 « 3 (0 Q ^ o> x: 10 E j: m £ O. O 1^ X u. lH 3 H o m M (J 5 ^.3S s;s

B kl H CD O 01 Ck (1 O Tl CM CO

li-l 1^

30
^ 01 s> 3 4.J «

4J

V OJ bO o CD b kl • 9 a u CO o •H b £ e 01 B 4-t s c *J C QO TJ u

10

O 3

i-( 01 £ •o •T3 P. M iJ 01 C

CO 0) •V

u o

iH

B

B 01 •H o 3 a a W

(w •o 4-1 o a OJ

01

m 01 ^ u c 01 01 p (0

«ea 4-> > o u V 01 CO c TJ .c 4J u HI

01 •o

a

C o CI (D <u T3 u 4-) 4J c u c 0> o 09 J3 go 01 a 3 4J TJ u

(0 cr (C 4-)

u

V

01 01 o 0> £ u 1^ < c C »

<U (S 0) t44 3

01

O -H

l-< ^ CW M-i

C

OQO

X £ -H 4J U U u 01 OJ t^ 0) 01 ^ CO « u 4J a 3

Of

VM

0) CO >-• 0) 01 Of O. iJ t^

>- £ U

C -H £ X -H • I- U i^ u u >-, 3 CO o a (Q « OD 13 0) . 4J OJ (U J-J I- -H iJ C tii O 4^ -H q; O £: a -H E c (J C OJ B o .a> AJ m o ^ c c o m u

4J -H

O OJ ec

"OO 03X **-< Xl

01 .-I

U 4-> 1-1

01 1-t T3 CD CO CD > a. c 3 3 to a (C 4J E O X 03 JJ

l-( c -^ i-* OJ CO "O OJ w c

be ^ --H -O

O flJ c "H Q> o a. c « c ^ o o- p O 3 'W a O'D.

4J t) 4-1 O 01 -H 2

4J

CD 3

4-1 01 J3

CO 4J 1CO

0< 01a

kl £i

td

U •H tl

u •H o 01 .. bO

01

UBu

m -H

CO

U o; 3 4-1

X s 01 a ki m d 01 a 01 Qj X o c 4J ,0

-O S -O ^ <H c a> 01 fl) CO u-i to > X 4.» c u o ^ o y o iH • 0)OD-H3NJJOOC F-CCX-O-Hl-iOtO O.Qj^C>-iOtU<H so. O O > 0) iJ

AJ

yX

to > •O <Li

0) Ot 00 •O 1-1y to 4J 0) > CCSCO tJ

U-4 ^ >. OJ •H 01 o CO fH 4-1 4-1 £

•o t-l •o c U

(D

C 14 •H 3 t) c

CO <0 OJ O.

U c 10

OJ 4-1 10 - 4-1 10

u

U 01 10 ki T3

n

10 4J

B 01 c ID CO 01 OJ >^ o 4-1 01 u u £ 01 o -H u U <J 01 > e 01

k< c SI c U 4-1 u-l 3S 4J 10 3 10 01 01 o o IS c T) •o a 1 01 T)

l-i

B CD •H 10 OJ c 3 4J > o 10 o- CO a •H

01

u » 4J

U

U 01 CO 01 •o U-l M 4J - c o 10 10 £ 3 O. a

BC 00

(0 -H a. -H

a *J I as •H C 03 > 3 -H -H cr T3 o;

<U •- 03X

<U 1-1 0) ^ c H X ^ cc X (0 O CJ CO ^

MJ -H >>

C

U (D iJ

O

O > -H .^ £ •o o

01 T3 01 o 4.4 0) cc 4J

CO c 01 3 o 3 u 10 O 01 10 c o u X a. ^ 01 10

c/3 o -t-*

mX ki

4J iJ £

10 t:

M t4 60 E 01 C 4J -H

.H S 4-1

H 10 JC 1 y. o. <ti O O 1 £•38 C -H C 1 01 OJ ^ OJ 1 a cr •c a a 4J 1 a u .H 01 ex u-l < 3 T3 10 O

OJ o o

1-H 4J ^ O 01 C JS o •r^ OJ 10 irj b E £ u>

>^ k4 4J 3 01 H 4-1 kl

CJU 3 a 3 CD a m DJ bO

10 4-1 OJ c u ID u •H a £

01 Uh

B

14-4

O u-l 3

10

O

CO >,

a

4.1 BO

eo •M E •o c kl .H c

•H bO 4-1 03 c 01 ID •H 4J 01 CO B c 4J rH u 0) V ^ w

4J T) 10 CO

01

B 5

0)

Q 10 >

u-l > 0} o

1-1 0) (/} 0) T) B CO -U

O) 03 Ji^ 0) U-l C CI > O O 0> -H (0 H AJ X a. C i-> 01 u O 0) k< (U •H C U u-l 4J *J -H C O 0) U B O fc- Ot 0) y !-• CJ

0) (u as a; E

•o i-i 0)a o

•o 3 ^- to o ^ w 3 c X to 4-1 -r-i o> >% u-l 3 i-i a>

u-l Li

O l-i

H c w u-l

y

OJ

u c 0)

u

•o o OJ en •H 3 -D 3 C

0) 0) rH

XX t C Xu-ibO-HUiJ OJ^O O U C CO > o> •H l-i3-HCO^ •H4-I4J S B k4 ex 10 CO 01 4J .H 00 OJ 10 CO ID OJ > 1 4J t3 3 3 4J 4J E 00 -O kl » B 4-1 c^ a X kl

CO 10 01 OJ

O E -H 01 XI 10 tl » bOQ 01 >. 10 OJ £ OJ < 01 3 kl OJ -H >< kl OJ u 3 4J a ^ OJ 01 4-1 4J •H m Q.X rH O 4J kl 4J 01 ^ c B 4-1 OJ -1 01 i-l B CO B •H o e k .H •^

kl o n

O kl . O.X »H

Q

CU

O 10 01 k4 •O OJ

X 4J

O 4-1 CD 4J o C O. 10 3 10 .H 4J E CD •H k4 E •*H 10 k4 u-l U B rr-v OJ OJ 3 -H

01 T) 10 T3 o 00

a o OJ 10 kl • 01

k- 01 01 OJ

u 01 10 OJ • X kl k4 kl 10 •C3 t-i 4-1 t-l !>^ 3 4-1 01 3 •u U T^ -O ^ E 4J U4 10 a q k4 4J y E O c 01 01 01 OO 00 a kl 10 •H bO .H 10 O 01 O kl o X >^ 01 kl kl •r4 E T3 X o 01 kl n kl V 3 -r-i a Xi 4-1 X kl 01 o CD 01 01 ex r4 B 4J o 01 a OJ E

k- £ CO

u

O klX E E kl

C 10 T)O 4J 4-1uO 4J 3

4-1 3 01 10 u-<

aO 73 o 01 4J t4M 10 kl c 10

k

n

O

CO ID kl < o OJ u-l 10 kl 4J

a

B bC a: u-l e t^B

a s X

•O

OXC

01

X 3

4J

u tja o

l-i

O 01 3 X

CO *-> 01 '-^ I Q. C rH t3 <

OJ UH -O 0) c T? o> o> ji: 0) -rH 1-1 *J (J • X tJ O ^ 1-1 4-> C CO OJ O. 01I I w to 1- C OJ -H *J

eg Ui 0) <->

to OJ

O bC

u

O 0)Q

O 01

H ^ rH > ga 0) OJ Uj OD ..

O OJ >N 0) -H OJ

OJX bO 1-1

u

4J

U l-l OJ 0>

a n)V > u

OJ u-lC

X to (J O OJ H 5 to

rH -^

X U-( iJ u •o (0 •H Cl •^

u > 03 to

OJ to CO OJ QD

O AJ ^ 1-1

u

1-1 o T) :» 1-1 c to <J

r OJ •o

4-> o C

03 o 3 •H kw OJ

u

CO

CO

X

T) c •D tc •-H

V 01 bO 0) o iJ

03 01 0> OJ 0) 3 X c 05 a.

4-> 03 4-1

UH or •o bc 01 c >s 3 OJ X 4-1 iJ iJ X to u

0» tcX t-J Ui • X CO

u 03 k. o X

l-l OJ

a 0) o o cn a. 01 l-l >s i-t 0) OJ 03 I-' o. c ^^ to ,~l -^ iJ ffi k< 13

U-( iJu to 03 k< CO

X 0) E o u 0)

1-1 bOu o bo c o c 03 >^ CO

•rH 01 o >^ a. kl o Im 01

XuX 3

T3

a 1- 3 OJ 01 4-1 a. (J -H o. o "0 4J 0) 4J jj T3 u 00 4-» e to OJ

U-J

u to 0)

X to to c OJ >^

X 0» Ut o ex. ex: B i-( CO E x tH J^J X 3 c ir. bC o;

mJ

— bc • o

3i
u «i •

ki t

0) c 3 O 1-t c a » o Xi a o u V l-t u a-D 00 K 0> U-i 00 >, u b c O 0) *j H o y

>H

w S CD o

CD c cr 4-J

V « C o 01 « O

01u 09 «

iJ o (4-1 ^ c .> OJ o ki D f u 3 u

01

n 00 c t-l >> IS o w a: 3 0^ 8 s e o 4-1 4J •*-) ^ •H u m o 00 01 00 C V 01 BO o HI •u E C a c a tD q a o K J3 u o a

•c o •-

l-i 00 C O' 4J

C TJ --t c O C -O 0) ^ fl « E

4J 4J D. 01 ^ « (B CS i-H 1-H • u u <Li a 4J ^ Of 6 00 W C O W 4J « a> c a u-( DO O 1^

•O

UM iJ 00C o -H y >s o H £ 3 0) -t -H

fc- 4-> cr *J - ^-

0> -H 01 01

Q bC

01 c

•o

u ^ o w s ^ V s o o o c

<Ja ^ £ o. t> 01 bO b c

>sh 3 •tH ^ (0 w

4J j:

u "O

u o 3 01 01 h 00 CD 11 01 w 01 ^ > a u > o l-> u QQ 0) w a c O w K o

•H

a

B

01

a

«M

K

a OfK

M 01 •o * 01 9 iH •u C i4 c

•H 01

B c U u 4J OJ e u a OJ o a £ o ki < U

01 £ o

j> «

•o c

•o OJ 01

a

•H 0) c a 3 ^ £ O £ («-< j: » OJ •o a V o o £ •o £ 4J 01 u »H OJ a h ^ e o a > W u OJ QD u OJ a >

0) o u OJ OJ b: IM a 4J T>

at i-i o c 01 c « -H L' £ o ^ a 1 11 o 0.-0 0) u a c OJ c B OS u c >, OJ -H 4J o X o u C 10 01 tM fH £ a ^ o •H y o a a C B

0) OJ >< •o £ ^ c c o OJ > 41 a .. a 01 O >. B a n o £ > u >^ u i-> o 4J o -a OJ £

OS J-> •H 1 £ O o tH OJU •DO

u

a

a

X

a OJ OJ ^ 01 ^ a t ^ u

M c a

u 4J o. ki iJa

a

u

O OJ 01 o ki OJ 01a

a

a

a

V

u o

a.

ua

u 00 TJ

a

a > s b: 4J ^ a

a o a £ a U »H : O a 4J »< . C a 41 *i3 OJ 0> u ^ OJ bo il -D 41 ace J a -rt

•o £ • 41 C £ a •o £ a o

41

u c 41 0) T< c •H a OJ •O 41

0> 3 41 e a

OJ

a iH

a k. £ •o •H a <H o o

OJ

w hi

u

a

w

w

a 4J OJ

H o -1

a

a

a 41 41a « £ «H a o U B £ OJ

01

a

a

O

a

41 k> >^

u

b c ^ a li C a a. o ii -rt ^ a £ u o o

(-" o e u < OJ 4-1

a o c o £ C a a ^

•o •c OJ

OJ QJ T3 OJ c £ 41 OJ w c

toC c o

41

u ^ OJ

a

a OJa o Ui 3 a w OJ s O tJ •H o.

01 OJ a> > bo 3 -o ^ ^ TJ cr 4) to

00

V •H t^ Ui

C -HC •H .D

01 » £ 3 -H

4j o y ff K C V OJ

m

O

(Li ^ 4J kj

y

B

O 4J 4J W -O C OJ

C -O 00 -H •

0) OJ OJ iJ 00

T-tU iJ

O

V *->

U -H 4-1U I-H 0) 3 c a 3

O. cr 03 TJ

U 00

X 01 fH

C 01 OJ U3 u a. to 4-» i-i £ •o OJ

u bo

o; "U c 4J •o

b

a

•o 41 OJ c a OJ

a OJ

V r-( a c o u fH OJ 3 k. -H a V s 41 •o O OJ a u •o o •ri u OJ £ a. u o> o c OJ OJ W 4J a E M a a c B OJ -I B 41 X a a o -^ o o o in —.

01 OJ 3 O -H a cx o '4-1 a H OJ B C OJ S T3 a .rf T3

j<f c c be

bi

a 41 41 ^•HOOCCbCOJ d. .-J •H OJ c • 41 a II u a ki E o c

•H c (0

a o c u

C (0 >^ OJ « c l-i •H ^ 4J «

•H 4J

C -H E c •H

*-> (ft -H fl

U -D OJ 1-1 eo -o m e U .-( . 01 OJ B 0) O -.-I c 4-> -H bc 0) 4J OJ J-i O O 0) U-i C 3 • 4J 0» .H <0 J > -u o H X) a> V) a 01 B

(0 -H . 14-1

(-1

m o

(4-1 (0 OJ --t OJ O > •«-( CO CD .o C "O -H o -H c O C © -H 4J (0 •H (0 C 4J CD U • 4J 0) m •H 'O

0) 00 -o i-< i-i en OJ CO) .o 01 bo c ^ -H C -H 4J C -H e 4j .H > y •H B t •H CO T7 Ed V 00 C O l-i <~< OJ 4J C O 00 (0 -H ^ .« c

4J £ O a 4J -H c c c ,_l cQ

OJ T5

a 41 1 a

a •o 1-1 41 OJ a •D X UH OJ c a CO u c OJ •o c X ^ OJ 11 1 bO a o c > a OJ 1^ c 3 »H CO 13 0) c o 01

a uj ^ c O

a T3

u >s o a •Hu 41

U OJ OJ U5 c o a OJ 4J 3 3 OJ CO

Ji! o 01

a OJa fH

a -H 3 a OJ 01 ^ ki £ • Ml T3 l->

X M-t 4J (D 41 • oX -H ^M £ li <J OJ 41 c ii a •rt a OJ m u c c •H <0 3 CJ OJ C o OJ >^ Q. O y tD kl o b kl iJ o M • 41 OJ • u £ a OJ 1 c a a Ji > 3 01 u OJ O OJ to U-i X) OJ 4J bO OJ OJ o 3 41 C £ £ 4J U H 01 X H ki >>-H o B •o 1-* a. y •o 01 41 H k' rH u w 4J c o kl 41 41 4^ ^ OJ O C O 4-J 41 C B •H •a > •o OJ -H E o a a a 41 CD c £ o 41 01 o •o 01 CD c o OJ OJ OJ kd kl U OJ U OJ -H £ a -H OJ a o 41 41 a a £ O c c a •c OJ CO 4J OJ o 3 CO o o 0) •V -H H U-l X3 £ V E ui 01 00 3 £ C V C -H 3 u 41 £ a c a c c lO a a kl M -o bO a y x: 00 E C CO •o 00 y 41 o 00 00 41 O C c O 14-1 k4 O U o OJ a a a a kt M CO 00 c kl a •H 4J <H y c C ^o u OJ OJ c OJ CO B- ° a o. » •H a o •o -H a kt »< 41 41 OJ •a OJ 'V c a OJ 4-1 01 £ o .-) -H 3 o :> a O a 3 OJ X OJ 6C E -1 a S u OJ o a OJ 41 u MH >^ 41 OJ c c f-l u £ u s 4J >^ c o u o; 1 41 o--a 4iJ B C O 41 -rt T) a £ 41 a ki o £ a •o 5^ OJ CO CD CO •o bO o CD D. 1-1 u o u l-l OJ c 3 b 3 o

r^ o a >%

a

O £ aH •T3

a 41a OJ 41 >% c £ a 4-f T3 OJ OJ c u

u OJ 01

y bO CO

y <N s

•H ^ 41 4-1 to QJ

a 3 41 o. s • a t4 t S-.-0 > o £ a 00 i-i c a

V •H a.

a to •D

a CD

M

00

u 4J

y

a DO c u 00

a o u •D

B OJ

a ^ 41 OJ

a OJ T3 OJ CD (0 3 •M kly (0 a> o o c T3 c to c a c 0) a OJ C M >% OJ a c OJ 41 41 a 41 3 t3 a OJ c OJ OJ 4J 3 OJ rH CD » to bo j= o .H 1 OJ a 00 OJ to to D. -H 4J c 41 •H OC ^ N a a 1 o c kl a t4H OJ OJ 41 o j: 4-' CO >. OJ a B O c bo 4J kl to lA 4J u a 1-1 u

•V 41 OJ

a o o rH >N

u OJ

a

u bO 3 J<! OJ (J bO

U o 4-* o c o OJ

O

W • •H

C a.

y 41 tl oo E •H a; c v> c -I a T3 E "H 41 a OJ £ OJ u u OJ OJ .H O 3 k< OJ c g

OJ tH •H Xi c 1—t c 4^ JZ -H

O CD 141 OJ

a c 3 X) 01

OJ -w rf o 3 a 41 a.

a OJ 41 41a o •o •oa 41 OJ •c o •u kl bo-i o CD CO cc > 4J OJ

a

a -H OJ tr o ^ (f) £ 3 VM X'44 3 £ a c a o a £ <-1 a B > £ c c £ 01 e c tn o £4 y x: vH 01 3 CD c

i£

OJO £ c c §g OJ

u to 01 3 £ O £ o £ 0. 3 a E 3 41 U OJ B M OJ a a H y •o CO 4-J < 3 3 4-t OJ OD 4-> H o-x: j= 4^ m (.1 o. 4J u

y^

a -r^

CO OJ •a OJ N u >s

lo

O

H fsl 3 COC

u-^ b. < 32

loX a<
C Tl •H

<l) » AJ

<u 00 ^ -o •H u <H M P CO u H <U 1 o « O U 1 £ iH (» U 1 V <0 1 u u >> u

CO ki c «

0) to j: H O B <J

•H c 00 c

bc

u o o 01 4J w c c

00 <M bo

a o « 01 c CL IH 4J •H 0) B

x>

a 00 iJ

N o a a j: 00 •H u

4^ •H 4-t 01 CO K DC iJ lU c o C t)s o b 01 M-( £

•H

a

u o !^

00

a 4J o U

kl

a QD >, 01

u

01 4J ii

v > !>^ 0> •H •H B c iM tH B c •H <H H V o o 00 XI i-H BO

<-• c o c o <«

01

u e u 01 O. 00 fi< •H CO S >M O

iJ -H >^

kl

a CO o > a

Bl,

Q 01

u 1 B •vH >> 0) u ID « kl •rt •o u rH u kl •O • • - kl CO •o c o 01 £ kl CO iki a u •H

«l o c kl kl c -o ° i m kl kl u a bo 01 e 01 01 u 00 c B a 00 9t kl kl W <w 01 01 01 S. u C £ <w o 00 kl ^ 00 CO kl E s

>kl •o •H kl 3 01 a c U 00 er « B bO

b • o *«> 01 01 u B tJ O T)

m -H 01 kl <kl e • • -H E 01 *j kl u 0, ^% 0) T3 O « kl kl •H -H a <H kl 01 3 •H B -H 3 -O <ki V G U i) o 5

•o a, 3

00

C kl > o CO <ki « B a01 O 3 nH -h 5 £

01

b kl o o> b: u 00 bo kl E a. bo a u

bo 01 00

00 01 >%

•o

C kl kl •• 01 01 bort 1 01 c 01 H 01 e 01 B O u •O E

bO (0 e C kl 01 -o o o a

H -H

kl

U •rt •HCB <s T3 to fH a.

aa ES 9 e CO be ^ o kl i 01 kl •o b E ca kl .o 01 C 01 ^ <J E •^H as .. CO o kl <kl 01 x> 01 a 01 00 kl

01 T) 01 o a. 6 kl £ 3 01 > .TJ c O -H 01 e

•rt iki rH >. .. eg o -o o 6 -O CO

00

O J^ kl

U 01

u

a CO 0) CJ c O O -H M bC kl IM U kl

01u •H ^g J) -o

B 3 klu •o

CL

C 3 a kl rtO 3 CO 01 01

K 3 o- -o o kl o kl £ CO <o

a k<

01

OO <kl kl

u 00 kl 01 CO o C B u -H O 01 01 -H o M B kl HH Q ^ bC 3 CU kl « » u 10 W Vkl 3 kl -H OJ O 0> (0 kl cn o kl a

kl 01 bOlkl c •o >. 0) V > E O

CO >% 01 kla • kl •H

H

u •-I kl to pH CO 00 •O 0) •H CO B TJ 01 kl s E kl •o kl •H -H E 01 01 01 3 3 to V TJ 0) B o kl a kl V a. kl -H o X 01 CO ij kl «-! (0 £ 01 T3 B

kl kl

to c E OJ •H B kl X o. to 2-35 a o- a u < o oo ve ST o o ir\ o

<o- COIkl 01 -o •H o bo & E 3 o OJ B • X CO o- o kl H n 0> £ 01 o to E kl • kl E u 00 OJ T) kl o Ikl CO B t» > pH E

kl to E

CO CO •H

OJ 01 kl •kl X B COB o

>ki Ikl kl •H £ O o to kl kJ

t^ BO 01 kl E • kl -H B kl CO 01 kJ to to kl kl 1-t u E > E iH

CO to kl

B •H •H OJ to OJ o U CO E

kl

B kl rH CO

B •H 01 CIO kl OJ •H iH

pH kl 01 OJ CO

B to 19

01

a Tl kl «kl OJ E tJ £ o. c B OJ Mh kl M-l OJ OJ H IS -H CO o 01 u kl B

0.-H B B O kl

kl 1 E •H E

CO •H 00

O CO

to Ikl o O fH B o 0) a. iH O o kl B BO CO pH kl 3 Ikl B »

kl o u •H

kl o OD •o >^

to E H

B E 3 kl

OJ «J o •H rH

B £ 6 u m u CO E 00

Ikl iH Ikl CJ E H to o iH o OJ O e

CO kl •H • B 3 E 01 kl 0) TJ O O o to #-H E H £ E to to kl BO kl •»H ^ o 3 tj CO B kl 01

OJ

O 01 Ikl to OJ kl

kl kl kl o iH kl 01

OJ £ 01 o 01 to

u

a kl •o kl TJ 6 CI

to • to kl to to E kl ^ 01 0) kl E m • kl kl

01 •o T3 E kl

O BO •H •C > kl to

O 3 3 OJ kl 01 01 bO

BO > B Ikl 01 • tH E M

B •H 10 •H •H to to

a o > u CJ

B 6 -H 3 £ o £ 10 o fr^ o B T> kl OJ kl to bo OJ • 3 kl ^^ kl B 1 o £ CJ < •H H

•H kl rH

O kl kl i-i E &-H to to kl 00 CJ TJ 00 bo 3 •kl E E •u 01 -^ kl CO > E a-o •H kl OJ BO Ikl 10 ,_4 OJ to O iJ u OJ 00 10 OJ OJ OJ £ •H OJ kl X B T3 •H kl 01 B a O BO B T3 B O £ j-i 10 o rH E m 01 to kl •H •kl kl o kl tH •H B kl kl £ u 01 3 E • « to o o to OJ 01 kl ^ CI to >^ OJ £ m OJ kl 3 H u kl o CO O E to rH a OJ kl O m o

kl kl OJ 0) OJ kl

X • UH fH

O •o TJ to kl OJ 3 tn !» •H kl 01 o. 01 01 10 CO £ 3 OJ

u 01 E OD TJ £ £ to 3 kl kl kl 0) E kl E E >, a CJ CJ to 10 01 00 OJ •H B kl £ 3 kl u 00 CJ 1 u O

kl kl kl 01 to OJ 3 10 3 10 UH •H CO CO

B

B OJ •O kl •H CI kJ

O OJ IT BO CO CO E iH o

00 OJ

H E >^ ,_l £ 10 ^ £ to 3 H

B

B o to

B CI TJ E ^ CI •H

O tJ OJ •kl > kl 01

OJ

B s O TJ rH OJ 10 kl ^ O

DU Ikl » OJ o kJ • BO OJ OJ

B •kl CD

B kl E 01

U kl > i kl kl rH £ 3 10 Mh kl OJ o 3 OJ O TJ rH > 00 to m E kl 01 to 01 kl H •u C OJ 3 •o 01 CO rH 10 •o E 10 10 u o* kl 01 B u o. 01 to •H Ikl •H 01 H OJ U OJ bo o T3 00 O 01 kl 01 to kl kl kl O £ o •H £ kl kl kl E r 00 £ kl V kl o T3 3 m T) 3 kl 01 £ 3 kl O E 01 w > kl OJ OJ kl rH U B 10 pH kl 3 u a TJ ^ to B 4-i a B rH 00 o CO kl u to iJ O •D E B bO rH kl 01 E kl o to 01 01 •H 10 10 O. CO 0> kl 1 OJ TJ CO o OJ o 10 o to to E k4 S^ CO a kl •«H <H rt Ji rH OJ CI 01 10 H kl TJ T) •H OJ 10 kl 10 bo u B > OJ 00 kl kl o £ £ 10 3 kl ^-v OJ CI kl E CO •H rH to BO o rH kl 01 E 41 11 kl kl TJ OJ 10 B B 10 3 ( E OJ u E kl •o 01 01 . kl CO CI Q E u

kl

m

U

a Ikl T^ OJ OJ ^ iH £ Om 01

BB •H •kl

O « TJ

u o aH 0) kl 01 kl kl Ck kl iJ 01 CO

09 . T3

B kl 0> T) > klO kl kl •a 01 kJ kl

M £ kl to 01

B 01 kJ 10 a. E 3 e kl OJ E kl

Bg

01 PO to 3 U

B OJ 10 o E kl

O « B

g

00 Ikl OJ

a 3 01

B 10 £

IS 01 3 kl 10 £ B

O CO

OJ 01 £ o 01 CO 10

H »0 CO tn CO to •H rH S kl < a>ki

B 3 •H o OJ

M 00 kl •r^ £ 3 u •o

O

B kJ

H kl

a iJ CJ T) CJ •H

u

IH CO 01 to BO to tn CO kl CI 01 B ^ Cl kJ • TJ kl 10 E -H • •H c

r^

C 01

u 00 •kl f^ kl IX> kl OJ CM to E CO CNI U kl CO CM 10 T3

kl 01 OJ 3 to OJ t-t E m t« a. H in en X H m U3 IH

rM £ g • OJ 10 tn en s: 33
I w L 1-t U 3 « 'O C B X to tT U

I -O a> O. CO 3 OJ 4) i(QwbBV<SV4J4i

U O O <H b C bOC CJ.Cb03<i^^

r^ rH qj C *-» O

I .-I fl) .- -H tH (0 fH 0)'T3'H4Jl-i4-(>-i3C

r- j: a)<8o^u-i 4)0} Q iucaao(04->ow

00 U C "O C OJ V 00

0) 00 0) •H

00 ij b u u

tg O 3 CO a>

b e 4J M-l a BO U -H <g O M «

C £ u O m H w £ CO u^ a

l-< <g •H o

3 C OD M-l m X a o <v h o >> 01 a ^

01 ^ ^ u

>^ > c « a u v o c a 0*0 i-t T? -H C 0) 3 cd q] .-"a

U O 4-> c

0) 4J 3

•H "H C J3 C t a. u -H

0^ u «

0) 01 u >s ^ -u *j y i-" "H

<0 1- tJ 03 -H as "O

4J O 41 Uh 3 CO •H U U ti 1-1 O* 0) CL o a> -H 3 41 u «

cu u o u k4 to t-i

w m *ij «j h. S s -^ c g 9i 00 4> a

kl 0) •r^ C • 3 ^ C 03 O 00

OJ (0 *^ )- 41 <0 £ U O i-i O. a

V bO

•g CO a> > (0 CI. Q) i4 4j at m ao w to i-( _ _ 30>%4)0!3a)C-H

E41 B « a « "O > o C a ^

a)4Ji^u)^a»b-H cCX34)OJ=03

»^ CO 01 o

o U U

o (U 01 T) a<M c

4J e <M a

3 01 -H X

O JJ -o jj

1to s u c

3 £ CO S u u

ij CO Mh

t^ e O

E

CO c «

0) 01 Uh CO u a o CO 01 • CO o c e

kl o c u « o

3 u c > •H u •H 01 *H 4J o £ 4J b 4J CO

CD bo u o; u

3 01 »« 01 3 u O 4J Uh »*-! a

o c « •H «M c z 01 •o O 01 ^

•H U iJ bC 00 a (0 ui 03

4^ 4) q) 41

(0 O .C ^ U

CO CO •o .* •

OJ ^ OJ c il a

o u o o 0) 3 3 CO M

> 4-1 CO CO 14-1 01

CO CO CD l-l u

kl a; 3 01 Oi o e s CO s

^ .o o >, 10 g 01 ^ 01 a c u j^ X <u

i-i CO OJ CJ 4J o

0( O -O -rt f 3 60 01 bO U CO >^ O- C O. C

4J fH •H O -H

CO C^ -W 0> C pH ts

CO 01 T) r-l C O; iH O M-l CO -H CO > •H

kl 01 01 £ U C 3 U 'O kl 3 CO 0) .A

0>a

kl kl

01 kl

CO 01 = a

Xu

01 ClO 0) > c • 4J .H .H BO

CO « "O C

kl c e -H

0) 0) o> u

"o kl a. CO O >« 01 01 z: u -o kl

O -O BO 4-> kl V C CO tt-O -H 01 01 0) -o 14-1 j: U CO 01 C I o • C -H C CO CO BO kl

9) JZ 4J •o CO C 0> •HklO) COCrH-Hikt

k4 kl kl 3 4 ta IS 0)£30)'4-l4J^C

o. 4.1 -a •Q e -H CO MllOl C'k40l3lH U3O30a.O4J

C 01 -H

C5 -H O

<4-l •H

• - »< C £ -< j:

BO CO U

•rt 3 0)

-rt c £ -H j:

BO CO U

OJ 4J kl

CO c

s V

a 4-1 X o. CO o H

3 a

a. oo. u

<

O U -H «

<n c y «8

O u t-i C • 3 O Mh C O 4) 00 u o u 4) *M a c OOrH Oe 4» O O 4J(tHU-i<*-003B>-'C^ U ktOOU«34)4J < oo4ja)o *4Jj-)aa4J(o OOtf'J -OffiOOfO u

^esi 0) 4*a»-^ C >v4J*J O W1-0>X B<rt-0>'H 00 a tfliH o o

o o

00 -^ o o o o *n

<n ^

0) 'M -H

l-i O C * CO 3 00 41 C u U ^ iH 00 4) tS 4J <0 "O -^ H c y th -rt O *H 0) ta Ui rH B U C 0) .O (0 TS

CO 4) -H U -H C

•O O -Q Q -a U q) U O (fi a 4) 4)

' & iH •* *a U 4J •

' 0> OB C "O CO Q 00

4J 4) (S (0 CO -H CX:>'HCtaaoi-t

« ^ -H 41 J^ t3 I 'o -^ a *-* y (0 ' «mCC*4hc04>4IUi lO QOSO'H'V'^bO

c -H ^ 0) y

o 4J CO 01 CO c 01 01 a 01 01 01 > f a M

u c .^ 01 O

c 4J CO 4J kl

CO a CO 01 a.

kl a 4J ji BO-O a o c c c BO o V c •H CO e a CO CO 0)

01 BO u o 3 kl CO

kl c kl 01 c

•H o. c •o kl 01 fH o 01 01 §

00 § ^ kl •H kl 1 •H kl 3 0) k 3 10 CO CO » kl

4> X U CO 3 ^

4J 01 rH kl

CO a ^ a 144 a

C -H

0> 00 a a BO

01 ^ c

kl e -H 3 CO -o

CO C p4

CO CO .H •

01 kl 3 CO a 4J ^ 4jc

3 kJ £ o> kl CO BO e

•H 0) 3 O

IB s: o a.

kl a

c <ki j: o

k-t O kl O

H 13 00

kl -o V •o

11 iH 4J •H £ »< CO 4J 3 ^ >

01 01 J3 3

c J= a c H » kl e o

e

01 •H H

><£ 4i

01 ^ kl CO <0 4J 01 •H fH

01 > 3 a •H M 4J 00 kl c e

o eg 01 ^

4J kl i-t e

•H ^ Mh

•o -4 CO a. H

01 CO 3 B

a 3 kl 3 cr CO u o

I o •

14.1 •H C

-H 4J O

>kl U

kl 0) CDa 14-1 uh « O 8-,-S

^« <0 4J01 C kl

CO u CJ O -H 62 3 -H a C kl 01 Q o u

U I- c

• OJ a a-H

T3 a o

4> a Q> U Q u 0) u a »

y 4J CO BO V kl c c w qj u a a

41 X 3 £ X

TJ u CO kl CJ

rH CO -H iH kl 1 OJ O 00 1 • • OJ 1 CO OJ <» -H o CO 01 '-I Ikl CO OJ -a O 1 kl BO 01 OJ -o a OJ OJ o eg £ CO rH 00 -H kl u » £ S

Mh OJ kl o CO e •O kl TJ OJ O u kl kl OJ kl rl 3 -o ig 9 » c CM Ikl 4 "O a. kl kl OJ CO ^ rH O 3 kl 3 a u •o O OJ BO CO T<

l-> -o Ikl OJ •r4 O O » TS a CO kl •C rH CO CO kl O. kl >^ -H rH C CO CO CO H £ C kl -o

OJ o £ OJ £ OJ £ OJ CO OJ kl 3 01 BO g) u a BO CO o OJ kl 4J -O kl hH 9

>4-l £ " ".2 4J "O OD JO V V JC a MH a CD 01 a c kl ^ kl kl kl X 3 -H o CO kl e 13 «i kl O O CD OJ kl • a H BO kl a 5 3 C > -H OJ o OJ OJ o cr CO OJ c o a CO a 3 u

a 01 £ 00 CO CO ^ CO 01 M CO 3 BO -H -H OJ -O o. to o a c .o OJ CO u OJ OJ O.M O rH « -O

kl kj T3 O O C H « 01 3 4-1 o 3 M4 T3 rH a -H 13 a OJ -H 3 o >< a

OJ a kl U U MH OJ

CO kl lH H a CO Ikl kl 0.-H O rH kJ OJ >^ C -H -H OJ c kl CO CO £ MH C kl U

•H CO 00 j= a u TJ O a a CO 01 o rH J= rH CO 00 00 3 H X -^ 4J rH W rH CD OJ 01 kl kl »< 3 O

CO 3 OJ a <k< 3 -1 > ^ Mh 4H rH C .O O a rH c a CJ tkl kl BO BO 00 01 C CO 01 o ^ CD O O CD •ri CO CO •> iH C XI o BO u -a CO CO H c 01 C C - rH

4J 4J £ O OJ kl u u c a 10 a kl £ H X > OJ 4J • kJ C -rt 01 -H kl £ !» > OJ -r* OP -O *< U OJ H BO 4J U o 00 00 g -rj o CO BO kl O CO O. CD u 01 •H kl rrH 4-1 kl OJ rH ki U OJ 01 ^ CO 3 CO b H kl OJ a CO

OJ ^H C U

a a -r* 01 3 B X £ o e C T) -H 13 kl rH C o l-i 1 CO CO kl U u C X <ki 4J 00 C OJ kl £ O OJ •H 01 -H a rH U Ck OJ 4J o a e OJ e MH kl '^ a a kl 3 b a c Ikl kl OJ e OJ U kl kl CD kl X OJ a a CO 3 r< OJ a CD CO kl OJ kj o > 5 U -H -o C rH ax rH 3 H a i 3 a e 8

CO 01 X o X 3 <ki £ CO O £ BO U £ .O u CO o c er 3 rH 3 CD OJ £

S Xt o ki iki a u 3 cs u u kJ -o a. kl a-H OJ £ M CD OJ X 4J e u 4J 3 01 a 01 CO

— K O !.

• CO a £ cTv kl kl a CSJ MH OJ CO

• £ £ " m i-i H 60

CN > 01 ID -rt • C £ OJ B m (U H H 3 in 33

• O

CM "O

34
U (0 (0 -Q 3 t3 « C

(U j: c 01 <u 01 •H •o u u a n OD u 01 41 >U Ui a. w 3 0) c » a r-4 Ui a c c u U %

4J 01 <0 »4H •H

V

(U

u

H <r> o. 01 41 o o •o c o u •H « • ^ a

4J •a

O •a o <S •o 41 c 01 41 > (0 u s c 11 4-> bO c o Ji 00

wi « o rH c a

u •H

u »w •H »w 3 •H o 41 c c

a. o 3 at «0 c CO pi

u « <0 o- 4J c •H 01 o. 01 01 41 o 11 • u 41 « <H 01 u 3 u 41 0( 41 TJ o iJ h 3 l1 O 3 a L' 00 n 01 e <0 01 4J u o o u a u u ki e t-H « a ,_^ o 00 41 u r-H ^ <r<t go •H iH kl H CO 01 •o c 00 OJ 3 •H 3 u U •H kl 4J IM <0 £ 41 a rH (T

09 J^ (M 10 01 "41 o u 3 c o; <0 OJ o «l a c > e a

iH

41c

<0u

11

01

-.1

u o li o 41 • (V o T) kl 00 o £ >^ c • OJ OJ •o 01 11 iJ tu Qt <0 gg 41 •H c 41

U

O 00 OJ

b 41 t41 01 <o 00 O O > M

Ml BO 13 c u 00 0) C C >1 a 3 <o « U T^ a 41 00 01 s c c 1-t u 01

OJ

B , >^ <o e

iH o 01 •a

V j>i

U 01 iH 41 -H

wu

O 4J « H 01

a

h •H

M OJ 3 c l1 <a <o £ W -o cr 3 O U iH

OJ <H 41 00 p^ 41 OJ OJ

CO o O CO 41 O iH 01

Ol, 73 ^ 10

41 T3

01

O

C

41

C -H

CO » 3 TJ

iH rH £ <0 3 60 > O -H

OJ £ j: n o

41 «^ ^ u c 0) 3

CO 4J « H "O

•HI- -H 3 0^3

f~i ^ o u

4J •H

U

U <4-l

t-i <Q (D {Q

O

OJ OJ o 41 OJ 41

u o e 00 41 OJ > U •o OJ

01 OJ tH

u 00 OJ OJ OJu CO

u 11 41 T3 a.u (Hau a. 4J 3 U OJ u r-( X •H u w 3 OJ 00 0( T3 OJ 3 £ OJ 3 OJ 3

o- J^ CO & 0) 41 CO BO cr 41 CO V <0 0> X 01 c u S

t4-l

u c OJ

n S e u e •Hu o ki •H kl

73

UC 4J 0^

Oa

rH CO

O Ui O4

O 4J 3 U CD 0) ki 4J o 0^ ki D. 01 n X a a; X X >M >v

c/3 o cl a> 4-1 o (0 8 2, c a 01 •H s 41 X a CO a o- o o o o o o

CO- </>

•H

Oc o H m

41

U

H

O

k> 41

U 0 •*- 3

-H aui k< OJ 1 M 3 £ OJ u £ 41 C c 41 4J 4J

00 -H 01 OJ OJ OJ « H 41

r-( 41 OJ 10 e u c tH 3

CO

C J> 3 <s £ CO OJ 41 c a kl OJ U CO U £ 00 c m OJ 3 B a CO X CJ B 41 CO •H £ 41 01 CO CO 60 TJ 41 »H 41 OJ >> OJ e Ji c OJ U 41 CO tJ (S kl ^ .H u 00 01 CO c c 0.

41 CD

H 0. c •H CO rt CM 5 » T3

OJ 3 CO

H

a e i e

41

CD 0. OJ OJ a rt 0! OJ •H IW -H

41u OJ pH 4J 09 -H c c Q £ OJ OJ OJ 0.

*-* <H

m Ul 41W -O

a kl kl 3

>>TS

g

kl OJ

H E CO to 41

B

0) • CO 00 SO 9 •H

B 3

•H

a

C kl -H

J OJ

B CO •H OJ -H OJ 1 OJ c a 01 OJ E T) •»^ 3 7) 00 a kJ E 73 11

C

M 0 4J • OJ

X kl CO -o OJ CO OJ klB kl 73 CO (0

H OJ

a ^ c c e c CO > 41

a rH E OJ kl OJ > >44 41 3 OJ >^ E CJ -H CD

X

•H -H CO 41

a OJ 3 OJ r-i 4 CO -H CO OJ OJ

B -rt -a kl 41 CO 41 ^ £ •H -H 41 E iH

41

U *kt

u £ OJ

q 3 ^ a OJa

B OJ £ CJ -H • u OJ 3 H

a <0 <4-l OJ 41 141 10 -rt ^ " c c c 00 CO 3 CJ 3 -fi m > T) X M 41 3 CO OJ 0 41 X

CO kJ COu

a OJ o > OJ •H -H kl

0) -H •H 3 kJ c 41

u OJ •H CO £ H OJ

u ig •0 00 CO 3 a 3 z 10 E 41 OJ 10

a kl >> «kl -H c -N OJ OJ OJ J= kl

m 3 00 00

X

B 00 E OJ 01 Uh kl Ck CO CO

u 3 00 OJ

X

10

q E H

H

a OJ

B

09

a 41 CD CO CO f*4 £ 41 41 3 0 3 00 3 0 J^ 41 <0 E kl E kl OJ OJ 41

H

a 10 00

C -H

V 10

H 41 OJ §

CO OJ pH 01 -a

B CJ CO <J O. (J £ e kl CJ > a • E

rt > kl CO o > OJ t41 CO OJ 00 CO

b kl

B CO <0 IS 00 kl 73 kl

a 3 3 OJ 1-1 CO > a » m 00 OJ c C CO u OJ a r-l B £ a-H x> E 41 OJ U OJ CO CO 3 CD Ul 73 E >% 00 tJ kl rH » •H 41 CO 3 a ^ • a SOU a »-» kl a W ^ OJ £ CJ CO OJ 01 OJ a 73 B 41 3

•rt OJ s«kl <8

B 0 41 O..H OJ 00 -o 4J 00 CO CO ^ Xa OJ

a 41 -H > »H

a c > tj r-t .. I1 ^ 01 E 00 op

T3 00 6

rH CJ I- rH OJ •0 41 E CO 01 41 > U

U 41 -H 3 -w > 73

H 9 u >> -r* OJ ^

•H 41 41 <0 CO

a 41 OJ

H

H >> kl

b CO a. • OJ OJ 00 CO kl kl O* 41 10 OJ CO OJ U •H 01 -H U 41 41 41 u •H 01 OJ -H H •0 T< 41 a > W OJ 41 3 CM CO OJ <j 41 0 > & a-H CJ > a -Q £ CD U j: 41 •H CO e H kl OJ 0 CO CJ kl 41 kl OJ CO U OJ •^ ^ j: E 00 00 9 CJ CO OJ k. a iH OJ

kl OJ 41 3 OJ 41

a 00 3 COM OJ

B 3 a 10 OJ 00 OJ OJ -H OJ E OJ

a 41 CO E £ •H u-i •0

X OJ -H

a

a OJ kl 00 41 CO a CO a<ki CO CO •0 oe u -H > 44 lU 41 a 3 CJ OJ 0. -H 41 •V > kl u 00 OJ -O CO CD -H CO /-v 3

'u r-i OJ

B

H 01 ts kl E a s 3 a S2!

OJ kl OJ CD E kl CO -HB OJ 3 OJ s^ kl

B E ui £ 3 £ -1 CO OJ 0 CO a 0 CO kl OQ u •H CJ Ck a. 3 •0 kl kl 3 -rt < a 41 3 3 CO 73 « £ 41 a a •^

kl ^ £ o n £

<s OJ o O kl 0) £ m 41 1-H 4j • -H 3 OJ 10 3 o. a:

O kl 00O

u-i 3 a.

u 35
« V

<4-l « c ^ o O O w O •u W 18 00 4J % M

•o >u 4J <d rt

a 4J •H •« U e b iH o

01 >H 3 0) .o « .. 01 H 3 00 §

.H 3 •c c

lu tJ -H 00

V c

•H 01b « 3 -1

M WJ bO 4J o -HO ^ U-l 1.4 O 00 •H « -H a e V 01 bi 4J 6 -o rH i-t x> fH •o 00 • CO 3 >>

4-» 01 o £ 01 8 4-1 to -H c • 4J ^ •H

•H 00 01 00 >

j: » B to c x> 4J 0) <s 4J 01 tS 01 01 o 00 iH o

•H -H

X

u 01

u 3 O s > 01 to c Cb B £ to

00V

u

B ^x;

u

00 o 1-1

u F-l t-i 1 9

01

H •H CO o c a • 60 00 •o c 3 rt 01 CO B to T-i 00 B V l-l 4J V 01 •H O 01 t-i .o c e p •c > 1-1 0) ^ •H

to •ri 0> 4J -H •H to > •o 01 u • 4-> U » tB to 5

x> 3 •o

u 01

M to o » 00 i-H OJ a o> 01 a

t« c to 01 l-l 00 £ O

l-l <9 01

H •H

B 4J

O 00 b. o sco

<W

B §

•H

4J

to o rt to 1-1

01M s >

00 01B e U

b ^ 4J •H U-l 01 0>

01 4J o to •o

O i-ia

00

u 4JuB 3 jo s 01 V 0) V CO o • •a a » •c a O. to 3 « X o 01 >, o; 1^ o 3 [d ij B •o 4J e o ij B

>HUco V o uc

01B 4J o m X a IS • o •H 8 o o u 3 o 01 a tr o o •-< a u \0 M < vy vy

to H

00 01 0) • » -1 kl w

CO J3 •rt

B kl iH 1-1 3 iH V

<« t» o- kl kl

00 01 CD

B

0) o kl OJ bo « o a ki B 01 a (0 01 iH o >

<M 09 3 OO kl » kl

q • •- B O CO kl 9 o j: CO 3 O l-l IW •a ^ kl kl a iH O ki kl f-l 01 < o

4J O. 3 o cd kl CO oj . to 00 •H 01 IB B iki fH O kl kl kl o » «- 1 B IH o •- o. iH «j £ 0) 1 O -C 09 3 01 U 1 B X ^ ClO er kl ; iH 60 1 00 -H 00 t« B 0) o 1-1 4J 3 1-1 1-1 b B CO •§5 U 01 k< B 09 60

01 to ki 01 to 0) kl 01 rH CO *J iH k) 01 kl ID U •H B V to B to iH

.3

VX 18 to

O VM

O

B

O iJ 01 » "O

•o

K 0)B 01 >. 01 ki • O kl

00H

a kl 1-1 to to 0. V 09 o 0)

01 0> S 09

a CO

u 01 £ .o O kl kl •H .o kl • •k CI M o> e £

01

B 3 4J 09

u

B

B > « O 00 B B 3 to 1-1 •H V kl V 1-1 to O <J

00 kl kl kl •V 1 B •- T3 O kl X >> 01 1 0> 01 01 .. iJ 4J u kl • 1 a (0 iH CO kl B 3 "O 1 K 3 l-l kl >^ 01 w o 09 ^

01a kl 00 kl kl CO t8 01 6 O a. to to to t« la 0) iH M u « a 0) » kl B B MH

in 01 1 CM 01 <J CO- o

u-l o. o o kl CO kl f—1

t8

B • j 0) 1-1 B o kl B O m OJ 1-1 IM 1-1 «• a-H o j-l

01 » ^^ 1 B kl iH kl to u-l kl c to o >^ to kl 0) kl iH iH 1-1 60 rH UH E kl • UH • B 1-1 o U-l > - B 1-i iH B ID kl CO tu u-l C u-l B to iH to iH to ^ to B 3 3 o • •H lH 1H u-l o U t8 01 kl 3 o 0) 03 T3 O 09 to JJ m

CO l-l l-l

B 1 <uO •H

B ^•d 0) 0) to >•> iH •o •o rH rH

B o o 60

u iH

U

B kl •H 3 C JS klB

BO 01

B UH UH •o to

O o 01 18 ^ te kl • r^ •H 01a iH o o O > J-l 01

O 01 JH •H kl Cl S -H u B a> TJ .c iH t) a iH 3 JJ T3 tn 01

B kl CO 3 0) o;

BB to kl ' to •V • K (U JH kl o BB 3 e

1-1 18 l-l

B kl XIB

OO l-lB

O 01 09 •o o UO kl •a to

to

O 3 iH 01 60

V iH

u to 0] -H rH <U 01u 3 UH 60 0) 1H >-, j-> s 1-1 Uh ^ to c kl (0 iH te H kl rH H •-I o P 09 J-l 09 f-{ o

1—1

01 •O o iH 3 B J^ kl J-l J-l to J-l r-< UH JH

M 60 09 <J j<: rH OJ & OJ l-l O X 3 to 01 o OJ j: t8 O kl lH lH B ID O B 0> OJ tj to o.

O. 3 01a 4J 01 to s 01 4J tj rH 0) to > UH iH

B 01

O kl kl to 3 ID < 1-1 iH iH 01 •H e

to 3 3 rH

B toB (UO .c rH JH 01 kl toB < u-l to 3 > B •o B to 00 01 iH tJ 3 kl o o to 09 a o 3 1H

V

•O JJB

V 1H o

JJ 0) S iH

t8 tJ iH 09 O to rH 09 O UH E

kl to to ^ 3 B

rH to 0) to

kl > kl

OJ >^ t8 4J a kl J= O E kl •

kl

O rH 01 01

ft. CO rH JJ JJ

to iH to to < a 3 3 kl

•n

B 0) O JJ 09 UH • 60 kl OJ kl OJ O 09 B UH OJ > ' SI 1 OJ ^ 01 •H > iH <U JJ JJ 09 3 -H

>> 01 iH to rH iH a) E SI OJ JJ UH 60 0) E O 3 E iH 1H 1H

1H

B E OJ iH iH OJ > > E to OJ O- X m e 0) kl 18 60 kl a X OJ kl 3 1H o 60 O i X OJ • rH 01 rH J3 B

0) OJ C9 UH Xi rH 0] iH UH

JJ E O 01 iH iH

B rH ^ O

OJ OJ E •H JJa UH UH OJ •-{ J3

f-{ rH OJ o o T3 JJ 18 to kl a X> e - 0) o rH B CO s B O

1H ta 3 OJ 01 09 01 to to >> to 01 iH o iH kl r^ ID rH O 01 kl B ftH JJ ft. 0] kl O iH CO o ID OJ lH 18 09 B to V B U E 60 JJ 3 kl

kl > B 1H rH iH 3 ft. OJ

B

B X.B

Oh < •H CO 60 e CO o rH iH iH JJ iH

CO c ^ ID UH >. >% o

j: o iHO

g

kl -H

kl 18

O UH CO kl tH C9 kl kl B ; JJ OB g 3 iH O OJ O •c 09 •o u o i

ft. iH UH OJ OJ 01

O CO >,iH 0) kl •O X OJ o JJ O JJ SI ^ JS UH OJ JJ JJ > O

01u o •-{ r^ to to JJ JJ 09

X »H to iH UH

kl 1H t8 01 toO

B o to J= 0) •H kl rH 6 60 6

01 j: UH > 01 o O o 1H

O • 8 4J 18 iH iH

!> 3 kl 01 > f^ iH JJ

B 60 to 60 3 XI >N

O 3 o 01 09 x: CD iH E u CD

B o- 8 to OJ CJ OJ 09 kl •o 09 60rH rH a -H Q iH O B k) >^ B iH 3 rH 18 : JJ 2 >, JJ kl tJ -H

09 "OO • o to 8 « B 18 rH

O

O 0)B

iH kl CD JJ 09 kl 3 O UH

O 01 0) iH •-•O iH TJ B •o 01 B SI tH O O rH kl TJ x: rH "kl OJ iH iH iH •o o to JJ >. JJ 60 iH 01 kl 18 .C OJ O 3 o OJ E • kl kl kl kl 01 B JJ kl 60 iH kl TJ

t8 cr

B

UH irH 3 > iH OJ 09 JJ kl BOO) s: iH

B ftB kl OJ rH CO 3 OJ O ft.XI JJ 09 OJ OJ 01 B OJ

M rH to t3a OJ to OJ kJ 09

OB kl kl JJ kl 3 kl B a kl •-< e

to 10 kJ 3 B

O 01 JJ

a UH o

to to -o to <« ft. UH 3 S ft.

B iH z ,0 UH ID 8 O 8

•o .—1

to u-l e O • O iH SI CM iH E .rH ^ rr, JJ 60 JJ £ m

p. 03 to o r o

OJ OJ

ft. ft O O

tj o

tv) <D 0) • kl O

CM 0) "O <n jP b • .r^ W m tl. •^

B

JJ o E iH

to JJ f) TJ kl U • 1H JJ OJ

tvl 3 0) (3. m or B 00 • iH OJ E

u-l r-J Ou •-< 3 rH 1 UH kl 18 !^ t8 JJ > CO 1 kl 6 09 W B "O M OJ -H iH to 0) O O

CO 01 E:;1•» XI

B T3 OJ -H x:

m JJ fT) 8 B > kl kl

to 01 XI

Q iH

O -H 18 OJ

m 3 Qu tom

O kl Z JJ 3 S

36
5. DESCRIPTION OF NDE METHODS

The descriptions of the NDE methods generally include information about the

methods, descriptions of the methods, applications of the methods, and the

advantages and limitations in using the methods. In some cases, other

information about the NDE methods is presented such as reliability of a method

and calibration of NDE equipment. In other cases, however, because information

was not available in the literature some information such as advantages and

limitations of the NDE methods may not be included in this section of the

report.

5.1 Acoustic Emission Method

In this method, stress waves originating within the test object are

detected by surface transducers [2]. The acoustic waves result from the

sudden release of stored strain energy when either pre-existing or newly

created flaws propagate under the action of an applied stress field. The

types of flaw propagation that can be detected include dislocation movement

in metals and microcrack growth in metals or brittle solids such as concrete.

Thus, acoustic emission can indicate the start of mechanical failure —

i.e., yielding or fracture. The test object must undergo stress so that

flaws will appear or propagate; static flaws are not detected by acoustic

emission.

Description of Method

Acoustic emission testing is a passive technique; only an acoustic wave

detection instrument is required. The acoustic waves, which may have a

frequency range from audible to ultrasonic, are detected by piezoelectric

transducers attached to the surface of the test object. The existence of

37
flaw growth can be detected by a transducer anywhere on the test object

(provided that there is enough wave amplitude to be detected). Thus, the

location of transducers relative to pre-existing flaws is not critical

in this method unless it is required to locate the flaw. The transducers

generally detect waves in the frequency range of 50 kHz to 10 MHz [2], Detected

signals are amplified; the amount of necessary amplification depends on the

source of the acoustic emission. Signals from dislocation movement require

greater amplification than signals from microcrack propagation. After

amplification, the acoustic emission activity is processed and displayed.

The most useful displays are the rate of acoustic emission events (detected

signals), or the cumulative number of events plotted as a function of a

pertinent parameter, such as time, applied load, or number of load cycles.

Growth of microcacks as small as 10~^ in. (2.5 x 10~^ mm) can be detected,

while the minimum static flaw detectable by ultrasonic or radiographic methods

is about 0.001 in. (0.025 mm).

Applications

The method has been used to monitor the in-service behavior of pressure

vessels (including nuclear reactors), to detect the onset of rapid crack

propagation under fatigue loading or caused by stress corrosion, and to

monitor the response of systems to proof-load tests. Because acoustic

emissions give forewarning of ultimate failure, the technique can be used to

signal when loads should be reduced to prevent total failure. By using both

multiple pickup of acoustic signals with transducers at different locations

and electronic data processing, regions of high acoustic emission activity

can be pinpointed, and a critical "weak link" in the system located,

38
Advantages

The most significant advantage of the acoustic emission method is that it

gives the response of the total structure or system (in "as-built" condition)

to applied loads. By observing the acoustic emission activity as loads are

applied, one can find the extent of internal material degradation (yielding

or fracture) as a function of load. Generally, the stage of incipient failure

can be determined because this is usually accompanied by a rise in the acoustic

emission rate and a rapid increase in the cumulative number of emissions.

Limitations

A major difficulty in interpreting acoustic emission results is the

separation of signals caused by the loading system or by microscopic slippage

at joints in the test object from the signals produced by flaw propagation

in the material. Users of the technique must be aware of all the possible

extraneous acoustic signals that may be detected by the transducers, and

must be careful not to confuse them with signals due to flaw growth. Some

background noise may be eliminated by using low frequency filters, but

elimination of other noise may require more complicated methods. A high

level of skill is required to properly plan an acoustic emission inspection

program. Equipment costs vary from moderate ($10,000) to very expensive,

depending on whether a single- or multiple-pickup system is required for the

particular application,

5.2 Acoustic Impact Method

Description of Method

Acoustic impact is the oldest and simplest form of acoustic inspection.

In this method, audible stress waves are set up in a test object by mechanical

39
impact; the frequency and damping characteristics of the vibrations can be

used to infer the integrity of the test object [3], In its most unsophisticated

form, the test object is struck with a hammer, and the operator listens to

the "ringing" caused by the resonant vibration of the object. In a more

sophisticated form, a transducer is attached to the test object, and an

amplifier and display unit are used to produce a visual display of the

frequency and damping characteristics of the "ringing." By comparing the

output with a standard representing acceptable quality, a decision is made

regarding the integrity of the object.

Applications

This method can be used to detect hollow zones and delaminations in

concrete and masonry structures, or it may be used to find studs behind

wall-board. It also has been used to detect delaminations in laminar and

composite materials.

Advantages

The equipment required to carry out the test is relatively inexpensive, and

the test can be done easily.

Limitations

Because the "ringing" can be affected by the mass and geometry of the test

object, an experienced operator may be needed to correctly interpret the

results.

40
5.3 Air Flow

5.3.1 Pltot Traverse

Principle and Applications

Air velocity at a point in an air duct can be determined by a simple method

using a pitot tube in conjunction with a suitable manometer. The velocity in

a duct is seldom uniform across any section, thus a traverse is usually made

to determine average velocity since a pitot tube reading indicates velocity

at only one location. In general, air velocity is greatest near the center

and lowest near the edges or corners. The ASHRAE Handbook indicates that

in round ducts, at least 20 readings should be taken along two diameters of

equal areas. In rectangular ducts, take readings in the center of equal

areas across the cross section of the duct. The number of spaces should be

at least 16, and need not exceed 64 [4]. To determine average velocity in

the duct from the readings obtained, average the calculated individual

velocities or the square roots of the velocity heads.

If there is a disturbance in the air flow in the duct, the pitot tube

should be located at least 7.5 diameters downstream from the disturbance.

The type of manometer used with a pitot tube depends upon the velocity

pressure being measured and the desired accuracy. A draft gage of appropriate

range is usually satisfactory for velocities greater than 1500 fpm. For low

air velocities, a precision manometer is essential. There are many forms of

pitot tubes that have been used to make air velocity measurements.

41
5.4 Air Infiltration Measurements

Principle and Applications

Air leakage is the uncontrolled entry of outdoor air into a building.

Air leakage tests are performed to determine the tightness of buildings and

to determine whether overall building ventilation is adequate. With regard

to building tightness, air leakage tests provide data to determine primarily

the natural air leakage rates occurring in the building under various climatic

conditions and use patterns, tightness of the building compared with other

buildings and with itself after corrective measures have been completed,

location of leakage paths in the building, and the magnitude of each leakage

path.

Measurements of both building air leakage and air exchange rate can be made

using tracer gases. The rate of decay of concentrations of these gases which

are introduced in the air in buildings is the technique used. Another way

to measure building envelope tightness is the fan pressurization technique.

5.4.1 Tracer-Gas Decay Method

The tracer-gas decay method is very versatile and is reported to be the

simplest of the tracer-gas measurement systems [5]. It can be used for both

short and long term measurements. The air measuring equipment may be located

on site or the air samples may be collected into air bags and analyzed off

site. Injection of the tracer gas and measurements of the concentrations

can be made manually or automatically to study the dependence of air exchange

rates as weather changes over time.

A single injection of tracer gas is sufficient for each measurement and

complicated apparatus is not required to control the concentration or

42
automatically inject gas, although several automated techniques have been

developed. As much time as necessary may be allowed for mixing of the tracer

gas with the air. A fan may be used initially to mix thoroughly the tracer

gas with the air, or the fan may be run throughout the entire measurement

procedure. It is convenient to inject tracer gas into the air handling system

for the building. In this case, air is sampled at the return air ducts. If

the building is large or divided into many rooms and does not have a mechanical

air handling system, it may be difficult to obtain a uniform concentration of

tracer gas throughout the building. It is possible that even if a uniform

distribution of tracer gas exists initially, concentrations may decay at

different rates at different locations in the building. The measurements

will reveal the extent of the nonuniformities such as differences in

ventilation rates and localized air leakage.

5,4.2 Fan Pressurization Technique

A building may be pressurized by a fan and the air flow rate measured to

estimate building envelope tightness. At a fixed pressure difference, the

lower the air flow rate, the tighter the envelope. In order to obtain

measureable air flow rates, large pressure differences are usually introduced

in order to overcome any natural pressure differences. For even medium size

buildings this may require the use of a very large fan or simultaneous use

of a number of fans. Measurement of isolated wall and roof areas may avoid

the necessity for using large fans. This stepwise method also provides information about permeability of individual building envelope components.

Buildings can be compared directly by expressing the induced air leakage at

a standardized pressure difference, usually 50 Pa [5].

43
The fan pressurization method has the advantage of simplicity, direct

comparability with other buildings and times of measurement, intrinsic

meaningfulness without reference to temperature and wind conditions, usefulness

in locating leakage openings when used in conjunction with infrared thermography,

and the ability to assess the effectiveness of retrofit measures applied one

at a time.

5.4.3 Acoustic Method

Principle and Applications

This method is based on the principle that sound and air readily pass

through openings in buildings. The method is simple, low cost, and can be

used with minimum of training. Small openings through building structures

serve as paths for both air infiltration and sound. Even very small openings

in walls can significantly increase acoustic transmission compared to the

case where the openings are sealed. A sound source is placed on one side of

a wall and probing is carried out on the other side seeking local increases

in sound levels. Almost any sound source of sufficient loudness can be

used; however, preferred sources are steady and broad-band noise containing

many frequencies and a saw-tooth warble tone that sweeps in frequency from

50 to 8000 Hz about three times per second. The broad band sound could be

produced by a vacuum cleaner. Both sounds could be produced using a cassette

tape and portable tape recorder. The warble tone works better because it

is easily discernable. If the sound source is placed outside the building,

the steady and broad-band sound is preferred because it is less annoying.

Sound can be detected near the surface and over a small area using a

mechanic's stethoscope, airline plastic headset, Type I and Type II sound

44
level meters, and low-cost sound meters consisting of a battery-powered

microphone and headphones.

Limitations

Lightweight walls (barriers) will only reduce sound levels slightly

making it difficult to detect leaks from normal sound transmission. Insulation in walls may greatly reduce the sound transmission, especially through an

air passage that is not straight through, thus making it difficult to detect

the leak. Noisy environments can also cause problems in the application of

this method.

5.4.4 Smoke Tracer

Ptinciple and Applications

Some of the commercial smoke tracer systems include guns, pencils, and

sticks. These systems provide a controlled smoke source so that at leakage

sites a thin stream of smoke may be observed. Pressurizing the interior and

thereby causing the smoke to flow outward through any openings is the preferred

method. The controlled smoke source should be located close to the suspected

leakage site.

Limitations

Knowledge of suspected leakage sites is necessary in order to limit leak

detection efforts. This will enable the controlled smoke source to be located

near the leak site. The smoke must be used sparingly because of annoyance

to building occupants and possible material damage. This is a locally used

technique and therefore no extensive use of smoke is recommended in the

building interior,

45
5.5 Air Permeability

Research results suggest that the measurement of the air permeability of

concrete is effective in forecasting the carbonation rate and compressive

strength of site concrete.

Description of Method

This test method provides an estimate of air permeability of concrete in

situ. The test method involves boring a small diameter hole about 2 in.

(50 mm) in depth in the concrete. The hole is plugged and sealed at the

surface of the concrete. A hypodermic needle is pushed through the plug and

a vacuum pressure is applied to the needle. The time for the pressure to

increase to a predetermined level is taken as a measure of permeability.

Research has concluded that the air permeability test is an effective tool

for evaluating the durability and carbonation rate of aged concrete and for

forecasting the compressive strength of site concrete [6].

Limitations

The feasibility of using the air permeability methods for inspecting

concrete has not been demonstrated. Further development work is required if

the air permeability method is to become a reliable NDE method to evaluate

the quality of concrete.

5.6 Break- Off Method

The break-off test is used to determine concrete strength at the site.

Description of Method

A circular slit about 2 in. (50 mm) in diameter and 3 in. (75 mm) in

depth is formed in the concrete either by placing plastic cylinder forms in

46
fresh concrete and removing them after curing, or by drilling into hardened

concrete [7,8]. A transverse force is applied, using a hydraulic testing

device, to the top portion of the concrete cylinder to fracture the resulting

core in the concrete. Fracture or break-off of the core generally occurs

along the embedded end (depth) of the circular slit in the concrete due to

the transverse force. The measured transverse force can be correlated with

the compressive strength by using calibration charts.

Advantages

This in situ test has proven to be a suitable method for in-situ monitoring

the quality of concrete. It has been accepted world-wide and has been approved

as a test method in a number of national codes and standards including those

in Norway and Sweden [7]. The test is a simple, economical, and practical

means to determine concrete strength at the site. Further tests can be

conducted immediately if the results suggest this to be necessary.

Limitations

The concrete needs to be repaired at locations where the cores were broken

off from the concrete.

5.7 Cast-in-Place Pullout

The pullout test measures the force required to pull out a steel insert,

with an enlarged end, which has been cast in the concrete. A pull-out

device may also be inserted into a hole drilled in hardened concrete. The

concrete is subjected to complex stresses by the pullout force, and a cone

of concrete is removed at failure. The pullout forces are usually related

to the compressive strength of the concrete, with the ratio of pullout

47
strength (force divided by surface area of the conic frustum) to compressive

strength being in the range of 0.1 to 0.3. Correlation graphs are used to

relate pullout force to compressive strength. There are several commercially

available test apparatuses for measuring the pullout resistance of concrete.

Description of Method

ASTM has issued a standard test method, C 900, which describes in detail

the pullout assembly and gives allowable dimensions [9]. The pullout insert

is cast in place during the placing of fresh concrete. As noted, a pull-out

device may also be inserted into a hole drilled in hardened concrete. The

insert is either pulled completely out of the concrete, or pulled until

maximum load is reached, with a manually operated hollow tension ram exerting

pressure through a steel reaction ring. Testing and calculation procedures

are also given in ASTM C 900. Techniques have been developed so that the

inserts can be embedded deep in concrete, thereby permitting testing of the

interior concrete.

Because the pullout insert is usually cast in place during placing of the

fresh concrete, these tests must be planned in advance. Alternatively, hardened

concrete can be drilled to receive the pullout insert. This necessitates

drilling through the bottom or backside of a concrete slab, for example, to

the proper depth and width to permit the insertion of the enlarged head. A

smaller hole, permitting insertion of the steel shaft, is drilled through the

remaining portion of the concrete slab. The insert is placed through the

bottom or backside, and the test is performed.

48
Reliability of Method

Malhotra [10] and Richards [11] have shovm that the pullout method can

reliably estimate the compressive strength of concrete. Malhotra [10] found

that the coefficients of variation for pullout test results were in the same

range as obtained from testing standard cylinders in compression. Correlation

coefficients of 0.97 to 0.99 have been obtained for normal weight concrete

from curve fitting of pullout and compression test results.

Advantages and Disadvantages

The pullout technique is a nondestructive test method which directly

measures a strength property of concrete in place. The measured strength is

generally thought to be a combination of tensile and shear strengths. The

major disadvantage of the pullout test is that a cone of concrete is sometimes

pulled out, necessitating minor repairs. However, if the pullout force is

quickly released just when failure begins, the concrete cone will not be torn

loose, and no repairs will be required. Another disadvantage is the need to

plan where inserts are to be located and to make provisions for them before

placing concrete. The feasibility of drilling holes into hardened concrete

and of inserting pullout devices was explored [12]. This would eliminate the

need to install the inserts prior to placing concrete.

5.8 Electrical Potential Measurements

Information on the corrosion state of metals can be obtained from

measuring the electrical potential difference of the metal using a standard

reference electrode and a voltmeter. If the metal has a certain difference

in electrical potential, active corrosion is very likely.

49
Measurements on Steel in Concrete

The electrical potential method is commonly used to assess the corrosion

condition of steel reinforcement in concrete. The electrical potential

differences of steel reinforcement are measured by making an electrical

connection from a voltmeter to the reinforcement, and a second electrical

connection from the voltmeter to a reference cell in physical contact with

the surface of the concrete. Dry concrete must be moistened before

electrical measurements are made. A saturated copper-copper sulfate electrode

is commonly used as the reference cell. The electrical potential difference

of the reinforcement below the location of the reference cell is measured.

If the electrical potential difference of the steel reinforcement is

more negative than -0.35 volts versus the copper sulfate electrode, active

corrosion is probably taking place. Values in the range of -0.30 to -0.35

volts seem to suggest that corrosive conditions are developing within the

concrete, while values less negative than -0.30 volts indicate that the

steel is probably passive — i.e., not corroding [13].

An electrical potential difference diagram of a concrete slab can be

constructed in which areas of similar potential differences are outlined.

This diagram can be used to identify areas where the reinforcement may be

corroding.

Advantages

The equipment is inexpensive, and only a moderate amount of skill is

needed to make the measurements. Measurements of the electrical potential

differences of steel reinforcement provide information concerning the

probability of corrosion.

50
Limitations

Information on either the rate or the extent of corrosion is not

obtained. In addition, a direct electrical connection must be made to the

reinforcing steel. If the steel is not exposed, then some concrete covering

must be removed.

5.9 Electromagnetic Methods

The presence of flaws or changes in composition of metals will affect

their electrical and magnetic properties. Therefore, it is possible to infer

the presence of anomalies by making measurements which rely on the electrical

and magnetic properties of metals. The following NDE methods can be used:

eddy current testing, magneto-inductive testing, and magnetic particle testing.

Also, a method has been proposed for in situ measurement of steel fiber content

of steel fiber reinforced concrete.

5.9.1 Eddy Current Inspection

Eddy current inspection is a versatile NDE method based on the principles

of electromagnetic induction; it is applicable to inspection of metals [2] and

to the measurement of the thickness of nonconductive coatings on a conductive

metal [14].

Description of Method

A coil carrying an alternating electric current will have an associated

alternating magnetic field which acts to oppose the flow of current into the

coil. When the coil is brought near a conductive material, the alternating

magnetic field will induce in the material a closed loop current flow known

as eddy current. The eddy currents will also be alternating, and, therefore,

51
a secondary magnetic field is associated with them. The secondary magnetic

field will oppose the magnetic field of the coil. When the energized coil

is brought near a metal surface, there will be a change in the current flow

in the coil. Measuring the changes in the current flow (or the coil impedance)

is the basis of eddy current inspection.

The magnitude of the changes in the coil current will depend on the

intensity of the eddy currents induced in the metal. Factors which influence

the intensity of eddy current flow include:

1

the frequency and magnitude of the coil current

2. the electrical conductivity of the metal

3. the magnetic permeability of the metal

4. the size and shape of the test object

5. the proximity of the coil to the test object

6. the presence of discontinuities or inhomogeneities in the metal [15].

The electrical and magnetic properties of the metal are controlled by

alloy composition, microstructure, and residual stress [2].

Eddy Current Inspection Systems

The principal elements of an eddy current inspection system include the

inspection coil, and oscillator to provide coil excitation, a detector to

monitor changes in coil impedance, and an output device to display the test

results. Various coil geometries are available, depending on the specific

application. An important principle when inspecting for discontinuities is

that the maximum signal is obtained when the eddy current flow is transverse

to the flaw. Thus, the user needs to understand the relationships between

coil configuration, eddy current flow and type of flaw to be detected.

The frequency of the excitation current affects the depth of the eddy

currents and the sensitivity of flaw detection. The coil frequency can be

increased to detect small, near-surface flaws; penetration is reduced, but

52
sensitivity is increased. If sub-surface flaws are to be detected, a lower

frequency should be used; however, the minimum size of flaws that can be

detected is increased. Thus, there is a trade-off between penetrating ability

and sensitivity; this is also common to other inspection methods. The range

of frequencies is from 200 Hz to 6 MHz, with the lower frequencies used

primarily for inspecting ferromagnetic metals [2],

The detector circuit can also take many forms, depending on the application

of the instrument. In any case, the changes in coil impedance that occur

during inspection are small; bridge circuitry, similar to that used to monitor

electrical resistance strain gages, is used to detect these changes. In

making a measurement, the impedance bridge is first balanced by using an

internal adjustment or placing the coil on a reference object of acceptable

quality; then the coil is placed on the test object. Any difference between

test object and reference object will result in an imbalance of the bridge

which is indicated on the output device. There are many output devices;

audible alarms, meters, X-Y plotters, strip-chart recorders, magnetic tape,

storage oscilloscopes, and computers.

Instrument Calibration

Because many factors may affect the coil impedance when a test is

performed, the object used to calibrate the instrument must be carefully

chosen. For example, to detect cracks, the reference object must have the

same electrical and magnetic properties as the test object; otherwise,

differences in alloy composition could be interpreted as a crack. Therefore,

a user must be knowledgeable about operating an eddy current device in order

to calibrate it properly and to interpret test results.

53
Applications

Eddy current inspection has many uses, including the detection of flaws

such as cracks, porosity, or inclusions in metals; detection of changes in

alloy composition or microstructure; and the measurement of the thickness of

nonconductive coatings on a metal.

Limitations

One important limitation of eddy current inspection is the volume of

material examined. The inspection depth depends on the penetration depth of

eddy currents, the intensity of which decreases exponentially with depth.

The strength of the signal due to a particular defect will depend on the

nearness of the coil to the surface of the test object. As this distance

called "lift-off" increases, the signal strength diminishes. The "lift-off"

effect is so strong that it may mask signal changes due to defects.

Therefore, care must be taken to ensure uniform contact between coil and

test object; it may be difficult to test objects with rough or irregular

surfaces. The "lift-off" effect may be used to measure the thickness of

nonconductive coatings on conductive metals, or non-magnetic metal coatings

on magnetic metals. Proper calibration samples are required in order to use

an eddy current instrument as a thickness gage.

5.9.2 Magneto- Inductive Methods (Magnetic Field Testing)

This technique is only applicable to ferromagnetic metals and is primarily

used to distinguish between steels of different alloy composition and

different heat treatments. The principle involved is electromagnetic induction.

The equipment circuitry resembles a simple transformer in which the test object

acts as the core [2], There is a primary coil connected to a power supply

54
delivering a low frequency (10 to 50 Hz) alternating current, and a secondary

coil feeding into an amplifier circuit. In the absence of a test object, the

primary coil induces a small voltage in the secondary coil, but when a

ferromagnetic object is introduced, a much higher secondary voltage is induced,

The nature of the induced signal in the secondary coil is a function of the

magnetization characteristics of the object. Changes in these characteristics

are used to distinguish between samples of different properties. As in the

case of eddy current inspection, this method can only be used for quantitative

measurement if proper calibration is performed.

5.9.3 Cover Meters

Cover meters are portable, battery-operated magnetic devices that are

primarily used to estimate the depth that reinforcing steel (bars and tendons)

is embedded in concrete, and to locate its position. In addition, some

information can be obtained regarding the dimensions of the reinforcement [10],

Principle and Applications

Cover meters are based on the magneto-inductive principle. A magnetic

field is induced between the two faces of the probe (which houses a magnetic

core) by an alternating current passing through a coil. If the magnetic

field passes through concrete containing reinforcement , the induced secondary

current is controlled by the reinforcement. The magnitude of this change in

inductance is measured by a meter. For a given probe, the magnitude of the

Induced current is largely controlled by the distance between the steel

reinforcement and the probe.

The relationship between the induced current and the distance from probe

to the reinforcement is nonlinear, largely because the magnetic flux intensity

55
of a magnetic material decreases with the square of the distance. In addition,

the magnetic permeability of the concrete, even though it is low, will have

some effect on the reading. Therefore, the calibrated scales on the meters

of commercial equipment are nonlinear. Also, a meter must be readjusted

if a different probe is attached.

The probe is highly directional — i.e., sharp maximum in induced current

is observed when the long axis of the probe and reinforcement are aligned,

and when the probe is directly above the reinforcement.

Some commercial cover meters can measure concrete cover over reinforcement

up to 8 in, (200 mm). By using spacers of known thickness, the size of

reinforcing between 3/8 and 2 in. (10 to 50 mm) can be estimated.

Another possible application of the cover meter is to estimate the

thickness of slabs which are accessible from both sides. If a steel plate is

aligned on one side with the probe on the other side, the measured induced

current will indicate the thickness of the slab. For this application, a

series of calibration tests must be performed first, British Standard

BS 4A08 gives guidance for the use of cover meters.

Advantages

Cover meters are portable, inexpensive instruments that can be easily

used. They are useful when reinforced concrete has only one layer of

widely separated reinforcing bars.

Limitations

In highly reinforced concrete, the presence of secondary reinforcement

makes it difficult to determine satisfactorily the depth of concrete cover.

Furthermore, reinforcing bars running parallel to that being measured

56
influence the induced current if the distance between bars is less than two

or three times the cover distance [10].

5.9.4 Magnetic Particle Inspection

Principle of Method

This inspection method relies on the tendency of cracks to alter the

flow of a magnetic field within a metal so that fine magnetic powder will be

attracted to the crack zone, allowing cracks to be Identified [2,16,17], For

example, consider a bar magnet in which the magnetic field flows through the

magnet from south to north poles. If ferromagnetic particles are sprinkled

over the middle surface of a crack-free magnet, there will be no attraction

because the magnetic field lies wholly within the magnet. Now consider a

cracked magnet; the two sides of the crack acts as north and south poles,

and the magnetic field bridges the gap. However, some of the magnetic field

will leak out of the magnet into the air, and ferromagnetic powder would be

attracted by the leakage field. Therefore, the attraction of the powder

indicates a crack. A subsurface crack would also produce a leakage field,

but the response would be weaker than for a surface crack.

Application of Method

In using the magnet particle method, it is necessary to magnetize the

object being inspected, apply ferromagnetic particles, and then inspect for

cracks. Two general types of magnetic fields may be induced in the test

object: circular and longitudinal. A circular field is produced by passing

an electric current through the test object: the magnetic field then would

be concentric with the direction of current flow. A longitudinal field

could be created by placing the test object inside a coil carrying electric

57
current: the magnetic field then would be parallel to the longitudinal axis

of the coil. The direction of the magnetic field relative to the test object

controls which cracks will be detected. Strong leakage fields are produced

by cracks which intersect the magnetic lines of force at an angle; no leakage

fields are produced by cracks parallel to the magnetic lines of force.

Therefore, complete inspection should include rotation of the test object

with respect to the magnetic field to make sure that all existing cracks

intersect the magnetic field lines.

In field inspections, it usually is not practical to pass a current

through the entire part or surround the part with a coil. Portable units are

available that permit inspection of small portions of the test object at a

time. For example, prods can introduce a flow of current between two contact

points on the object. In this case, a circular magnetic field is Induced. A

yoke — a U-shaped electromagnet in which the poles are brought into contact

with the test object — can also be used. With a yoke, a longitudinal magnetic

field is set up in the object, and the lines of force in the electromagnet

run from one pole to the other. With either portable method, only a small

portion of a large test object can be inspected at one time; 12 in. (300 mm)

is a practical limit for spacing between prod contacts [2].

The choice of current used to magnetize the test object is important.

If subsurface cracks are to be detected, direct current should be used because

alternating current will only produce a magnetic field near the surface.

The direct current may be from a constant or pulsating source, though the

pulsating type is preferred because it imparts greater mobility to the

ferromagnetic powder. The current supply is low voltage and very high amperage

for user safety, but still permits strong magnetization of the test object.

58
Inspection is usually carried out with the current on, but if the metal has

high retentivity (permanent magnetism), the current may be turned off before

the powder is applied.

The powder used to indicate the leakage fields may be dry or suspended

in a liquid. Dry powders are preferred for the best sensitivity to subsurface

cracks and should be used with direct current. Wet powders are superior for

detecting very fine surface cracks. To improve visibility, powders are

available in various colors, providing high contrast with the background. In

addition, fluorescent particles are available for increased visibility.

Advantages

The magnetic particle inspection method has several advantages over

other crack detection systems [2]. Portable equipment is available that can

be readily taken to the inspection site. This equipment is inexpensive

and simple to operate; positive crack indications are produced directly on

the part and no electronic equipment is needed. Any part that is accessible

can be Inspected.

Limitations

This method will only work with ferromagnetic metals. For complete

inspection, each area needs to be inspected more than once using different

magnetic field directions; very large currents are needed to inspect large

areas at once. Experience and skill are needed to interpret properly the

particle indications and to recognize patterns which do not indicate cracks.

Demagnetization may be required after inspecting steels with high magnetic

retentivity. The maximum depth of the flaw detection is about 0.5 in. (13 mm),

and the detectable flaw size increases as flaw depth increases.

59
Portable equipment is limited with regard to the current available for

the inspection. For detection of deep lying discontinuities and for coverage

of large areas with one prod contact, a larger machine, such as a mobile

unit or stationary unit with higher-amperage output is required.

5.9.5 Steel Fiber Content

Description of Method

The electromagnetic apparatus for measuring steel fiber content of steel

fiber reinforced concrete consists of a measuring device and several

attachments having circular or square openings in the center into which the

test specimens are inserted [18]. In the attachments there are coils for both

excitation and induction of an electric current. With an increase in steel

fiber content of the specimen in the attachment, the induced electric current

increases. Based on this principle, the steel fiber content can be determined

from a reading of the induced current. This method can be used for both

hardened and fresh concrete. For fresh fiber reinforced concrete, it must

be placed in molds that do not contribute to the induced electric current.

Limitations

This electromagnetic method for in situ measurement of steel fiber

content in hardened and fresh concrete shows promise as a research tool.

The method has not been used extensively in the field. Further development

work is required it if is to become a reliable NDE method.

5.10 Holography

Description of Method

Two methods available for nondestructive inspection are optical holography,

using visible light waves, and acoustical holography, using ultrasonic waves.

60
In these methods, a two step process creates a three-dimensional image of a

diffusely reflecting object [14], The first step involves recording both the

amplitude and phase of any type of coherent wave motion emanating from the object,

The recording of this information in a suitable medium is called a hologram.

At a later time, the wave motion can be reconstructed from the hologram to

regenerate a three-dimensional image having the shape of the object. The

nondestructive inspection of an object is accomplished by using the regenerated

three-dimensional image as a template against which any deviations in the

shape or dimensions of the object can be observed and measured [14],

Limitations

Skill is required in developing holograms (three-dimensional images) and in

the interpretation of comparing holograms in order to measure deviations that

have occurred in the shape or dimensions of the object that is inspected.

5.11 Leak Testing Method

Principle of Method

Leakage testing is the detection and sizing of holes in pipes and tanks

which permit the escape of liquids or gases [19]. There are many different

methods of leak testing, but they can be generally classified into two

categories. In the first, the leaking system is monitored under normal

operating conditions. This includes the use of pressure meters, the application of a soap solution, or the use of audio or amplified listening devices.

In the second category, a particular substance is added into the system flow

to provide special indications of leakage. This includes additives such as

colored dyes, Freon 12 and helium gas, radioactive tracers, and odorous

indicators.

61
Applications

Many leak detection methods are suitable for fi«ld application. Liquid

storage vessels and above ground piping can usually be checked visually for

leakage under normal operating conditions with no special equipment. Gascarrying systems usually can be checked best in the field with a soap solution

or (with freon gas added to the system) a propane torch. These systems have

no special power requirements, and none of the equipment involved weighs

more than 5 lb (2 kg).

Advantages

Leak detection methods can locate flaws too small to be found by any

other NDE technique. Leaks with rates as small 10"^^ cc/sec can be detected

with radioactive tracers and radiation monitoring devices, while a soapy

water solution can locate leaks with rates as low as 10"^ cc/sec [19].

Limitations

Flaws can be detected only if they penetrate through a structure that

can be held at pressure conditions exceeding those of the surrounding

atmosphere.

5.12 Longitudinal Stress Waves

Description of Method

The speed that longitudinal (parallel to the grain) stress waves travel

in wood has been measured by resonant frequency, impact, and by ultrasonic

stress-wave devices [20]. Stress wave-speed (speed of sound) of waves that

travel in the longitudinal direction is affected by several factors such as

moisture content, temperature, knots, specific gravity, and orientation of

62
grain in the wood (grain angle). The type of longitudinal stress wave induced

in wood does not have a significant effect on stress wave-speed. Stress

waves show promise for rapid lumber grading and predicting mechanical

properties of wood [20].

Development of an effective in situ test method to evaluate the soundness

of wood subject to deterioration would be useful in appraising its service

life. Wood members under some environmental exposures may lose some structural

integrity through decay or chemical degradation. Stress-wave transmission

has been investigated to determine nondestructively the extent and location

of degradation in wood [21].

Limitations

Additional research is needed to demonstrate the feasibility of using

longitudinal stress waves to assess the mechanical properties of wood and for

rapidly determining the quality of wood members.

5.13 Maturity Concept

Principle and Application of Method

The maturity concept has been proposed as a method for predicting early

age strength development of hardening concrete. It relates the combined

effect of temperature and hydration time of concrete to its strength [22].

Maturity (M) is usually expressed as:

M = Z (T-To)At

where T = temperature of the concrete

Tq = the highest temperature below which the strength of

hardening concrete does not change

At = the increment of time for each temperature.

63
According to the maturity concept, the strength of a given concrete mix is a

single-valued function of maturity, independent of the actual temperature

history [22]

To apply this method, one first experimentally determines the strengthmaturity relation of the concrete mix to be used in building the structure.

This is done by making and curing standard specimens in a laboratory, monitoring the actual concrete temperature, and testing strength at various ages.

From the temperature record, the corresponding maturity value at each test age

is calculated, and strength versus maturity data are generated. Various

equations for the strength-maturity relation have been proposed, and can be

used in analysis of the data [23~25]. During construction, the in-place

concrete temperature is recorded, from which maturity values at any age can

be determined. The previously determined strength-maturity calibration

curve is used to predict the strength of the in-place concrete. The maturity

method is identified in ACI Committee Report 306R-78 as a viable means of

predicting the in situ strength of concrete [26].

Maturity can be calculated using temperature records from continuous

strip-chart recorders or from digital data-loggers, which print out the

temperature at regular time intervals. As an alternative, commercial

"maturity meters" are available; these monitor the in-place temperature and

automatically compute the cumulative maturity. Such instruments cost about

$3000. Multi-channel maturity meters have been developed to allow monitoring

maturity at many locations with a single instrument. In addition, single-use,

disposable meters have been produced, although their reliability has not

been tested. Finally, one may use programmable data-loggers as maturity

meters.

64
Advantages

Because In-place temperatures are measured, the maturity method accounts

for one of the major factors affecting early-age strength development of

concrete.

Limitations

Since only temperature and time are measured, another method is needed

to verify that the in-place concrete has the correct mix proportions. Otherwise, the user has no way of knowing if the strength-maturity calibration

curve is appropriate. Accelerated curing tests of samples taken from the

concrete batch, or other in-place tests discussed in this report may be

used. Because of the nonuniform temperature distribution in the structure,

the temperature probes must be carefully located to avoid overestimating

maturity development in the critical strength regions. In addition, there

is a question about whether the equation given earlier in this Section (5.13)

is the best temperature-time function for computing maturity. Carino discussed

this problem and suggested alternative methods [25]. Finally, the maturity

method is only applicable for strength prediction in new construction and

cannot be used to estimate the strength of concrete in existing structures.

5.14 Microwave Inspection

Microwaves (or radar waves) are a form of electromagnetic radiation

which have frequencies between 300 MHz and 300 GHz corresponding to wavelengths of 1 m to 1 mm. Microwaves are generated in special vacuum tubes

called klystrons and transported in a curcuit by waveguides. Diodes are

commonly used to detect microwaves.

65
Applications

Because of their electromagnetic nature, microwaves can be reflected,

diffracted, and absorbed. These waves are absorbed by water and this has led

to development of a method for determining the moisture content of concrete.

The use of microwaves to estimate the moisture contents of concrete and

roofing materials has been explored [10,27,28], Similar to capacitance

instruments (see Section 5,16,2), changes in the dielectric properties of

materials are detected. Since moisture affects the dielectric properties of a

material, changes in moisture content in the material can be detected. Boot

and Watson report that the microwave technique only estimates the moisture

content of concrete within 12 to 30 percent of its mean value [29], The low

accuracy of micowave inspection is largely attributed to the heterogeneity of

concrete, and the internal scattering and diffraction it causes.

Limitations

The feasibility of using microwaves for inspecting installed construction

materials has not been demonstrated. Further development work is required if

the microwave method is to become a reliable field NDE method.

5,15 Middle Ordinate Method

Description of Method

In this method a laboratory instrument is used that is capable of

detecting stiffness variations within boards (lumber) over lengthwise regions

of less than two feet [30], A bending moment is applied to each end of the

board under test. Stiffness calculations are based upon the assumption that

short segments of a board undergoing bending approximate arcs of circles with

varying radii. The middle ordinate instrument measures, either on a continous

66
basis or in discrete steps, the perpendicular distance between the midpoint

of a chord and its arc. This distance or deflection is inversely related to

stiffness. The instrument provides a means of assessing in the laboratory

the strength-reducing potential of defects in lumber.

Limitations

This research method has not been used in the field. Additional research

and field use are needed to demonstrate the feasibility of using the middle

ordinate method as a reliable NDE method to inspect lumber at the job site.

5.16 Moisture Detection Methods

Many of the problems encountered in a building are caused by moisture.

Visual inspection can reveal obvious surface moisture, but even if a surface

is dry, subsurface moisture can be present. Four NDE methods are often used

for moisture inspection measurements. The types of instruments or methods

used include electrical resistance probes, capacitance instruments, nuclear

meters, and infrared thermography [27,28,31].

5.16.1 Electrical Resistance Probe

Principle and Applications

The resistance probe method involves measuring the electrical resistance

of a material, which decreases as the moisture content increases. Most

instruments consist of two closely spaced probes and a meter-battery assembly

which are enclosed in one housing or in two attached assemblies. The probes

are usually insulated except at the tips so that the region being measured

lies between the tips of the probes. The probe can penetrate soft materials,

such as roofing membranes, so that moisture at various distances below the

67
surface can be detected. Operation of a resistance probe is very simple. A

voltage is impressed between the probes and the resistance measured.

Probe instruments have been used for moisture detection in plaster,

brick, concrete, and roofing materials. Similar procedures have been used for

determining the electrical resistance of soils, except a four probe system is

used.

Calibration

The electrical resistance probe and other moisture measuring instruments

are usually calibrated by obtaining relationships between their response and

the moisture content of materials similar to those being inspected. The

moisture contents of the reference specimens are gravlmetrlcally determined — l,e., specimens are weighed before and after oven drying with the differences

in weight considered to be their moisture contents.

Advantages

The simple, inexpensive Instruments, while giving only an approximation

of the extent of wetness, are useful in identifying wet areas and for

determining moisture migration patterns. More sophisticated instruments

appear to be capable of giving semi-quantitative information if they are

properly calibrated.

Limitations

Electrical resistance probe instruments do not determine moisture

contents precisely. When used on roofing membranes the test method is

considered to be destructive.

68
5.16.2 Capacitance Instruments

Principle and Applications

Capacitance instruments used to detect moisture are based on the

principle that moisture can affect the dielectric properties of a material [31]

The dielectric constant, K, of a material is a relative measure of the ability

of a material to store electrical energy and is given by:

K = C/Co

where C is the capacitance of a material and Cq is the capacitance of a

vacuum

.

The dielectric constants for many dry building materials are usually

low; e.g., for dry roofing materials, K ranges from 1 to 5, while water has

a K of approximately 80 [28]. The value of K for a moist material will

theoretically increase linearly as the volume fraction of water increases.

Capacitance-radio frequency instruments have been used to measure the moisture

contents of paper products, wallboard, and roofing materials. Commercial

capacitance Instruments have various electrode configurations. The electrodes

are attached to a constant frequency alternating current source and establish

an electrical field in the material to be tested. Current flow or power

loss — indicating moisture content — Is then measured. Most Instruments

operate in the radio frequency region (1 to 30 MHz).

Advantages

Capacitance instruments are portable and measurements can be taken

rapidly.

69
Limitations

Capacitance meters have extreme sensitivity to surface moisture; because

of this it is essential that the roof surface be dry when capacitance surveys

are made [32]. An investigation by Knab et al. suggests that capacitance

Instruments may not give reliable quantitative measurements of the moisture

contents of roofing systems beyond the "threshold" moisture content [31].

5.16.3 Nuclear Meter

Principle of Method

Fast neutrons, emitted during the decay of radioactive isotopes, are

used in making moisture content measurements [28,29]. Fast neutrons from the

isotope source enter the material and are both scattered and slowed by

collisions with the nuclei of the atoms composing the material. Nuclei of

all materials slow down the neutrons by momentum exchange, but the speed

reduction is greatest for collisions with hydrogen nuclei, which have about

the same mass as the neutrons. Some of the slow or thermal neutrons are

scattered so that they reach the slow neutron detector in the instrument

and are counted for a specific period of time. The thermal neutrons reaching

the detector are much more likely to have collided with hydrogen nuclei than

with other atomic nuclei because the scattering cross-section of hydrogen is

greater than for other atoms likely to be present. The detector measures

primarily the backscattering of slow neutrons which have collided with hydrogen

nuclei in the surface region of materials. For example, the depth of

measurement is limited to 2 to 8 in. (51 to 203 mm) in soils.

70
Commercial Meters and Applications

Nuclear meters are used to measure both moisture content and density of

soils, portland-cement concrete, asphaltic concrete, and roofing materials

[10,27,28]. These meters consist of a shielded radioactive isotope source,

a detector or counting device, and readout equipment. In commercial meters,

the isotopes used are radium 226-beryllium, and americium 241-beryllium.

Both americium and radium are alpha particle emitters. These particles

interact with the nucleus of beryllium, resulting in the emittance of fast

neutrons.

In addition to neutron sources, most commercial nuclear moisture meters

also have gamma ray sources. The gamma rays are used to determine the density

of materials. See Section 5.25 about Radioactive Methods for an explanation of

the principle.

Advantages

Nuclear meters are portable, and moisture measurements can rapidly be

made on materials.

Limitations

The hydrogen atoms of building materials in addition to those of water

will contribute to the number of detected thermal neutrons. For example,

asphalt in a roofing membrane may contribute to a reading because it contains

bonded hydrogen atoms. For hydrogen-containing materials, the meter must be

calibrated with samples identical to those expected during field inspection.

Also, a license must be obtained from the Nuclear Regulatory Commission to

use the radioactive isotopes in the neutron source of the neutron moisture

meters. Transportation of meters may be difficult because of restrictions.

71
5.16.4 Infrared Thermography

In addition to locating heat loss, infrared thermography can be used to

detect moisture in building materials if heat is flowing through them. The

presence of moisture will affect the heat transfer properties of materials;

this permits the identification of wet areas by thermography. The principles

involved in making thermography scans are discussed under Thermal Inspection

Methods (Section 5.29). The infrared thermography method is being used in

making aerial scans of roofs. Large roof areas and many buildings can be

scanned in a relatively short time [27,28]. Handheld infrared cameras also

are being used to measure heat losses and to detect moisture in roofing

systems [32,33]. Additional applications of infrared thermography are given

in Section 5.29. In using thermography to detect moisture in roof systems,

it is necessary to assume that temperature gradients are caused by moisture

and are not associated with differences in roofing composition or thickness.

Because construction and thickness variations can be present, results from

thermographic inspections should be interpreted carefully.

Limitations

Some destructive testing may be necessary to verify roofing composition

and thickness.

5.17 Nuclear Density Meter

See Section 5.16.3.

72
5.18 Paint Inspection Gages

5.18.1 Tooke Gage

Principles and Applications

The Tooke Gage measures dry paint film thickness by the microscopic

observation of a small v-groove cut into the paint film. In addition, the

number of paint layers and their individual thicknesses can be determined.

The thickness of dry coating applied to any type of surface can be measured — e.g., to wood, metal, glass, or plastic. The Tooke Gage is easily portable,

with overall dimensions of 4.5 x 3.5 x 1 in. (114 x 89 x 25 mm); and it weighs

26 oz (0.7 kg). Three cutting tips are furnished; these permit measurements

of film thicknesses up to 50 mil (0.13 mm).

Limitations

A disadvantage of this method is that a cut is made in the paint film

which may have to be repaired, depending on the substrate and the severity

of the environment.

5.18.2 Pencil Test

Principle and Applications

This rapid and inexpensive method can be used to determine film hardness

of an organic coating on a substrate using pencil leads of known hardness.

Testing is started with the hardest pencil lead and continued down the scale

of hardness to either of two end points: (1) the pencil that will not cut

into or gouge the film, or (2) the pencil that will not scratch the film.

Advantages

The method causes only slight damage to the coating.

73
5.18.3 Magnetic Thickness Gages

5.18.3.1 Magnetic Pull- Off Gage

Principle and Applications

These instruments measure thickness by using a spring calibrated to

determine the force required to pull a permanent magnet from a ferrous base

coated with a nonmagnetic film. The instrument is placed directly on the

coating surface to take a reading. The attractive force of the magnet to the

substrate varies inversely with the thickness of the applied film. The spring

tension required to overcome the attraction of the magnet to the substrate is

shown on the instrument scale as the distance between the magnet and the

substrate.

5.18.3.2 Magnetic Flux Gage

Principle and Applications

These instruments measure coating thickness by changes in the magnetic

flux within the instrument probe or the instrument itself. The instrument

probe must remain in direct contact with the coating at all times during

measurement. The magnitude of flux changes as an inverse (nonlinear)

function of the distance between the probe and the ferrous substrate. The

testing apparatus is mechanically or electrically operated. The mechanically

operated instruments house an integral horseshoe magnet, the contacts of

which are placed directly on the coated substrate. The electrically operated

gages utilize a separate instrument probe that houses the magnet and the

gages must be placed directly on the coated surface. In both types, the

coating thickness is shown on the instrument scale or meter.

74
The methods for nondestructive measurement of dry film thickness of

nonmagnetic coatings applied to a ferrous base are described in ASTM Standard

D 1186 (Appendix D) . In addition, the method for nondestructive measurement

of film thickness of pipeline coatings on steel is described in ASTM Standard

G 12 (Appendix D) .

5.18.4 Wet Film Thickness

Measurements of wet film thicknesses of organic coatings using the

Interchemical Wet Film Thickness Gage and the Pfung Gage are described in

ASTM Standard D 1212 (Appendix D) . Wet film thickness measurements using

Notch Gages are described in ASTM Standard D 4414 (Appendix D)

.

5.18.4,1 Interchemical Wet Film Thickness Gage

The gage consists of an eccentric center wheel supported by two concentric

wheels so as to provide two scales that are bilaterally symmetrical. The

gage is rolled on the wet film; as it rotates there is a change in clearance

between the wet film and the eccentric wheel. The point at which the film

first touches the eccentric center wheel is a measure of the thickness of the

paint film. The gage is available in a variety of ranges and can measure wet

film thickness up to 60 mils on the English scale and up to 700 yra on the

metric scale.

Limitations

At locations where thickness measurements are made, the coating film may

have to be repaired.

75
5.18.4.2 Pfung Gage

Principle and Applications

The gage consists of a convex lens that is mounted in a short tube that

slides freely in an outer tube. The lower surface of the convex lens has a

radius of curvature of 250 mm. Compression springs keep the convex surface

out of contact with the wet film until pressure is applied to the top of

the short tube forcing the lens down through the film to the substrate.

After the pressure is released, an oversized circular spot is retained on the

lens. The diameter of the circular spot retained on the lens is a measure of

the wet film thickness.

Limitations

At locations where thickness measurements are made, the coating film may

have to be repaired.

5.18.4.3 Notch Gage

Principle and Applications

Square or rectangular, and circular, notch rigid metal gages are used to

measure film thicknesses ranging from 0.5 to 80 mils (13 to 2000 pm) for square

or rectangular gages and from 1 to 100 mils (25 to 2500 ym) for circular gages.

These gages are used on coatings on flat substrates. Notched gage measurements

are neither accurate nor sensitive, but they are useful In determining

approximate wet film thickness of coatings where sizes and shapes of coated

objects prohibit the use of the more precise methods given in ASTM Standard

D 1212. The square or rectangular gages are pushed perpendicular into the

film and the circular gages are rolled perpendicularly across the film.

Thickness is determined from tabs and notches wetted by the film.

76
Limitations

At locations where thickness measurement are made, the coating film may

have to be repaired.

5.19 Pin Hole Dectector

Principle and Applications

This type of device Is used to find pin holes (holidays) In nonconductlve

coatings applied to metals. Pinhole and holiday detectors are of three

general types; low voltage wet sponge, direct current high voltage, and

alternating current electrostatic types [34]. Most low voltage commercial

Instruments consist of a probe or electrode, which makes contact with the

coating through a moist sponge, and an earth lead, such as alligator clip,

which Is attached to an area of bare metal. When the moist sponge passes

over a pin hole, an electrical circuit Is completed and an alarm sounds.

Most high voltage detectors use In general a direct current power source In

the range of 500 to 1500 volts [35]. High voltage detectors basically

function on the same operating principle as the low voltage detectors except

that a sponge Is not used. The alternating current electrostatic type

detector Is used for testing conductive linings applied over steel substrates.

Limitations

There are several problems In using the detectors to Inspect for pin holes,

If a metallic object is completely coated, part of the coating must be removed

so that the earth lead can make contact with the metal. The voltage must be

carefully selected to match the coating thickness because too high a voltage

would break through a thin film even if pin holes were not present. The

77
results are qualitative since no information on the size of a pin hole

is given.

5.20 Point-Load Test

This test is intended to estimate the compressive and tensile strength

of concrete using small cores.

Description of Method

Relatively small cores of plain or fibrous concretes about 2.7 in. (68

mm) in diameter and 4 in. (100 mm) in length are tested using a point load in

a diametral test [36]. Cores have to be drilled and extracted from the concrete

for which strength determinations are to be made. The apparatus for the

point-load test is a portable testing machine consisting of a loading system

and load measuring capability. A truncated steel cone is used to apply

the point load at mid-length of the core along its diameter until failure

occurs. The point-load test is essentially an indirect tensile test and will

give a maximum tensile stress which differs from the actual direct tensile

stress because of high compressive stress under the load. The compressive

strength can be related to the tensile strength through empirical formulae.

Advantages

This test is quick to carry out, is relatively inexpensive, and can be

performed in the field on a simple and easily portable apparatus. A total of

six point-load tests may be expected to provide a realistic estimate of concrete

strength.

78
Limitations

Additional research is needed to demonstrate the reliability of using

the point-load test to assess the strength of concrete and for this test to

become a reliable in situ NDE method. The concrete needs to be repaired where

cores are taken,

5.21 Probe Penetration Method

Principle of Method

The probe penetration method involves measuring the exposed length of a

cylindrical steel probe driven into concrete by a powder charge. This method

is useful for assessing the quality and uniformity of concrete in situ, and

for delineating areas of poor quality or deteriorated concrete in structures.

Probe penetration results have also been used to estimate the compressive

strength of concrete by using correlation graphs. The graphs are constructed

by plotting the exposed lengths of probes versus experimentally measured

compressive strengths. This can be done by performing penetration tests on a

concrete slab and taking core samples for compression testing.

Probe Equipment and Its Use

The Windsor Probe is the most commonly selected, and possibly the only,

commercially available apparatus for measuring the penetration resistance of

concrete. It consists of a special driving gun which uses a 32 caliber blank

with a precise quantity of powder to fire a high-strength steel probe into

the concrete. A series of three measurements is made in each test area.

The length of a probe extending from the surface of the concrete can be

measured with a simple device.

79
Operating procedures for the Windsor Probe are given by the manufacturer.

In addition, testing procedures are given in ASTM Standard C 803 (Appendix D)

The probe can be easily operated by concrete inspectors, and is readily

portable.

The manfacturer supplies a set of five calibration curves, each

corresponding to a specific Moh's hardness for the coarse aggregate used in

the concrete. With these curves, probe measurements can be converted to

compressive strength values. However, Ami observed that use of the

manufacturer's calibration curves often resulted in grossly incorrect

estimates of the compressive strength of concretes [37], Therefore, the

Windsor Probe should be calibrated by the individual user, and should be

recalibrated whenever the type of aggregate or mix design is changed.

The Windsor Probe can be used for assessing the quality and uniformity

of concrete because physical differences in a concrete will affect its

resistance to penetration. A probe will penetrate deeper as the density,

subsurface hardness, and strength of the concrete decrease. Areas of poor

concrete can be delineated by making a series of penetration tests at regularly

spaced locations.

The Windsor Probe has been used to estimate the compressive strength of

concrete. However, the relationship between the depth of penetration of the

probe and the compressive strength can only be obtained empirically because

the penetration of the probe depends on a complex mixture of tensile, shear,

frictional, and compressive forces [37]. The estimation of compressive

strengths with the Windsor Probe, therefore, must be made using a correlation

diagram with appropriate confidence limits.

80
The probe technique appears to be gaining acceptance as a practical NDE

method for estimating the compressive strength of concrete. Improved

correlations between probe results and in-place strength can be obtained by

keeping the curing conditions of the test specimens close to those expected

for in-place concrete, and by making sure that the test concrete is representative of the in-place concrete. If the Windsor Probe is calibrated using concrete

specimens taken from an early construction stage, the calibration chart could

be used to estimate the strength of concrete placed during later stages

(assuming that the concrete design is the same).

Advantages

The Windsor Probe equipment is simple, durable, requires little maintenance,

and can be used by inspectors in the field with little training. The probe test

is very useful in assessing the general quality and relative strength of

concrete in different parts of a structure.

Limitations

Care must be exercised, however, because a projectile is fired; safety

glasses should be worn. (Note: The gun can only be fired when it is pushed

against the spacer plate.) The Windsor Probe primarily measures surface and

subsurface hardness; it does not yield precise measurements of the in situ

strength of concrete. However, useful estimates of the compressive strength

of concrete may be obtained if the probe is properly calibrated.

The Windsor Probe test does damage the concrete, leaving a hole of about

0.32 in. (8 mm) in diameter for the depth of the probe, and may cause minor

cracking and some surface spalling. Minor repairs of exposed surfaces will

be necessary.

81
5.22 Proof Load Testing

Principle of Method

Proof load testing is based on the concept that a structure capable of

surviving the stresses of a severe overloading should be serviceable under

normal operating conditions [19]. Proof loading requires overloading a

structure in a load pattern similar to operating conditions (e.g., high

pressure in a pipeline).

Applications

Proof load testing can be used with leak testing (see Section 5.11)

in pressure vessels and pipelines inspection to increase the sensitivity of

leak detection. This method is generally used as a last resort to determine

the adequacy of a structural system.

Advantages

An entire structure can be tested in its "as-built" condition.

Limitations

The test may cause the premature failure or the destruction of a

structure. Proof load testing requires extensive planning and preparation,

and is usually expensive.

5.23 Pull-Off Test

The pull-off test is used to estimate the in situ strength of concrete.

Description of Method

The pull-off test, used as a means of predicting the compressive strength

of concrete, involves bonding a circular steel probe, 2 in. (50 mm) in diameter,

82
to the surface of the concrete to be tested [38]. The concrete surface should

be properly prepared and epoxy resin used to bond the probe to the concrete.

A tensile force is applied to the adhered probe using a portable mechanical

system; the force is increased until the concrete fails in tension. From the

tensile force at failure, the compressive strength of the concrete can be

determined from calibration graphs based on data from a large number of pulloff tests and corresponding cylinder compressive strength tests. Since the

tensile strength of the bonded area is greater than the concrete, the concrete

will eventually fail in tension. The amount of overbreak is usually small so

that the area of failure can be taken as being equal to that of the probe.

Advantages

The procedure is simple, inexpensive, and does not require a highly

skilled operator to make the measurements. Tests can be conducted on horizontal

and vertical surfaces. The stress at failure is a direct measure of the

tensile strength. Inspection of the probe after test will indicate if failure

occurred in the concrete, thus unsatisfactory failures can be discounted. It

is not necessary to plan the location of the test areas in advance of placing

the concrete; as is the case for some other partially destructive tests.

The internal concrete strength can be estimated by partial coring to the

desired depth and conducting the test on the cored area.

Limitations

Although considerable testing has been done and the tests gave consistent

and reliable results, a standard test such as an ASTM test has not been

developed. The concrete needs to be repaired in areas where the test was

conducted.

83
5.24 Radar

Radar is capable of rapid nondestructive assessment of materials such as

asphalt, concrete, soil, and rock by penetrating them to varying depths to

indicate material changes, separations, voids, and other discontinuities [39].

Radar may also be used to estimate material quality.

Description of Method

Radar techniques are based on the principle that electromagnetic waves

are reflected by concrete and other materials. Radar wavelengths can be

longer than those associated with NDE microwave inspections. Portable

equipment is available commercially for application to assessment of concrete,

but the method has yet to be standardized. The radar technique has been

used with success in New York and New Jersey to evaluate concrete pavements

and bridge decks [40]. An attractive feature of this technique is the speed,

approximately 17 km/h, at which pavements can be scanned. It is noted that

great planning and skill are needed to evaluate the data.

The frequencies of the electromagnetic energy selected for radar NDE

inspections range from 100 to 1200 MHz depending on penetration depth and

resolution desired. The resolution or ability to differentiate closely spaced

objects is a function of the signal frequency and bandwidth. Very small

changes over short distances require a higher frequency and wider bandwidth.

With lower frequency and narrower bandwidth, the ability to see small changes

is lessened but the depth of penetration is greater. The energy travels

through different materials at a specific speed for each material depending

on the material's dieletric properties. As an example, at a frequency of

1200 MHz and in 1 nanosecond, the radar wave will travel 6 in. (152 mm) in air,

84
2.5 in, (64 nnn) in concrete, and 3 in, (76 mm) in asphalt. When a change in

material dieletric occurs such as at an interface of air to asphalt or asphalt

to concrete it is indicated by a change in wave shape.

Low frequency radar is used for macro-studies, such as soil mapping and

location of material changes in the subsurface. In micro-studies, higher

frequency radar is used for locations of voids or delaminations in thin

sections such as roadways and bridge decks.

Advantages

Radar can rapidly scan pavements and bridge decks. The data can be

stored and compared with perodic scans to determine changes which occur with

time.

Limitations

Skill is required in interpretation of data to determine with a reasonable

degree of confidence the condition of materials with regard to voids, cracks,

and delamination. Further development work is required if the radar method

is to become a reliable field NDE method.

5.25 Radioactive Methods

There are two types of radioactive NDE methods, radiography and radiometry,

used to assess the properties of in situ concrete and other materials. The

radiography method uses a radioactive source in order to take a graphic picture

of the interior of building components. The radiometry method involves

detecting the intensity of the emerging radiation which passed through a

building component. Prior calibration charts can be used to determine in situ

density of building components and their thickness. Internal defects and

85
location of Internal parts In building components can be determined using

both radiography and radiometry methods. A British standard (BS 4408, Part 3,

1970) outlines testing procedures with regard to gamma radiography.

5.25.1 Radiography

Radiography allows the internal structure of a test object to be inspected

by penetrating radiation, which may be electromagnetic (X-ray, gamma rays, etc.)

or particulate (neutrons) [2,41,42]. The object is exposed to a radiation

beam, and the intensity of the radiation passing through is reduced according

to the object's variations in thickness, density, and absorption characteristics,

The quantity of radiation passing through the object is measured and used to

deduce internal structure. X-rays and gamma rays have been most widely used.

5.25.2 X-ray Radiography

X-rays are produced by bombarding a target material with fast moving,

high energy electrons. The high energy electrons collide with electrons in

the target, which are promoted to higher energy levels. As the promoted

electrons return to their ordinary energy levels, their excess energy results

in the emission of X-rays. X-rays are generated in an evacuated chamber

(X-ray tube) in which high energy electrons are generated by applying a very

high voltage between an incandescent filament (the electron source) and the

target material. By varying the voltage. X-rays with different penetrating

abilities can be generated. For example, for routine Inspections using

exposures of several minutes duration and with medium speed film, 200 kV

X-rays are capable of penetrating about 1 in. (25 mm) of steel, while 400 kV

X-rays can penetrate up to 2 in. (51 mm) of steel [25], which is generally

about the maximum radiation emitted with portable equipment. Recent

86
developments, such as linear accelerators can speed up and Increase the

penetrating power of field radiographic methods [14]. In general, the

penetrating ability of X-rays of a given energy level decreases as the

thickness or the density of the object increases,

5.25.3 Gamma Radiography

Gamma rays are physically indistinguishable from X-rays; they differ

only in the manner in which they are produced [14]. Gamma rays are the

result of radioactive decay of unstable isotopes. Thus, there are some

basic differences between gamma ray and X-ray radiography. Because gamma

rays are produced by nuclear disintegrations, a gamma ray source will lose

its intensity with time. In addition, each source produces rays of fixed

penetrating ability. Isotopes of thulium, iridium, cesium, radium and cobalt

have been used for radiography. Thulium has a penetrating ability of 0.5

in. (13 mm) of steel, while cobalt produces gamma rays capable of penetrating

up to 9 in. (230 mm) of steel. The gamma sources usually used for inspecting

concrete are given in Table 14. Note that the relative penetration abilities

of the gamma rays are controlled by their energies.

87
Table 14

Gamma Ray Sources [41]

Gamma Optimum Working

Radioactive Energy Half-life Thickness of

Source (MeV) (tl/?) Concrete (mm)

Iridium 192 0.296

and

0.613

70 days 30-200

Cesium 137 0.66 33 years 100-300

Cobalt 60 1.17

and

1.33

5.3 years 150-450

Dose Rate*

0.55

0.39

1.35

* Roentgens per hour per curie at 1 m. One curie is equal to 3.7 x 10^^

disintegrations per second.

Portable gamma radiography units are available for field inspections.

Using iridium-192 or cobalt-60 in these units enables short exposure times

and good image sharpness in field applications.

Principles and Applications

Gamma and X-ray radiation is attenuated (reduced) when passing through

materials. The extent of attenuation depends on the density and thickness of

the material, and on the energy of gamma rays. In radiography, differences

in radiation attenuation produced by variations in the density and thickness

of a material are recorded on photographic film. For example, when reinforced

concrete is radiographically inspected, steel reinforcement attenuates the

radiation more than concrete and appears as a lighter area in the film.

Voids and cracks in the concrete appear as darker areas on the film because

the incident radiation is attenuated little.

88
In practice, penetrating rays generated by a suitable source are allowed

to pass through materials, with the emerging radiation being recorded on Xray film held in a light-tight cassette. Some of the applications of gamma

radiography are inspecting concrete to locate reinforcing bars, and to

determine if excess microscopic porosity or macroscopic voids are present [43];

inspecting welds for cracks, voids, and slag inclusion; and inspecting masonry

walls for the presence of reinforcement or grout.

Advantages

Radiography provides a method for readily characterizing the internal

features of an in-place material or building component. This method is

applicable to a variety of materials.

Limitations

The most important drawback of radiography is the health hazard associated

with the penetrating radiation. The relatively high cost is another limiting

factor in the use of gamma radiography. A radiographic inspection program

should be planned and carried out by trained individuals who are qualified to

perform such inspection. All personnel involved in radiographic inspection

must carry devices that monitor the radiation dosage to which they have been

subjected, and must be protected so that the dosage rate does not exceed

Federal limits. Gamma ray sources are Inherently hazardous because they emit

rays continuously, and high energy sources have extremely high penetrating

ability. As a result, gamma ray sources require large amounts of shielding

material; this limits the portability of gamma radiography equipment. The

use of gamma-producing isotopes is closely controlled by the Nuclear Regulatory

Commission; users must have a license.

89
5.25.4 X-ray Fluorescence Analyzer

Principle and Applications

This method is generally carried out in the laboratory but there has

been some limited use in the field. The basis of the x-ray fluorescence

technique lies in the relationship between the atomic number and the wavelength

of the x-ray photons emitted by the sample element. Although almost any high

energy particle can be used to excite characteristic radiation from a specimen

in the laboratory, application of an x-ray source offers a reasonable compromise

between efficiency, stability and cost. Almost all commercial laboratory xray spectrometers use an x-ray source. "Since primary (source) x-ray photons

are used to excite secondary (specimen) radiation, the technique is referred

to as x-ray fluorescence spectrometry" [44].

In the potential NDE field method, the material is irradiated with a

radioactive isotope and absorbed energy is re-emitted as x-rays characteristic

of elements present in the material. The method is used for determination of

the elements present in a material.

Advantages

The potential NDE field method provides for a rapid analysis to

determine elements present in installed materials. The analyzer is portable

and can be used in the field and the laboratory.

Limitations

Field analysis is limited to small regions of material per test and the

technique is not capable of detecting all elements. The field apparatus

requires periodic calibration with reference standards.

90
5.26 Seismic Testing

Principle of Method

Seismic testing is the evaluation of material integrity by analysis of

shock wave transmission rates and effects [19], An array of sensing devices

around an explosive charge of known energy (the most common shock load input

system) is used to record shock wave transmission rates. These rates can be

related to material densities. Vibrational patterns induced from shock loading can be used to determine resonant frequencies in structures.

Applications

Seismic testing can measure soil densities and locate density variation

boundaries. Soil density values can then be related to load bearing capacities

and foundation preparation requirements. Seismic testing can also be used to

check structures for possible resonant frequencies that could cause failure

under operating dynamic loads.

Advantages

All components of some seismic test systems are portable.

Limitations

Seismic testing is applicable only to monitoring soil conditions and

structural vibrations. Multi-channel recording systems, power cables, and

many sensing devices are needed. The hazards of explosives are also involved

in the testing.

91
5.27 Soil Exploration

5.27.1 Cone Penetration Test

Principle and Applications

The Cone Penetration test is described in ASTM Standard D 3441. It is

widely used in European practice and is gaining increasing popularity in the

United States [45]. The test is performed by pushing a cylinder having a

conical tip into the ground. The cylinder can be described as having a 1.55

in. 2 (1000 mm^) cross sectional area, a 23.25 in.^ (15,000 mm^) surface

area, and the conical tip has a 60 degree apex angle. The soil resistance

is measured by the resistance to the penetration of the conical tip into the

ground and the frictional forces exerted on the surface of the cylinder

which are measured separately. The cone penetration test has been correlated

both empirically and theoretically with the bearing capacity of deep and

shallow foundations, and with the shear strength, density, stiffness and

compressibility of soils.

5.27.2 Helical Probes

Principle and Applications

Helical probes have been found to be a practical and economic method

for exploring soils at a shallow depth [45]. Test results correlated well

with traditional in situ exploration methods and the probes were also

found to be applicable for compaction control. The probes can be inserted

into the soil to a depth of 6 feet (1.8 m) . The magnitude of the torque

required to insert the helix into the soil is taken as a measure of soil

resistance. The probes can be operated with ease by one person. A probe

could also be coupled with drillrods and used at a greater soil depth.

92
The probes consist of a helical screw connected to a 5-1/2 to 6 foot

(1,7 - 1.8 m) long steel shaft. A hexagonal nut at the upper end of the

shaft is used for applying the torque. The probe is inserted into the ground

by turning it in a clockwise direction using a torquemeter. The torquemeter

has a dial gage to read the torque needed to insert the probe into the soil.

Torque readings are generally taken at 6 in. (15 cm) penetration levels,

however, it is possible to also continuously monitor the torque. The rate of

advance of the probe during a torque reading is kept to correspond to

approximately 4s for a 180 degree turn of the torquemeter. The average

torque rather than the peak value is recorded. Upon completion of the in

situ soils test, the probe is withdrawn by turning it in a counter clockwise

direction.

Limitations

Although extensive testing indicated that the probe test results correlated

well with traditional in situ exploration methods, it was recommended that

research be continued [45], Additional data are needed for controlled conditions

and for soils whose characteristics are well defined. There is also a need

for more data for clays and for compacted fills.

5.27.3 Standard Penetration Test

Principle and Application

The Standard Penetration test is described in ASTM Standard D 1586. It

was developed in 1927 and is the most widely used soil exploration test in

the United States and in worldwide geotechnical engineering practice [45]

.

The test involves dropping a 140 Ibm (63.5 kg) hammer from a height of

93
30 in. (0.76 m) to drive a drillrod with a standard split-tube sampler into

the ground. The number of blows to achieve a 1 ft (0.30 m) penetration by the

split-tube sampler, is used as a measure of soil resistance. The Standard

Penetration test has been empirically correlated with many soil characteristics,

including allowable bearing capacity of foundations, in situ shear strength,

density, stiffness and compressibility, and liquefaction potential during

earthquakes.

5.28 Surface Hardness Testing

Surface hardness methods are generally used to indicate the strength level

or quality of a material rather than to detect flaws. Hardness in these

tests refers to the resistance a material offers to indentation by an object.

Indentation is produced under static or impact loading conditions. The most

common applications are in testing metals and concrete.

5.28.1 Static Indentation Tests

Static indentation tests are primarily used in testing metals. They

usually involve indenting the surface with an indenter of fixed geometry under

specified loads [2]. The indenter has a small point and thus at the point of

contact produces stresses high enough to cause the metal to yield. A permanent

indentation results. The magnitude of the indentation will depend on the

hardness of the metal, the applied load, and the geometry of the indenter.

Therefore, by measuring the size of the indentation under a given set of

conditions, one can get an approximate measure of the hardness. For some

metals such as hardened and tempered steel, the hardness value can be used

to predict with resonable accuracy the tensile strength, impact resistance.

94
and endurance limit [2]. Portable hardness testers are available for in-place

testing of metal structures.

Standard Methods

There are three widely used methods for hardness testing of metals. The

Brlnell method involves applying a constant load (500, 1500, or 3000 kg) on a

0.4 in. (10 mm)-diameter hardened steel ball-type indenter, and measuring the

diameter of the indentation with a microscope. A hardness number is determined

by substituting the values of the applied load, ball diameter, and indentation

diameter into a standard formula. An example of a Brinell test result would

be 400 HB; 400 is the number calculated from the standard formula, "H" stands

for hardness, and "B" for Brinell. For softer metals, one would use a smaller

load to cause the indentation.

The Vickers method is similar to the Brinell method, except that a squarebased, pyramidal diamond indenter is used, and the applied loads are much

smaller. The diagonal of the square indentation is measured, and its value

and the applied load are substituted into a standard equation to calculate

the Vickers hardness number (HV).

The most common method is the Rockwell hardness test, which measures the

depth of additional permanent indentation that occurs as the load is increased

from a small load to the test load. The test instrument measures the depth

automatically, and the hardness number is read directly from a scale on the

instrument. The Rockwell test can be performed much faster than the previously

described methods. There are 15 Rockwell hardness scales — five different

indenters and three different loads. A hardness number of 60 on the Rockwell

95
C scale would be designated 60 HRC. The variety of scales permits testing a

wide range of metals from very soft to very hard.

Usefulness of the Hardness Number

Tables are available that permit conversion of the hardness number from

one test method to the equivalent number of another test method, for example,

see ASTM Standard E 140 (Appendix D) . There are also tables which give the

approximate tensile strengths of metals corresponding to the different hardness

numbers. Care must be taken in using the strength tables because each applies

to only certain types of metals.

5.28.2 Rebound Hammer Method

The rebound method is based on the rebound theories of Shore [46], He

developed the Shore Scleroscope method in which the height of rebound of

a steel hammer dropped on a metal test specimen is measured. The only

commercially available instrument based on the rebound principle for testing

concrete is the Schmidt Rebound Hammer [47],

The technique has gained wide acceptance by researchers and concrete

inspectors. It is one of the most universally used nondestructive test

methods for determining the in-place quality of concrete, and for deciding

when forms may be removed. According to Clifton, standards have been

drafted in Poland and Romania for the rebound hammer [48]. The British

Standards Institution has issued Building Standard 440 which covers nondestructive test methods for concrete, and includes the rebound hammer method

in part 4 of the Standard [48]. The ASTM has issued Standard C 805, which

gives procedures for the use of the rebound hammer (Appendix D),

96
Description of Method

The Schmidt Rebound Hammer consists of a steel weight and a tension

spring in a tubular frame. When the plunger of the hammer is pushed against

the surface of the concrete, the steel weight is retracted against the force

of the spring. When the weight is completely retracted, the spring is automatically released, the weight is driven against the plunger, and it rebounds.

The rebound distance is indicated by a pointer on a scale that is usually

graduated from zero to 100; the rebound readings are termed R-values. The

R-values indicate the hardness of the concrete; the values increase with the

hardness of the concrete.

Each hammer has a calibration chart, showing the relationship between

coiiipressive strength of concrete and rebound readings. However, rather than

placing too much confidence in the calibration chart, users should develop

their own calibration for each concrete mix and each rebound hammer.

Applications

Numerous investigators have shown that there is some correlation between

the compressive strength of concrete and the hammer rebound number [49-51].

There is, however, extensive disagreement about the accuracy of the strength

estimates from rebound measurements [52,53]. Mitchel and Hoagland found that

the coefficient of variation for estimated compressive strength, for a wide

variety of specimens from the same concrete, averaged 18.8 percent [54], Ami

found that the rebound hammer gave a less reliable estimate of compressive

strength than the Windsor Probe [37]. Some investigators have attempted to

establish correlations between the flexural strength of concrete and the hammer

rebound number. Relationships similar to those for compressive strengths

97
were obtained, except that the statistical variations were even

greater [53,55]

Mltchel and Hoagland attempted to correlate rebound numbers with the

modulus of specimens [54], They concluded that no valid correlations could be

made. Peterson and Stoll, and Klieger have developed some empirical relations

between the dynamic modulus of elasticity and hammer rebound [49,56].

Advantages

The Schmidt Rebound Hammer is a simple and quick method for the

nondestructive testing of concrete in place. The equipment is inexpensive,

coating less than $1000, and can be operated by field personnel with a limited

amount of instruction.

The rebound hammer, like the Windsor Probe, is very useful in assessing

the general quality of concrete and for locating areas of poor quality concrete.

A large number of measurements can be rapidly taken so that large exposed

areas of concrete can be mapped within a few hours.

Limitations

The Schmidt Rebound Hammer, however, has recognized limitations. The

rebound measurements on in situ concrete are affected by:

1. Smoothness of the concrete surface

2. Moisture content of concrete

3. Type of coarse aggregate

4. Size, shape, and rigidity of specimen, e.g., a thick wall

or beam

5. Carbonation of the concrete surface [10,53,57].

The rebound method is a rather imprecise test and does not provide a

reliable prediction of the strength of concrete.

98
5,29 Thermal Inspection Methods

Thermal inspection includes methods in which heat-sensing devices or

substances are used to detect irregular temperatures. Thermal inspection of

objects can be used to detect flaws and to detect undesirable distribution

of heat during service [14], There are several methods for carrying out

thermal inspections and many types of temperature measuring devices and

substances. The two main types of thermal inspection are thermography and

thermometry. Thermography involves mapping of isotherms, or contours of equal

temperature, over a test surface; while thermometry is the measurement of

temperature. Both of these methods can be conducted by means of contact and

noncontact inspections. The most commonly used materials or substances for

contact thermographic inspections are heat-sensitive paints, heat-sensitive

papers, thermal phosphors, and liquid crystals. Infrared detectors are used

for noncontact thermographic inspections. There are several basic thermal

detectors used for contact thermometric inspection and they include bolometers,

thermistors, thermocouples, and thermopiles. Surface temperature can be

measured by noncontact thermometric inspections using radiometers and

pyrometers or infrared thermometers.

The presence of discontinuities in an object, such as cracks, voids, or

inclusions, will change the heat transfer characteristics of the object. Thus,

if there is a transient heat flow condition, there will be nonuniform surface

temperatures. The pattern of the surface temperatures can be used as an

indirect indicator of subsurface anomalies [2]. Thermal inspection can also

detect anomalous operating characteristics of a system, such as overloaded

electrical wiring or heat loss through walls and roofs of buildings. The

following discussion addresses primarily the application of thermal inspection

99
to detect anomalies in the internal structure of test objects such as structural

metallic components and roofing systems.

Principle of Thermal Inspection

To establish the condition for thermal inspections, a temperature gradient

must exist or be created in the test object. If necessary, this can be done

by applying a temporary heat source to the front or back surface of the test

object. The flow of heat from the warm to the cold surface will be affected

by the material's thermal diffusivity, which is a function of the material's

thermal conductivity, density, and specific heat. If there are discontinuities

which have thermal dif fusivities different from that of the bulk, material,

local "hot" or "cold" spots will exist on the surfaces directly over the

location of the voids. Therefore, by measuring the pattern of surface

temperatures under heat flow conditions, subsurface flaws can be detected.

As stated above, surface temperatures can be determined by contact or

noncontact inspection methods. With contact methods, the surface is covered

with a temperature-sensitive material, and differences in surface temperature

are recorded as a pattern on the coating material. Examples of coatings

developed for this application are: heat sensitive paints and papers; phosphor

coatings for which the fluorescence, under ultraviolet light, is affected by

temperature; melting point coatings which melt when a specific temperature is

reached; and liquid crystals which change color as their temperatures vary.

Contact methods are generally not very sensitive, have relatively long response

times, and require an application procedure before thermal inspection.

Noncontact methods permit remote sensing of the thermal patterns, and are the

more popular thermal inspection methods.

100
5.29.1 Infrared Thermography

Principle of Method

An object having a'^temperature above absolute zero will radiate

electromagnetic waves. The wavelengths of the radiation fall within certain

bands, depending on the temperature. For example, at room temperature, the

wavelengths are typically from 4 to 40 micrometers, with a peak wavelength of

about 10 micrometers [2]. At very high temperatures, the wavelengths of the

emitted radiation are reduced to less than 1 micrometer and fall within the

visible spectrum, which explains why some metals give off a red color when

heated to high temperatures. The longer wavelength radiation associated with

room temperature is not visible to the eye. This is infrared radiation. By

using instruments that can detect infrared radiation, differences in surface

temperatures can be "seen." This is the basis of the thermal inspection

method known as infrared thermography.

The rate of radiant energy emission per unit area of surface (W) is given

by the Stef an-Boltzmann Law:

W=eaT^

where: T = the absolute temperature

e = the emissivity

a = the Stefan-Bolt zmann constant (5.67 x lO"!^ watt/cm2/°K^)

.

Thus, changes in the temperature of a surface produce more than proportional

changes in emitted energy, and this allows the testing equipment to detect

temperature differences as small as 0.2°C. Emissivity refers to the efficiency

of energy radiation by the surface. The maximum radiation efficiency occurs

in a "black body," and this is given an emissivity value of 1. All real

surfaces have an emissivity less than 1; polished metallic surfaces have low

emissivity, while roughly textured nonmetals have high emissivity. Since

101
detection methods are based on the intensity of emitted radiation, a change

in emissivity at various points on the surface may be incorrectly interpreted

as a change in temperature. Surfaces with nonuniform or low emissivity can

be painted with high emissivity coatings.

Remote Inspection

Infrared thermography permits remote inspection of the test object.

This is possible because air is practically transparent to the infrared

wavelengths associated with conditions near room temperature [28]. However,

high water content will reduce the transmission of infrared radiation through

air, so problems may arise when the weather is humid. Semiconductor

crystals are most often used to detect infrared radiation. Their electrical

properties are altered by incident infrared radiation. For best sensitivity,

the crystals should be kept cold with liquid nitrogen. This places some

limitations on the portability of the detection systems. Dewar flasks are

needed to hold the liquid nitrogen, and the nitrogen needs to be replaced as

it evaporates.

Infrared Scanners and Display

Operating on a scanning principle similar to television, infrared scanners

allow the user to view a picture of the test object's surface. Through a

system of special mirrors, the surface is scanned, a small spot at a time;

the intensity of radiation is measured by the detector and is displayed on a

cathode ray tube. The horizontal and vertical scans occur so quickly that a

picture (thermogram) of the surface is reconstructed on the cathode ray

tube. The picture is presented as shades of gray corresponding to variations

in surface temperatures of the viewed object. A calibration strip is also

102
shown so that the shades can be converted to absolute temperatures if desired.

It is also possible to have a color display showing different temperatures

in different colors.

Applications

Thermal inspection methods have been applied for detecting disbonds in

laminated materials, entrapped moisture, material density gradients, and

anomalies in castings [2]. In the construction area, infrared thermography

has been applied to compare thermal resistances of roofs, to detect water

penetration into built-up roofs, to detect heat loss through walls and roofs

of buildings, and to detect overloaded electrical circuits [28]. Infrared

thermography has also been used to detect deteriorated regions in bridge

decks [58].

Advantages

Thermal inspection equipment is generally portable, and a permanent record

(photograph) can be made of the inspection results. By using infrared

thermography, inspections can be performed without direct contact with the

surface, and large areas can be rapidly inspected.

Limitations

In determing the size and location of detectable flaws, it should be

recognized that under heat flow conditions the surface temperature patterns

will be a function of the type and size of the discontinuity, its distance

from the surface, the heat intensity applied or flowing to the surface of

the object, and the observation time [2]. The sensitivity of infrared

thermography in detecting internal flaws is a complex function of these

103
variables. Therefore, the results of such inspections should be carefully

interpreted.

5.29.2 Envelope Thermal Testing Unit

Principle and Applications

The envelope thermal testing unit consists of two blankets which are

attached to opposite sides of walls and through which the heat flux to opposite

wall surfaces can be controlled [5]. This testing unit was developed by the

Lawrence Berkeley Laboratory in order to evaluate the in situ transient

thermal performance of walls. It was designed to overcome some of the

difficulties in using heat flow meters and calorimeters for the in situ

evaluation of building components. The difference between the envelope

thermal testing unit and these techniques is that the heat flow is controlled

and not the temperature.

The slightly flexible blankets made to conform to slight irregularties

in wall surfaces are placed in direct thermal contact with the wall, thus

eliminating complications associated with air film and considerably reducing

the bulk of the unit. Each blanket consists of two large area electric

heaters separated by a low-thermal-mass insulating layer. An array of

temperature sensors is embedded in each heat layer. The electric heaters are

designed to provide heat output that is uniform over the entire area and the

heat output is controlled by adjusting the voltage applied to the heaters.

In calculating the thermal resistance of a wall, the data are analyzed in

the manner as the data obtained from heat flow meters and calorimeters.

104
Limitations

The envelope thermal testing unit has been used only for research purposes

and is considered as being under development. Only qualified technicians

experienced with this procedure and also having an understanding of the

fundamentals of building heat transfer should carry out this procedure.

5.29.3 Heat Flow Meter

Principle and Applications

A heat flow meter consists of a thin flat wafer, either circular or

rectangular in shape, that is comprised of a series of pairs of thermocouple

junctions [59]. The wafer contains an embedded thermopile which produces

a voltage (millivolt) signal that is proportional to the rate of heat flow

passing through the wafer. The sensitivity of a heat flow meter (millivolts

per Btu/h ft^) is a function of its average temperature. "In selecting a

heat flow meter for a particular application, it is Important that the heat

flow meter provide a signal sufficiently large for measurement and resolution

by the readout device at the lowest expected heat flow rate [5].

The thermal resistance of a building component can be measured by using

a heat flow meter spot-glued to a representative location on the interior

surface of the component, and temperature-sensing probes attached to the

inside and outside surfaces at the same location. After the heat flow meter

is bonded to the surface, it should be covered with the same or similar

coating used on other parts of the surface, so that the radiative exchange

between the monitored location and other surfaces in the room will be

comparable. The measured thermal resistance of the component is determined

by dividing the average difference in surface temperature, for a sufficient

105
period of time, by the average heat flow measured during the same time

interval. For accurately calibrated heat flow meters, this technique has

been shown to be accurate to within 6 percent [5], The thermal resistance

measurement is applicable only to the particular spot where the heat flow

meter is attached to the building component. However, when used with a

thermographic survey this technique becomes an effective tool for

assessing the thermal performance of building components.

Limitations

This technique can only be used during periods when there is no reversal

in direction of heat flow. Only qualified technicians should carry out this

procedure. They should be experienced with techniques for making proper lowlevel electrical measurements and also have an understanding of the fundamentals

of building heat transfer. If the thermal dynamic response of the building

component is to be determined, graduate level training in mathematics is

needed.

5.29.4 Portable Calorimeter

Principle and Applications

The portable calorimeter is essentially a guarded hot box and is used

for measuring in situ heat transmission through building components. It was

developed by the Building Research Division of the National Research Council

of Canada [5], The calorimeter is an insulated box having five sides; the open

side is sealed against the inside surface of the building envelope component

for which heat transmission tests are to be performed. The temperature inside

the box is kept equal to the indoor temperature of the building enclosure by

means of a thermostatically controlled electric heater. The electric

106
energy supplied to the electric heater is essentially equal to the heat

transmission through the metered area since the reverse heat loss through the

box and edge loss where the box edge contacts the metered surface are

essentially nulled to zero [5], This technique has the advantages that it

provides a minimum disturbance to the measured heat transmission and a

sufficiently large surface area is metered so that the measurements are

representative of the performance of a building component. It is reported

that the accuracy of the technique is about 5 percent [5].

Limitations

Calorimeter measurements should be conducted only during periods when

the outdoor to indoor temperature difference (AT) is greater than 10° F.

Solar heating of walls in the winter season may frequently produce AT less

than 10° F. During the measurement of heat transmission through building

components, the indoor temperature must be thermostatically controlled at a

constant level in order to minimize differences in temperature between the

calorimeter and the room. Also, solar radiation into the building and

conditioned air from a warm air supply must not be permitted to strike the

calorimeter. Only qualified technicians experienced with this technique and

also having an understanding of the fundamentals of building heat transfer

should carry out this procedure.

5.29.5 Spot Radiometer

Description of Method

Spot radiometers can be used to determine qualitatively whether a wall

or other building component is insulated or if insulation voids or other

thermal defects are present. They are hand-held devices used to

107
radiometrically measure the equivalent blackbody temperature of a relatively

small area of a surface [5], Spot radiometers are generally small, light

weight, and most are gun-shaped. They are calibrated by pointing them at a

surface of known temperature and adjusting a meter so that the device

radiometrically determines the correct temperature of the reference surface.

Manufacturers often provide reference surfaces having approximately black

body characteristics (i.e., reflecting little radiation from surrounding

surfaces) for calibration purposes. Interior surfaces of buildings generally

have emittances which range from about 0.80 to 0.95. Since the emittance of

an interior wall surface to be measured may differ from the reference surface,

the apparent surface temperature determined using a spot radiometer may

differ from the actual surface temperature by a small amount [5].

In using the spot radiometer, it is pointed at the surface for which

temperature is to be measured and the on-off trigger is depressed. The device

senses the total infrared radiation over a particular wavelength band emanating

from the surface, including both the self-emitted surface radiation and

reflected radiation from surrounding surfaces. The device is calibrated to

read the apparent radiance temperature on either a digital or meter display.

The apparent radiance temperature is defined as the temperature of a perfectly

black surface (emittance =1) which would radiate the same amount of thermal

radiation as the self-emitted and reflected radiation emanating from the

real surface at its actual temperature and having a surface emittance different

from unity. The devices generally have their principal spectral response

in the range of 10 microns, and a response time less than 2 seconds. Contact

with the surfaces to be measured is not necessary with these devices.

Operation close to a wall or building component will indicate apparent surface

108
temperature of a small region, while operation at a distance will indicate

apparent surface temperature for a larger region. Spot radiometers may be

equipped with an audio device that will produce a change in audible tone when

a thermal anomaly such as an air infiltration path or missing insulation is

found while scanning a wall or building component. Gross thermal defects can

be readily detected while quickly scanning the envelope of a building.

Limitations

This technique is not sensitive enough to permit detection of small

diffrences in effectiveness of insulation such as to distinguish an R-13 wall

from an R-15 wall.

5.30 Ultrasonic Pulse Methods

In the ultrasonic pulse methods, sound waves which are beyond the audible

range are induced in a test object by a piezoelectric transducer, and either

reflected waves or those passing through the object are detected by a similar

type of transducer [2,10,60-63]. When reflected waves are detected, the

technique is called "pulse-echo," and the transmitting transducer may also

act as the receiver. Waves passing through the object are detected with a

second transducer, i.e., a receiving transducer.

Ultrasonic inspection is based on two principles: (1) the velocity of

the acoustic waves in a material is a function of that material's elastic

constants and density; and (2) when an acoustic wave encounters an interface

between dissimilar materials, a portion of the wave is reflected. The amount

of reflection depends on the mismatch in acoustic impedance (product of wave

velocity and density) of the materials, with the amount of reflection increasing

with the mismatch.

109
5.30.1 Ultrasonic Pulse Velocity

The ultrasonic pulse velocity method is one of the most universally used

NDE methods for assessing the quality of concrete.

Principle of Method

The ultrasonic pulse velocity method measures the travel time of an

ultrasonic pulse passing through a material. The pulse generated by an

electroacoustic transducer is picked up by a receiver transducer and in some

cases the pulse may be amplified. The time of travel of the pulse is

measured electronically [63].

When a mechanical pulse is applied to a material by an electroacoustic

transducer, waves are induced in the material. Longitudinal waves are used

most often in testing concrete. These waves are transmitted by particles

vibrating parallel to the direction of propagation. The waves' velocity,

controlled by the elastic properties and the density of the material, is

virtually independent of the geometry of the object being tested.

If a longitudinal wave encounters a discontinuity such as crack or void,

it may "bend," i.e., be diffracted around the discontinuity. This increases

the internal distance the wave must pass between the transmitting and pickup

transducers, and consequently its travel time increases. The travel time of

a longitudinal wave will also be affected by changes in density and elastic

properties of a given concrete along the travel path.

Several ultrasonic pulse velocity units are commercially available for

testing concrete; these cost about $4000. Some models can be used to test

concrete as thick as 75 ft (30 m)

.

110
Application for Assessment of Condition of Concrete

The ultrasonic pulse velocity method Is best for nondestructive evaluation

of the uniformity of in-place concrete. (ASTM Standard C 597 gives the

standard test procedure, see Appendix D). For example, velocity measurements

have been successfully used to detect deteriorated regions In concrete bridges

and to check the uniformity of concrete in walls. In general, if substantial

variations in pulse velocities are found in a structure, without any apparent

reason (such as intentional changes in materials, concrete mix, or construction

procedures), this indicates that the concrete is unsound.

A general rating which has been proposed to assess the relative quality

of concrete is presented in Table 15 [64]. These criteria should be used with

caution because differences in the qualities of concrete cannot be as sharply

delineated as indicated in Table 15. In addition, velocity is affected by

the density and amount of aggregate in the concrete. A crude assessment of

the quality of similar types of concrete can be made, however, using these

criteria. For example, if one concrete has a pulse velocity of 15,000 ft/sec

(4570 m/sec) , while another concrete with a similar composition has a velocity

below 10,000 ft/sec (3050 m/sec), then there is clearly a significant difference

in their qualities.

Table 15

Pulse Velocities in Concrete [64]

Feet per Second (Meters per Second)

Above 15,000

12,000-15,000

10,000-12,000

7,000-10,000

Below 7,000

(4570)

(3660-4570)

(3050-4570)

(2130-3050)

(2130)

General Condition

Excellent

Good

Questionable

Poor

Very Poor

111
Estimation of Strength Properties of Concrete

Many investigations have attempted to correlate compressive and flexural

strengths of concrete with pulse velocity [63]. Some correlations have been

obtained in laboratory studies, provided that mix proportions, the cement,

types of aggregate, and curing conditions were not varied. If these factors

were altered, however, no usable correlations were obtained. For example,

Parker [65] compared pulse velocities and compressive strengths for concretes

made from only one type of aggregate, but containing different cements from

different sources and a variety of admixtures. His analysis of the data

indicates that at the 95 percent confidence level the estimated strength of

4440 psi (30.7 MPa) concrete ranged from about 2100 to 6000 psi (14.5 to 41.8

MPa). Obviously, the ultrasonic pulse method cannot be used to obtain reliable

estimates of compressive strength when the composition of concrete in a

structure is unknown.

Jones has offered these concluding remarks regarding strength

prediction from wave propagation methods: "In spite of some of the promising

results of the early investigations, it must be concluded that no general

relation has been found between the dynamic modulus of elasticity and its

flexural or compressive strength" [66]. This statement still holds if one

substitutes "pulse velocity" for "dynamic modulus of elasticity."

Extraneous Effects on Velocity Measurements

The measurement of the pulse velocity of concrete is affected by several

factors which are not intrinsic properties of concrete, and, therefore, are

not a function of the quality or strength of concrete [10], These factors include:

112
1, Smoothness of concrete at transducer contact area. Good acoustical

contact between the transducers and concrete is required. In addition, a

coupling agent such as an oil or a jelly must be used.

2. Concrete temperatures outside the range between Al° and 86°F (5° and

30° C) affect the measured pulse velocity. Below this temperature range, the

velocity is increased, and above, the velocity is decreased.

3. Moisture condition of concrete. Pulse velocity generally increases as

the moisture content of concrete increases, while compressive strength decreases

as moisture content increases.

4, Presence of reinforcing steel. The pulse velocity in steel is 1.2 to

1.9 times the velocity in concrete. Measurements made near steel reinforcing

bars, therefore, may not be representative of the concrete. If possible,

measurements should be made perpendicular to the longitudinal axis of the bars.

If measurements must be made parallel to the longitudinal axis of the steel

bars, crude correction factors are available.

5.30.2 Ultrasonic Pulse Echo

Principle of Method

In the ultrasonic pulse echo method, waves which are reflected off

discontinuities (e.g., cracks and voids) and from interfaces (e.g., those

between concrete and steel or between concrete and air) are recorded. Both

the transmitting and receiving transducers are contained in the same probe;

thus, only waves which are reflected back at nearly 180 degrees are detected.

The penetrating ability of the ultrasonic pulse and the minimum size of

detectable flaws are influenced by the frequency of the generated waves. High

frequency results in less penetration but better sensitivity than low frequency.

113
Applications

Echo techniques have been extensively used to identify and locate

discontinuities and defects in metals and welds [2,60-62]. The echo technique

is one of the most versatile and accepted NDE methods for metals. However, it

has not been used often with concrete — largely because the extensive pore

system, the presence of cracking, and the heterogeneous nature of concrete

cause multiple reflections when very high frequency pulses are used. Therefore,

the reflected waves are significantly attenuated and the interpretation of the

observations complicated. As noted, the heterogeneous nature of concrete poses

problems not encountered in pulse-echo evaluation of metals, thus, progress

in this area of concrete nondestructive testing has been slow. A review of

research indicates that the pulse-echo method has been used successfully to

detect flaws within concrete, however, standardized methods do not currently

exist for pulse-echo evaluation of concrete structures [67]. Pulse-echo

methods have been used for detection of very large cracks in dams, for

integrity testing of piles and other slender concrete structures, and for

measuring the thickness of slabs and pavement. In addition, it may be possible

to combine the echo method with acoustic impact (see Acoustic Impact Method,

Section 5.2) so that low frequency waves are generated. These would be

insensitive to microscopic flaws but could be used to detect large

discontinuities [68]. Commercial equipment is not yet available for such

testing.

Advantages

Ultrasonic pulse-echo inspection offers several advantages over other NDE

methods — such as gamma radiography — capable of detecting internal flaws in

114
a test object [2]. For example, acoustic waves have excellent penetrating

ability, and with proper Instrument selection, thick sections of 30 ft (10

m) or more can be inspected. Very small flaws may be detected, and their

location and geometry estimated with reasonable accuracy. In addition, test

results are immediately available and the equipment is lightweight and

portable.

Limitations

Because of the indirect nature of flaw detection by ultrasonic pulse-echo

inspection, personnel with a high level of expertise are needed to plan an

inspection program. A thorough understanding of the nature of the interactions

between the acoustic waves and different discontinuities is required in order

to interpret test results properly. The physical testing, on the other hand,

may be performed by technicians after proper training. Before ultrasonic

inspection equipment can be used, calibration and referencing with standards

must be performed; otherwise, test results have no meaning. The nature of the

calibrations will depend on the particular inspection program.

5.31 Uplift Resistance

Description of Method

The resistance of built-up roofing systems to uplift pressure can be

determined using the ASTM Standard E 907 test method (Appendix D) . A controlled

negative pressure is created on top of the roof surface using a chamber, 5 x 5 ft

(1.5 x 1.5 m) in area, fitted with a vacuum pump and a pressure measuring device.

Provisions must be made to provide a smooth surface along the roof to allow the

edges of the chamber to be in complete contact with the roof surface so that a

negative pressure can be applied inside the chamber. For roofs containing mineral

115
aggregate surfacing, the loose surfacing should be removed by sweeping a path

about 12 in. (300 mm) wide and applying a heavy pouring of hot asphalt over

the swept area. When the asphalt cools it will provide the smooth surface

necessary for contact with the chamber. The bottom flanges of the chamber are

equipped with a foam strip to seal the chamber to the roof surface. The chamber

is oriented on the roof so that the edges are parallel with the direction of

the structural framing of the building.

The negative pressure is applied in increments and the deflection is

continuously monitored during the test for sudden or variable rates of movement.

The predetermined increments of pressure are held for 1 minute and further

increments are applied until a preselected negative pressure is reached or

failure (adhesion or cohesion) occurs. Most roof systems subjected to a

negative pressure will exhibit an upward deflection that will increase with an

increase in negative pressure. Poorly adhered roofing systems will exhibit

relatively large increases in upward defections with relatively small

increases in applied pressure. For well adhered roofing systems the increase

in deflection will be gradual and at a relatively constant rate up to a point

at or near failure.

5.32 Visual Inspection

Surface defects often can be detected visually using methods to improve

ordinary observations. Optical magnification or other techniques which can be

used to increase the apparent size of surface cracks are covered in this section.

5.32.1 Optical Magnification

Available magnifying instruments range from simple, inexpensive glasses

to expensive microscopes. Some fundamental principles about the operating

116
characteristics of magnification instruments should be understood before a

system is chosen for a particular application. For example, the focal length

decreases as the magnification power increases. This means that when high

magnification is desired, the primary lens must be placed close to the test

object. The field of view (the portion of the object that can be seen at any

instant) also decreases as magnification power increases. A small field of

view means that it will be tedious to examine a large surface area. Another

important characteristic is the depth of field — the elevation difference of

rough textured surfaces that can be viewed in focus simultaneously; the depth

of field decreases as the magnification power of the instrument increases.

Therefore, to inspect a rough-textured surface, a magnification power should be

selected that gives a large enough depth of field so that the "hills" and

"valleys" are simultaneously in focus. Finally, the illumination intensity

required to clearly see surface flaws will increase as the magnification power

increases. High magnification may require a light source to supplement

the available lighting.

A useful tool for field inspection is a pocket magnifier with a built-in

viewing scale, which allows measurement of flaw dimensions. A stereomicroscope

is very useful when a three-dimensional view of the surface is required. With

this instrument, one can determine whether a wide crack is shallow or extends

deep into the object. If calibrated, a stereomicroscope can also be used as a

depth gage to measure the approximate height of surface irregularities.

5.32.2 Fiberscope

Another useful instrument is the fiberscope, which is composed of a bundle

of flexible optical fibers and lens systems. The fiberscope can be inserted

117
through a small access hole so that the inside of a cavity can be seen. Some

of the fibers in the bundle carry light into the cavity and illuminate the

field of view. The viewing head can be rotated so that a wide viewing angle

is possible from a single access hole. A fiberscope, because of the discrete

nature of light transmission of the fibers, may not have as good resolution

as a borescope, which is straight, rigid tube using a lens system for

viewing. The best resolution is obtained with an instrument having smalldiameter fibers in which the fiber density per unit area is high. To use a

fiberscope, one must drill access holes if natural channels are not present,

and the hole must intercept cavities. The acoustic impact technique

(Section 5.2) can be used to locate hollow spots for subsequent fiberscope

inspection.

5.32.3 Liquid Penetrant Inspection

In this method a highly visible dye is used to coat the surface to be

inspected [2,69]. Any cracks open to the surface will soak up the dye because

of low surface tension and capillary effects. After application of the dye,

the surface is cleaned. However, the dye which penetrated into cracks remains

and reveals the presence of cracks. The method is one of the most inexpensive

inspection tools, but it only permits detection of open flaws on the surface of

the test object.

Description of Method

Dye penetrant inspection involves the following steps: (1) cleaning

the surface, (2) applying the dye, (3) removing excess dye from the surface,

(A) applying a developer, and (5) interpreting the results.

118
The objective of the cleaning is to remove foreign matter from cracks so

that the dye can penetrate. The specific procedures depend on the condition

of the surface. Care must be taken to ensure that the cleaning process does

not smear the cracks or fill them with residues. For example, sandblasting a

soft metal may "hammer" the surface so much that cracks become closed and

undetectable.

The dye may be applied to the surface by spraying, painting, or dipping.

Two types of dye are available: one is for viewing under ordinary light and is

usually a brilliant red color, the other is fluorescent and viewed under

ultraviolet light. Fluorescent dyes offer the best sensitivity for detecting

small cracks. The dye is allowed to remain on the surface from 10 to 30 minutes

(dwell time) before the excess is removed.

Cleaning can be done by flushing the surface with water or by wiping with

a rag dampened with solvent. An emulsifying agent is needed so that the dye

can be completely removed with water. The agent is either already included in

the dye, or it is added to the coated surface before washing. This phase is

very important; all excess dye must be removed, otherwise some indications of

cracks will be false. If the surface is very porous, inspection by this method

may be difficult; if dye is not removed from the pores, there will be a loss

of contrast because the surface will take on a color that is a light shade of

the dye. If the dye is removed from all pores, it probably will be removed

from some of the cracks as well.

After cleaning, the surface is allowed to dry, and a developer is added.

Developer is a fine powder which: (1) provides a uniform, colored background

to increase contrast, and (2) has a blotting effect, thereby drawing up the

dye from the cracks. The blotting action increases the apparent width of the

119
cracks so that they are clearly visible. Developer can be applied as a dry

powder or as a paint. The thickness of the developer layer is important; if it

is too thin, there will not be good contrast, and if it is too thick, it may

mask the cracks.

Finally, the prepared surface is inspected. If the application was done

correctly, the cracks will be clearly shown.

However, the inspector needs to be familiar with the patterns associated

with "irrelevant indications," i.e., patterns not from cracks but from other

sources, such as improper cleaning.

Applications and Limitations

Although dye penetrant inspection relies on simple principles, a certain

amount of skill is necessary to carry out do the process correctly. The

operator needs to recognize what materials to use for a particular application,

and to understand how the materials respond to different temperature conditions.

Portable kits are available with the various chemicals in aerosol cans, thus

making field inspection possible. The technology is now geared primarily

toward inspection of metals. The applicability of the procedures to masonry

or concrete structures having surfaces of high porosity has not been demonstrated,

5.33 Water Permeability of Coated Masonry Walls

Principle and Applications

The transmission of water through coated masonry walls is proportional to

the number of "pin holes" in the coating. The exterior coating and its

application are the most significant variables in preventing excessive

permeation into the masonry. A reservoir, about 7 in^ (12 x 10^ mm^)

,

with an open face is sealed to the masonry and kept pressed against the wall

120
by a spring which is stretched between two hooks that are secured to the masonry

wall. The reservoir is filled with water and the water is allowed to permeate the

wall for 15 minutes or the time required to absorb 25 ml of water. The water

absorbed by the wall is determined from a burette connected to the reservoir.

From a measurement of the diameter of the reservoir, the rate of water absorption

can be expressed in gallons per square foot per hour. When the rate of water

disappearance from the reservoir is less than 1 gal/ft^/h there are no damaging

effects. In order to provide a margin of safety, a limit of 1/2 gal/ft^/h was

established [70]. A properly coated masonry surface will have a water transmission

rate of about one-tenth that amount.

5.34 Combinations of Nondestructive Evaluation Methods

While no single NDE method may be entirely satisfactory for predicting the

strength or quality of material, combinations of methods which respond to

different factors may give more definite information. The combined NDE approach

has been developed mainly for evaluating concrete; therefore, only applications

to concrete will be described.

The results of two methods can be combined in a linear equation of the

form:

f^ = A(NDEp + B(NDE2) + C

where f is the estimated compressive strength from the combined method, NDEi

and NDE2 are the results of the individual methods, and A, B, and C are

empirically determined constants.

Two combinations often used are the ultrasonic pulse velocity method and

the measurement of the damping constant of concrete [71], and the ultrasonic pulse

121
velocity and pulse attenuation methods [72]. These combinations are essentially

laboratory research techniques and therefore will not be discussed further.

The most popular combination has been the ultrasonic pulse velocity method

and the rebound hammer [73]. This combination has been used primarily in Europe,

with the most exhaustive studies being carried out by Facaoaru [74-77]. In this

combined approach, measurements of ultrasonic pulse velocity and rebound

number are made on in situ concrete. The pulse velocity and rebound number are

substituted into a previously derived regression equation to predict compressive

strength. It is generally believed that the multiple regression equation

should give a more accurate estimate of compressive strength than either

of the individual measurements alone.

For standard concrete mixes, Facaoaru has developed calibration charts

from which the compressive strengths can be estimated when the pulse velocities

and rebound numbers are known [74]. Correction factors have also been developed

to be used in the case of nonstandard concrete mixes. This combined method has

been used often in Romania to estimate the compressive strength of in situ

concrete [74,76]. Based on his experiences, Facaoaru contends that the combined

method offers the following accuracy in predictions of compressive strengths:

1. When composition is known and test specimens or cores are available

for calibration purposes, accuracy is within 10 to 15 percent.

2. When only the composition of the concrete is known, accuracy is within

15 to 20 percent.

3. When neither the composition is known nor test specimens or cores are available, accuracy is within 20 to 30 percent [76],

This suggests that for case 3, the combined method gives no better prediction

of the compressive strength than can be obtained by measuring only the ultrasonic

pulse velocity or only the rebound number; in case 2, the improvement is marginal.

122

I
Therefore, only when the concrete is well characterized is this combined method

better than the individual nondestructive methods.

123
6 . SUMMARY

Nondestructive evaluation (NDE) methods for evaluating In situ

construction materials and condition assessment of building components and

systems were Identified and described. This report Is Intended to help

Inspectors and those Involved In condition assessment choose appropriate NDE

methods for specific building materials, components, and systems. Important

properties of building materials along with Important performance requirements

for building components are listed, and appropriate NDE methods for determining

these properties are recommended. In many cases the advantages and limitations

for the NDE methods are presented. Potential NDE methods which may or may

not require further research and development before they are ready for routine

use were also identified and briefly described. In addition, ASTM standards

for NDE methods for concrete and other building materials and components were

identified.

In a related aspect of the study, current Navy practices relative to the

use of NDE methods in the construction and service cycle of buildings and

other structures were reviewed. This review was based on Navy reports and

documents provided by the Naval Civil Engineering Laboratory (NCEL) and the

Naval Facilities Engineering Command (NAVFAC), and on discussions with NAVFAC

personnel involved with buildings and structures problems where NDE methods

are used for diagnostic purposes. Navy Guide Specifications were examined

for required tests, both NDE and destructive, of in situ building materials

and components. Twenty nine of the 239 Guide Specifications reviewed contained

required NDE tests.

124
7 . ACKNOWLEDGMENTS

This study was sponsored by the Naval Civil Engineering Laboratory

(NCEL) , Port Hueneme California, and the Naval Facilities Engineering Command

(NAVFAC). The authors appreciate the support and assistance of Joseph Berke

(NCEL) and Melvin Hironaka (NCEL) who provided liaison between NCEL and

NBS. The authors also thank their NBS colleagues, James Pielert , Walter

Rossiter, and Leonard Mordfin who gave important review comments on this

report. The authors acknowledge the excellent and extensive support of

Denise Herbert for typing the manuscript.

125
8. REFERENCES

1. Clifton, James R. , Carino, Nicholas J., and Howdyshell, " In-Place

Nondestructive Evaluation Methods for Quality Assurance of Building

Materials," U.S. Army Corps of Engineers Construction Research Laboratory

Technical Report M-305 (1982).

2. Metals Handbook, Vol. 11, "Nondestructive Inspection and Quality Control,"

8th Edition, American Society of Metals (1976).

3. Botsco, R.J. , "Specialized NDT Methods," Lesson 12, Fundamentals of

Nondestructive Testing, Metals Engineering Institute (1977).

4. ASHRAE Handbook and Products Directory, 1977 Fundamentals, American

Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

(1977).

5. Grot, Richard A., Silberstein, Samuel, Burch, Douglas M. , and Galowin,

Lawrence S., "Measurement Methods for Evaluation of Thermal Integrity of

Building Envelopes," National Bureau of Standards (U.S.), NBSIR 82-2605

(November 1982).

6. Kasai, Yoshio, Matsui, Isamu, and Nagano, Motoshi, "On site Rapid Air

Permeability Test for Concrete, SP 82-26, American Concrete Institute

(ACI) SP-82 (1984), In Situ/Nondestructive Testing for Concrete, V.M.

Malhotra, Editor, pp. 525-541.

7. Carlsson, M. , Eeg, I.R. , and Jahren, P., "Field Experience in the Use

of the Break-Off Tester," SP 82-14, American Concrete Institute (ACI)

SP-82 (1984), In Situ/Nondestructive Testing of Concrete, V.M. Malhotra,

Editor, pp. 277-292.

8. Dahl-Jorgensen, Einar and Johansen, Randulf, "General and Specialized

Use of the Break-Off Concrete Strength Testing Method," SP 82-15,

American Concrete Institute (ACI) SP-82 (1984), In Situ/Nondestructive

Testing of Concrete, V.M. Malhotra, Editor, pp. 293-308.

9. Test Method for Pullout Strength of Hardened Concrete, American Society

for Testing and Materials (ASTM), C 900-82 (1982).

10. Malhotra, V.M., "Testing Hardened Concrete: Nondestructive Methods,"

American Concrete Institute (ACI) Monograph No, 9 (1976).

11. Richards, 0., "Pullout Strength of Concrete in Reproducibility and

Accuracy of Mechanical Testing," American Society for Testing and

Materials (ASTM), STP-626 (1977), pp. 32-40.

12. Milhot, G. , Bisaillon, A., Carette, G.G., and Malhotra, V.M.

,

" In-Place Concrete Strength: New Pullout Methods," Journal of the

American Concrete Institute, Vol. 76 (1979), pp. 1267-1282.

126
13. Clear, K.C. and Hay, R.E., "Time-to-Corroslon of Reinforcing Steel In

Concretes," Vol. 1; Effects of Mix Design and Construction Parameters,

Federal Highway Administration Report No. FHWA-RD073-32 (1973).

14. Metals Handbook Desk Edition, Edited by Howard E. Boyer and Timothy L. Gall,

American Society for Metals, Chapter 33, Nondestructive Testing (1985).

15. McGonnagle, W.J. , Nondestructive Testing, Gordon and Breach (1969),

16. Dunn, F.W. , "Magnetic Particle Inspection Fundamentals," Lesson 3,

Fundamentals of Nondestructive Testing, Metals Engineering Institute

(1977).

17. Betz, C.E. , "Magnetic Particle Inspection Applications," Lesson 4,

Fundamentals of Nondestructive Testing, Metals Engineering Institute

(1977).

18. Uomoto, Taketo and Kobayashi, Kazusuke, "In Situ Test to Determine Fiber

Content of Steel Fiber Reinforced Concrete by an Electro-Magnetic

Method," SP 82-34, American Concrete Institute (ACI) SP-82 (1984), In

Situ/Nondestructive Testing of Concrete, V.M. Malhotra, Editor,

pp. 673-688.

19. Sevall, G.W. , "Nondestructive Testing of Construction Materials and

Operations," U.S. Army Corps of Engineers Construction Engineering

Research Laboratory Technical Report M^67/AD774847 (1973).

20. Gerhards, Charles C. , "Longitudinal Stress Waves for Lumber Stress

Grading: Factors Affecting Applications: State of the Art,"

Forest Products Journal, Vol. 32, No. 2 (February 1982).

21. Gerhards, Charles C. , "Comparison of Two Nondestructive Instruments

for Measuring Pulse Transit Time in Wood," Wood Service, Vol. 11,

No. 1 (July 1978).

22. Saul, A.G.A., "Principles Underlying the Steam Curing of Concrete,"

Magazine of Concrete Research, Vol. 1, No. 2 (January 1949),

pp. 21-28.

23. Plowman, J.M., "Maturity and the Strength of Concrete Research,"

Magazine of Concrete Research," Vol. 8, No. 22 (1956), p. 13.

24. Lew, H.S. and Reichard, T.W. , "Prediction of Strength of Concrete from

Maturity in Accelerated Strength Testing," SP 56, American Concrete

Institute, 1978.

25. Carino, N.J., "Temperature Effects on the Strength-Maturity Relations

of Mortar," National Bureau of Standards (U.S.), NBSIR 81-2244

(October 1980).

127
26. ACI Committee Report 306R-78, "Cold Weather Concreting," American

Concrete Institute (Revised 1983).

27. Bushing, H. , Mathey, R. , Rossiter, W. , and Cullen, W. , "Effects of

Moisture in Built-Up Roofing — A State-of-the-Art Literature Survey,"

National Bureau of Standards (U.S.), Technical Note 975 (July 1978).

28. Jenkins, David R. , Mathey, Robert G. , and Knab, Lawrence I., "Moisture

Detection in Roofing by Nondestructive Means - A State-of-the-Art Survey,

National Bureau of Standards (U.S.), Technical Note 1146 (July 1981).

29. Boot, A., and Watson, A., "Applications of Centimetric Radiowaves in

Nondestructive Testing, in Application of Advanced and Nuclear Physics

to Testing Materials," American Society for Testing and Materials,

STP-373 (1965), pp. 3-24.

30. Kass, Andrew J., "Middle Ordinate Method Measures Stiffness Variation

within Pieces of Lumber," Forest Products Journal, Vol. 25, No. 3

(March 1975).

31. Knab, L. , Mathey, R. , and Jenkins, D. , "Laboratory Evaluation of

Nondestructive Method to Measure Moisture in Built-Up Roofing

Systems," National Bureau of Standards (U.S.), Building Science Series

131 (January 1981).

32. Tobiasson, Wayne and Korhonen, Charles, "Roof Moisture Surveys:

Yesterday, Today and Tomorrow," Proceedings NBS/NRCA/RILEM Second

International Symposium on Roofing Technology, 18-20 September 1985,

pp. 438-443, available from U.S. National Roofing Contractors

Association, Chicago, IL.

33. Tobiasson, Wayne and Korhonen, Charles, "Summary of Corps of Engineers

Research on Roof Moisture Detection and the Thermal Resistance of Wet

Insulation," Special Report 78-29, U.S. Army Cold Regions Research

and Engineering Laboratory (1978).

34. Steel Structures Painting Manual, Vol. 1, Good Painting Practice,

Second Edition, Senior Editor John D, Keane, Steel Structures Painting

Council (1982).

35. Hess's Paint Film Defects, Their Causes and Care, Third Edition, Edited

and Revised by H.R. Hamburg and W.M. Morgans, Chapman and Hall

Publishers, London (1979), Distributed in the U.S.A. by Halsted Press.

36. Robins, P.J., "The Point-Load Test for Tensile Strength Estimation

of Plain and Fibrous Concrete," SP 82-16, American Concrete Institute

(ACI) SP-82 (1984), In Situ/Nondestructive Testing of Concrete,

V.M. Malhotra, Editor, pp. 309-325.

128
37. Arni, H.T., "Impact and Penetration Resistance Tests of Portland

Cement Concrete," Federal Highway Administration (U.S.), Report No.

FHWA-RD-73-5 (1972).

38. Long, A.E. and Murray, A. McC. , "The Pull-Off Partially Destructive

Test for Concrete," SP 82-17, American Concrete Institute (ACI)

SP-82 (1984), In Situ/Nondestructive Testing of Concrete,

V.M. Malhotra, Editor, pp. 327-349.

39. Cantor, T.R. , "Review of Penetrating Radar as Applied to Nondestructive

Evaluation of Concrete," SP 82-29, American Concrete Institute (ACI)

SP-82 (1984), In Situ/Nondestructive Testing of Concrete, V.M. Malhotra,

Editor, pp. 581-601.

40. Malhotra, V.M., "In Situ/Nondestructive Testing of Concrete - A Global

Review," SP 82-1, American Concrete Institute (ACI) SP-82 (1984),

In Situ/Nondestructive Testing of Concrete, V.M. Malhotra, Editor,

pp. 1-16.

41. Aman, J.K., Carney, CM., McBride, D. , and Turner, R.E., "Radiographic

Fundamentals," Lesson 8, Fundamentals of Nondestructive Testing, Metals

Engineering Institute (1977).

42. McBride, D. , Carney, CM., Turner, R.E., and Lomerson, E.O. , "Fundamentals of Radiography," Lesson 9, Fundamentals of Nondestructive

Testing, Metals Engineering Institute (1977).

43. Forrester, J. A., "Gamma Radiography of Concrete," Proceedings of

Symposium on Nondestructive Testing of Concrete and Timber, Session No. 2,

London: Institute of Civil Engineers (1969), pp. 9-13.

44. Nondestructive Testing Handbook, Second Edition, Vol. 3, Radiography

and Radiation Testing, Lawrence E. Bryant Technical Editor, Paul

Mclntire Editor, American Society for Nondestructive Testing (1985).

45. Yokel, Felix Y. and Mayne, Paul W. , "Helical Probe Tests for Shallow

Exploration," National Bureau of Standards (U.S.), NBSIR 86-3351 (1986).

46. Shore, A.T. , "Properties of Hardness in Metals and Materials,"

Proceedings of the American Society for Testing andd Materials,

Vol. 9 (1911), p. 733.

47. Schmidt, E. , "A Nondestructive Concrete Test, Concrete," Proceedings

of the American Society for Testing and Materials, Vol. 59, No. 8

(1951), p. 34.

48. Clifton, J.R. , "Nondestructive Test to Determine Concrete Strength — A Status Report," National Bureau of Standards (U.S.),

NBSIR 75-729 (1975).

129
49. Peterson, P.H. and Stoll, V.W. , "Relation of Rebound Hannner Test Results

to Sonic Modulus and Compressive - Strength Data," Proceedings of the

Highway Research Board, Vol. 34 (1955), p. 387.

50. Boundy, C. and Hondrus , G. , "Rapid Field Assessment of Strength of

Concrete by Accelerated Curing and Schmidt Rebound Hammer," Journal

of the American Concrete Institute, Vol. 61, No. 1 (1964), p. 1,

51. Victor, D.J., "Evaluation of Hardened Field Concrete with Rebound

Hammer," Indian Concrete Journal, Vol. 37, No. 11 (1963), p. 407.

52. Greene, G.W. , "Test Hammer Provides New Methods for Evaluating

Hardened Concrete," Journal of the American Concrete Institute,"

Vol. 26, No. 3 (1954), p. 249.

53. "Discussion of G.W. Green, "Test Hammer Provides New Method of

Evaluating Hardened Concrete," Journal of the American Concrete

Institute, Vol. 27, No. 4 (1955), p. 256.

54. Mitchel, L.J. and Hoagland, G.G., "Investigation of the Impact-Type

Concrete Test Hammer," Highway Research Board Bulletin 305 (1961),

p. 14.

55. Williams, C.H. , "Investigation of the Schmidt Concrete Test Hammer,"

Miscellaneous Report No. 6-267, U.S. Army Engineering Waterways

Experiment Station (1958).

56. Klieger, P., Discussion of P.H. Peterson and V.M. Stoll, "Relation

of Rebound Hammer Test Results to Sonic Modulus and CompresslveStrength Data," Proceedings of Highway Research Board, Vol. 34

(1955), p. 392.

57. Erickson, G.A. , "Investigation of the Impact-Type Concrete Test

Hammer, Model II," Concrete Laboratory Report C-928, Division of

Engineering Laboratories, Dept. of Interior (U.S.) (1959).

58. Manning, D.G. and Holt, F.B., "Detecting Delamination in Concrete

Bridge Decks," Concrete International, Vol. 2, No. 11 (1980),

pp. 34-41.

59. Grot, Richard A., Persily, Andrew K. , Chang, May Y. , Fang, Jin B.,

Weber, Stephen, and Galowin, Lawrence S. , "Evaluation of the Thermal

Integrity of the Building Envelopes of Eight Federal Office Buildings,"

National Bureau of Standards (U.S.), NBSIR 85-3147 (September 1985).

60. Smith, A.L. , "Ultrasonic Testing Fundamentals," Lesson 5, Fundamentals

of Nondestructive Testing, Metals Engineering Institute (1977).

61. Lovelace, J.F. , "Ultrasonic Testing Equipment," Lesson 6, Fundamentals

of Nondestructive Testing, Metals Engineering Institute (1977).

130
62, Moberg, A.J. , "Ultrasonic Testing Applications," Lesson 7, Fundamentals

of Nondestructive Testing, Metals Engineering Institute (1977).

63, Whltehurst, E.A., "Evaluation of Concrete Properties from Sonic Tests,"

American Concrete Institute, Monograph No. 2 (1966),

64, Leslie, J,R, and Cheesman, W.J. , "An Ultransonlc Method fo Studying

Deterioration and Cracking In Concrete Structures," Journal of the

American Concrete Institute, Vol. 21, No. 1 (19A9), Proceedings,

Vol. 46, pp. 17-36,

65, Parker, W.E,, "Pulse Velocity Testing of Concrete," Proceedings of the

American Society for Materials and Testing, Vol, 53 (1953), p. 1033.

66, Jones, R, , "Nondestructive Testing of Concrete," Cambridge University

Press (1962),

67, Carlno, N.J, and Sanalone, M, , "Pulse-Echo Methods for Flaw Detection

in Concrete," National Bureau of Standards (U,S.), Technical Note 1199

(July 1984).

68, Sansalone, Mary and Carlno, Nicholas J., "Transient Impact Response

of Plates Containing Flaws," Journal of Research of the National

Bureau of Standards (U,S.), Vol. 92, No. 6 (November-December 1987),

pp. 369-381,

69, Lomerson, E.G., "Liquid Penetrants," Lesson 2, Fundamentals of

Nondestructive Testing, Metals Engineering Institute (1977).

70, Naval Civil Engineering Laboratory Techdata Sheet 75-31, "Measuring

Water Permeability of Masonry Walls," Port Hueneme, G (December 1975).

71, Wiebenga, J.G. , "A Comparison Between Various Combined Nondestructive

Testing Methods to Derive the Compressive Strength of Concrete,"

Report No. Bl-68-61/ IHI.8 , In Situ TNG Voor Bouwmaterlalen en Bouw Constructies, Delft, Netherlands (1968).

72, Galan, A., "Estimate of Concrete Strength by Ultrasonic Pulse Velocity

and Damping Constant," Journal of the American Concrete Institute,

Vol, 64, No. 10 (1967), p. 678.

73, Jones, R. and Facaoaru, I., "Analysis of Answers to a Questionnaire on the Ultrasonic Pulse Technique," Materlaux et Constructions/Materials

and Structures, Vol. 1, No. 5 (1968), p. 457.

74, Facaoaru, I,, "Nondestructive Testing of Concrete in Romania," Paper

4C, Symposium on Nondestructive Testing of Concrete and Timber, London,

Institution of Civil Engineers (1969).

131
75. Facaoaru, I., Dumitrescu, I. and Constaninescu, L. , "Concrete Strength

Determination by Nondestructive Combined Methods," RILEM Report, Aachen,

41 (1966).

76. Facaoaru, I., Dumitrescu, I. and Stamate, G.L. , "New Developments and

Experience in Applying Combined Nondestructive Methods for Testing

Concrete, RILEM Report, Varna, 26 (1968).

77. Facaoaru, I., "Chairman's Report of the RILEM Committee on Nondestructive

Testing of Concrete," Materiaux et Constructions/Materials and

Structures, Vol. 2, No. 10 (1969), p. 253.

132
APPENDIX A. REVIEW OF NAVY GUIDE SPECIFICATIONS

The Navy Guide Specifications that were reviewed with regard to NDE in situ

tests of building materials and components are listed in Table A.

Twenty nine of the 239 Navy Guide Specifications listed in this table

contained required NDE tests. The twenty-nine Guide Specifications along with

the NDE tests required for each specification are given in Appendix B.

The tests included in the Guide Specifications are listed for each specification

and they include field tests, laboratory tests, and NDE tests. Some of the

field tests and laboratory tests are of the destructive type.

A-1
Table A. Review of Navy Guide Specifications

Guide Spec. No & Date Guide Spec. Title

1. TS-T18 a (July 1965)

2. NFGS-02050

(March 1984)

3. NFGS-02102

(August 1982)

4. TS-02200

Amendment-l (November 1980)

Field Tests

• gradation of fill

or backfill material

• liquid limit and plasticity

of fill or backfill material

• moisture density relationship

of fill or backfill material

• density of in place material

• moisture content of in place

soil material (ASTM D 3017)

5. NFGS-02247

(March 1983)

Tests

• aggregate or existing

soil aggregate materials

-sieve analysis of combined

material

-liquid limit

-plasticity index

• compressive strength of cement

treated materials

• smoothness of paved area

• thickness of base or subbase course

Specification for Timber Harvesting

No tests specified

Demolition and Removal

No tests specified

Clearing and Grubbing

No tests specified

Earthwork

NDE Tests

None specified

Portland Cement Stabilized [Base] [or]

[Subbase] Course for Airfields, Roads

and Streets

NDE Tests

None specified

AGuide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

• field density

• laboratory tests

-optimum moisture content

and maximum density

-moisture-density relationship of existing soils

(for site preparation)

6. NFGS-02250

(June 1981)

Soil Treatment for Subterranean

Termite Control

7. NFGS-02361

(July 1983)

Tests

• load test of piles

8. TS-02362.3

(October 1980)

Tests

• load tests of piles

• grout consistency

(flow cone test)

• grout compressive

strength

9. NPGS-02363

(August 1981)

Tests

• load tests of piles

• concrete testing

10. NFGS-02367

(August 1981)

Tests

• load tests of piles

• concrete testing

(aggregates, compressive

strength of concrete)

No tests specified

Round Timber Piles

NDE Tests

None specified

Auger-Placed Grout Piles

NDE Tests

None Specified

Cast-ln-Place Concrete Piling, Steel

Casing

NDE Tests

None specified

Prestressed Concrete Piling

NDE Tests

None specified

A3
Guide Spec. No & Date

11. TS-02360.1

(October 1980)

Table 4. (Continued)

Guide Spec. Title

Round Timber-Concrete Composite Piles

Tests

load tests of piles

NDE Tests

None specified

12. TS-02368

(January)

Tests

• load tests of piles

13. NPGS-02369

(March 1984)

Tests

• load tests of footings,

measure deflection or settlement

14. NFGS-02369.1

(September 1983)

Steel H-Piles

NDE Tests

None specified

Pressure- Injected Footings

NDE Tests

None specified

Sheet Steel Piles

No tests specified

15. NFGS-02452

(September 1984)

Tests

• verify gauge, alignment, and

surface elevation of track

16. NFGS-02485

(December 1982)

No tests specified

17. NFGS-02490

(November 1982)

Railroad Trackwork

NDE Tests

• ultrasonic inspection of

welded rail joints

Turf

Trees, Plants, and Ground Cover

No tests specified

A-4
Guide Spec. No & Date

Table 4. (Continued)

Guide Spec. Title

18. TS-02513.1

(September 1979)

Tests of Pavement Course

• density using cores

• thickness

• straightedge of compacted surface

19. NPGS-02559

(October 1983)

Tests at job site

• slump

• air content

• temperature of plastic concrete

In-place

• surface smoothness

• pavement thickness (core samples);

note, cores can also be used

to evaluate condition of the concrete

• flexural strength (from job site beam

specimens)

20. NFGS-02573

(March 1984)

Tests

• density using cores

• thickness of binder and

wearing courses

• smoothness of compacted surfaces

• finish grades of each course placed

21. NFGS-02576

September 1981

Tests

• slurry mixture

water content

residual asphalt content

gradation of extracted aggregate

calculate percent of emulsified asphalt

Asphalt Concrete Base Course

(Central Plant Hot Mix)

NDE Tests

None specified

Portland Cement Concrete Pavement

for Roads and Air Fields

NDE Tests

None specified

Bituminous Hot Mix Pavement

NDE Tests

None specified

Asphalt Slurry Seal

NDE Tests

None specified

A5
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

• trial application (demonstrate

ability to apply slurry seal)

22. TS-02577

(July 1980)

Field Testing

None specified

23. NFGS-02578

(August 1982)

Field Testing

• demonstrate rubber and

paint removal on 50 ft.

long test area

• recommended friction and texture

testing after removal work

24. TS-02581

(September 1978)

Tests

• measure flow and drawdown

25. TS-02614

(January 1978)

Pavement Markings (Airfields and

Roads

NDE Tests

None specified

Rubber and Paint Removal from

Airfield Pavements

NDE Tests

None specified

Rotary Drilled Water Well

NDE Tests

None specified

Joints, Reinforcement and Mooring

Eyes in Concrete Pavements

26. TS-02616

(October 1979)

27. NFGS-02622.1

No tests specified

Resealing of Joints in Rigid Pavement

No tests specified

Fiberglass Reinforced Plastic (FRP)

Piping (for Petroleum Products)

Field Tests

• initial pneumatic test at a pressure of 15 psig

• second pneumatic test at a pressure

of 50 psig

NDE Tests

None specified

A-6
Table A. (Continued)

Guide Spec. No & Date

• hydrostatic pressure test

• hydrostatic cycle test of system

• operational test of system

• backfill density

28. TS-02671

(September 1980)

No tests specified

29. TS-02672

(September 1980)

Tests

• sulfonatlon Index test for tar

• spot test for asphalt

Guide Spec. Title

Bituminous Tack Coat

Bituminous Prime Coat

NDE Tests

None specified

30. TS-02673

(September 1980)

Tests

• stripping test

• spot test

31. TS-02675

(March 1979)

Field Tests

None specified

32. NFGS-02676

(February 1982)

33. TS-02677

(August 1980)

No tests specified

No tests specified

Bituminous Seal Coat , Spray

Application

NDE Tests

None specified

Coal Tar Seal Coat with Unvulanlzed

Rubber

NDE Tests

None specified

Fog Seal

Bituminous Surface Treatment

A7
i

Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

3A. TS-02685

(October 1980)

Field Tests

• aggregate gradation

• smoothness of top layer

• density of each layer of base course

• thickness of base course

35. TS-02686

(October 1980)

Select-Material Base Course for

Rigid Pavement

NDE Tests

None specified

Graded Aggregate Base Course for

Flexible Pavement

Field Tests NDE Tests

• aggregate gradation

• smoothness of top layer

• density of each layer of base material

• thickness of base course

36. NFGS-02696

(November 1981)

Field Tests

• aggregate gradation

• smoothness of top layer

• density of each layer

• thickness of subbase course

37. NFGS-02714

(July 1982)

Field Tests

• test system to demonstrate

compliance with contract

• before Insulation is applied,

hydrostatically test each

piping system

None specified

Selected-Material Subbase Course

for Flexible Pavement

NDE Tests

None specified

Exterior Steam Distribution

NDE Tests

None specified i

A-8
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

38. TS-02722

(July 1980)

Field Tests

• straightness of pipelines and

gross deficiences

• leakage

• deflection of plastic pipelines

• pressure test of the system

• field tests for concrete (Section 03300,

"Cast-in-Place Concrete")

slump

compressive strength (from job-site

cylinders)

temperature tests

39. NFGS-02734

(March 1984)

Field Tests

• measure flow and drawdown

(pump test)

• well plumbness and alignment

40. NPGS-02854

(March 1983)

Field Tests

• (visual) inspect new rail

fittings thoroughly (bolted

joints and welds)

• verify gage, alignment and surface

elevation of track

41. NFGS-02881

(November 1981)

No tests specified

Exterior Sanitary Sewer System

NDE Tests

None specified

Rotary-Drilled Water Well

NDE Tests

None specified

Railroad Track Work

NDE Tests

None specified

Dredging

AGuide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

42. TS-02886

(August 1980)

Field Test

• load tests on piles

43. NFGS-02891

(March 1982)

No tests specified

44. NFGS-02910

(November 1982)

Tests

• visual inspection of each

welded joint

• ultrasonic inspection of

each welded joint

• hardness of the weld 6 in. on each

side of joint (Brinell Hardness

Number)

45. TS-03300

(June 1980)

Amendment-3 (February 1984)

Field Tests of Concrete

• slump

• ball penetration

• compressive strength or flexural

strength (from job site cylinders)

• yield (when challenged by contracting

officer)

• temperature

• aggregate sampling and testing for

specified requirements

Wood Marine Piling

NDE Tests

None specified

Pier Timberwork

Welding Crane and Railroad RailThermite Method

NDE Tests

• ultrasonic inspection of each

welded joints

• hardness of the weld (6 in. on each side of the joint)

Cast-In-Place Concrete

NDE Tests

None specified

A-10
Guide Spec. No. & Date

Table A. (Continued)

Guide Spec. Title

46. NFGS-03302

(April 1981)

Amendment-1 (February 1984)

No tests specified

47. NFGS-03361 Shotcrete

(April 1985)

Field Tests NDE Tests

Cast- In-Place Concrete

(Minor Building Construction)

• visual inspection None specified

• make test panel

• compressive and flexural strength

(cores and beams)

• durability factor (from core)

• air content

48. TS-03410

(December 1978)

Testing at Casting Site

• slump

• air content

• unit weight for lightweight concrete

• compressive strength (cylinders made

at casting site, core testing required

if compressive strength fails to meet

requirements)

Other Requirements NDE Tests

Precast Structural Concrete

(Non-Pres tressed)

• tolerances of finished products

• finished appearance

49. NFGS-03411

(August 1981)

Testing at batch plant

• aggregate tests (mechanical analysis,

including specific gravity) from samples

• slump

• compressive strength (cylinders made at plant)

None specified

Precast Concrete Wall Panels

A-11
Guide Spec. No. & Date

Other Requirements

Table A. (Continued)

Guide Spec. Title

NDE Tests

• tolerances of finished panels and

In Installation

• finished appearances

50. TS-03420

(December 1978)

Testing at Casting site

• slump

• air content

• unit weight of lightweight concrete

• compressive strength (cylinders

made at casting site)

Other Requirements

• tolerances of finished products

• finished appearances

• measurement of cracks In

precast-prestressed concrete

• camber

51. TS-03501

(March 1979)

Field Tests (test specimens

taken at job site)

• compressive strength

• oven dry density

• coefficient of heat transmission

52. NFGS-04200

(November 1983)

None specified

Precast Prestressed Concrete

NDE Tests

None specified

Insulating Concrete Roof Deck System

NDE Tests

None specified

Unit Masonry

No field tests specified

A-12
Guide Spec. No & Date

53. NPGS-04230

(July 1984)

Tests at Job-Site

Table A. (Continued)

Guide Spec. Title

Reinforcing Masonry

• compressive strength of mortar

and grout

• compressive strength of masonry prims

• efflorescence (masonry units and

for mortar)

54. NPGS-04250

(November 1982)

NDE Tests

None specified

[ceramic Glazed Structural Clay

Facing Tile] [AND] [Prefaced

Concrete Masonry Units]

55. NFGS-05120

(August 1981)

Tests

• visual Inspection of welds

• test for embrlttlement of welds

56. NFGS-05210

(December 1983)

No field tests specified

Structural Steel

NDE Tests

• radiographic

• ultrasonic

• magnetic particle

• dye penetrant

Steel Joists

No tests specified

57. NPGS-05311

(May 1983)

Field Tests

• Inspect decking top surface for

flatness (straight edge)

58. TS-05321

(September 1979)

Field Tests

visual inspection of welds

Steel Roof Decking

NDE Tests

None specified

Steel Floor Deck

NDE Tests

None specified

A-13
Guide Spec. No & Date

59. NFGS-05400

(August 1983)

60. TS-05500

(November 1980)

Table A. (Continued)

Guide Spec. Title

Cold- Formed Metal Framing

No field tests specified

Metal Fabrications

61

62

No field tests specified

NFGS-07110

(April 1983)

Field Tests

sample bulk liquid asphalt

(conformance with specification

requirements)

watertightness (cover membrane

waterpoofing horizontal surfaces with

ponded water for 24 hours)

TS-07111

(September 1980)

Field Tests

• watertightness of horizontal

surfaces of elastomeric waterproofing

(cover with ponded water for 24 hours)

NDE Tests

None specified

63. TS-07120

(June 1980)

Field Tests

• prior to application of fluid-applied

waterproofing, check moisture

content of substrate using a moisture meter

• check wet film thickness

• watertightness, cover waterproofing

with ponded water for 24 hours

Membrane Waterproofing

NDE Tests

None specified

Elastomeric Waterproofing

Sheet Applied

NDE Tests

None specified

Elastomeric Waterproofing

System, Fluid Applied

NDE Tests

None specified

A- 14
Table A. (Continued)

Guide Spec. No & Date Guide Spec. Title

64. TS-07130 Bentonite Waterproofing

(December 1980)

No field tests specified

65. NFGS-07140 Metallic Oxide Waterproofing

(February 1983)

No field tests specified

Guide Spec. No & Date Guide Spec. Title

66. NFGS-07160 Bituminous Dampprooflng

(April 1983)

No field tests specified

67. NFGS-07211 Loose Fill (Celluloslc and

(July 1981) Mineral Fiber) Insulation

No field tests specified

68. TS-07220 Roof Insulation

(March 1980)

No field tests specified

69. NFGS-07221 Masonry Wall Insulation

(November 1982)

No field tests specified

70. NFGS-07222 Tapered Roof Insulation

(December 1982)

No field tests specified

71. NFGS-07232 Ceiling, Wall, and Floor

(September 1981) Insulation

No field tests specified

A-15
Guide Spec. No & Date

72. NFGS-07250

(February 1984)

Field Tests

73,

• thickness

• density

NFGS-07310

(August 1983)

Table A. (Continued)

Guide Spec. Title

Sprayed-on Fireproofing

NDE Tests

None specified

Asphalt Shingles

No field tests specified

74. NFGS-07410

(May 1983)

Preformed Metal [Roofing] [and]

[Siding]

Factory tests to be conducted by manufacturer

salt spray

f ormability

accelerated weathering

chalking resistance

color change

Field Tests

None specified

75. NFGS-07511

(June 1981)

Field Tests

• abrasion resistance for color coating

• humidity test

• fire hazard

• specular gloss

NDE Tests

None specified

Aggregate Surfaced Bituminous Built-Up

Roofing

NDE Tests

• fastener resistance to pullout

• watertightness of roofing system

(24 hour ponded water)

76. NFGS-07512

(July 1981)

Field Tests

None specified

Smooth Surfaced Bituminous Built-Up

Roofing

NDE Tests

• fastener resistance to pullout

• watertightness of roofing system

(24 hour ponded water)

None specified

A-16
Table A. (Continued)

Guide Spec. No & Date Guide Spec. Title

77. NFGS-07520 Prepared Roll Roofing

(February 1984)

Field Tests NDE Tests

• fastener resistance to pullout None specified

78. NFGS-07540 (August 1979) Silicone Rubber Roof Coating

Amendment- 1 (June 1984)

Pages missing [only pages 1, 1.1, 4, and 8 f guide spec, are given)

79. NFGS-07545 Sprayed Polyurethane Foam (PUF)

(July 1984) for Roofing Systems

Field Tests NDE Tests

None specified None specified

80. TS-07600 (September 1978) Flashing and Sheet Metal

Amendment-1 (June 1981)

[only Amendment-1 given]

81. NFGS-07920 Sealants and Calkings

(August 1981)

No field tests specified

82. NFFGS-08110 Hollow Metal Doors and Frames

(November 1981)

No field tests specified

83. NFGS-08120 Aluminum Doors and Frames

(February 1984)

No field tests specified

84. NFGS-08129 Aluminum Storm Doors

(July 1982)

No field tests specified

A-17
Table A. (Continued)

Guide Spec. No & Date Guide Spec. Title

85. TS-08210 Wood Doors

(February 1980)

No field tests specified

86. NFGS-08301 Steel Sliding Hanger Doors

(November 1982)

Field Tests NDE Tests

• complete operating test of doors None specified

87. NFGS-08310 Sliding Fire Doors

(March 1983)

No field tests specified

88. NFGS-08320 Metal- Clad (Kalamein) Doors and

(March 1983) Frames

No field tests specified

89. NFGS-08331 Overhead Coiling Doors

(March 1983)

No field tests specified

90. NFGS-08360 Overhead Metal Doors

(July 1982)

Field Tests NDE Tests

• demonstrate proper installation, None specified

and proper functioning of operators,

safety features, and controls

91. NFGS-08367 Vertical Uft Metal Doors

(July 1982)

No field tests specified

92. NFGS-08371 Aluminum Sliding Glass Doors

(July 1983)

No field tests specified

A-18
Table A. (Continued)

Guide Spec. No & Date Guide Spec. Title

93. TS-08510 Steel Windows

(January 1980)

Field Tests NDE Tests

• steel windows to comply with None specified

specified feeler gage tests

94. NFGS-08520 Aluminum Windows

(June 1982)

No field tests specified

95. TS-08525 Storm Windows and Storm Doors

(June 1978)

No field tests specified

96. NFGS-08529 Aluminum Storm Windows

(July 1982)

No field tests specified

97. TS-08610 Wood Windows

(April 1980)

No field tests specified

98. NFGS-08710 Finish Hardware

(March 1985)

No field tests specified

99. NFGS-08800 Glazing

(December 1983)

No field tests specified

100. NFGS-09100 Metal Support Systems

(February 1984)

No field tests specified

A-19
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

101. NPGS-09110

(August 1982)

102. NFGS-09150

(April 1981)

103. TS-09215

(August 1979)

104. NFGS-09250

(March 1985)

105. NFGS-09310

(March 1984)

Lathing

No field tests specified

Plastering and Stuccoing

No field tests specified

Veneer Plaster

No field tests specified

Gypsum Board

No field tests specified

Ceramic Tile, Quarry Tile,

and Paver Tile

No field tests specified

106. NFGS-09331

(October 1983)

Field Tests

• chemical resistance of mortar

and grout

• water absorption of mortar

• hardness of mortar

• before tile is applied test

structural floor for levelness

and uniformity of slope

107. NFGS-09411

(September 1983)

Chemical-Resistant Quarry

Tile Flooring

NDE Tests

None specified

Terrazzo, Bonded to Concrete

No field tests specified

A-20
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

108. NFGS-09561

(March 1984)

109. NFGS-09563

(July 1982)

110. NFGS-09570

(August 1983)

HI. NFGS-09595

(July 1983)

112. TS-09661

(September 1980)

113. NFGS-09666

(February 1982)

Tests

Gymnasium-Type Hardwood Strip

Flooring Systems

No field tests specified

Portable (Demountable) Wood

Flooring

No field tests specified

Wood Parquet Flooring

No field tests specified

Wood Block Industrial Flooring

No field tests specified

Vinyl Composition Tile on Concrete

No field tests specified

Institutional Sheet Vinyl

Flooring

NDE Tests

• stain resistance of flooring material None specified

• moisture test for concrete subfloor

114. TS-09670

(January 1980)

Field Tests

• None specified

115. NFGS-09682

(January 1983)

Field Tests

None specified

Fluid Applied Resilient

(Resinous) Flooring

NDE Tests

None specified

Carpet

NDE Tests

None specified

A-21
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

116. NFGS-09690

(July 1981)

Field Tests

None specified

117. NPGS-09785

(April 1984)

Field Tests

• ground resistance of studs, rods,

and interconnecting ground wire

• conductivity of finished floor

surface

• spark resistance of finished floor

surface

Carpet Tile

NDE Tests

None specified

Metallic Type Conductive and Spark

Resistant Concrete Floor Finish

NDE Tests

None specified

118. TS-09804

(January 1978)

119. TS-09805.1

(September 1979)

Linseed Oil Protection of Concrete

Surfaces

No field tests specified

Coating Systems ( Coal-Tar for Sheet

Piling and Other Steel Waterfront

Structures

Field Tests NDE Tests

120.

thickness of coatings

holidays and pin holes in coatings

visual inspection of coatings

TS-09805.2

(May 1980)

• holidays, pin holes and other

defects/electrical flaw detector

Coating Systems (Vinyl and Epoxy)

for Sheet-Steel Piling and Other

Steel Waterfront Structures

Field Tests NDE Tests

thickness of coatings

holidays, pin holes, and other

defects in coatings

visual inspection of coatings

holidays, pin holes and other

defects/electrical flaw detector

A-22
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

121. NPGS-09815

(April 1981)

Field Tests

• dry film thickness/Tooke gage

122. NPGS-09809

(September 1981)

Field Tests

• test protective system for holes,

voids, cracks, and other damage,

visually

123. NPGS-09910

(September 1981)

Field Tests

None specified

124. NFGS-09951

(August 1982)

Field Tests

• Test walls for moisture content

with an electric moisture meter

125. TS-10152

(April 1980)

Field Tests

None specified

126. NPGS-10162

(November 1982)

Field Tests

None specified

High-Build Glaze Coatings

NDE Tests

None specified

Protection of Burled Steel Piping

and Steel Bulkhead Tie Rods

NDE Tests

• test with an electrical flaw

detector

Painting of Buildings (Field Painting)

NDE Tests

None specified

Vinyl- Coated Wall Covering

NDE Tests

None specified

Hospital Cubicle Track

NDE Tests

None specified

Toilet Partitions

NDE Tests

None specified

A-23
Guide Spec. No & Date

127. NPGS-10201

(January 1983)

Field Tests

None specified

128. NFGS-10270

(July 1983)

Field Tests

• floor system electrical

resistance

129. NFGS-10440

(March 1981)

Field Tests

None specified

130. TS-10623

(September 1979)

Field Tests

• Visual tests for light leakage

131. NFGS-10800

(October)

Field Tests

None specified

132. TS-11162

(November 1980)

Field Tests

• visual inspection of welds

• proof-load dockboard

• drop tests on dockboard

• low temperature environmental

test of loading ramp

• visual inspection of dockboard

• roll over load test of dockboard

Table A. (Continued)

Guide Spec. Title

Metal [Wall] [And] [Door] Louvers

NDE Tests

None specified

Access Flooring

NDE Tests

None specified

Signs

NDE Tests

None specified

Accordion Folding

NDE Tests

None specified

Toilet and Bath Accessories

NDE Tests

None specified

Fixed Type Industrial Dockboard

NDE Tests

• welds dye penetrant examined

• welds magnetic particle tested

A-24
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

133. TS-11171

(October 1978)

Field Tests

• hydrostatic pressure of oil

piping systems (using oil)

• pneumatical test of gas piping

systems; soap bubbles to verify

tightness of system

• performance test of incinerator

including controls

• shell temperature (outer shell)

of incinerator

134. TS-11301

(April 1980)

Field Tests

• hydrostatic test of piping

• performance test of separator

• test for contaminants in effluent

135. NPGS-11334

(August 1982)

Field Tests

• performance test of coimninutor

136. TS-11361.1

(September 1980)

Field Tests

• performance test of rectangular

clarifier mechanism

137. TS-11361.2

(September 1980)

Field Tests

• performance test of circular

clarifier mechanism

Incinerators, Packaged, ControlledAir Type

NDE Tests

None specified (other than pneumatic

test)

Packed, Gravity Oil/Water Separator

NDE Tests

None specified

Comminutor

NDE Tests

None specified

Rectangular Clarifier Equipment

NDE Tests

None specified

Circular Clarifier Equipment

NDE Tests

None specified

A-25
Guide Spec. No & Date

138. NFGS-11371

(December 1982)

Table A. (Continued)

Guide Spec. Title

Trickling Filter

Field Tests NDE Tests

• performance test of distributor

mechanism

139. NFGS-11700

(April 1984)

Field Tests

performance test of installed

equipment

140. NFGS-11701

(June 1981)

141. TS-11702

(July 1980)

Field Tests

None specified

General Requirements for

Medical Equipment

NDE Tests

None specified

Casework, Metal and Wood

Medical and Dental

No field tests specified

Medical Equipment , Miscellaneous

NDE Tests

• performance test of equipment

142. NFGS-11704

(April 1985)

None specified

[Casework, Movable and Modular for

Laboratory and Pharmacies] [And]

[Materials Handling Units] for

Medical Facilities

No field tests specified

143. TS-11720

(September 1980)

Field Tests

Stills and Associated Equipment

• performance test of water

distilling apparatus

NDE Tests

None specified

A-26
Guide Spec. No & Date

144. TS-11722

(September 1980)

Field Tests

Table A. (Continued)

Guide Spec. Title

Sterilizers and Associated Equipment

• performance test of equipment

145. TS-11730

(September 1980)

Field Tests

• performance test of equipment

146. TS-11744

(August 1980)

Field Tests

• performance test of equipment

147. NFGS-11757

(August 1981)

Field Tests

• performance test of equipment

148. TS-11770

(August 1980)

Field Tests

• insure equipment is

operational

149. NFGS-12322

(August 1982)

Field Tests

None specified

150. NFGS-12331

(March 1985)

NDE Tests

None specified

Washing Equipment

NDE Tests

None specified

Dental Equipment

NDE Tests

None specified

Radiographic Darkroom Equipment

NDE Tests

None specified

Government-Furnished and Contractor

Installed Existing Medical Equipment

NDE Tests

None specified

Wardrobes

NDE Tests

None specified

Prefabricated Vanities

No field tests specified

A-27
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

151. NFGS-12332

(March 1985)

152. TS-12391

(January 1981)

153. NFGS-12510

(April 1981)

Field Tests

Wardrobe Storage Cabinets

No field tests specified

Kitchen Cabinets [and Vanity

Cabinets]

No field tests specified

Blinds, Venetian (and Audio Visual)

• test for light Intensity

154. NFGS-12540

(July 1984)

155. NFGS-12711

(February 1984)

156. TS-13092

Field Tests

• Visual inspection

157. NFGS-13121

(October 1983)

Field Tests

NDE Tests

None specified

Draperies

No field tests specified

Theater Seating

No field tests specified

X-Ray Shelldlng

NDE Tests

• sample panels tested for con- formance to specified requirements [salt spray, accelerated

weathering, flexibility,

adhesion (film)]

None specified

Pre-englneered Metal Buildings

Rigid Frame)

NDE Tests

None specified

A-28
Guld^ Spec. No & Date

Table A. (Continued)

Guide Spec, Title

158. NFGS-13411

(June 1981)

Water Storage Tanks

No field tests specified

159. NFGS-13625

(February 1982)

Field Tests

• test in-place the flow

measuring equipment to

demonstrate it meets

the accuracy requirements

160.. NFGS-13657

(March 1983)

Field Tests

• lead-in-air tests

(after cleaning)

161. NFGS-13661

(August 1981)

Field Tests

• test panels, steel plate,

for sand blast for use as standard of comparison

• air inhibition test (for evidence

of undercure of lining)

• fill test (for leakage of tank)

162. TS-13765

(April 1979)

Field Tests

• door sag test

• attentuation testing

(RF shielded enclosures)

• door static load test

Flow Measuring Equipment (Sewage

Treatment Plant)

NDE Tests

None specified

Cleaning Petroleum Storage Tanks

NDE Tests

None specified

Fiberglass Reinforced Plastic Lining

System for Bottotns of Steel Tanks (for

Petroleum Fuel Storage)

NDE Tests

• holiday detector test of lining

Radio Frequency Shielded Enclosures,

Demountable Type

NDE Tests

• seam leak detector testing

(shielding), "sniffer"

A-29
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

163. TS-13766

(April 1979)

Field Tests

• swinging door static load test

• swinging door sag test

• sliding and swinging door closure

test

• attenuation testing

• visual Inspection of welds

164. NFGS-13947

(August 1983)

Radio Frequency Shielded Enclosures,

Welded Type

NDE Tests

seam leak detector testing of

welds, "sniffer"

Energy Monitoring and Control System

(EMCS) Large System Configuration

No field tests specified

165. NFGS-13948

(August 1983)

166. NFGS-13950

(August 1983)

167. TS-13981.1

(March 1980)

Field Tests

Energy Monitoring and Control System

(EMCS) Medium System Configuration

No field tests specified

Energy Monitoring and Control System

(EMCS) Micro System Configuration

No field tests specified

Solar Energy Systems Flat Plate

Collectors (Liquid Type)

• hydrostatic testing

• pneumatic testing

• start-up and operational tests

NDE Tests

None specified

A-30
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

168. TS-14200

(May 1980)

Field Tests

• operational tests

• speed load tests

• temperature rise tests (motor, etc)

• car leveling tests

• brake test

• insulation (electrical) resistance

tests

• buffer tests

169. NFGS-14214

(February 1984)

Field Tests

• operational tests

• speed load tests

• car leveling tests

• stop test

• pressure test (pump and cylinder

head)

• insulation (electrical) resistance

tests

170. NPGS-14304

(January 1984)

Field Tests

• grout compressive strength

• visual inspection (fittings,

bolted joints, welds)

• as-built survey

• load test of trackage and curve

• throw mechanism operational test

Electric [Passenger] [Freight^

Elevator

NDE Tests

None specified

Hydraulic [Passenger] [Freight^

Elevator

NDE Tests

None specified

Portal Crane Track Installation

NDE Tests

• ultrasonic inspection of welded

rail joints

A-31
Guide Spec, No & Date

Table A. (Continued)

Guide Spec. Title

171. TS-14305

(February 1980)

Field Tests

• operational tests

• tolerances (vertical movement)

• joint mismatch tolerances (vertical,

horizontal)

• joint gap tolerance

172. NFGS-14334

(March 1983)

Field Tests

• operational iqspection and tests

173. NFGS-14335

(April 1982)

Field Tests

• operational inspection and tests

174. NFGS-14336

(January 1982)

Field Tests

• operational inspection and tests

175. NFGS-14637

(July 1984)

Field Tests

• operational inspection and

tests

176. NFGS-15011

(February 1981)

Fabricated Portal Crane Track

Switches and Frogs

NDE Tests

None specified

Monorails with Manual Hoist

NDE Tests

None specified

Monorails with Air Motor Powered

Hoist

NDE Tests

None specified

Cranes, Overhead Electric,

Overrunning Type

NDE Tests

None specified

Cranes, Overhead Electric, Underrunning

(Under 20,000 pounds)

NDE Tests

None specified

Mechanical General Requirements

No field tests specified

A-32
Guide Spec, No & Date

Table A. (Continued)

Guide Spec. Title

177. NFGS-15116

(July 1982)

Field Tests

• Visual Inspection of welds

178. TS-15200

(September 1979)

Field Tests

• check for vibration and noise

transmission through connections,

piping duct work, foundations,

and walls

• vibration tests for conformance

with criteria

• sound level tests for conformance

with criteria

179. NFGS-15251

(January 1984)

Field Tests

None specified

180. TS-15301

(December 1978)

Field Tests

Welding Pressure Piping

NDE Tests

NDE personnel shall be certified

as qualified

radiographic examination of welds

liquid penetrant examination of welds

magnetic particle examination of welds

ultrasonic examination of welds

Noise, Vibration, and [Seismic]

Control

NDE Tests

None specified

• leakage tests

• alignment of pipeline

Insulation for Exterior Piped

Utilities

NDE Tests

None specified

Exterior Sanitary Sewer and Drainage

System Piping

NDE Tests

None specified

A-33
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

181. TS-15355

(October 1980)

Field Tests

• metal welding or brazing inspection

• PE Fusion welding inspection

• pressure test piping system

• operational tests for conformance

with criteria

182. NFGS-15361

(January 1984)

Field Tests

• acceptance tests

• pneumatic test (leakage)

183. NFGS-15362

(January 1984)

Field Tests

• pneumatic test (leakage)

• acceptance tests (conformance

with specified requirements)

184. NFGS-15365

(February 1984)

Field Tests

• pneumatic test (leakage of system)

• acceptance and opeational tests of

system

185. TS-15388

(October 1973)

186. TS-15390

(May 1972)

Fuel Gas Piping

NDE Tests

None specified

Carbon Dioxide Fire Extinguishing

Systems (High Pressure)

NDE Tests

None specified

Carbon Dioxide Fire Extinguishing

Systems (Low Pressure)

NDE Tests

None specified

Halon 1301 Fire Extinguishing

System

NDE Tests

None specified

Screening Equipment (Sewage)

No field tests specified

Aeration Equipment ( Sewage

)

No field tests specified

A-34
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

187. TS-15395

(October 1973)

188. TS-15399

(March 1979)

Field Tests

Sludge Digestion Equipment

No field tests specified

Package Rotating Biological Contractor Wastewater Treatment Unit

• cathodlc protection Inspection

• pressure test each pipeline

• acceptance and operational tests of

system for conformance to specified

requirements

NDE Tests

None specified

189. NFGS-15400 Amendment-1

(September 1983)

Plumbing

190. NFGS-15403

(March 1981)

Field Tests

No field tests specified

Nonflammable Medical Gas Systems

• leak tests of systems

• equipment pressure tests of joints

• vacuum tests

191. NFGS-15411

(July 1983)

Field Tests

NDE Tests

None specified

• visual Inspection of welds

• destructive tests of welds

• hydrostatic and leak tightness

tests of system

• operational tests

Compressed Air Systems (NonBreathing Air Type)

NDE Tests

• NDE personnel shall be certified

• radiographic (for welds)

• liquid penetrant (for welds)

• magnetic particle (for welds)

A-35
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

192. NFGS-15460

(July 1984)

Field Tests

• operational and acceptance tests

193. TS-15502

(October 1980)

Field Tests

• hydrostatic pressure test of system

• acceptance and operational tests

194. NFGS-15540

(February 1982)

Field Tests

• hydrostatic pressure tests

• acceptance and operational tests

195. TS-15609

(April 1978)

Field Tests

hydrostatic pressure tests of

piping systems

acceptance and operational tests

196. NFGS-15612

(April 1984)

Field Tests

• visual inspection of welds

• piping strength and tightness

(pressure test)

Hospital Plumbing Fixtures

NDE Tests

None specified

Fire Extinguishing Sprinkler

Systems (Dry Pipe)

NDE Tests

None specified

Fire Pumps

NDE Tests

None specified

Aviation Fuel Distribution Systems

NDE Tests

None specified

Gas Distribution System

NDE Tests

• electrical holiday detector for

discontinuities in pipe coatings

A-36
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

197. NPX;S-15631

(September 1981)

Field Tests

• acceptance and operational tests

for compliance with contract

requirements

• strength and tightness (hydrostatic test)

• pneumatic tests (air casing and ducts)

• combustion tests

• capacity and efficiency tests

198. NFGS-15632

(September 1981)

Field Tests

• acceptance and operational tests

for compliance with contract requirements

• strength and tightness (hydrostatic test)

• pneumatic tests (air casing and ducts)

• combustion tests

• capacity and efficiency tests

• steam tests

Steam Boilers and Equipment

500,000 - 18,000,000 Btu/h)

NDE Tests

None specified

Steam Boilers and Equipment

18,000,000 - 60,000,000 Btu/Hr

Input)

NDE Tests

None specified

199. NFGS-15651

(January 1983)

Field Tests

Refrigerant, Chilled Water,

Condenser Water, Hot and Cold

Water (Dual Service) Piping

NDE Tests

• tightness of system

• pressure test (refrigerant system)

• operational tests

200. TS-15652

Amendment1

(July 1982)

None specified

Central Refrigeration System for

Air Conditioning

No field tests specified

A-37
Guide Spec. No & Date

201. NFGS-15653

(June 1984)

Field Tests

• operational tests

• sound tests

202. NFGS-15707

(September 1981)

Field Tests

• hydrostatic pressure test of

system

• operational test

• moisture-density test of backfill

• In-place compaction test

203. NFGS-15711

(March 1981)

Field Tests

Table A. (Continued)

Guide Spec. Title

Unitary Air Conditioning Systems

NDE Tests

• leak testing (electronic type

detectors)

[Factory Insulated] Glass Fiber

Reinforced Plastic (FRF) Pipe

Coondensate Return System

NDE Tests

None specified

• strength and tightness

(hydrostatic test) for

boiler and piping system

• combustion test

• operational test

• capacity and efficiency test

204. NFGS-15721

(March 1981)

Field Tests

• hydrostatic pressure test of

piping system

• operational test

205. TS-15802

(November 1972)

Hot Water Heating System

NDE Tests

None specified

Steam System and Terminal Units

NDE Tests

None specified

Air Supply Systems

Note: The last part of this specification was missing

A-38
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

206. TS-15813

(October 1980)

Field Tests

• operational test

• fire test

• duct test

207. TS-15820

(September 1980)

Field Tests

• operational test

208. TS-15822

(October 1980)

Field Tests

• operational test

209. NFGS-15840

(November 1982)

Field Tests

• operational test

• pressure tests for air leakage

(ducts, plenums, and casings)

210. TS-15852.2

(May 1980)

Field Tests

• operational test

211. NFX;S-15852.3

(January 1983)

Field Tests

• operational test

Warm Air Heating Systems

NDE Tests

None specified

Air Handling and Distribution Equipment

NDE Tests

None specified

Evaporative Cooling System

NDE Tests

None specified

Ductwork and Accessories

NDE Tests

None specified

Duct Collector, Electrostatic Precipitation

Type (Flue Gas Particulates)

NDE Tests

None specified

Duct Collector, Fabric Filter Type

(Fly Ash Particles in Flue Gas)

NDE Tests

None specified

A-39
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

212. TS-15901

(August 1980)

Field Tests

• operational test

213. TS-16011

(November 1978)

Space Temperature Control Systems

NDE Tests

None specified

General Requirements, Electrical

214. NFGS-16113

(February 1984)

Field Tests

No field tests specified

Underfloor Raceway System

• electrical continuity test

215. NFGS-16202

(October 1981)

Field Tests

• hydrostatic test of piping

• operational tests and acceptance

tests

216. NFGS-16203

(October 1981)

Field Tests

• hydrostatic test of piping

• electrical Insulation resistance

tests

• operational and acceptance tests

NDE Tests

None specified

Power Generating Plants, Diesel Electric

(Design 1) 500 to 2500 kW Continuous Duty

Units

NDE Tests

None specified

Power Generating Plants, Diesel Electric

(Design 2) 2,501 kW and Larger Continuous

Duty Units

NDE Tests

None specified

A-40
Guide Spec, No & Date

Table A. (Continued)

Guide Spec. Title

217. NFGS-16204

(November 1981)

Power Generating Plants, Diesel Electric

(Design 3) 300 to 1,000 kW Standby Duty

Units

Field Tests

• hydrostatic test of piping

• electrical Insulation resistance

tests

• operational and acceptance tests

218. NFGS-16205

(September 1981)

Field Tests

• hydrostatic test of piping

• electrical Insulation resistance

tests

• operational and acceptance tests

219. NFGS-16207

(November 1981)

Field Tests

• hydrostatic test of piping

• electrical Insulation resistance

tests

• operational and acceptance tests

220. NFGS-16208

(July 1982)

Field Tests

• operational test

221. TS-16262

(November 1982)

NDE Tests

None specified

Power Generating Plants, Diesel Electric

(Design 4) 1,001 kW and Larger Standby

Duty Units

NDE Tests

None specified

Power Generating Plants, Diesel Electric

(Design 6) 1,001 kW and Larger Emergency

Duty Units

NDE Tests

None specified

Diesel Engine-Generator Set

(25-250 kW

NDE Tests

None specified

Automatic Transfer Switches

No field tests specified

A-41
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

222. NFGS-16301

(April 1984)

Field Tests

• test 600 volt conductors for

short circuits or accidental grounds

• test high voltage cables

• test ground rods for ground resistance

value

Underground Electrical Work

NDE Tests

None specified

223. NFGS-16302

(February 1984)

Field Tests

• test ground rods for ground

resistance value

• operational test

• test transformer secondary voltages

224. NFGS-16304

Amendment -1

(July 1982)

No field tests specified

225. NFGS-16335

(September 1981)

Field Tests

Overhead Electrical Work

NDE Tests

None specified

Pier, Electrical Distribution

for Naval Stations

Transformers, Substations and

Swltchgear, Exterior

NDE Tests

• acceptance tests

• test transformer secondary voltages

• dielectric tests (low voltage

swltchgear)

226. NFGS-16402

(February 1983)

Field Tests

None specified

• operational and acceptance tests

• test 600-volt wiring (no short circuits

or accldential grounds)

• grounding system test

A-42

Ulterior Wiring Systems

NDE Tests

None specified
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

227. TS-16475

(August 1979)

Field Tests

• operational and acceptance tests

• ground resistance tests

Interior Transformers

NDE Tests

None specified

228. NFGS-16462

(July 1981)

Field Tests

• operational and acceptance tests

• ground resistance of ground rods

229. NPGS-16465

(March 1983)

Field Tests

• operational and acceptance tests

• relay testing

• transformer tests

• field dielectric tests

• ground resistance tests

230. TS-16475

(August 1979)

Field Tests

• operational and acceptance tests

• ground resistance tests

231. NFGS-16492

(January 1983)

Field Tests

Pad Mounted Transformers

NDE Tests

None specified

Interior Substations

NDE Tests

None specified

• operational and acceptance tests

• voltage and frequency transiet tests

• ground resistance tests

Interior Switchgear

NDE Tests

None specified

Motor-Generator Sets, 400 Hertz

NDE Tests

None specified

A-43
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

232. NPGS-16530

(March 1985)

Field Tests

• operational tests

• insulation resistance test

• ground resistance tests

233. NFGS-16560

(June 1982)

Pield Tests

• operational tests

• electromagnetic interference

• test 600-volt class conductors

(no short circuits or accidental

grounds)

• counterpoise and ground rod tests

• progress testing for series airfield

lighting circuits

• electrical acceptance tests for series

and multiple airfield lighting

circuits

• low voltage continuity, ground, and

insulation resistance tests

• high voltage insulation resistance test

• electric tests

234. TS-16641

(March 1979)

field Tests

• static pull test of anode with

lead wires

• operational test

Exterior Lighting

NDE Tests

None specified

Airfield Ughting

NDE Tests

None specified

Cathodic Protection by Galvanic

Anodes

NDE Test

None specified

A-44
Guide Spec. No & Date

Table A. (Continued)

Guide Spec, Title

235. TS-16642

(March 1979)

Field Tests

• static pull test of anode with

lead wires

• wire for power service (free from

short circuits and grounds)

• operational test

Cathodlc Protection by Impressed

Current

NDE Tests

None specified

236. NFGS-16650

(June 1983)

field Tests

• operational and acceptance tests

237. NPGS-16721

(December 1972)

Field Tests

• ground resistance

• dielectric strength and Insulation

resistance

• operational tests ( power supply, alarm,

box and transmitter, signal

transmission and recording, trouble line

operation, manual-set transmitter

test)

238. TS-16722

(October 1978)

Field Tests

• operational and functional tests

• ground resistance

• dielectric strength and insulation

resistance

Radio Frequency Interference

Power Line Filters

NDE Tests

None specified

Exterior Fire Alarm System

NDE Tests

None specified

Fire Alarm and Fire Detecting

System (Local)

NDE Tests

None specified

A-45
Guide Spec. No & Date

Table A. (Continued)

Guide Spec. Title

239. NFGS-16723

(October 1981)

Field Tests

• acceptance test

• ground resistance

Fire Alarm System Radio Type

NDE Tests

None specified

A-46
APPENDIX B. REVIEWED NAVY GUIDE SPECIFICATIONS HAVING NDE TESTS

The Navy Guide Specifications that contain required NDE tests are listed in

Table B along with the corresponding NDE tests. Of the 239 Guide Specifications

reviewed (see Appendix A), 29 contained required NDE tests. Some of the tests

included under NDE tests in Table B were listed as field tests in the

specifications. Those tests listed as field tests in the specifications are

denoted with a footnote.

B-1
Table B. Reviewed Navy Guide Specifications that Contain Required NDE Tests

Guide Spec. No & Date

NFGS-02452

(September 1984)

NFGS-02854

(March 1983)

NFGS-02910

(November 1982)

NFGS-05120

(August 1981)

NFGS-07110

(April 1983)

TS-0711

(September 1980)

TS-07120

(June 1980)

NFGS-07511

(June 1981)

NFGS-07512

(July 1981)

NFGS-09666

(February 1982)

Guide Spec. Title

Railroad Trackwork

Railroad Track Work

Welding Crane and Railroad

Rail - Thermite Method

Structural Steel

(some papers were missing from this spec.)

Membrane Waterproofing

NDE Tests

• Ultrasonic inspection

of welded rail joints

• Ultrasonic inspection

rail joints (MIL-STD1699)

• Ultrasonic inspection of

each welded joint

• Hardness of the weld

(6 in. on each side of

the joint)

• Nondestructive evaluation

of welds

*• Watertightness (ponded

water for 24 hours)

Elastomeric Waterproofing *• Watertightness (ponded

Sheet Applied water for 24 hours)

Elastomeric Waterproofing *• Prior to waterproofing

System, Fluid Applied

Aggregate Surfaced

Bituminous Built-Up

Roofing

Smooth Surfaced

Bituminous Built-Up

Roofing

Institutional Sheet

Vinyl Flooring

application, check

moisture content of

substrate using a moisture meter

*• Watertightness (ponded

water for 24 hours)

*• Watertightness (ponded

water for 24 hours)

Watertightness (ponded

water for 24 hours)

Moisture test for

concrete subfloor

* Listed as field tests in specifications.

B-2
Guide Spec. No & Date

NFGS-09785

(April 1984)

Table B. (Continued)

Guide Spec. Title

Metallic Type Conductive * and Spark Resistant Concrete

Floor Finish

NDE Tests

Ground resistance

of studs, rods, and

interconnecting ground

wire

TS-09805.1

(September 1979)

TS-09805.2

(May 1980)

NFGS-09815

(April 1981)

NFGS-09809

(September 1981)

NFGS-09951

(August 1982)

NPGS-10270

(July 1983)

*•

Coating Systems (Coal-Tar) * for Sheet Piling and Other

Steel Waterfront Structures

Coating Systems (Vinyl and *• Epoxy) for Sheet-Steel Piling

and Other Steel Waterfront

Structures

High-Build Glaze Coatings

Protection of Buried Steel * Piping and Steel Bulkhead

Tie Rods

Vinyl-Coated Wall Covering

Access Flooring

Conductivity of

finished floor surface

Spark resistance of

finished floor surface

Thickness of coatings

Holidays, pin holes

and other defects/

electrical flaw

detector

Thickness of coating

Holidays, pin holes

and other defects/

electrical flaw

detector

Dry film thickness/

Tooke Gage

Visual inspection of

protective systems for

holes, voids, cracks,

and damage

Test with an electrical

flaw detector

Test walls for moisture

content/eletric moisture

meter

Floor system electrical

resistance

* Listed as field tests in specification.

B-3
Guide Spec. No & Date

TS-11162

(November 1980)

TS-11171

(October 1978)

TS-11301

(April 1980)

NFGS- 13661

(August 1981)

TS-13765

(April 1979)

TS-13766

(April 1979)

NFGS-1A304

(January 1984)

Table B. (Continued)

Guide Spec. Title

Fixed Type Industrial

Dockboard

Incinerators , Packaged

,

Controlled-Air Type

Packaged, Gravity Oil/

Water Separator

Fiberglass Reinforced

Plastic Lining System for

Bottoms of Steel Tanks

(for Petroleum Fuel Storage)

Radio Frequency Shielded

Enclosures , Demountable

TZ£e

Radio Frequency Shielded

Enclosures, Welded Type

Portal Crane Track

Installation

NDE Tests

*• Visual inspection of

dockboard and welds

*• Proof-load dockboard

• Welds, dye penetrant

examined

• Welds, magnetic patricle

tested

• Pneumatical test of

gas piping systems;

soap bubbles to verify

tightness of system

*• Hydrostatic pressure

of oil piping systems

(using oil)

• Hydrostatic test of

piping

• Holiday detector test

of lining

Seam leak detector

testing (shielding),

"sniffer"

Seam leak detector

testing of welds,

"sniffer"

Ultrasonic inspection

of welded rail joints

* Listed as field test in specification.

B-4
Guide Spec. No & Date

NFGS-15116

(July 1982)

NFGS-15403

(March 1981)

NFGS-15411

(July 1983)

NFGS-15612

(April 1984)

NFGS-15653

(June 1984)

Table B. (Continued)

Guide Spec. Title

Welding Pressure Piping

Nonflammable Medical

Gas Systems

Compressed Air Systems

(Non-Breathing Air Type )

Gas Distribution System

Unitary Air Conditioning

Systems

NDE Tests

*• Visual inspection of

welds

• NDE personnel shall be

certified as qualifiedradiographic, liquid

penetrant, magnetic

particle, ultrasonicexamination of welds

conform to "ASME Boiler

and Pressure Vessel Code,

Section V."

*• Leak tests of

systems

*• Visual inspection

of welds

• NDE personnel shall be

certif ied-radiographic

,

liquid penetrant,

magnetic particle-for

welds

*• Visual inspection of

welds

• Electrical holiday

detector for discontinuities in pipe

coatings

• Leak testing (electronic

type leak detector)

* Listed as field test in specification

B-5

APPENDIX C. LISTS OF REVIEWED NCEL TECHDATA SHEETS AND NCEL TECHNICAL AND

RESEARCH REPORTS THAT CONTAIN NDE METHODS

The Navy publications provided by NCEL and NAVFAC which were reviewed are

listed in this appendix. Section 2.4 provides information about these types

of reports. Table Cl contains a list of reviewed NCEL Techdata Sheets and

Table C2 contains a list of reviewed NCEL technical and research reports.

C-1
Table CI. List of Reviewed NCEL Techdata Sheets that Contain NDE Methods

NCEL Techdata Sheet 79-09, "Inspection of Painting," Port Hueneme , CA,

September 1979.

NCEL Techdata 75-31, "Measuring Water Permeability of Masonry Walls,"

Port Hueneme, CA, December 1985.

NCEL Techdata Sheet 82-13, "Leak Detection in Pipelines," Port Hueneme, CA,

September 1982.

NCEL Techdata Sheet 84-05, "Infrared Thermometers for Roofing Inspectors,"

Port Hueneme, Ca, March 1984.

NCEL Techdata Sheet 77-20, "Use of Windsor Probe Test System for Strength

Evaluation of Concrete in Naval Construction," Port Hueneme, CA, December 1977

NCEL Techdata Sheet 80-12, "Problems with Underwater Ultrasonic Inspection,"

Port Hueneme, CA, October 1980.

NCEl Techdata Sheet 76-13, Inspection Methods for Wood Fender and Bearing

Piles," Port Hueneme, CA, September 1976.

NCEL Techdata Sheet 82-14, "Locating and Tracing Buried Metallic Pipelines,"

Port Hueneme, CA, September 1982.

C-2
Table C2 . List of Reviewed NCEL Technical and Research Reports that Contain

NDE Methods

NCEL Technical Memorandum M-43-81-07, "An Evaluation of Pulse Echo Ultrasonic

Techniques for Underwater Inspection of Steel Waterfront Structures,"

R. L. Bracket t and L. W. Tucker, Port Hueneme , CA, May 1981.

NCEL Technical Memorandum M-43-81-08, "Ultrasonic Inspection of Wooden

Waterfront Structures," C. A. Keeney, Port Hueneme, CA, May 1981.

NCEL Technical Memorandum M-51-81-11, "Concepts for Detecting Weak Spots

in Pavement-Encased Trackage on Waterfront Facilities," G. E. Warren,

Port Hueneme, CA, August 1981.

NCEL Technical Note N-1594, "Nondestructive Test Equipment for Wire Rope,"

H. H. Haynes and L. D. Underbakke, Port Hueneme, CA, October 1980.

NCEL Technical Memorandum M-52-80-10, "Specialized Roof Moisture Inspection,"

Robert L. Alumbaugh and John R. Keeton, Port Hueneme, CA, September 1980.

NCEL Technical Memorandum M-52-81-06, "Inspection of POL Supply Facilities,"

Thorndyke Roe, Jr., Port Hueneme, CA, September 1981.

NCEL Technical Memorandum M-55-81-04, "Inspection of Underground Utility

Lines-Milestone Zero Report," S. S. Wang, Port Hueneme, CA, July 1981,

NCEL Technical Memorandum M-55-81-06, "Inspection of Underground Utility

Lines," S. S. Wang and S. J. Oppedisano, Port Hueneme, CA, November 1981,

NCEL Technical Memorandum M-43-78-09, "Underwater Inspection and Nondestructive

Testing of Waterfront Structures: A State of the Art Assessment,"

R. L. Brackett, Port Hueneme, CA, June 1978.

NCEL Technical Memorandum M-51-80-27, "Noncontact Displacement Measurement

as an Inspection Tool for Naval Shipyard Trackage," G. E. Warren, Port

Hueneme, CA, December 1980.

NCEL Technical Memorandum M-52-77-3, "Roofing Survey of Naval Shore Bases,"

J, R. Keeton and R. L, Alumbaugh, Port Hueneme, CA, March 1977.

NCEL Technical Note N-1624, "Underwater Inspection of Waterfront Facilities:

Inspection Requirements Analysis and Nondestructive Testing Technique

Assessment," R. L. Brackett, W. J. Nordell, and R. D, Rail, Port Hueneme, CA,

March 1982.

NCEL Technical Note N-1632, "Evaluation of NDT Equipment for Specialized

Inspection," G. Warren, Port Hueneme, CA, June 1982.

NCEL Technical Report R-903, "Pulse Echo Ultrasonic Techniques for Underwater

Inspection of Steel Waterfront Structure," R. L. Brackett, L. W. Tucker, and

R. Erich, Port Hueneme, CA, June 1983.

C-3
Table C2. (Continued)

NCEL Technical Note N-1233, "Calibration of Windsor Probe Test System for

Evaluation of Concrete in Naval Structures," J, R. Keeton and V. Hernandez,

Port Hueneme, CA, June 1972.

NCEL Technical Note N-1703, "Evaluation of Nondestructive Underwater Timber

Inspection Techniques," C. A. Keeney and S. E. Pollio, Port Hueneme, CA,

August 1984.

NCEL Technical Memorandum M-43-84-01, "Evaluation and Comparison of

Commerical Ultransonic and Visual Inspections of Timber Piles," A. P. Smith,

Port Hueneme, CA, December 1983.

Technical Memorandum M-53-85-03, "Detection of Underground Utilities and

Obstacles with Ground Penetration Radars - An Initiation Decision Report,"

M. C. Hironaka and G. D. Cline, Port Hueneme, CA, January 1985.

Technical Memorandum M-53-82-02, "Dectection of Underground Utilities and

Obstacles - An Initiation Decision Report," M. C. Hironaka, Port Hueneme,

CA, September 1982 .

Technical Memorandum M-53-84-5, "Ground Probing Radars and Hand-Held Detectors

for Locating Underground Utility Lines and Other Objects," M. C. Hironaka and

G. D. Cline, Port Hueneme, Ca, August 1984.

NCEL Technical Memorandum M-43-81-07, "An Evaluation of Pulse Echo Ultrasonic

Techniques for Underwater Inspection of Steel Waterfront Structures,"

R. L. Bracket t and L. W. Tucker, Port Hueneme, CA, May 1981.

NCEL Technical Memorandum M-43-78-09 , "Underwater Inspection and Nondestructive

Testing of Waterfront Structures: A State-of-the-Art Assessment Report,"

R. L. Brackett, Port Hueneme, CA, February 1984.

NCEL Technical Memorandum tm no: 52-84-04, "Design and Development of a Portable Infrared Spectrophotometer for NDT Analysis of Coatings,"

T. Novinson, Port Hueneme, CA, November 1983.

NCEL Technical Memorandum tm no: 52-83-03, "Laboratory Prototype of a Portable Infrared Spectrophotometer for NDT Field Analysis of Coatings and

Other Organic Materials," T. Novinson and D. S. Kyser, Port Hueneme, CA,

November 1982.

NCEL Technical Note N-1179, "Measuring Water Permeability of Masonry

Walls," H. Hochmam, Port Hueneme, CA, August 1971.

NCEL Technical Memorandum M-55-82-01 , "Leak Detection in Underground

Utility Lines-Status Report," S. S. Wang and S. J. Oppendisano, Port

Hueneme, CA, May 1982.

C-4
APPENDIX D. ASTM STANDARDS FOR NDE METHODS FOR CONSTRUCTION MATERIALS AND

BUILDING COMPONENTS

ASTM has recognized the need for standards covering nondestructive evaluation

methods for a variety of materials and applications. Consequently, a number

of ASTM standards for NDE procedures have been issued. ASTM standards for

NDE methods for concrete are listed in Table Dl . Some ASTM standards for other

common NDE methods are listed in Table D2. As new ASTM standards for NDE appear,

they can be located by reviewing the index to ASTM standards which is published

annually.

D-1
Table Dl . ASTM Standards for NDE Methods for Concrete

NDE Method ASTM Standard and Designation

Rebound Hammer Test for rebound number of hardened

concrete: C 805

Penetration Probe Test for penetration resistance of

hardened concrete : C 803

Ultrasonic Pulse Velocity Test for pulse velocity through

concrete: C 597

Nuclear Moisture Meter

Cast-in-place Pullout

Test for moisture content of soil and

soil-aggregate in place by nuclear

methods (shallow depth): D 3017

Test for pullout strength of hardened

concrete: C 900

Visual Practice for examination of hardened

concrete in constructions: C 823

Corrosion of Rebars

Mechanical Properties

Test for half cell potentials of

reinforcing steel in concrete: C 876

Test for fundamental transverse,

longitudinal, and torsional frequencies

of concrete specimens: C 215

(laboratory method)

D-2
Table D2 . ASTM Standards for NDE Methods for Construction Materials and

Building Components

NDE Method

Acoustic Emission

ASTM Standard and Designation

Practice for acoustic emission monitoring

during continuous welding: E 749

Practice for acoustic emission monitoring

of structures during controlled stimulation:

E 569

Practice for acoustic emission

examination of reinforced thermosetting

resin pipe: E 1118

Air Leakage Method for Determining Air Leakage Rate

by Tracer Dilution: E 741

Method for Determining Air Leakage Rate

by Fan Pressurizatlon: E 779

Coating Thickness Testing Practice for measuring coating thickness

by magnetic-field or eddy-current

(electromagnetic) test methods: E 376

Measurement of thickness of anodic coatings

on aluminum and of other nonconductive

coatings on non-magnetic basis metals with

eddy-current instruments: B 244

Measurement of dry film thickness of

nonmagnetic coatings applied to a ferrous

base: D 1186

Measurement of dry film thickness of

nonconductive coatings applied to a nonferrous metal base: D 1400

Measurement of film thickness of pipeline

coatings on steel: G 12

Measurement of dry film thickness of

protective coating systems by destructive

means: D 4138 (Tooke gage)

Practice for measurement of wet film

thickness by notch gages: D 4414

Measurement of wet film thickness of

organic coatings: D 1212

D-3
Table D2 (Continued)

NDE Method

Eddy Current Method

ASTM Standard and Description

Test for electrical conductivity by

use of eddy current : B 342

Practice for In situ electromagnetic

(eddy-current) examination of

nonmagnetic heat exchanger tubes:

E 690

Practice for electromagnetic (eddy-current)

testing of seamless copper and copper

alloy tubes: E 243

Hardness Testing Hardness conversion tables for metals

(relationship between Brlnell hardness,

Vlckers hardness, Rockwell hardness,

Rockwell superficial hardness, and

Knoop hardness) : E 140

Test for Brlnell hardness of metallic

materials: E 10

Test for Vlckers hardness of metallic

materials: E 92

Test for Indentation hardness of metallic

materials by portable hardness testers:

E 110

Rapid indentation hardness testing of

metallic materials: E 103

Test for Rockwell hardness and Rockwell

superficial hardness of metallic

materials: E 18

Test for film hardness by pencil test:

D 3363

Magnetic Particle Practice for magnetic particle

examination: E 709

Specification for magnetic particle

Inspection of large crankshaft

f orglngs : A 456

D-4
Table D2 (Continued)

NDE Method

Magnetic Particle

(Continued)

ASTM Standard and Description

Reference photographs for magnetic

particle indications on castings: E 125

Method for magnetic particle examination

of steel f orgings : A 275

Terminology of symbols and definitions

relating to magnetic testing: A 340

Penetrant Testing Practice for liquid penetrant inspection

method: E 165

Reference photographs for liquid

penetrant inspection: 433

Radiographic Testing Reference radiographs for steel coatings

up to 2 in. (51 mm) in thickness: E 446

Reference radiographs for heavy-walled

(2 to 4-1/2 inch) steel castings: E 186

Reference radiographs for steel fusion

welds: E 390

Method for controlling quality of

radiographic testing: E 142

Practice for radiographic testing: E 94

Soils Inspection Method for density of soil in place by

the sand-cone method: D 1556

Methods for density of soil and soilaggregate in place by nuclear methods

(shallow depth): D 2922

Methods for moisture-density relations

of soils and soil-aggregate mixtures,

using 5.5-lb (2.49 kg) rammer and

12-in. (305 mm) drop: D 698

Method for penetration test and

split-barrel sampling of soils: D 1586

D-5
Table D2 (Continued)

NDE Method

Soil Inspection

(Continued)

ASTM Standard and Description

Classification of soils for engineering

purposes: D 2487

Method for deep, quasi-static cone and

friction-cone penetration tests of

soil: D 3441

Ultrasonic Testing Practice for measuring thickness by

manual ultrasonic pulse-echo contact

method: E 797

Practice for ultrasonic pulse-echo

straight-beam testing by the contact

method: E 114

Practice for ultrasonic contact

examination of weldments : E 164

Practice for ultrasonic examination of

heavy steel f orgings : A 388

Straight-beam ultrasonic examination

of steel plates: A 435

Practice for ultrasonic inspection of

metal pipe and tubing: E 213

Practice for measuring ultrasonic

velocity in materials: E 494

Testing for leaks using ultrasonics: E 1002

Practice for ultrasonic examination of

longitudinal welded pipe and tubing: E 273

Uplift Testing Field testing uplift resistance of roofing

systems employing steel deck rigid

insulation and bituminous built-up roofing;

E 907

Window Testing Method for strucutural performance of

glass in windows, curtain walls, and

doors under the influence of uniform

static loads by nondestructive

method: E 998

D-6
FORM NBS-1 MA (REV, n -84)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See /n struct/on s)

I. PUBLICATION OR

REPORT NO. NBS/TN-1247

2. Performing Organ. Report No. 3. Publication Date June 1987

4. TITLE AND SUBTITLE

Review of Nondestructive Evaluation Methods Applicable to Construction Materials

and Structures

5. AUTHOR(S)

Robert G. Mathey and James R. Clifton

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

7. Contract/Grant No.

8. Type of Report & Period Covered

Final

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

Naval Civil Engineering Laboratory

Port Hueneme, CA 93043-5003

10. SUPPLEMENTARY NOTES

[^21 Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a si gnificant

bibliography or literature survey, mention it here) Nondestructive evaluation (NDE) methods for evaluating in situ construction

materials and for condition assessment of building components and systems were identified and are described. This report is intended to help inspectors and those involved

in condition assessment choose appropriate NDE methods for specific building materials,

components, and systems. Important properties of building materials along with

important performance requirements for building components are listed, and appropriate

NDE methods lot determining these properties are recommended. In many cases the

advantages and limitations of the NDE methods are presented. Potential NDE methods

which may or may not require further research and development before they are ready

for routine use were also identified and are briefly described. In addition, ASTM

standards for NDE methods for concrete and other building materials and components were

identified.

In a related aspect of the study, current Navy practices relative to the use of NDE

methods in the construction and service cycle of buildings and other structures were

reviewed. This review was based on Navy reports and documents provided by NCEL and

NAVFAC, and on discussions with NAVFAC personnel involved with buildings and

structures problems where NDE methods are used for diagnostic purposes. Navy Guide

Specifications were examined for required tests, both NDE and destructive, of in situ

building materials and components

12. KEY WORDS (S/x to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

building components; building diagnostics; building materials; condition assessment;

construction materials; in situ evaluation; nondestructive evaluation

13. AVAILABILITY

[X]Un I incited

I I For Official Distribution. Do Not Release to NTIS

UT] Order From Superintendent of Documents, U.S. Government Printing Office, Washington, DC * 20402.

Order From National Technical Information Service (NTIS), Springfield, VA 22161

14. NO. OF

PRINTED PAGES

203

15. Price

USCOMM DC 85 AOOC
INSTRUCTIONS

FORM NBS-114A: BIBLIOGRAPHIC DATA SHEET. This bibliographic data sheet meets the standards adopted for use by all U.S. Government agencies. It is needed forNTIS processing and must accompany all NBS papers, those appearing in nongovernmental media as well as those in N BS series, since all reports of NBS technical work are normally entered into the NTIS system. For all GPO publications, it becomes an

Integral part of the document and is widely used by librarians and abstractors.

Items 1, 2 — Complete if information is available; otherwise Pub! ications Office will complete later. If non-N BS publication, state "see item 10" (Enter other agency sponsor's report number if requested to do so, and enter NBSIR number under item 2).

Item 3 — Complete if known; otherwise Publications Office will complete.

Items 4, 5 —Complete as shown on manuscript. When NBS-il4A is resubmitted along with NBS-266,

following publication of non-NBS media papers, these items must agree with published paper.

Item 6 — If not NBS, blank out and enter Grantee/Contractor name and address, or if performed

jointly, show both.

Item 7 — Complete when applicable.

Item 8 — Enter "Interim," "Final," or period covered.

Item 9 — Enter all sponsors* names and addresses. Include NBS if also a sponsor.

Item 10 —Enter other relevant information, i.e., related or superseded documents. Also used by

Publications Office for Library of Congress catalog number, and entry of non-N BS media

citation upon receipt of Form NBS-266 from author. Check block if appropriate and attach SFI85,

Item 11, 12 — Prepare abstract and key words with special care. These are published separately by NBS, NTIS, and other bibliographic services, and are vital elements in guiding readers to your paper. The key words will be used as entries in a subject index. See NBS Communications Manual

for additional guidance.

Item 13 — Indicate "Unlirnited" — for open-literature documents cleared under NBS editorial procedures,

or "For official distribution. Do not release to NTIS" — for limited, restricted, or need-to- know material (See Communications Manual). Publications Office will mark appropriate

"order" box and complete Stock Number when known.

Items 14, 15 -Leave blank. NBSIR's,

To be completed by Publications Office or call Printing and Duplicating for

FORM NBS-1 MA (REV. 1 1-84) USCOAAM-DC 85-6006

>U. S.GOVERNmENT PRINTING OFF ICE 1

1

988- 20

1

-597 i82531


NBSTechnical Publications

Periodical

Journal of Research—The Journal of Research of the National Bureau of Standards reports NBS research and development in those disciplines of the physical and engineering sciences in which the Bureau is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Papers cover a broad

range of subjects, with major emphasis on measurement methodology and the basic technology underlying

standardization. Also included from time to time are survey articles on topics closely related to the Bureau's

technical and scientific programs. Issued six times a year.

Nonperiodiccds

Monographs—Major contributions to the technical literature on various subjects related to the Bureau's scientific and technical activities. Handbooks—Recommended codes of engineering and industrial practice (including safety codes) developed in cooperation with interested industries, professional organizations, and regulatory bodies.

Special Publications—Include proceedings of conferences sponsored by NBS, NBS annual reports, and other

special publications appropriate to this grouping such as wall charts, pocket cards, and bibliographies.

Applied Mathematics Series—Mathematical tables, manuals, and studies of special interest to physicists,

engineers, chemists, biologists, mathematicians, computer programmers, and others engaged in scientific and

technical work.

National Standard Reference Data Series—Provides quantitative data on the physical and chemical properties

of materials, compiled from the world's literature and critically evaluated. Developed under a worldwide pro- gram coordinated by NBS under the authority of the National Standard Data Act (Public Law 90-396).

NOTE: The Journal of Physical and Chemical Reference Data (JPCRD) is published quarterly for NBS by

the American Chemical Society (ACS) and the American Institute of Physics (AIP). Subscriptions, reprints,

and supplements are available from ACS, 1155 Sixteenth St., NW, Washington, E)C 20056.

Building Science Series—Disseminates technical information developed at the Bureau on building materials,

components, systems, and whole structures. The series presents research results, test methods, and perfor- mance criteria related to the structural and environmental functions and the durability and safety

characteristics of building elements and systems.

Technical Notes—Studies or reports which are complete in themselves but restrictive in their treatment of a

subject. Analogous to monographs but not so comprehensive in scope or definitive in treatment of the subject

area. Often serve as a vehicle for final reports of work performed at NBS under the sponsorship of other government agencies.

Voluntary Product Standards—Developed under procedures published by the Department of Commerce in Part 10, Title 15, of the Code of Federal Regulations. The standards establish nationally recognized re- quirements for products, and provide all concerned interests with a basis for common understanding of the

characteristics of the products. NBS administers this program as a supplement to the activities of the private

sector standardizing organizations.

Consumer Information Series—Practical information, based on NBS research and experience, covering areas of interest to the consumer. Easily understandable language and illustrations provide useful background

knowledge for shopping in today's technological marketplace.

Order the above NBS publications from: Superintendent of Documents, Government Printing Office,

Washington, DC 20402. Order the following NBS publications—FIPS and NBSIR's—from the National Technical Information Service, Springfield, VA 22161.

Federal Information Processing Standards Publications (FIPS PUB)—Publications in this series collectively constitute the Federal Information Processing Standards Register. The Register serves as the official source of

information in the Federal Government regarding standards issued by NBS pursuant to the Federal Property

and Administrative Services Act of 1949 as amended. Public Law 89-306 (79 Stat. 1 127), and as implemented

by Executive Order 11717 (38 FR 12315, dated May 11, 1973) and Part 6 of Title 15 CFR (Code of Federal

Regulations).

NBS Interagency Reports (NBSIR)—A special series of interim or final reports on work performed by NBS

for outside sponsors (both government and non-government). In general, initial distribution is handled by the sponsor; public distribution is by the National Technical Information Service, Springfield, VA 22161, in paper copy or microfiche form.
U.S. Department of Commerce

National Bureau of Stahdards

Gaithersburg, MD 20899

Official Business

Penalty for Private Use $300

v^^"°^e,

Stimulatrng America s Progress 1913-1966