u T'

ij AlllOD T103S2 — NBS

PUBLICATIONS

NBSIR 80-2171

Selected Methods for Condition Assessment of

Structural, HVAC, Plumbing and Electrical

Systems in Existing Buildings

•' c. Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Washington, DC 20234

•"•tAU o» ^

U S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

Frank H. Lerchen

James H. Pielert

Thomas K. Faison

NatiQnai;,But^^

2 7 1981

nCi-t CLCr -CJrCOc too

&

. ush

NBSIR 80-2171 “ MSO

SELECTED METHODS FOR CONDITION ASSESSMENT 6f

STRUCTURAL, HVAC, PLUMBING AND ELECTRICAL

SYSTEMS IN EXISTING BUILDINGS

Frank H. Lerchen

James H. Pielert

Thomas K. Faison

Building Economics and Regulatory Technology Division

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Washington, DC 20234

November 1980

Sponsored by the: Energy, Building Technology and Standards Division

Office of Policy Development and Research

Department of Housing and Urban Development

Washington, DC 20410

and

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Washington, DC 20234

U.S. DEPARTMENT OF COMMERCE, Philip M. Klutznick, Secretary

Jordan J. Baruch, Assistant Secretary for Productivity, Technology, and Innovation

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
iiS

«wa

•' :eei >{ s a3^

^irvr^-08 mgairt

lu i >mai/ic j bq^ aaoH^ l^^

JADlHf03J3 O^/'tA Dl/IiaMUJ*^ OAVH *JARUT0UflT8

ec)WMJ^Ja Dt>1lT8IX3 \A\ ZMBTZYZ

nufloioj .H,

noeio^ .X'

noieiviq bn« io«rm..oo3B V

j'r,nflof*T on»W'w9 K>T .

it>i6L-n«i3 W iwwi'S {»no»f

^k£SOC r)Q .noigniriiiW

06€r tedn.avoW

Hfii yd b®^«noq2

.otetviO iJt)i6Lw«l2 0.18

bnjs fn6'tvM>,.'':»veO ip<la*i

^ yainO

in©f»*»voa nsdiU On® auoH k. jn6*.Tine<|»a ^

01 K:.S OQ ,noronirt26W

bna

. ^ ^ibiiijB ^o\ vjjjnaO

•'

' Y^roTfi,>od6J nnhswnifXT i ler^oiiaM

L'k’. ..I,-- .‘-ibiGOncJii; lo gBanuS IsnoiJR^

DO noienifts^W

1 - .3OflA0aWra IJA3

l.r.' E . ’ id '<K) •«: ^rHA<»:
MOST COMMON SI UNITS AND THEIR

EQUIVALENT VALUES IN

CUSTOMARY UNITS

INTERNATIONAL CUSTOMARY

(SI) UNIT UNIT APPROXIMATE CONVERSION

LENGTH eter (a) foot (ft) 1 a - 3.2804 ft Billlaeter (an) inch (in) 1 mm - 0.0394 in

AREA square aeter (a^) square yard (yd^) 1 - 1.1960 ydj square foot (ft^) 1 B^ - 10.764 ft^, , square Billlaeter (aa^) square inch (in^) 1 aa^ - 1.55 X 10“^ in

VOLUME cubic aeter (a^) cubic yard (yd^) la^ - 1.3080 yd^

cubic foot (ft^) 1 B^ - 35.315 ft* , cubic allllaeter (bb^) cubic inch (in^) 1 - 61.024 X 10 ® in

CAPACITY liter (L) gallon (gal) 1 L * 0.2642 gal

VELOCITY. SPEED aeter per second (a/s) foot per second (ft/s) 1 a/s - 3.2808 ft/s

kilometer per hour (ka/h) Bile per hour (alle/h or a.p.h) 1 ka/h “ 0.6214 aiile/h

ACCELLERATION aeter per second squared (a/s ) foot per second squared (ft/s ) 1 a/s^ - 3.2808 ft/s“

MASS metric ton (t) ton (2000 lb) 1 t - 1.1023 ton kilogram (kn) pound (lb) 1 kg - 2.2046 lb gram (g) ounce (oz) 1 8

- 0.0353 oz

DENSITY metric ton per cubic aeter (t/a^) ton per cubic yard (ton/yd^) 1 t/m^ 0.8428 ton/yd^

kilogram per cubic aeter (kg/m^) pound per cubic foot (Ib/ft’) 1 kg/m^ - 0.0624 Ib/ft^

FORCE kilonewton (kN) ton-force (tonf) 1 kN • 0.1124 tonf kip (1000 Ibf) 1 kN - 0.2248 kip newton (N) pound-force (Ibf) 1 N - 0.7376 Ibf

MOMENT OF FORCE. kilonewton aeter (kN<a) ton-force foot (tonf. ft) 1 kN*m - 0.3688 tonf/ft

TORQUE newton aeter (N^m) pound-force inch (Ibf

10) 1 N.m - 8.8508 Ibf. in

PRESSURE. STRESS megapascal (MPa) ton-force per square inch (tonf/ln^) 1 MPa - 0.0725 tonf /inf

kllopascal (kPa) ton-force per square foot (tonf/ft^) 1 kPa « 10.443 tonf/ft

pound-force per square inch(lbf /in^) 1 kPa - 145.04 Ibf /in

pascal (Pa) pound-force per square foot (Ibf /ft^) 1 Pa - 20.885 Ibf /ft 2

WORK, ENERGY. kilojoule (kJ) British theraal unit (Btu) 1 kJ - 0.9478 Btu QUANTITY OF HEAT ioule (J) foot pound-force (ft* Ibf) 1 J - 0.7376 ft-lbf

COEFFICIENT OF HEAT watt per square meter kelvin Btu per square foot hour degree 1 W/(m^.K) - TRANSFER (U-Value) (W/m'^.K) Fahrenheit (Btu/ft^.h**F) 0. L761 Btu/(ft^.h.’F)

THERMAL CONDUC- watt per meter kelvin (W/m*K) Btu per foot hour degree Fahrenheit 1 W/(m.K) TIVITY (k-Value) (Btu/ft.h.’F) 0.5778 Btu/(ft-h-*F)

MOTES: (1) The above conversion factors are shown to four significant digits, where appropriate.

(2) Unprefixed SI units are underlined. (The kilogram, although prefixed, is an SI base unit.)

REFERENCES: NBS Metric Guidelines, LC1056, August 1977; NBS Special Publication 330, "The International System of Units (SI);” NBS Technical Note 938, "Recommended Practice for the Use of Metric (SI) Units In Building Design and Construction;” ASTM Standard E621-78, "Standard Practice for the Use of Metric (SI) Units In Building Design and Construction;”

ANSI Z210-1976, "American National Standard for Metric Practice;" ASTM E380-76, or IEEE Std. 268-1976.

iii
TABLES OF CONTENTS

Pages

MOST COMMON SI UNITS AND THEIR EQUIVALENT VALUES IN

CUSTOMARY UNITS Ill

FIGURES AND TABLES vll

ABSTRACT vlll

ACKNOWLEDGEMENTS lx

PREFACE X

1. INTRODUCTION 1

1.1 CONDITION ASSESSMENT PROCESS 1 1.2 FORMAT AND LIMITATIONS OF THE REPORT 3

1.3 EVALUATION METHODS 3

1.3.1 General 3

1.3.2 Age of a Structure 4

1.3.3 General Considerations In Selection of

Test Methods 5

1.3.4 Definitions 5

1.3.5 References 5

2. STRUCTURAL MATERIALS 6

2.1 CONCRETE 6

2.1.1 Nondestructive Tests 6

2. 1.1.1 Visual-Optical Inspection 13

2. 1.1. 2 Rebound Test 16

2. 1.1. 3 Penetration Test 17

2. 1.1.4 Electrical Tests 18

2. 1.1. 5 Electro/Magnetic Test 20

2. 1.1. 6 Acoustic Tests 21

2. 1.1. 7 Ultrasonic Test 23

2. 1.1. 8 Radiographic Tests 23

2. 1.1. 9 Microwave Absorption Test 25

2.1.1.10 Dynamic Tests 26

2.1.1.11 Nuclear Tests 27

2.1.1.12 Infrared Test 28

2.1.1.13 Load Test 29

2.1.1.14 Radar Test 30

2.1.1.15 Pullout Test 31

2.1.2 Destructive Tests 32

2. 1.2.1 Core Drilling 33

Petrography 34

Iv
TABLES OF CONTENTS

Pages

2.1.3 References 36

2.2 WOOD (STRUCTURAL TIMBER) 39

2.2.1 Visual Tests AA

2.2.2 Penetration Test A6

2.2.3 Metered Tests A8

2. 2. A Miscellaneous Tests 50

2.2.5 References 5A

2.3 METALS 56

2.3.1 Nondestructive Evaluation of Metals 56

2.3.2 Destructive Evaluation of Metals 68

2.3.3 References 70

2.

A MASONRY 71

2.A.1 General 71

2. A. 2 References 77

3. HEATING, VENTILATING, AND AIR CONDITIONING SYSTEMS (HVAC) ... 79

3.1 BUILDING ENVELOPES 79

3.1.1 Evaluating the Amount of Air Leakage Using

Air Pressure 79

3.1.2 Determining Air Exchange Using Tracer Gas 80

3.1.3 Determining Paths of Leakage Using

Thermography 81

3.2 BUILDING INTERIORS 81

3.2.1 Determining Humidity with Color Changing

Agents 81

3.2.2 Determining Humidity with an Electric

Hygrometer 82

3.2.3 Determining Heating System Efficiency by

Using Electric Co-Heating 83

3.3 MISCELLANEOUS TESTS FOR HVAC SYSTEMS 8A

3.3.1 Physical Inspection 8A

3.3.2 Determining Wall Thickness of Containment

Vessels 85

3.

A REFERENCES 85

V
TABLES OF CONTENTS

Page

4. PLUMBING SYSTEMS 87

4.1 PLUMBING SYSTEMS COMPONENTS 87

4.1.1 Determining Condition of the Plumbing

System 87

4.2 DRAINAGE AND VENT SYSTEMS 90

4.2.1 Water Testing for Leaks 90

4.2.2 Air Testing for Leaks 91

4.2.3 Trap Tests 92

4.3 REFERENCES 93

5. ELECTRICAL SYSTEMS 95

5.1 ELECTRICAL BRANCH CIRCUITS 95

5.1.1 Determining the Condition of the System 95

5.1.2 Determining Electrical System Efficiency 97

5.1.3 Circuit Analysis 98

5.2 ELECTRICAL CIRCUITS 99

5.3 REFERENCES 100

Vi
FIGURES AND TABLES

Page

FIGURE 1 Evaluation Plan 2

TABLE 1 Concrete Test Methods and Parameters 7

TABLE 2 Test Methods for Concrete 8-12

TABLE 3 Test Methods for Wood 40-43

TABLE 4 Test Methods for Metals 58-60

TABLE 5 Types of Magnetizing Currents in Magnetic Particle

Testing 66

TABLE 6 Test Methods for Masonry 72-76

vii
ABSTRACT

This report was developed with the intent of assisting government officials,

designers, builders, code officials, and others involved with evaluating the

condition of existing buildings to determine whether it is feasible to

rehabilitate the building and its systems (e.g., structural, mechanical,

electrical, etc.).

The report describes evaluation methods specifically for use with the structural materials of concrete, steel, masonry, and wood, as well as for use with

the heating/ventilating/air conditioning, plumbing, and electrical support

systems. Both commonly used field methods and other possible laboratory

methods are described for the reader. Comparative tables are provided where

possible to aid in making a selection of the evaluation method most appropriate for the particular parameter to be tested.

Keywords: Building rehabilitation; concrete; electrical; evaluation; HVAC;

masonry; plumbing; steel; structural systems; test methods; wood.

viii
ACKNOWLEDGEMENTS

The authors would like to extend appreciation to those individuals who generously

provided information on many aspects of the assessment of existing buildings.

Special appreciation is extended to Mr. James G. Gross, Chief, Building Economics

and Regulatory Technology Division, CBT, NBS, for overall direction of the

report; Mr. William J. Meese, General Engineer, NBS, for input in the electrical

area; Dr. James R. Clifton, Research Chemist, NBS, for input on evaluation of

concrete; Messrs. David P. Crist and Jeffrey F. Clark, students of engineering

at Purdue University and Carnegie-MelIon University, respectively, for their

overal assistance; and Mary M. Chaney, Secretary, Rehabilitation Technology

Group, CBT, NBS, without whose clerical assistance the completion of the report

would not have been possible.

It is with great appreciation, also, that the authors acknowledge the efforts

of individuals outside the National Bureau of Standards in providing a review

of the report for technical accuracy. In particular, appreciation is extended

to Dr. V. M. Malhotra, P.E., Head, Construction Materials Section, Department

of Energy Mines, and Resources, Canada, for his review and comments on concrete

evaluation; Mr. William L. Galllgan, Project Leader, Engineering Properties of

Wood, Forest Products Laboratory, Forest Service, U.S. Department of Agriculture;

and Mr. Alan H. Yorkdale, P.E., Director of Engineering and Research,

Brick Institute of America.

ix
PREFACE

The research to develop this report was conducted by the Rehabilitation

Technology Group, Building Economics and Regulatory Technology Division,

National Bureau of Standards. The report contains a general description of

methods currently available for condition assessment of the following building

systems: structural; heating, ventilating, and air conditioning (HVAC);

electrical; and plumbing.

The intended audience for this report Includes government officials, designers,

builders, code officials, and others involved with making technical decisions

on building rehabilitation. It is not aimed at a non-technlcal audience

unfamilar with the performance of building materials and basic engineering

principles

The report was developed with partial funding from the Department of Housing

and Urban Development (HUD) through the Division of Energy Building Technology

and Standards of the Office of Policy Development and Research. Additional

funding for the effort was provided by the National Bureau of Standards (NBS)

Center for Building Technology (CBT) through the development of building condition assessment data in the structural area by the Building Rehabilitation

Technology Group.

This report is not presented as an all-inclusive listing of building condition

assessment methods. Additionally ^ neither NBS nor HUD endorses or claims to

have evaluated all of the methods described in this report. It is anticipated

that this preliminary report will be periodically updated, and the authors

would appreciate comments and recommendations for revisions

,

X
1 . INTRODUCTION

The process of rehabilitating an existing building can present unique construction problems because most of the building systems within it may be affected.

Thus, it becomes necessary to assess the condition of the systems in order to

determine their ability to support the modifications.

Condition assessment techniques vary from rather simple visual inspection to

more complicated laboratory, or in-situ, testing which may require sophisticated

equipment and operating personnel. While this report presents some information

on visual techniques, its primary thrust is toward the more technically complex

evaluation techniques. This report lists such methods currently available to

assess the following building systems: structural; heating, ventilating, and

air conditioning, (HVAC); electrical; and plumbing. Such information can assist the building owner, designer, builder, or regulatory official in making

decisions on the type and magnitude of modifications required in a building

undergoing rehabilitation.

1.1 CONDITION ASSESSMENT PROCESS

Building condition assessment is just one phase of the overall rehabilitation

process which includes social, economic, and political as well as other technical facets. Figure 1 shows an outline of the various aspects of condition

assessment as they relate to different stages of a rehabilitation project.

Section 1.2 suggests how the information in this report can be useful in the

building condition assessment process.

The preliminary evaluation phase of a rehabilitation project usually is based

on information collected in both on and off-site Investigations. The on-site

investigation can include a general site examination, a building condition

survey which includes sketches and photographs, selection and collection

of specimens for analysis, document collection related to the configuration

and performance of the building, simple field testing, and owner/ occupant

interviews. The purposes of this on-site investigation are to; (1) identify

the types of construction in the building (structural, plumbing, electrical

and HVAC systems); (2) provide data for an initial assessment of the condition

and capacity of these components (e.g., extent of deterioration of concrete

structural members); (3) determine the actual occupancy related loads (structural, plumbing, etc.) to which the structure will be subjected; (4) obtain

indications of the past performance of the building (e.g., maintenance records);

and (5) identify areas where more detailed analysis may be required.

Additional information may be obtained off-site during the preliminary evaluation to provide a more complete picture of a building and its potential for

rehabilitation. Such investigation may consist of theoretical analysis of

system performance, testing specimens removed during on-site investigations,

and gathering and reading documents. The latter Includes drawings, specifications, construction records, operation and maintenance data, records of

alterations made to the building, information on original materials in the

building, and site records. Documentation of this type may be available from

the builder, facility engineer, building contractor, surveyor, building

official, or the builder designer.

1
2

Preliminary

Evaluation

Detailed

Evaluation
The results of on and off-site investigations should be used together to assess

the feasibility of rehabilitating a building. It should not be assumed that

the actual construction of a building is as shown on drawings and specifications.

If a decision is made to proceed with the rehabilitation and it is felt more

information is needed, a detailed evaluation phase should be carried out.

This could include in-situ or laboratory testing of specimens removed from the

building, and more detailed analysis of the building based on better definitions

of materials' properties and component performance. Building information

collected in this systematic process provides the basis for the analysis and

redesign of the building to be rehabilitated.

1.2 FORMAT AND LIMITATIONS OF REPORT

The building condition assessment methods in this report are organized as follows:

Chapter 2 - Structural Materials

Chapter 3 - HVAC Systems

Chapter 4 - Plumbing Systems

Chapter 5 - Electrical Systems

Since many assessment techniques are available, it is not possible to provide

the level of detail which allows the user to apply each technique directly.

Instead, a presentation format is used which includes either a summary table or

a short discussion of the principles involved in using the technique, a listing

of advantages and limitations of the technique, and references to additional

information.

The Intended audience for this report includes designers, consultants, builders,

code officials, government officials, and others involved with making technical

decisions on building rehabilitation. While the report is directed toward the

technical audience, it also provides policy makers with an awareness of some

of the economic and technical Issues that affect rehabilitation decisions. For

example, economic and technical data on the condition of a building must be

made available to those making financial arrangements for rehabilitation

programs.

Reference numbers at the end of each section are to indicate the general sources

of information contained within that section.

1.3 EVALUATION METHODS

1.3.1 General

Finding and studying good documentary evidence of the design and/or construction phase of a building is the most satisfactory method to evaluate its

behavior. If documents are not available, more costly and time consuming

methods or performing field and/or laboratory tests may be the only way to

obtain sufficient data on which to base an evaluation. The best solution, of

3
course, is to obtain original design and construction contracts and to have the

option of using field and laboratory tests to confirtn the contract documents.

For the structural system, one of the most useful, but most expensive, methods

to determine structural behavior is the full-scale load test of a building.

The main drawback to this method is the possibility of causing permanent

structural deflections or even structural failure. Many alternatives^ such as the following, are available and should be considered:

1) Review any test previously conducted and interpolate the effect elapsed time

may have on estimates of strength properties.

2) Field test certain structural components (using laboratory tests where

needed) and analytically apply the test results to evaluate the entire

structure.

3) Test scaled-down models (with either the same or analogous materials).

4) Analyze the performance of similar structures and apply the results of the

analysis to the structure in question.

Evaluating existing HVAC, plumbing, or electrical systems presents a special

problem since they usually are concealed. Often, inspection and testing of

critical elements of these systems may not seem to be feasible after the initial

construction of the building. Frequently, this difficulty results in a preference for new construction or total replacement rather than selective

rehabilitation. However, techniques such as those mentioned in this report

for evaluating these systems may provide a key to determining the performance

of the system adequately enough to make a sound decision in favor of selective

rehabilitation (even though complete Inspection may not be possible).

Current methods of analyzing the properties of materials and systems can be

very helpful in determining safe load capacities and performance levels as well as limit states (deflection, stability, etc.). But, the soundness of any

evaluation still rests ultimately on experience and sound judgment on the part

of the Investigator. It should be remembered that, while the evaluation methods

mentioned in this report generally are recognized as being good practice, it

is advisable to consult local codes and building officials on any specific

local performance requirements for the building and its systems.

1.3.2 Age of a Structure

Often it is helpful to know the date of construction of a structure so that

the investigator can use the then-current codes and journals as a fairly

reliable source of design practices and strengths of materials. In cases where conclusive documentation is not available, dates can be estimated by

architectural style.

A
1.3.3 General Considerations in Selection of Test Methods

One of the keys to success in the evaluation of materials and/or systems of a building is to recognize the existing conditions which require evaluation and

then to use testing techniques which are best suited to evaluating those

conditions. Summary charts and brief descriptions of some appropriate test

methods to use for given test conditions and for the specific parameters to

be evaluated are provided.

While equipment operating costs and material costs are Important factors to

consider in selecting the appropriate test method to use, this report does not

cover this cost aspect.

1.3.A Definitions

A. Nondestructive Evaluation - The process of inspecting, evaluating, and/or

measuring the properties of materials or systems without changing, damaging,

or destroying the properties or affecting the service life of the test specimen.

B. Destructive Evaluation - The process of inspecting, evaluating, and/or

measuring the properties of materials or systems in a manner which can change,

damage, or destroy the properties or affect the service life of the test specimen.

1.3.5 References:

Kemp, E., "An Introduction to the Structural Evaluation of Historic Reinforced

Concrete Structures,” CONCRETE INTERNATIONAL, (October, 1979).

"Standard Method for Load Tests of Floors and Flat Roofs," E 196, American

Society for Testing and Materials, (1974).

5
2. STRUCTURAL MATERIALS

2.1 CONCRETE

With the techniques available for evaluating concrete properties, the building

official, contractor, designer, or owner can be selective in determining which,

if any, of the components of a concrete structure need repair or replacement.

This ability to evaluate and selectively rehabilitate has been a significant

factor in encouraging rehabilitation of concrete buildings (as opposed to

complete replacement).

The following discussion provides an overview of methods available to evaluate

the concrete components of a building. Some of the techniques described can

be accomplished easily with little or no special training, while others are complex in nature and will require a specialist to conduct the test and interpret the results. Tables 1 and 2 provide a guide for selection of the test

methods available to determine various parameters of concrete which are discussed in more detail later.

2.1.1 Nondestructive Tests

The objective of this section is to present currently available methods for

nondestructive evaluation (NDE) of concrete properties which assist the examiner

to evaluate physical properties and performance.

NDE includes a system of test methods to: (1) estimate the properties of

concrete material (such as compositional variations, hardness, strength, modulus

of elasticity, and integrity), (2) detect harmful defects in the concrete

(such as cracks, seams, voids, porosity, non-bonds, and inhomogeneities), and

(3) determine physical dimensions of the concrete as well as location and size of

reinforcement. NDE also can be used to determine conditions of internal stress

without damage to the specimen.

This information is useful in: (1) determining the condition of concrete

members (after they have been used for a long period of time), and (2) monitoring

concrete to detect signs of failure. In many cases (such as the investigation of cracks in concrete) nondestructive tests may be the only reasonable means of determining the extensiveness of the damage.

Selection of the most appropriate and effective method for nondestructive

evaluation of the concrete requires sound judgment based on the needed

information and the cost of the evaluation. Generally, on-site nondestructive

or destructive testing should be preceded by a visual inspection of the concrete

in all accessible parts of the structure and is used to evaluate further the

effects of already observed distress on the concrete members. A good general

procedure to follow (in order of priority) is to use: 1) visual evaluation,

2) NDE, 3) destructive evaluation, and lastly 4) load tests. Past photos and

written records which could reveal changes in the condition of the concrete

should be reviewed when available. In other words, in-situ testing can be used

to correlate strength and condition estimates already derived from the visual

inspection.

6
CONCRETE TEST METHODS AND PARAMETERS

Table No. 1

7
REFERENCE 

METHODS

CAPABILITIES

DEGREE

OF

SENSITIVITY

APPLICATIONS

ADVANTAGES

LIMITATIONS

PAGE

NO.

'd' <

rH fH c G •30 o a 0 •H

•H •H •H 4J 4J 4J I y y y y H 4J u y • •H 3 *3 a C *3 y y *3 y rH y iH Ml 3 V4 o C 3 4J ,3 y *3 M y y y y

y

y o 0 a 3 M 4-> y 0 0 U > 0 *3 Ml Vt • CM x: CM 4J y •H O •H •H ?s y y a y y y y y y 0 Ml c y y y 3 <M U y *3 pH 3 •3 > 0 oc

y

•H

y *3 • y 3 0 y

y > •3y iH *H »3

y •H

y 3 3 Ml

yy

G 3. *3 4J

y >s Cl

M 3 •H 0 y

y

u 3 y 00

y 0 y

y

y 02 CM

ya

yy

y

yy 3 0 y Ml

y 0 y pH

y •pHM

M

yu

y 3 73

y 3 y CM *3 Ml •H CM • 0 0 3 Ml Ml 3 y 3 y y •H y 3 0 3 0 y 3 3 3 x: Ml y • y y y

<M • yy

a

y 3 y P •H *3 0 x: rH 0 < Vi . 0 0 y

y

yy

u c c rH •u o y 4J

y Vt •H

u p3 •H 0 Vi •H •Hu *3

y > •H

y

y 3 y c y y y y «H y y y 3 y 4J y Mi Ml y Ml Ml 0 y Mi •H •3 Ml u > y u M 4J •H 4J X) M > •H y y a y y • y y y y Vi y y 3 y Ml y y 0 y *3 y 1 u y y y •H *3 y 3 y y 3 •H 3 3 •H M 0

>. CO

d

y

u *3

y 4J

y 00y Viy rH

y pH 3 XI iHy rH rH 3 3*

yy 3

rM

M D.

ay •3 3 y 4J

y iH •H

a 3 yy

y rH

y 3 y

y & y 3 G y y a CM y a M 0 X5 y 0 x: a 0 iH > y 0 > y y *3 XE 0 y O •H •o y o M O. a pH 0 < 3 y H y CM y y 3 y y X M y w H y •H y V4 *3 3 y y y y 0 CM • y 3 *3 y >s •H 0 y 3 *3 1 Ml y o y u M CM a y y y y y a y y y y a 0 y y Ml y rH y y y c y y • a u y x: rH y •H Cl y Ml CM CM pH y y C 3 M Ml 3 XI X5 a y 3 • 0 o y y •3 a 0 4J y a 0 0 •H 3 3 y 1 a y •H *3 y O •H MH y 3 y •H y rH •H y Ml x: y y > rH u y M y pH Ml a > a 3 00 3 M 3 > y XI

•H

y 4J

y 4Jy *3yy

y 3 y •H

y rHy •H 0 0 • XI

y •H 3 pH

y rH 3 0. • •H •H to

yy •H

y *3a XE •H CM hH

y

y *3

C

y

y

y

M

a

y

O 3 a •3 *3 Ml •H Ml 3 3 3 y Ml 0 Mi Ml 3 3 y

yy

a

y

y »Hy

y

y

y •Hy Mlyy

y

y Vi

A 3 y

y

y

y Ml

a

aa >%*3u «H 4J

y 4J 0 > 3 Vi

y Vi

ay •H 3 V rH

y

y

y

ay

y

X

y •H

y rH

yd pH •H •H 0 y

y

X > > 3 y

y 0 00 a. •*HX Vi

y 3 C 4J x:

y iH

M »3 Vi

a > 3 y Vi 0 y

y

y

y

y XI

y *3

y c o 3* y o M >v y y 3 U y 3 3 0 3 3 0 •H 92 pH y g 3 3 3 3 CL M c y CJ 3 O CJ u X5 y 0 *3 < y •H y M y Ml Ml a CJ M •H •H y M y 0 y y CM 1 • 0 *3 • 3 3 0 • 3 y y y •3 Mi y y

rH

y

O •H

y

A 0 3 w Ml

y 3 Vi

y > u o y M a -H a y y 3 •H Vi 3 y y •H Vi y > 0 0 y y M 3 {4 M }H iH u y Vi 0 Ml Ml *H Vi 3 0 X y a y U y 3 4J 3 y y y y y 3 M 3 •H y y 0 y 3 x: y Ml y 3 y y 4J ^ 4J 3 4J > M y y y M y y 3 3 y 0 y u y y Ml

Vrf iH *H

My

Ou

y •H

a

My 3 Vi 0 0 XI 0 y

y

M rH •H

y O.yy 3 a 00

y *3 4J

y

y 3 y Miy 3 y rHy

y

y 3 y Cly

G

a 1 c Ua 3 y •H > 3 Vi 3. 3 0 3 yy

u

y 3 a 1 O y C 0 4J o 0 ^ 0 0 0 M X 0 M «H 3 y 0 Vi Vi 0 0 y 3

CJy •Hy

y

y 0 4J

y

a

y

y Cd

y 0 Mi •H CJ Ml

y

yy 0 y •H

y c 4J o 3 • y y • A y y y y a y y oc /rs g > u *3 y y y *3 x: XE 3 • g V y •H y > y u Ml •H y XE CM 3

CM JZ 0 4J Mi Ml 0 0 a

y

U-t

u

u

a

y CM 3 3 y 00 CO 3 0 o y 3 *H • y 0 0 y •3 3 CO 0 3 M 3 G y 3 /—S iH M y • a y 41 A y rH 0 CM 0 c O M y y x: 3 00 M 3 y y y iH 60 •H •H o Wi 4= M •3 y M »3 M 0 3 3 a 3 Vi 0 3 3 Ml XE Ml •H y M y rH •H 3 •H •H y y 00 M •H y y Mi y M *M O iH y <M M y 3 y >» a *3 pH y a. 3 *3 a pH 00 M y a O iM .3 •H y ^ •H •H y 3. 3 y y *H •H 0 3 a • 3 3 XI y a y -3 3 3 y > •H y 3 •H iH cn y •H *3 y y •H w m y a 3 OO M f>^ 4J y u 3 a 3 > y Vi Pu 3 y rH Vi iH y 1 y y y M y •H M 3 3* y y 01 y 0 CM y u* y y Ml y Q CM y NM 4= a c/5 a s a y y a a *3 0 *3 y 3 CJ y y y y y pH

Ml x:

y

y

y CM • pH

y 3 y 3 y y y 0 a y y y CM 00 CM rH •H •H XE M y • A y 3 A y y y 3 O y y 0 x: x: y y y 3 y y Vi y y • CM y •H *H • y IH ^ y Ml 3 y 0 Vi *3 Ml y *3 CM y M 35 3 c CM M y y Ml •H y Q X •H y 3 Ml Ml •H CM u rH 3 •H o y 3 4J a M CM y y > y Ml iH y y 3 0 •H 3 XI y a

•H

yyy 3 •H 0 0 3 y

A • A •H pH •H > y

y • V

My

M

U

yM CM 0 -Hy 00

A •3 •H • A rH

y pH

y

y

y

yy 3 y

a *H *3a Mi 3 y 3 CM

y

y

y

A 0 hH

y

y Ml

y CM

y CM

y x:

y Ml Ml 3 y

y •Hy 0 00

y Mi

y

y Mly

M

y

y

M

u

y CM > M

y •H *H pH Vi rH 3 y Ml

y •H

y pH > 3 3 *3

y 3 y Ti 0 •H

y •3

X5 y iHy 3 a

a

yy CM XE

yy •3

Q

y

a

y Vi 3 >. 0 3 y

y *3 •H

yy Mly Mly Vi Vi x: y 0 y U 0 3.XI 3 0 y x: y u u y y y y 0

CJ > y

a 0.

y

y

yy *IH

y

y 0 y 0 a. hh x: CM

G * iH O oc y

•H 3 rH ij

M

M •H

y 3 3 a Ml '3 5 »H y >% y 0 y >> y z •3 3 < CJ y y y «H N a Ml y M y ED •H 3

ED

M 3 a > M •Hy 3 > hH 0 a 0 C/5 H y y 1-4 H *3 M > •H M Ml PQ x: X5 hH Ou *»-» c 3 y 3 0 0 0 3 •H a Cd y y > O > M CO > y PE X CO Cm 0 02 w 02

C

Q>

O

U ^

COu

CO T5

4J

C

•H

O 0 u co

•H

C3o

Xi

0) 0^ 0» W P Wi

CO a;

(0 c; 0) 3

O' IQ) 3

02 CJ

•3 • C ^

CO occ0)

a; qj > 3

CO

COWi • 3 CO 4J M O 0) 3 ^aG

>>C

O

4J o a o

•H -H 3 > u

•H CO CO 4J iH -3 3 C U 0^ C rH O. 3y

CO o> 3 o yy • CO (0

a*

a o

(i> I 3

l-i <u

0) Q) CL U o y *3 M 3 C * 3 y o y 4^ mh y C OO O p c O C 3 y y (0 x: 4J

}-i

y CO CM 4J H *H *H O C/2 M 3 *3

y

ocyaco 8
a

Cx3 zMHZo

U3H

U

O

O Z z

b3

M 0^ P U < Pu pu 3 ,3 c 4J 3 4-1 3 3 >^ 3 1 pH 3 • 4J 4J o 3 1 M •3 1 3 4-1 3 fH •H 3

pH •HM 3 PO •H

M

G 3 3 1 3 3 3 a 3 -X

y 3 3 M c 4H 4H • 3 (4-1 4H 3 3 •H •H >* U 3 a 3 O 3 M M a 4-> 4H 3 3 C 3 3 X a o 3 3 fH 3 3 4J 3 •H •H •H PO M O O 3 3 3 y M o «H C 4H X •p4 o 3 CL M M •H O •3 3 4-t 3 *3 3 > (4H a y U •H 3 3 PO 3 3 O 4J U a 3 4-t 3 y 3 cr 3 •H 'O 3 fG 3 3 4H 3 3 3 4J M P. c pH a 3 3 3 3 3 3 M 3 3 N o 3 3 4-> «p4 M •H 3 M 3 >> *o •3 3 3 3 M 3 3 4J PO 3 o •H M o 3

ss 3 3 *3 3 (4H

O (4-1

MM 3 M 3 a 3 *3 4J 3 •3 pH >. 3 3 o 3 3 M o 3 4J *3 O 3 y o 4-t 3 CL O 4J 3 3 iM M 3 3 M 4J M 4J (M M PO 3 C •H M 3 > 3 (4-1 •H > 3 N 9 *3 •H 3 3 M 3 3 (4H -o O rH x: H 3 M •H > c M PO ,C y a 3 •H 3 3 3 4J 3 4-t M • o pH 3 < a y O o O c 4-t 3 3 •H a 3 rH 3 3 3 •3 4-t 4J 3 3 3 M •H 3 H 3 3 S M •H y •H CL 4J •p4 3 •H f-H pH 3 PC M 3 3 3 a 3 3 3 z a M *3 O g CL U 3 3 •H 3 (4-t 3 •H 3 y 3 M Xi o M M v X y 3 3 o *3 M U O 3 o y 4-t 3 3 >> 3 3 3 X M Sh O 4J c fC y G •3 • •H 3 3 • 3 •3 o 3 CL 3 4-t rH 4-t pH • .J fM (4-1 iTi O •H 4J 3 c 3 3 3 PO U PC *3 a 3 M 3 y M a o •H 3 3 4-t •H 4-t o c s 3 3 O a 3 3 3 *3 3 3 3 3 3 4J 3 3 -o 3 M M 4J 3 3 X O M O 3 3 y a •H 3 O •H M O y y 4J 4J 3 0 3 3 3

PO 3 4-t 3 3 *c > •H 3 4J 4J

X 4.) PO •fH

y 3 u 3 4-J 4J 3. 3 O 3 fH

•H 3 4J 4J

M 4J •3 3 > 3 3 4J 3 1 U 3 (4-4 3 •H TJ

M rH

y

a 3 3 rH rH M m 5 3 •H 3 3 G CT iH 3 O 3 3 3 3 3 3 (M 3 O 3 O •H 3 3 3 (4-t M 3

CO 3 CS

Q •3

y -o 3 U 3 4J

y z 4JOOy •H 3 a

a 3 PL4 (M 4-t

M •Ha

COuI<>5

CO§M

C-> M

hJ

PU

O.< O M>

pa

M

u

H

plS

M

O CO

pa z o uCO

COQsZ 0) iH 0) g.^ B • •H C PO

CO (Q f C O TJ 4J «H

CO i-H «H

C

•H 0) > «H C *H (0 4J CO iH }-i C 0> 0) 0) >> C g tH ,0 C « a .O O iH

•H (0 *0 00 4J 3 Wi 0) ^ 4J

cr 3 CO

V iH

pa *o 3 o. fH ^ 0> ^ .c a; 0= <M

4J ^ 4-t a.

4J 0)

C 0) (4-1 *o O CM ,3 O

CLO 4J *3 3 3 0) 3 *3 O -U

CO

O 3 *H 3

*3 *H 3 3 M

•H ,3 y *H 3 3 «H 3 M 3 33 3

CL <J 3 O O 3

PO33

CLy po 3 3

•3 ^

CJ 9 *H l4 Z

•3 3 3

•H 4J3 U 0 3 O 3 4J a 3 a 3

•H33* «H 3 -H•3 3 3 ^ 3 H V4

•33 3 3 U 3 3

Lh 4J 3 3 U *H2 3 8 *4J 3 3 3 cn 3

csu 3*3 3 . O X +l y 3

g-a • •H 3 3 33 3

•H

O 3 >. 3 3 a 3

O. 3

•H3 *3 3* 3

pa 3 U 4J •u 3 y *H 3 3

fH 3

pa oi • 3 4J • M pH 3 3 3 O • M rH 3 O 3 4-t 3 M 4-t 3 3 o 3 4J 3 3 M 3 3 CL O • 4J X 3 3 M 3

4-t 3 3 iJ 3 3 3 3 LJ 3 no 0 3 3 4-t 3 3 4-t 3 3 3 3 4J 3 4-t 3 3 3 O 3 3 3 U 3 iH 3 3 4-t 3 4J 3 M rH •pH M y O Xt X M •H *H a 3 M rH *H M y O y CL 3 y 3 CL 4-t >* O CL rH 3 3 y O. 3 y 3 CL 3 a 1 3 M a 3 iH X g a 1 > *3 3 a 1 3 M a O 3 3 O 4J o 3 3 3 3 3 a 3 3 3 0 3 3 0 4-t o o 3 *H y 3 y X •H O fH 3 < *H a 3 o 3 *H y 3 y • X 3 (M 3 3 X 3 Mt •H O 4-t 3 3 1 4J 3 o 4J O •H 3 O •H • 3 3 4J y 1 y 3 O iH

CO Ob «H !» • 3 a 4J 3 3 3 3 •H 3 3 3 •H 3 u 3 4J 3 3 3 •H PO 3 3 •H 3 3 y 4-t O 'O 3 3 4J X M •o 3 > •H 33 O 8 3 (4H 3 X PO *H a .X X rH 3 X o 3 M 3 O 4J 3

EhM •H 3 •H

M •H

O 4J 3 Mt

M

yM PO 3 y 4J • iH 3 4J

O CL 3 y

X • M 3 4-t 3 X Ml 4J 3 3 3 •H *pH 3 •H 2 3 3 y 3 3 PO y y a M o u X 3 3 3 4J 3 3 4J M 3 O U X H 4J X O •H •H 3 X 4J O 3 3 0 y rH a 3 M M 3 3 PC «H M 3 3 3 y 3 3 *H 3 4-t 3 •H M M 4J PO 3 4J a iH >> y 3 3 y X 3 3 M 3 3 4-t 33 > 3 M •H X *3 M 4J 3 4J 3 3 M o 3 fH O X "C3 3 < 3 CL a 3 3 M 3 y 3 3 X 3 3 y •H o y »3 M iH 3 y 4J (M

CL 3 aM

M 3 3 3 PO

M 3 3 O. 3 3 *3

y 3 3 3 M 3 3 M •3 3 > o •oM < 3 (4H o 4J O 3 3 X 3 3 O 3 3 3 rH 3 o 3 iH 3 X 0 3 3 3 y •H 3 X 3 3 O Z o CJ 3 y Ou CJ 4J 33 4J y •H y O 3 3 iH a 3 M 4J y D (M 3 •H 4-t •H >- 3 3 3 3

•H 3 *0

*3 [x3 3 3 3 * M 3

Lj • 3 >% > O <U 4J iH *H

CL 3 3 3 3 3 M > 3 a 3 *H 3 4J CL 3. 4J a J •H O 3 X

POD »-t 3

•H cr

O 3 3

eJ 3 4J

M *W3 3 3 O

y 3 M 00 3 3 PO 3 ^ 3"333 3 y O f-l O a X y a 4J O *H <4^ y o

4J . 3 a

-o ou 33 3 U (4-1

•3333 I MOM 3 ,3 3

4J

y 4J 3 3 3 a cu a 9

See

more

detailed

description

on

page

indicated
\ ouozHzoou

CQ< u • o o z z —

CM cn cn

Cx} CM CM CM CM u u o< 01 &4 Vi 01 >> P • S O 0k fH CO *9 01 y y

4J CO 01

a

p 01 • P p

y 9 9

CO CO 1 CO •H OO • CL Cd P CQ

yy

p CO

y P

4J 4J • yu UH Cd *9 9 •9 •H P 9 y

p Cd CO 9 0 y

1-1 CO 9 9 01 9 9 9 o « 4J 01 CO

a 9 O > y •HX

p 9 o •H OO O .9 Vi 01 01 01 CO CO 0k •H 01 y •H 9 CO P p y

CO 4J c «H x:

a 4J > 9 Vi *9 iH

a CO

O

y 03

p

0) COU Cd 4J 9 CO 01 CO •H pH 01 01 01 01 9 y

y

y 9 • y • •H 01 •H Cd Cd > o CO Cd > P 01 p x: • y p •H a *9 9 • 4J •9 4J u y u 9 *9 • Cd X 9 4J pH O •H P 9 p 01 a 9 9 9 y O y

<4^ l-t 9 4J 0 ,9 9 00

a 01 9 9 CL 9 Cd CO iH

X

p

O CD CO ^9y

p o 01 01 a 4J cd 9 9u 01 O y Cd Cp kO y •H CD DO p p 9

CL CO

@ >4 • •H Vi • X

a

a >» 01 CO 01O •H P o y

y P c X •H o O > 01 9 *9 O 01 01 CL a > P 9 a CO •9 9 O p p 9 CO

C/2 0 01

O

y C4-( Cd > 01 01 o C4H *9

O o CdO CO CO 9 y

O Cd 9 p CO z •H c 1—

•H

X •9 Vi cd CO pH

y 01 (0 •H CO 01 01 Cd COH o p COy o c < *9 «4H CO cd 00 Vi •H 01 x: •H P CO y y 9 P p y p y

1-4 (d (0 •9 01 9 o rH 00 > iH CD 01 CD

y CDa

X 0 y

H 4JC *9 MH 01 >> pH 01 9 1 4J 01 o *9 P P 9 cp cd > *9 •H CO o fH CD < 0) CO 9 • C O a pH Vi •iH 9 9 *9 9 9 9 9 P cd •9 9 y CO H Ui 01 O CO 01 X 9 CO Cd Cd O 01 Cd 01 P y 9 01 y y CD o y p y y M a u L4 u a 9 01 O •H a 1 a 01 CO a CL H CO Xi 9 •H P •H 9 9 y 9 s 1-1 -H OOiH a 0 CO CO CL^ •H 01 a P x: <P P p 9 Cd M 0) 9 9 o •H >» *9 01 > •9 *9 •H ^ 00 -H 01 p 4= p >% 9 9 cr p p u CP y CO y 4J Vi 01 u Cd 01 Cd 9 *9 P 9 P p CO P P p y p CO c 01 Cd 01 01 Cd 01 CD 9 rH CO fH C 9 9 Cd y 9 0 o 9 y O O 9 9 73 9 9 M u PQ u u > 9 u C4-I p (0 01 *H Cd 01 •H p X a > Ip X •H CO Cd CO a

*9

CO 0 9

cd 01 • CO 0 p

y Cd •

4->

u oo •fH 4J 9 01 CO •H 5s •9

Cd •H 6 Cd

p •H •9 iH P

CO

p 9 H »9

y Cd • O

p fH

y

O 9

(d 9* c 01 CO • 01 P x: 9 > y

O

CO 01 01 CQ Cd •9 *9 CO

p •H

p P •H

y

•H • U Cd 9 0) 9 01

u Cd 01 Cd Cd P p CO

C/3 •9 01

u Cd 4J 9 P •k

a

p

y cd

a

u 4-1 c 4J 00

u 4J

m Cd 01 9 >> CD 9 9 p

y c cd Cd e 9 9 * a a y fH 5s y P CO 9 < 1-1 •H 01 pH 01 o 01 y P rH 01 y P y y 9 H S 01 01 U A a u u p Cd 9 9 P cd CD *9 9 O z O. iH a 01 g CL Cd cd 9 9 01 O 9 y •H Cd P • •H CL o •H •p4 u Vi Cd CO >^ P CD CO *9 > a a a > 9 £ c 9 Vc 01 Cd p P 01 Cd CO 9 o p rH o Cd •H cr 0 a 01 01 01 9 X 01 y O p y Mh •H U CO 4-t oo a U a O .9 X > U p a 9 9 Pm a o Ip

CO CO CO CO

y

01 01 01 P 9 a

y

p

pH 9 O

a ••

p

y

c/3a

a CLy

a P CL

p z s a a a Cd 9 a y o CO • Cd • cd • a fH Cd o y

.2

CD 9 • M CO 9 iH CO CO 9 pH CO CO 9 iH CO •H 9 rH a o CO P O P CO H 4J Cd 4J 4J Cd 4J p Cd p 9 O a p o y cd p < 01 •r4 01 u 9 01 •H 01 u 9 01 «H 01 P 9 9 y • p X y P 9 u 4J (0 u 9 01 4J CO 4J 9 9 p CO P 9 01 y y p CD 9 P *9 p CO 9 9 y M 01 1 01 4J c 01 1 01 4J 9 01 01 P 9 CO y y cr 9 y y y p p 9

hJ 1-i c uy o u 9 Vi

y

O

p 9 pyO 5s 9 p fH

y

Oppp P y

O

CU <J

y 9 a

y •Hy 9 a

y •H

y 9 a Cdy CL

p

y CL CO 9 a c c L4 a 9 9 V4 a 9 9 P a P 9 9 a X 9 CL 9 a P a < 0 o 4J o O Vi O 4J o O P O P o 1 CO O Cd CO Cd a O Cd 9 p o o O y CO y o o y CO y U 0 y CO y X y y 03 p y CD y CO p CO y >

CO p 01 0

u* 9 p

p o M CO 01 01 u > CO a p 01 M 01 01 y p • u H 9 p 9 Cd ai M 9 O p o O C/3 y CO y 9 • u z •H cd y in Q u X 01 ip y

c/3

Ha o Cd +1 9 DO Cd •9

*9 0 9 a

r 9 1 Cd 9 •H P a "9 CO Cd CO 73

u

y • >>

p Cdy P T3 Cd 9 p 9 9

00 *H Cd 01 CO

p <p 9 • p Cd 9 o cd CD

y

p Cd

4-i

a 4J 9 *9 •H o CO 5s Soy 5s 9 y

O 9 p

a

CO CO 0 Cd

a

y •H •H fH Cdp CO

p P 0 9 9 y

y

p

X 9 CO u 9 •H 01 iH O 01 Cd 01 •H P •H y fH • 0 p p y p

C/3 o 01 fH

u Vi > 9 p

a

yy 9 CO 9 •9 CO P y

p

p

U3 o y 1.1 CO M-t 01 r-4 M-l 9 01 «H P y •H o 9 a 9 P 0k 9 p P p 9 y COp

M Cd 4J •9

O

u Cd

O •9 4J Cd T3

a >» iH

y

y

p

y CO 9 CO o O •9 9 o H oo CO Cd 9 9 Cd x: 9 QC •k P Xi 01 y .G CO p p y y y M c 01 9 •H CO • 00 O 9 Cd 9 CO o > x •H y CO O o 9 «k *9 CO • hJ •H o O 9 OO 9 U pH p •H CO cp 01 00 9 rH p p a 9 O 9 00 CO y M c: CO •H OO 9 •H cd CD M P 01 •H p 01 •H O •• Cd y Cd P P 9 p y p

CQ o 01 4J 9 p iH >% > *9 CO Cd 9 9 01 z ,9 CQ CO 9 9 9 CO P P o 9 y < 4J 9 Cd (0 y •H CO 9 OO 01 9 9 9 p p Cd 5s P 0 y CO •• P CD p p

0U •H O' c 01 01

y CD Vi o y

y

y (d

p Cd

y

y P y CO •9 •9 9 9 y

y < c 01 00 > 4J O Cd Cd (d 01 *9 CO cd •H *9 9 00 p p p p X 9 P O O p 9 O o *H Cd 01 1-1 Vi 01 9 9 01 Vi > 9 0 9 <p 1 9 Mh Ip p <d O O P P 9 0 X <4-( (0 *9 00 «4-c y X 01 cd *9 y cxa p cd y •H o 9 X •H o 0 CO y > 00 p p y

-9

X o y c y CQ 9 Cd CQ •H o •iH O Cd P O H 4.) •H 4J 4J 1 CQ 1 M o CQ (0 CO CD y o <1 CJ o X X Cd z Z 9 CO 9 Cd X qc K M M Oi Cd H o O •d 0 a o u H z G < p

ui

u

y

ay

a

M z hJ o < \ Cd T. < < ua < M X w X CQ o X o

10

MICROWAVE

Application

of

the

Yields

values

Concrete

samples

Easy

to

use,

and

is

Low

degree

of

accuracy,

ABSORPprinciple

of

microof

moisture

or

in-situ

conmoderately

priced.

and

two

opposite

faces

of

TION

wave

absorption

to

content

crete

structural

specimen

must

be

determine

moisture

within

30%

components.

accessible,

content.

of

the

mean
CMU

•-3 H

Uio • o

U3 z vD r*^ i*N. ON

0^ CM CM CM <M CM

tz3

uo< S y

Vl *9 VI 9 9 9 y Vi 1 O 9 CO 9 y 1 * CO CO •H y y *iH y 9 CO E CO Li •

4-1

yy p9 00 0 X

yy <0y • CO CO > 9 9 9 •H y Vl Vl a B

O

X 9 v» Vl • •H

O • CO • CO Vi CO CL *H

y

X

u

C 4-» 1 0 • o *9 VI 4J CO 4J 4J 73 Vl (0 Li 9 V

X

CO 00 9 • •H CO 9 •H

O

y 9 4J o y •k

y

y

y 9 O'

a

•o c y CO 9 4-1

u

E?

^9 rH 9 >>

y CO 9 >vy

X 00 9 y

y CL

0) • y

y o.y o CO rH 9 0) CO 9. Vl iH

y 9 O'

y > VX 9

CO 'O

X Vi «H Vi 9 y CO

O

y CO

X

X

y CO

X Vi o CO

y o

c/3 •H

u •H iJ

y •H 4J Xi CO > > CO

y •H > CO CO CO rH CO 9 o 9 z pH > CO 9 CO •H y *9 »9 CO rH CO •H y •H CO Vl CO CO CO o O' 9 o CO cr Vi > Vi CO y 9 • X *9 CO CO X •9 rH CO Vl y o X Vi y M 0) (0 u C4-t •H y ^ •H 4J CO *9 y *H O y y y o y < 9 X H O a 0 Vi *H ^9 4J <0 y 0) N CO N Vl Vi 4-1 y >x 9 9 y < V4 V> rH 9 y 4J y y CO y •H 4J y •H c CO O O H (0 4-1 y 9 -9 CO 9 y 9 •H > 9 Vl •9 9 • M *9 oo CO Z X • E •9 M •H 0) o 4J y 9 y O VM y 4H •H 9 Vl y X 9 Vl Vl 9 Vi E Vi y CO 9 z N c B CO Vi 4h s 03 CO TJ CO a y *9 CO y «H •H C Vl Vl CO M Ss S a *9 00 CO CL -H 9 rH y *9 9* rH y •9 > y o • 0 9 y

•-3 fH CO •H •H

y iH •H p9y

y

y 9 •Hay 9 X «H 4h

y Vi

X 00 9

•H COy 9 > yy 9 9 9. 9. *9 o CO 9 a o CO 4J rH Li rH CO

X

u

O

C o CO a* •H *H

<s

CO crO

X •H Vi 4.1 9* o Vl 4J o (0 CO

y

X

X CO CO

X

CO CO o y Ex3 CO «4-ly » CO

y

a CO Edya CO z •H > a CO *9

XXX

73 *9

CO Vi

X

y 1 y 9 o y 00 9 00

}-t 4J 9 B CO

X

y •H

O CO Vl 9 o CO y o >> VJ OO 44 X y X

C/3 oo • B 4J

y rHyy c y >.y 73 73

(z3 c >> •H

U o y

y > 6 •H 73 CO Vi Vi o 9 CO

O 4J *H 4J

X

O 00 > •H Vi 4-4 •H 9 4J 9 O < c c y «H o 4H 9 y • •H CO y y y CO o r-H VJ X o •H 4-1 s Vi •H Vl 4H y o Vi 9 VI y VJ y •H y Sh B z iH e y 9. *9 Vl 9 9 X Vi CO y CO Vi y 73 y X 9 4H Vl X < Ui u o a O 9 4-1 y u iH a Vl y Vl y CO Vl X o (0 > o 0> y 4h CO X CO CO 4J rH y X 9 'O y > Vl •H 4H X X e Q u 4J c •H 4J CO •H 9 CO CO Vl y y 9 O 00 rH CO X Vl u X o o 9 9 y O 0 CO •H 9 y 4-1 O Vl y y X y o u *o y 9 < B B 6 y X 4H CO •H CO o y cv •9 Vl CO CO CL 9

CO • • Z }-l fH CO Vi CO Vl fH CO Vl iH CO o X o o 9 4J O CO 4H o CO 4J o CO VJ Vi CO M 0) y U 9 y y U 9 y y V4 9 y y u 9 y Vl • 4J CO 9 4J 9 y 4-> CO 9 4J 9 y 4J CO 9 4-1 9 y 4-1 CO 9 Vi 9 y *9 9 Vi 9 CO < o o 4J y 4.) 9 y y 4H y 4J 9 y y 4J y 4J 9 y y Vi y Vi 9 y Vi y Vi 6

C-3 rH •H Viy

O Vi rH •H Vly 0 M rH •H VlyO Vl iH •HVy

O •H •H Vly

y

M

y 6* CO

y 9 a

y

a COy 9 9.

y 9. CO

y 9 a

y

a CO

y 9 Cl rH CO

y 9 Vi c 6 1 9 Vi e 9 6 9 M a 9 6 1 9 U a 9 B 1 9 Vl 6 CL 9 Vl CO o <0 c O U o O CO 9 O 4H o O <0 9 O 4J o O CO 9 O Vi O a 9 O VJ >»

Ou< o CO •Hy COy o CO •Hy COy

O CO •H

y

yy CJ CO •Hy 03y < H

y CO CO

•cc y CO *9 • »9 CO 4-1 (A CO > •H 9 0 CO O c y •H y 9 y 4h *9 X o p 4J *9 •u •H 0 CO > • O 4J y

•H 4J CO (0 9 9 • 44 9 o y

y *9 00

iJ •d 4J CO •H 4h 9 X

M CO rH

y

B rH CO Vi

y • ph CO 4J O Vl O 9. •H *9 y y 4J 9 Vl y o M e C 4J rH y y *9 4-4 •H 0 •H CO CO 9 4J •H y CO y (0 rH rH > iH o •H CO Vi *9 y M-i o > 4J 00 9 >% 9 CO CO 4-4 .9 a y X u M JJ CM 9 9 9 CO O •H y CO 9 y y 0 B y • CO 9. CO > CO u H (0 •H C cr 4J 4J CO y 4J 9 *9 y •H y CO •H n Vi y O 9 •H O Vi •H •H M o 9 •H CO O 9 CO y •H 9 O •H *9 ,9 Vi VI o X 4-1 y -9 iH rH Vi rH o C/3 9 4J >» 9 9 y p

Vi CO cr,c fH rH 9 03 4H CO 4J > 4-1

y 9 COy

u Z o c Vi 9 CO

u 00 9 y

U a*H 4J

yyu •H 4J o > CO fH Vi

Q

U M-l o y 9 CO «H

y

y

y •9

a 9 yy 9 y

X 9 y Vl VJy

y

y 9 •

C/3

H

Oy > •Hy 73 4-> •9 CO < B CO .9 < O' Hi 4-1 •H >>a < *9 Vl Vi 9 • y Vi Ji 9 CO *9

A Vi •H v< CO 9 9 • 9 O Vl y 73 y E • c y •9 9 O •H 4h 4-1 y B Vl x: CO Vl CO <0 VJ y

C/3 o 4J 9 rH 4h Vi 0 9 4J 9 0 4J

y 4-1 •9y CO

X CO • y CO Vi

X

Cx3 0) CO

Xy CO 9 4-i

O 4-1 CO

y 9 COy 9 X •H 9 > 4J CO CO CO M-l iH 5 CO *9

X

M > CO 00 *0 •9 >> 73 o 9 V) 9 4J

O

yy 4J > CO •H CO •H

X o y >> CO

X

H (0

u 9 >%

O 4J 9 CO

y fH

O 9 y 9 4J CO 9 X CO

y Vl Vi CO 0 X

Mu 4J o o •u

B T* CO 4-J 9 9 •H

O

y 4H

y CO 03

Vy fH CO 9 73 o yX

X

m3

u iH

u 4J •H

w

y >^ 9 CO 4J

y Vi 4-1y 0 rH CO

y 73 9 4-1 *9 Vl o CO Vl

X CO

M 9 fH •H 4-» • y •9

y CO 9 y

X 9.

y 9. Viy CO 9 y •H

O * y CO

n CO 4J

y COX 4J >» •Hy

By Vl 9 yy Vly 4-1B

y Vi •H fH CO Vi rH

y 9 Vl

X oo < o 4J 9 4J CO 4J rH 4J y CO rH Vl B y 4J 4J CO 9 03 CO 4-i CO CO 00 CO Vi O 9 X 9

Pm o CO

y a* 00 CO •H •H

y Vi CO >% CO 9 y 9 OO -H CO

y 9 9. *H Vi 9 «« 9 y 9 yy VJ

uX < 9 y Vi 9 fH •9 *9 Vi 9 y 00 > 4J y O 6 9 > u 0 Vi y V CO •H •H OO Vl y y o CO y CO y y y y •H CO y CO Vi u y CO y •H •H •H 4-1 y •H 4-i 9 y y *9 rH •H y CO 9 > u

CO

€ 9 9 Vi OO Vi 9 COyy •H

y 4-1 Vl Vi CO 4-1 Vl CO

y 4-1 Vi •H

O CL CO 9 Vu

0) *H 9 0 •H 4-» 4-1 •H 9 o y

y 9 9 O -9 9 CO CO

y

y

y CO

y 73y 9 O

u

ayO 0 Vi o <0 Z 4J a y B CO o Vi 'O y Z •9 y CO B P •H y 9. CO 4J V > X •H 73 •H > 00 < •9 y Vi CO VJ y X y 00 9 o z •H * 9 O o 9 >> 4-> y •H •H CO Q 73

CO

u

MO 4-1 9 9 9 Vl 9 4-1 •H Edy 00

Q

M

H CO •H CO

yO

y

O CO CO Vl 9 O JC < CO y y 9 9 u Vi 4J Vl > >» 2 (0 X X Vi CO o O 9* m3 4-1 4J Vi •H iH OC Vl Vi q 73 Vi H z OQ v> iH *9 CO y O 9 CO 9 VI CO Ev 4-i CO < CO (0

tx3

M rH 9 y 9 yM

yyy

y 9 Z 9 y o o y £ o > O a > CO Vi 4h z z c/3 z < < M M H X X H

11

See

more

detailed

description

on

page

indicated
TABLE 2

(CONTINUED) / u • o o z z u o<cu §

q/5 zoM%OM

<-3 04

O

M> W M O CO

03 Z Q 03CO

COoozH

03z O

cn

Vi V> 4J 3 6 u 6 3

60 3 O 3 3 3 3 6 *• 6 CJ 3 6 > • 3 3

rH •H 3 O o 4J

a 3 i-H

V

U 3 CJ > • H •H 3 3 6 o

L4 «H 60 4J

O CM CM 6 ^ CJU Z o

4J IM

•H

C

0) 0) u

(0C -H O C

O. 00 X *0 (0

0) 0)3 u

U 3 3 3 3 4J 0

Xi 60 >% 6 3 a CM

N 3 •H 6 4= 60 3 6 Vi tH 3 X o •H 3 M-l O 6

•H •H 3 V 3 4J 3 T3 ViO >»

V <r *H

fH 6 > o 0 1 3 Vi 6 fH 60 CNl CJ 3 •H 4J •H 6 3 3 3 *6 6 .6 6

Vi 3 • 3 6 •H Xi 6 •o 3 60

B 4J 3 u Z Vi Z 4= 3 6 CJ •H 3 X 3 g

U 6 3 3 CJ 6 CJ 3 O 3 3 o 3 § o O 3 a 3 •H 3 4-1 U 3 3 a 3 O z CJ 6 o 4J CJ 3 CL O 3 [d CJ c

CO

(0u

0)

D

iH

h

4J

l-i

M

CO OJ o« 'O

OZ

•O6 0)

CO 6

CO : 00 iH

0) <-l 3 «H TJ

00 P C 5 T3 CO

0) •

c; 0) >»

(0 .A «H

»-i

a

u 3 <0 -H

00 cj 3 cc

(0

CJ

00 (U 00 00 CO 01

•H CO T3

UO

0) 4J 00 3

0) 0) 4J

1-t tH -H O CL (0 c s O CO CJ 00 ^ •

<0 c

•H

O

iH •H

0) -H 4J

Vrf

O

U > 0)

O <4^ 01 00 o -o U 4J (0

01 (0 *3

4J ,0 -H

01 3 O O « >

(0 4J

OO 3* 00 1-1

M *3 Jd 3 0) O > 4-» 3 O

01 1 *3 -H C •-<

01

4-t ^ 00

U

C o o 3 iH Z A >1 • 3 • iH *3

iH 01 CL i-» a > a 01 B -H 3 *H

•H 3 U-4 *3 3 6 0 3 4J 3 3

•-a z M

M <u 4J X >> 4J 3 3 3 3 3 3 M-l 4J 3 6 3 C ^ 3 4H

C&4 -H

U -H

O *3O 3 3 60 M 6 6 3

iH 3 4J p p g3U 3 6 4J3 4J

Vi

O ^ e o u O 3 3 O i-H 3 6 6 M O «H 3 I 1 CLiH U 6 iH 3 0 6 3 U O. O3 • 03 O

a. o> 1^30ViO CO 6 < 3

*336 • Z 3 3 3 4J *3 4J U 60 W 3 6 3 3 3 3 Z 3 I U 3 6 -U M-i S *H 3 O

•33

'363

603a6O6Ouo33

•33

*33

ViOB33

12
NDE methods cannot now be expected to yield a value for strength (although

developments in metals are beginning to show promise in this respect). These

methods attempt to measure other properties from which the evaluator can estimate the strength and related parameters of the concrete. Examples of these

properties are listed in Table 2 which shows the relationship between test

method, the parameters checked by the test, and advantages and limitations of

the test.

REFERENCES - 2, 4, 7, 8, 14, 37, 38

2. 1.1.1 Visual/Optical Inspection

A. Test Method - visual - Optical Inspection

Material - Concrete

Parameter - Surface Flaws (Finish, Roughness, Scratches, Cracks, Color).

Discussion

Visual inspection is one of the most widely used methods for evaluating surface

condition of concrete. It can be performed with or without the use of optical

aids such as low-power magnifiers. Defects such as missing components, cracks,

erosion, corrosion, and misaligned joints, etc., can often be detected with

the naked eye. And, with the use of five to 10 power magnifiers, even surface

flaws as small as a few microns wide can be detected.

Advantages and Limitations

The most obvious advantage of using the visual method to evaluate surface flaws

in concrete is that it is inexpensive and requires little or no special equipment. It sometimes can be used to find defects which otherwise cannot be

found. However, the visual inspection method can be time consuming and is

completely dependent upon the visual acuity and the experience and training

of the inspector. It should be understood that no subsurface information can

be obtained using this technique and that, even for surface conditions, a correlation already must have been established between surface conditions and

serviceability of the concrete.

REFERENCES - 1, 2, 3, 4

13
B, Test Method - Surveying-Horizontal and Vertical Movement

Material - Concrete

Parameter - Differential Structural Movements

Discussion

Differential measurements of structural movement can be made by making use of

horizontal and vertical control standards. Survey points are established at

various key areas on a structure, and their movement in both horizontal and

vertical directions is measured over extended time intervals. These movement measurements can be compiled into history plots that may cover months or even years. The history plots may reveal normal cyclical movements associated

with temperature moisture condition, or applied load, and may also reveal some type of structural deficiency. The observed movements must be interpreted

relative only to the structure under observation, and only those movements

that exceed the expected values should be considered as a source of deficiency.

Advantages and Limitations

This method requires a long period of time to compile enough data to make

accurate judgments of the structure’s stability. Many times an evaluation of

the structure is needed quickly which makes the surveying method impractical.

This method requires trained personnel to operate the surveying equipment and

to gather data. Surveying is very useful only when some form of structural

distress is suspected and structural movement is believed to be the cause.

C. Test Method - Joint Survey

Material - Concrete

Parameter - Deficiencies in Joints

Discussion

A periodic Inspection of all expansion, contraction and construction joints

should be made when considering the condition of concrete structural members.

It must be determined whether or not each joint is in good condition and

functioning as designed. Consultation of construction drawings may be

necessary for a complete listing of the joints and their designated function.

The inspection of each joint should include an examination for spalling or D-cracking (cracking along a joint in a "D" shape), evidence of seepage,

chemical attack, or erosion. Openings in each joint should be measured. A

measurement of surface offsets on either side of the joint should be included

in the inspection procedure.

lA
Advantages and Limitations

The joint survey is an inexpensive and fast method of assessing the quality of

the various types of joints. Since joints are essential in the construction of

all concrete structures, there exists a probability that at least some of these

joints are not functioning as designed and may be a source of some type of

concrete deficiency. A trained inspector is necessary to complete a thorough

inspection. Caution should be taken to evaluate the entire joint when making

the final decision as to its overall condition.

REFERENCE - 3

D. Test Method - Fiber Optics

Material - Concrete

Parameter - Detection of Internal Cracks, Voids, or Flaws

Discussion

The innovation of fiber optic inspection techniques came from the need for

remote visual inspection of areas accessible only through small diameter

openings. The principle of fiber optics makes use of a 1.0 - 2.7 mm (.04 -

.11 in) diameter single glass fiber with a graded index of refraction

surrounded by flexible light-conducting fiber bundles that are approximately

20 microns in diameter. The larger glass fiber acts as the lens that transmits

the remote image that is illuminated by the light-conducting fiber bundles.

The entire fiber assembly is covered by a stainless steel sheath to protect it

from damage while inspecting. The probes range in working length from 30 to

1330 mm (1.2 to 52 in). The probe is attached to a portable halide or cold

light source that is adjustable and provides 150 watts of concentrated white

light to the fiber bundles. The application of this method to a concrete

structural member involves inserting the probe into a crack or drilled hole

and looking through the eyepiece for various flaws such as cracks, voids, or aggregate de-bonds. The fiber optic apparatus is adaptable to photographic

and television equipment for permanent records of inspection. It is most

commonly used to look into cracks or areas where cores have been removed.

Advantages and Limitations

Fiber optical equipment can provide clear high-resolution images of remote

inspection subjects. This equipment is also easy to handle and operate.

However, its applications to a material such as concrete are limited. A

complete visual inspection of a concrete member using fiber optics requires

a large number of boreholes which might weaken the member. The equipment is

also quite expensive; and many times, more than one size of probe (costing

about $150 each) is necessary to complete a detailed inspection. Fiber optic

equipment is best applied to inspections of machined parts or other mechanical

assemblies, but can also be used, when necesary, for inspection of small areas

of a noticeably deficient structural member.

REFERENCES -5,6

15
2. 1.1. 2 Rebound Test

Test Method - Schmidt Hammer

Material - Concrete

Parameter - Quality and Uniformity, and Compressive Strength Estimates

Discussion

An instrument which can be used to estimate the compressive stength of concrete

by measuring the height of rebound of a hardened steel hammer dropped on con- crete is the test hammer developed in 1948 by Ernst Schmidt, a Swiss engineer.

The Schmidt Rebound Hammer consists of a spring-actuated hammer and plunger

mounted within a tubular housing. To operate the hammer, the Impact plunger is

placed against the surface of the concrete specimen and the hammer housing is

pressed down until the plunger almost disappears into the housing. The hammer

then will release itself. A built-in scale measures the rebound value in

percent of the forward movement of the hammer mass after it strikes the concrete

surface. The amount of rebound is affected by many factors such as the composition of the concrete, aggregate properties, surface texture and hardness,

moisture content, and mass of the concrete specimen. User's charts (provided

with the equipment) are based on empirical correlations which have been

established between strength properties, hardness, and the rebound number.

ASTM Standard C805 “Test for Rebound Number of Hardened Concrete” describes

this test method.

Advantages and Limitations

The Schmidt Hammer provides the advantages of being able to compare quality

of concrete from different areas of the specimen, thereby detecting areas of

potentially low strength. Since the equipment is so lightweight, simple to

operate, and inexpensive, it is suitable for both laboratory and field use.

Use of published calibration data to estimate strength of concrete from

rebound readings is of only limited value and is not recommended because of

the number and nature of the factors affecting the rebound. Therefore, the

user should use strength estimates derived from this test method with extreme

care. It is advisable to calibrate the test equipment frequently with the

strength of cores drilled from the structure. By doing so, the user will be

able to determine the degree of reliance that can be placed on the strength

estimates from the rebound readings.

The user of this test should be aware that no correlation has been determined

to exist between rebound readings and modulus of elasticity. Its use should

be limited to determining the quality control and uniformity of concrete and

estimating the compressive strength with a maximum accuracy of + 20 percent.

Even then, these accuracies can be expected only if the specimen has been

cast, cured, and tested under conditions which were identical to those from

which the calibration curves were established.

REFERENCES - 3, 7, 12

16
Z.1.1.3 - Penetration Test

Test Method - Windsor Probe Device

Material - Concrete

Parameter - Quality and Uniformity, and Compressive Strength

Discussion

The Windsor Probe device consists of a driving gun which uses a powder charge

to drive a high-strength steel probe into the concrete to be tested. Generally,

three probes are driven in a triangular pattern; and the amount of penetration

is determined by measuring the length of the probe extending from the surface

of the concrete. Then, the depth of penetration measurements can be converted

to concrete strength determinations by using calibration curves supplied by

the manufacturer of the Windsor Probe device.

Advantages and Limitations

The Windsor Probe equipment is simple, durable, requires little maintenance,

and can be used by la5nnen in the field with little training. It is fast - three

tests are made in approximately five minutes. ASTM Standard Test for Penetration

Resistance of Hardened Concrete (C 803) describes this test method.

The Windsor Probe primarily measures subsurface hardness and does not yield

precise measurements of the in-situ strength of concrete. The probe test,

however, is useful in assessing the quality and relative strengths of concrete.

As with the Schmidt Hammer (rebound) test, interpretation of test results

depends on other known factors which are based on correlation plots. When

used on concrete which is 40 to 50 years old, this test method may yield a higher strength than actually exists.

The Windsor Probe Test does minor damage to the concrete over an area of

approximately 25 to 50 mm (1 to 2 in) in diameter, leaving holes about

8 mm (0.3 in) in diameter for the depth of the probe. It may also cause minor cracking, necessitating superficial repairs.

Care should be taken to insure that the user observes normal safety precautions

concerning its use and handling.

REFERENCES - 3, 7, 9, 13, 14

17
2. 1.1. 4 Electrical Tests

A. Test Method - Dielectric Measurements

Material - Concrete

Parameter - Moisture Content

Discussion

The technique of using dielectric measurements to determine the moisture

content of concrete Is based on the principle that the dielectric properties

of concrete change with changes In Its moisture content. To conduct this

test, the dielectric testing equipment Is placed on the specimen, the oscillator

Is energized, and the overall capacitance of the specimen Is measured between

two co-planar electrode plates. The two electrode plates are separated by

Insulation to prevent short circuiting and to assure that the measurement Is

of the current traveling through the specimen.

It has been determined by developers of dielectric measurement equipment that

the best frequency range to use when measuring the dielectric constant Is

10-100 MHz. By using these high frequencies, the effects of conductance caused

by dissolved salts and faulty contacts with the electrodes are greatly minimized.

Advantages and Limitations

The greatest advantage to using dielectric measuring equipment Is that It Is

readily automated. However, dielectric measurement equipment Is very costly

due to the need to use high frequency currents. This limits Its use to only

those specialized applications which can justify the expense. The test method

Is further limited by the fact that It can test only for moisture content of

the concrete. Also, successful use of dielectric techniques Is contingent upon

careful and frequent calibration of the measuring Instruments.

Another limitation to consider carefully Is the fact that the dielectric

properties of concrete are highly dependent on the moisture, salt content, and

temperature of the specimen. This can pose problems In the Interpretation of

test results.

REFERENCES -2,4,7

18
B. Test Method - Electrical Resistivity Test

Material - Concrete

Parameter - Thickness of Slabs and Location of Reinforcing Steel

Discussion

Electrical resistivity tests are based on the principle that different materials

offer different degrees of resistance to the passage of electricity. Thus, a concrete pavement has a resistivity characteristic which differs from that of

the underlying subgrade layers; and this change in resistivity is measiirable

with electrical equipment. To conduct the test, four electrodes are placed in a line on the concrete specimen at equal distances. A voltage is applied across

the inner two electrodes. For practical purposes, the penetration of the

applied current is considered to be equal to the spacing between the electrodes.

After testing, resistivity is computed by using the following formula:

P = 2 SE/I where S = Spacing between electrodes, cm. E = Potential drop between inner two electrodes, volts

I = Current flowing between outer two electrodes, ampheres

Resistivity is then plotted against electrode spacing (or depth) and slab

thickness, and the location of reinforcing steel is determined from the curves.

Advantages and Limitations

Although electrical resistivity test methods and equipment are simple and easy

to use, the one major drawback is that they are limited to testing of concrete

pavements. Furthermore, the test results are affected by air entrainment; mix

proportions and density of the concrete; and the presence of steel reinforcement, moisture, salt, and/or temperature gradients. Hence, the effectiveness of

the test results may be questionable. Another limitation to the widespread use

of this test method is the high cost of the generators required to produce the

high frequency currents needed to satisfactorily determine the desired results.

REFERENCES -2,4,7

19
2. 1.1. 5 Electro/Magnetic Test

Test Method - Magnetic Electric Field Evaluation

Material - Concrete

Parameter - Location and Size of Internal Reinforcement or Other Electrically

Conductive Components

Discussion

The magnetic-electric test is based on the principle that ferromagnetic and

electrically conductive materials effect the field of an electromagnet. It is

used primarily to detect ferromagnetic components, such as rebars in concrete,

but also is effective in locating electrically conductive components in masonry

and other nonconductive materials.

Several portable, battery-operated, magnetic electric field test devices are now commercially available. Generally, those that measure the depth of reinforcement cover in concrete are known as cover meters, and devices that measure

both the cover and the size of reinforcement bars are called Pachometers.

Typically, these devices weigh about lAkg (9 lb).

The devices are easy to use and require only that the user place the attached

probe device over the reinforced concrete and move it about until the reinforcement is determined to be parallel to the length of the probe at which time a reading is obtained on the dial of the Instrument. For a known diameter of a rebar, the dial gives a direct reading of the cover to steel.

Advantages and Limitations

The biggest advantage to using the magnetic electric field evaluation method

for detecting internal reinforcement and electrically conducting components is

its portability of operation. It is limited, however, to detecting concealed

ferromagnetic and electrically conductive components located within 180 mm

(7 in) of the surface of a nonconductive base specimen. Also, in heavily

reinforced sections, the effects of secondary reinforcement cannot be

eliminated, and the cover of the steel cannot be determined accurately.

An operational characteristic that could prove to be a drawback (depending on geographic location) is the fact that the battery pack for portable units will

not perform satisfactorily in temperatures less than 0"C (32”F).

REFERENCES - 1, 7, 15, 16

20
2. 1.1.6 Acoustic Tests

A. Test Method - Acoustic Emission Evaluation

Material - Concrete

Parameter - Structural Integrity (Cracks, Non-bonds, Inclusions, Interfaces,

Etc.)

Discussion

Acoustic emission evaluation consists of monitoring and evaluating high

frequency acoustic signals (stress waves or pulse) which are produced naturally

by the test materials themselves when placed under stress. These acoustic

signals are related to the internal physical changes taking place within the

specimen being tested. Detection of the stress waves is accomplished by

affixing sensors to the specimen, amplifying the acoustic emissions, and

recording them on a tape recorder or processing them through a digital computer

for recording and analysis.

The technique is based on the Kaiser Effect - the principle that, under a load,

almost all materials produce a significant level of small-amplitude elastic

stress waves above the base level of stress waves produced without a test load

(unless a flaw occurs or the original load is exceeded). A high emission rate

above the base level of emission at operating load, design load, or test load

level indicates that a flaw is growing.

Advantages and Limitations

Although the equipment is relatively portable and easy to learn to operate,

the interpretation of the results requires an expert who has had considerable

experience in this specialized field. Detection of crack growth is only the

beginning of the evaluation. Determining the location of a crack with this

equipment is very complex and often requires the use of a microcomputer (for

high speed triangulation). This test is very advantageouly combined with load

testing.

A significant disadvantage to this method of crack evaluation is the large

expense involved. It is the type of test that is most appropriately accomplished by contracting the service from a testing company that specializes in

nondestructive testing. Also, the reliability of the detection of flaws is

affected by noise sources other than structural defects. Research currently

is going on to develop methods for noise source identification and discrimination to minimize this problem.

REFERENCES - 1, 2, 4, 7, 13, 17, 18, 19, 20

21
B. Test Method - Acoustic Impact Evaluation

Material - Concrete

Parameter - Integrity (De-bonds, Cracks, Voids, Etc.) and Modulus of Elasticity

Discussion

Acoustic impact evaluation equipment utilizes the principle that the acoustic

and impact energy transmission characteristics of a material are related to

the geometry and mass effects (e.g., shape, density, and structure) of the

material. As compared to the characteristic energy transmission patterns for an unflawed specimen, these patterns will be changed due to flaws or changes

in the internal structure of the specimen to be evaluated. In other words, a specimen with flaws (de-bonds, hairline cracks, voids, etc.) will dissipate

acoustic energy more rapidly than a specimen in sound condition.

For certain cases, these energy transmission patterns can he detected audibly,

amplified electronicaly , and displayed on an oscilloscope, a computer interfaced cathode ray tube (CRT) or graphic printer, or a voice print spectrograph.

Advantages and Limitations

Acoustic impact evaluation equipment is mounted on a trailer, is easy to

operate, and can be automated. It provides a method of detecting and evaluating de-bonds, hairline cracks, and voids in specimens (although its

reliability has not been demonstrated clearly to date). Either acoustic or rebound energy sources can be used to stimulate the test energy pulse which

is measured.

It should be realized that before test results can be interpreted, a standard

acoustic pattern must be determined for each given application on specific

materials. Also, when using acoustic impact sources, acoustic isolation is

required because of the possibility of outside acoustical interference with

test results.

A disadvantage of this test method is the expense of the equipment. It is

still in the developmental stage and is used mainly by the Department of

Transportation for determining properties of pavements. A potential use is seen in slabs-on-grade for structures.

REFERENCES - 1, 2, 4, 7, 13, 17, 18, 19, 20

22
2. 1.1. 7 Ultrasonic Test

Test Method - High Energy Ultrasonics

Material - Concrete

Parameter - Thickness, Quality, and Uniformity

Discussion

Measuring thickness and estimating the quality of concrete by the high energy

ultrasonic evaluation method is accomplished by measuring the travel time of a large unit of acoustic energy driven through the concrete specimen. A high

energy ultrasonic source (one million electron volts energy with pulse duration

of a few nanoseconds) is required to produce measurable ultrasonic indications,

since the signal from a standard ultrasonic unit is scattered through the con- crete so completely that no information from the reflected signal is available.

Advantages and Limitations

Some manufacturers of this equipment claim that high energy ultrasonics can measure thickness of concrete masses with an accuracy of + 5 percent. This

technique is limited to measuring thickness of only heterogeneous materials

such as concrete. Also, the information received as a result of the test is

limited to thickness measurement and does not include information on Internal

f laws

Another limitation to the use of this equipment is the weight and size of the

electrical power supply. Although the power supply is considered to be portable, available products weigh approximately 91 to 181 kg (200 to 400 lb).

REFERENCES - 1, 2, 4, 7, 13, 17, 18, 19, 20, 42

2.1. 1.8 Radiographic Tests

Test Method - Radiographic Evaluation

Material - Concrete

Parameter - A. Using X-Ray:

Density and internal structure of concrete, size and location

of reinforcement, and bonding stress.

B. Using Gamma Ray:

Location, size, and condition of rebars, voids in concrete,

voids in grouting on post-tensioned prestressed concrete,

variable compaction in concrete up to about 600 m (20 ft)

thick, density of structural concrete members, thickness of

concrete slabs, and density variations in drilled cores from

concrete road slabs.

23
Discussion

Radiographic evaluation techniques are based on the principle that the rate of

absorption of x-rays or gamma rays is affected by the density of the test

specimen. X-rays or gamma rays are emitted from a source (x-ray tube, radioactive isotope, etc.), penetrate the specimen, and exit the opposite side of the

specimen where they are recorded on a sensitive film as radiographs (pictures)

or viewed on an electro-optical imager (screen).

Flaws having a diameter as small as about 1 percent of the material thickness

(in the direction of the radiation penetration) can be detected in a wide range

of materials. Orientation of the defect (parallel or perpendicular to the

beam) will affect detection of the flaw. Voids or relatively low-density areas

of the specimen allow a relatively higher rate of passage of the rays which

will appear as dark indications on the film (as compared to the relatively

lighter background). The reverse holds true for areas of higher density, such

as steel reinforcement, which are clearly detected and recorded on the film.

Advantages and Limitations

Radiographic evaluation techniques offer the advantage of providing a permanent

record on film for inspection, or a "live" image on an electro-optical system.

Since x-ray evaluation equipment for concrete evaluation is heavy and costly,

it has very limited application as a field test. It lends itself better to an application in a laboratory environment. On the other hand, gamma ray equipment is easily portable because sources (such as cobalt 60, iridium 192, and

cesium 137) do not require electrical power. Thus, gamma rays are becoming

increasingly accepted as a viable field test method. Gamma radiography can be

carried out only by personnel who are licensed by the Nuclear Regulatory

Commission. As a word of warning, x-ray and gamma ray sources are harmful to

organic tissue; and the test environment must be shielded (or isolated) as necessary to prevent radiation hazards. Lead shielding required for gamma ray

sources can be very heavy, sometimes weighing up to 227 kg (500 lb).

Other drawbacks to the use of radiographic evaluation equipment are the high

initial cost of the equipment and film, the time delay required to develop

film, and the requirement that access to both sides of the test specimen is

necessary to set up and use the equipment.

REFERENCES - 1, 2, 4, 7, 41

24
2. 1.1. 9 - Microwave Absorption Test

Test Method - Microwave Absorption Test

Material - Concrete

Parameter - Moisture Content and Quality, Rebar Size and Location

Discussion

Microwaves are electromagnetic wave emissions which lie between television and

infrared emissions in wavelength and frequency. Due to the fact that they are electromagnetic in nature, they can be reflected, diffracted, and absorbed by

different materials at differing rates. Water, for example, absorbs microwaves

at a much higher rate than concrete. Microwave testing methods employ this

principle of absorption to measure the moisture content and quality of concrete

and other porous building materials and to measure size and location of

reinforcement.

The testing apparatus consists of a portable 3,000 MHz (100 mm wave-length)

radio transmitter which is modulated at 3 kHz by a square wave, and a 3kHz

receiver which has attached to it an attenuator calibrated in decibels. The

transmitter and receiver are attached to opposite sides of the specimen and

switched on. The receiver attenuator is adjusted to a null reading both with

and without the specimen present. The difference between the two null readings

then is translated into moisture content by use of a calibrated chart which is

developed by the user. Instruction for developing the calibrated chart and for

making the test measurements are supplied by the test equipment manufacturer.

Advantages and Limitations

Although microwave absorption testing equipment is easy to use and is moderately

priced, the major limitation to its widespread use is its low degree of accuracy

and the difficulty in interpreting test results. For measuring moisture content

in concrete, the expected accuracy is no better than 30 percent of the mean

value. This low accuracy is due partially to the fact that concrete is a heterogeneous material which causes internal scattering and diffraction of the

microwave emissions (scattering is caused, also, by reinforcement).

REFERENCES -1,2,7
2,1,1.10 - Dynamic Tests

Test Method - Dynamic Tests (Ultrasonic Pulse Velocity and Resonant Frequency)

Material - Concrete

Parameter - Quality and Uniformity, Strength, Modulus of Elasticity

Discussion

The ultrasonic pulse velocity test method works on the principle that vibrational wave propagation is affected by the general quality of a dense medium

such as concrete. Assuming concrete to be an inherently heterogeneous medium,

the path of travel of the ultrasonic pulses must be long enough to test an "average" section of the structural member. The equipment makes use of an electro-acoustic transmitter and a receiver that are placed in contact with the

concrete surface. The distance between them is measured to a high degree of

accuracy by the travel time of an ultrasonic pulse. The average pulse velocities have been correlated with general concrete conditions and strength

qualities in the following table:

Pulse Velocity (m/sec) Condition/Strength Evaluation

Above 4575

3660 - 4574

3050 - 3659

2135 - 3049

Below 2135

Excellent

Good

Questionable

Poor

Very Poor

The main point to remember is that the less impedance (velocity slowing) that

the ultrasonic pulse experiences, the higher the quality of the concrete.

The resonant frequency test method is applied almost exclusively in the laboratory

and is used to determine the natural frequency of vibration of a standardized

concrete prism or cylinder. The vibration frequencies found in the test are used in turn to calculate Young's modulus of elasticity and rigidity, Poisson's

ratio, and durability ratings. A simplified description of the testing process

is as follows: 1) a drive unit applies standardized mechanical vibrations

to a concrete sample, 2) the vibrations are picked up by piezoelectric sensors,

and 3) the vibrations are fed into a cathode-ray oscilloscope that gives a digital and graphic readout of the natural reasonant frequency of the sample.

Advantages and Limitations

Both test methods yield an accurate assessment of concrete quality and uniformity.

Strength then can be estimated by preparing calibration charts. The accuracy of

estimation is + 15 to 20 percent. Both methods are applicable only to laboratory

tests and require a trained operator to evaluate the results. They are in

frequent use, and the equipment is relatively Inexpensive to purchase.

REFERENCES - 7, 21, 42

26
2.1.1.11 - Nuclear Tests

A. Test Method - Neutron Scattering Methods (Neutron Moisture Gages)

Material - Concrete

Parameter - Moisture Content

Discussion

The neutron scattering method for determining moisture content in concrete is

based on the principle that hydrogen containing materials (such as water)

decrease the speed of fast neutrons (greater than 0.1 mev.) In accordance with

the amount of hydrogen produced in the test material. In the case of concrete,

the moisture in the concrete is the major source of hydrogen and calcium

hydroxide.

Thus, the evaluator can obtain an estimate of the hydrogen content of the

specimen by counting the slowed-down neutrons which result from interaction

with the hydrogen. Most neutron moisture gauges use isotopic neutron sources.

Advantages and Limitations

Although neutron moisture gauges are satisfactory for measuring moisture content

in concrete, they have not been used widely since procedures for calibration

and measurements have not been adequately standardized. One of the biggest

drawbacks is the fact that gradients of moisture content near the surface of

the test specimen and the presence of neutron absorbers within the specimen can cause erroneous results. The adequacy of this test method for field application

has yet to be proven.

REFERENCES -1,7

B. Test Method - Neutron Activation Analysis

Material - Concrete

Parameter - Cement Content

Discussion

The neutron activity method of nondestructive evaluation is based on the

principle that concrete becomes radioactive when bombarded by neutrons. The

unstable radioactive isotopes that are formed emit beta and/or gamma radiation

which allows a clear characterization of the radioisotope and its parent nuclide.

To perform the test, a reference standard (of the element being determined) is

activated under the same conditions as the unknown sample. Then, the weight of

the element in the sample under investigation can be determined by comparing

the activities induced in both the test sample and the reference sample.

27
The major use of neutron activation analysis techniques for evaluating concrete

is to determine the cement content of concrete. Since the neutron activation

process is independent of chemical bonding and the internal physical condition

of the specimen, these respective properties cannot be measured using this

method of evaluation.

This test is not widely used for several reasons, the first of which is that

it is expensive and complex. Since it is a recently developed test method,

the procedures for calibration and measurement have not been standardized

adequately. Then too, the accuracy of the test results is questionable due to

the fact that gradients of moisture content near the surface of the concrete

and the presence of neutron absorbers within the concrete will induce errors

in the test measurements. Performance of this test method in the field has

yet to be proven.

REFERENCES -1,7

2.1.1.12 Infrared Test

Test Method - Infrared Test

Material - Concrete

Parameter - Internal Flaws, Crack Growth, Internal Voids in Slabs

Discussion

Infrared evaluation techniques detect flaws in concrete by using selective

infrared frequencies to detect various passive heat patterns which can be

identified as belonging to certain defects. There are three commonly used

variations of this technique of nondestructive evaluation of materials - one based on steady-state heat patterns, one based on transient heat emission, and one based on low amplitude vibrations.

1) Steady-State Heat Pattern Method . In this method of infrared evaluation,

the heat pattern in the specimen is produced by a boron-epoxy laminate

during cyclic loading at 30 Hz. The heat pattern is caused by the dissipative nature of the internal friction Inherent in the specimen material. As

fatigue damage develops, changes in the heat pattern can be observed.

2) Transient Heat Emission. The heat pattern resulting from the transient

heat emission method is produced by the dissipative part of the strain

energy released when a material fractures. This strain energy released at

the time of fracture is partly in the form of heat which produces the image seen by the infrared camera. For this test, a boron-aluminum laminate is

used on the test specimen to produce the heat patterns.

3) Vibrothermography . Rather than Inducing a cyclic (fatigue) loading in the

specimen, low amplitude vibrations can be used to produce heat patterns

without the need for a fatigue machine. Standard shaker tables or transducers are used to produce the vibrations needed to conduct the test.

28
Advantages and Limitations

The greatest advantage of using the transient heat emission method is the

ability to monitor quantitatively energetics of fracture events by reviewing

Images produced on infrared film. The steady-state heat pattern method for

detecting flaws in concrete currently is not reliable enough to make its use widespread. It shows great potential and is undergoing research and development. Concrete is a good material to use with these two test methods because

it is a good Insulator, it has a low specific heat value, and it has high heat

capacity.

Vibrotherraography has four advantages over the other two infrared test methods

in that 1) the low level of input energy does not damage the test specimen in

any way, 2) the equipment is less expensive and easier to use, 3) the frequency

of the excitation can be varied over a wide range, and 4) often flaws can be

selectively discriminated by varying the frequency of the excitation.

Infrared evaluation techniques can be used advantageously in conjunction with

load testing.

REFERENCES - 22, 23, 24

2.1.1.13 Load Test

Test Method - Load Testing

Material - Concrete

Parameter - Performance Under Load (Rigidity, Failure Under Stress)

Discussion

Load testing verifies design load carrying ability of a structure (unless

failure occurs during the test). The test procedure is based on the principle

that any structure which is capable of withstanding the stresses of a design

load should perform satisfactorily under actual loading conditions.

To conduct the test, a test load is applied to the structure in a manner that

will simulate the load pattern under design conditions. The test failure

indications (such as leakage, distortion, or even structural failure) then are monitored and measured visually or with detection devices. Structural loading

can be accomplished by the use of heavy dead weights such as concrete, lead, or water.

Advantages and Limitations

The advantage of using load testing for nondestructive evalution of concrete

is that it provides a high degree of reliability on the structure's ability

to perform satisfactorily under normal loading conditions during the present

time. However, its validity concerning the long-range performance of the

structure is questionable.

29
A serious limitation to the use of this test method on old buildings is the

fact that it may cause cracks or distortion, or may even cause premature

failure of the structure or some of its elements. Load testing has the

disadvantage of requiring a significant amount of preparation and clean-up

time before and after the test. Because of its high cost, it has limited

application.

REFERENCES - 1, 25, 40

2.1.1.14 Radar Test

Test Method - Radar

Material - Concrete

Parameter - Detection of Substratum Voids

Discussion

Since slab-on-grade is one of the most common construction techniques used in

buildings, it is useful to know that an alternative test method is being

developed to check the Integrity of the subgrade material. Some manufacturers

claim that radar, which employs the use of transmitted electromagnetic impulse

signals, has an 80 percent reliability of substratum void detection. This new

test method is more time and cost efficient and less destructive than the

previously used "guess and drill" techniques.

Advantages and Limitations

Radar equipment is expensive. A major disadvantage of the radar system is

that the reliability of void detection is greatly reduced if the slab contains

reinforcing bars or mesh. In such cases, the data must be interpreted by an expert trained in the field of electromagnetic impulse analysis. This test

method may also have further applications in geotechnical and highway

engineering where void detection is important in determining the strength and

service life of a concrete slab.

REFERENCE - 26

30
2.1*1.15 Pullout Test

Test Method - Pullout Test

Parameter - In-Sltu Pullout Strength of Hardened Concrete

Discussion

A modification of the ASTM C 900 pullout test of cast-in-place plugs has been

developed for determining pullout strength of hardened concrete using drilled

and set-in-place wedge anchors. The test is based on the determination of the

pull force required to cause shear failure of the concrete. The pull force is

derived from a tension ram connected to the anchor at one end and a portable

hydraulic pump at the other end.

Two types of wedge anchors currently are considered acceptable for use in this

test; namely, 1) the split-sleeve assembly, and 2) epoxy grouted bolts. The

split-sleeve assembly consists of a tapered steel rod threaded at the small end

and a specially designed high-strength sleeve that includes a split shell at one end. The other end of the sleeve is threaded so that it can be screwed to

the base plate of a tension ram. To prepare for the test, holes measuring

19 mm (3/4 in) in diameter and 38 mm (1 1/2 in) deep are drilled in the hardened

concrete with special drilling equipment designed to permit rapid drilling of

holes perpendicular to the surface of the concrete sample. A description of

the remainder of the two test methods follows:

Using Split-Sleeve Assembly Using Epoxy Grouted Bolts

1. Insert and secure the steel rod

and split-sleeve assembly in the

drilled hole with tapered end

down*

2. Screw the assembly to the base

plate of the ram.

3. Gradually apply a pullout force

on the rod through the tension ram until the plug breaks out of the

concrete.

1. Clean and dry the drilled hole.

2. Fill the hole with a flowing epoxy.

3. Place the anchor bolt (a threaded steel

rod) into the epoxy with a slow rotary

motion (to avoid the formation of entrapped

air at the interface).

4. Hold the bolt in a perpendicular position until the initial set of the epoxy

takes place.

4. Record the maximum pull reading 5. After proper curing of the epoxy

observed. (usually 24 hours), the bolt and resulting

concrete plug is pulled out using a tension

ram assembly. The load is applied uniformly

until failure of the concrete occurs.

The test results of the pullout test on hardened concrete indicate good correlation with the strength results obtained from compression tests on cylinders

and drilled cores. In fact, the correlation coefficient values of around 0.81

to 0o85 are comparable to those reported from the pullout test of cast-in-place

anchors (ASTM C 900).

31
Advantages and Limitations

The pullout test on hardened concrete is a simple, quick, and inexpensive test

which can be carried out easily in the field on in-situ concrete. It offers

the advantage of direct determination of some strength parameters and shows a good degree of correlation with the standard strength test (compression test on cylinders or drilled cores). However, due to the lack of standardization

of the test procedures and the equipment, high within test variations may be

expected to occur. For this reason, at least 6 pullout determinations per test

should be performed.

For the split-sleeve assembly method, the effectiveness of the test is dependent

upon the design and geometry of the split-sleeve assembly itself. Proper design

of the split-sleeve assembly is important because it is the mechanism used to

transmit the whole pullout force to the concrete.

For the epoxy grouted bolt method, the epoxy must have suitable pot-life

characteristics and provide satisfactory bonding action with the concrete.

It also must be able to develop high elastic and strength properties at a very

early age under variable ambient temperatures. Preliminary use of this test

method indicates that research is needed to develop epoxies that will allow

the pullout tests to be performed in a matter of hours rather than after

2A hours of set time.

REFERENCE - 38, 39

2.1.2 Destructive Tests

In contrast to the many and varied nondestructive test methods available to

evaluate concrete, there are fewer destructive methods which have been developed

thoroughly for this purpose. This section on destructive evaluation methods

shares a similar objective with Section 2.1.1 on nondestructive evaluation,

namely, to present the most commonly used methods for destructive evaluation

of concrete structures and their components which will assist the examiner

in evaluation of physical properties and performance.

Destructive test procedures include the test methods of core drilling and

petrography which can be used together to determine the strength and internal

quality of concrete and its cement and aggregate components. Such characteristics as deleterious chemical reactivity betwen components, and physical

condition and composition of the cement and aggregate can be determined best

by these destructive test methods.

REFERENCES - 2, 4, 7, 8, 14, 37, 38

32
2. 1.2.1 Core Drilling

A. Test Method - Core Drilling

Material - Concrete

Parameter - Strength and Internal Quality

Discussion

The existence of some surface aberrations such as scaling, leaching, pattern

cracking, and freeze-thaw weathering may suggest the need for an Investigation

of the Internal condition of a concrete structural member. A widely accepted

destructive test method to check for internal quality is core drilling.

Drilled cores of 50-250 mm (2-10 in) in diameter and of varied lengths are obtained using a gasoline or electric powered drill rig. Cores from older

members with rehabilitation potential tend to be 50-150 mm (2-6 in) in diameter.

The drill bits are either calyx (steel shot) or diamond (bort). The diamond

bit drills are much faster and cleaner but require a more skilled operator and are much more expensive. Cores should be catalogued when drilled. They should

then be labeled carefully and packaged for transport to a test laboratory.

The sample types can be placed in two broad categories: 1) samples that are Intended to be representative of the concrete in place, and 2) samples that

display specific features of interest, such as a core taken at the site of a cracking pattern.

Subsequent tests performed on the sample vary significantly. The core size

requirements vary with the type of test to be performed. The basic testing

list includes: 1) visual inspection (surface condition, depth of deterioration,

fractures, unusual deposits, coloring or staining, distribution and size of

voids, location of construction joints, and contact with the foundation or other

surfaces); 2) compressive and tensile strength; 3) transverse, longitudinal and

torsional frequencies; 4) static modulus of elasticity; and 5) Poisson's ratio

of concrete in compression. Other tests that might be warranted are dynamic

loading and seismic loading tests. These last two test methods require cyclic

loading techniques used with various time intervals.

ASTM C 42 "Standard Method for Obtaining and Testing Drilled Cores and Sawed

Beams of Concrete" gives a more complete description of this test.

Advantages and Limitations

This is the most widely accepted method to determine strength and quality of

in-place concrete. The process of drilling and analyzing concrete cores is

expensive and requires a relatively long time period (1 to 3 weeks) for a thorough analysis. This test method is termed destructive because repeated

core drilling in a concrete structural member could affect its integrity.

Cores obtained from appropriately located drilling sites are a very accurate

representation of the internal composition of the concrete. Core drilling is

best suited to concrete structural systems such as walls and foundations. It

33
should be used very judiciously when dealing with structures being evaluated

for rehabilitation purposes.

REFERENCES - 3, 23, 27, 29, 30

B. Test Method - Petrography

Material - Concrete

Parameter - Physical Quality of Aggregate and Concrete

Discussion

Petrographic examination uses microscopy and/or x-ray diffraction and

differential thermal analysis in conjunction with core testing to aid in

determining the physical and chemical properties of aggregates and concrete.

1) Aggregates

By the use of this test, the aggregate is identified according to mineralogical

and chemical differences, and the following properties of the aggregate may be

determined

a) The extent to which the particles are coated.

b) The nature of the coating substance.

c) Particle shape.

d) Potential deleterious reactivity with cement alkalies.

e) Chemical reactivity.

f) Condition of the aggregate.

g) Cement-aggregate reactions.

h) Composition of fine and coarse aggregate.

To accomplish this test of aggregate found within a concrete core sample, the

aggregate is examined by a hand held lens or a microscope. The aggregate then

is analyzed in accordance with the following three criteria;

Petrographic Identity

An experienced petrographer can examine the aggregate samples to identify

whether the particles are coated with either mineral or organic coatings, to

identify the coatings, and to determine the potential physical and chemical

effects of the coating on quality and durability of the concrete. The particles are examined further to determine their classification (type).

Physical Condition

Aggregate samples are examined to determine their shape, flatness, angularity,

and other pertinent properties than can lead to classification of the aggregate

as: 1) satisfactory (contributes to high or moderate strength, abrasive resistance, and durability of concrete), 2) fair (contributes to moderate strength,

durability and abrasive resistance under ideal conditions, but concrete might

3A
breakdovm under rigorous conditions), and 3) poor (contributes to low strength

and poor durability of concrete or breakdown of concrete).

Anticipated Chemical Stability in Concrete

The amount of deleterious aggregate particles (alkali reactive rock types such

as opal) may be determined. The deleterious particles can be responsible for

producing adverse effects on the concrete through chemical reactions with the

cement alkalies.

2) Concrete

The condition of the concrete also may be evaluated by using petrography. For

this purpose, the most useful samples of concrete are diamond-drilled cores with a diameter of at least two to three times the maximum size of the coarse

aggregate used in the concrete. For concrete with 150 mm (6 in) aggregate, a core of 200 to 250 mm (8 to 10 in) diameter is commonly used rather than the

more costly and harder-to-handle 305 to 457 mm (12 to 18 in) cores prescribed

by this general rule-of-thumb.

The following features of concrete can be studied and evaluated:

a) Denseness of cement paste.

b) Homogeneity of the concrete.

c) Occurrence of settlement and bleeding of fresh concrete.

d) Depth and extent of carbonation.

e) Occurrence and distribution of fractures.

f) Characteristics and distribution of voids.

g) Presence of contaminating substances.

h) Evidence of cement-aggregate reaction.

1) Proportion of unhydrated granules of cement.

j) Presence of mineral admixtures.

k) Volumetric proportions of aggregate, cement paste, and air voids.

l) Air content and various parameters of the air void system.

Care should be taken in selecting core samples to assure a maximum true representation of the material and to avoid unusually poor or unsound materials.

Sampling should include near-surface concrete as well as concrete at depth

because of the possible affect of depth on the properties of the materials and

the defects. Also, the number and size of samples should be carefully selected

to permit all necessary laboratory tests. It is important to use virgin

samples in order that there be no Influence from previous tests.

Evaluation should be performed only by a qualified petrographer who is familiar

with problems commonly encountered with concrete. The petrographer should

be consulted before proceeding with the core sampling and should be provided

with as much preconstruction, construction, and post-construction performance

information as possible to assist in the evaluation. Following petrographic

examination and analysis, the petrographer prepares a report summarizing observations and conclusions regarding the suitability of the aggregate under the

anticipated conditions of service and indicating any possible effects the

aggregate may have had on problems encountered with the concrete.

35
ASTM C 295 "Recommended Practice for Petrographic Examination of Aggregate for

Concrete," and ASTM C 856 "Recommended Practice of Petrographic Examination of

Hardened Concrete" give a more complete description of this test.

REFERENCES - 3, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41

2.1.3 References

1. Sevall, G. W., "Nondestructive Testing of Construction Materials and

Operations," AD-774 847, U. S. Department of Defense, Army Construction

Engineering Research Laboratory, (December 1973).

2. Annual Report 1979 , NBSIR 80-2007 (Washington, D.C.: National Bureau of

Standards, 1980); and Annual Report 1978 , NBSIR 78-1581, 1978.

3. "Practices for Evaluation of Concrete in Existing Massive Structures for

Service Conditions," No. ACI 207 R-79, CONCRETE INTERNATIONAL (March 1979).

4. NDE (Nondestructive Evaluation), LC 1080 (Washington, D.C.: National

Bureau of Standards, April, 1978).

5. Olympus Corporation of America, Promotional Information, New Hyde Park,

New York.

6. Fiber Optics Equipment, Deteck, Inc., Promotional Information, Camp

Springs, Maryland.

7. Malhotra, V.M., "Testing Hardened Concrete: Nondestructive Methods,"

American Concrete Institute Monograph No. 9, (1976).

8. "Strength Evaluation of Existing Concrete Buildings," ACI 437, American

Concrete Institute, (1975).

9. "Standard Test for Penetration Resistance of Hardened Concrete," C 803,

American Society for Testing and Materials, (1975).

10. Halstead, P. E., "The Covermeter Apparatus for Measuring the Depth of

Reinforcement Below the Surface of Hardened Concrete," Technical Report

No. TRA 197, Cement and Concrete Association, London, (July 1955).

11. Raiding, F.J., "A Portable Reinforcement Covermeter," Report No. BI-66-26,

Institut TNO Voor, Bouchomaterialen en Bouwconstructles , Rijswijk (ZH),

The Netherlands, (March 1966).

12. "Nondestructive Testing: Trends and Techniques," Proceedings of the

Second Technology Status and Trends Symposium at the Marshall Space Flight

Center, (October 26-27, 1966).

13. Whitehurst, E. A., "Evaluation of Concrete Properties from Sonic Test,"

American Concrete Institute Monograph No. 2, (1966).

36
lA. ''Recommended Practice for Evaluation of Strength Test Results of

Concrete," ACI 214, American Concrete Institute, (1977),

15. "Recommended Practice for Concrete Inspection," ACI 311, American

Concrete Institute, (1975).

16. Clifton, J. R., Nondestructive Tests to Determine Concrete Strength - A Status Report , NBSIR 75-729 (Washington, D.C.: National Bureau of

Standards, July 1975),

17. Leslie, J., and Cheeseman, W., "An Ultrasonic Method of Studying

Deterioration and Cracking in Concrete Structures," ACI Journal,

(September 1949).

18. An Infrared Technique for Measuring Heat Loss , NBSIR 78-1557

(Washington, D.C.: National Bureau of Standards, September 2, 1977),

19. "Nondestructive Testing Techniques," MATERIALS EVALUATION (September 1970).

20. Warren, C., "Proceedings of the Third Biennial Infrared Information

Exchange," the AGA Corporation, (August 24, 1976).

21. "Building Code Requirements for Reinforced Concrete," ACI 318, American

Concrete Institute, (1977).

22. "Radar Spots Substratum Voids Without Drilling Slabs," ENGINEERING NEWS

RECORD, (September 7, 1978), p. 15,

23. "Standard Method of Obtaining and Testing Drilled Cores and Sawed Beams

of Concrete," C 42, American Society for Testing and Materials, (1977).

24. "Recommended Practice for Examination and Sampling of Hardened Concrete

in Construction," C 823, American Society for Testing and Materials, (1975).

25. U.S. Department of the Interior, "Concrete Manual - A Water Resources

Technical Publication," Bureau of Reclamation, (1975, Eighth Edition).

26. Erlin, B., "Methods Used in Petrographic Studies in Concrete Paste,"

JOURNAL OF THE AMERICAN CONCRETE INSTITUTE, Vol. 27, No. 12, pages

1083-1097, (June 1956).

27. "Standard Test for Cement Content of Hardened Portland Cement Concrete,"

C 85, American Society for Testing and Materials, (1966 rev. 1973).

28. "Standard Test for Fineness of Portland Cement by Air Permeability

Apparatus," C 204, American Society for Testing and Materials, (1979).

29. "Standard Test for Fundamental Transverse, Longitudinal, and Torsional

Frequencies of Concrete Specimens," C 215, American Society for Testing

and Materials, 1960 (rev. 1976).

37
30. "Recommended Practice for Petrographic Examination of Aggregates for

Concrete," C 295, American Society for Testing and Materials, (1965,

rev. 1973).

31. "Recommended Practice for Microscopical Determination of Air-Void Content

and Parameters of the Air-Void System in Hardened Concrete," C 457,

American Society for Testing and Materials, (1971).

32. "Standard Test for Static Modulus of Elasticity and Poisson’s Ratio of

Concrete in Compression," C 469, American Society for Testing and

Materials, (1965, rev. 1975).

33. "Standard Test for Resistance of Concrete to Rapid Freezing and Thawing,"

C 666, American Society for Testing and Materials, (1977).

34. "Standard Test for Critical Dilation of Concrete Specimens Subjected to

Freezing," C 671, American Society for Testing and Materials, (1977).

35. "Recommended Practice of Petrographic Examination of Hardened Concrete,"

C 856, American Society for Testing and Materials, (1977).

36. "Standard Test for Rebound Number of Hardened Concrete," C 805, American

Society for Testing and Materials, (1979).

37. "Guide for Making a Condition Survey of Concrete in Service," ACI 201,

American Concrete Institute, (1975).

38. Mailhot, G.; Bisaillon, A.; Carette, G. G. ; Malhotra, V. M.; "In Place

Concrete Strength: New Pullout Methods," JOURNAL OF THE AMERICAN CONCRETE

INSTITUTE, pp. 1267-1282, (December, 1979).

39. "Tentative Test Method for Pullout Strength of Hardened Concrete," C 900,

American Society for Testing and Materials, (1978).

40. "Standard Method for Load Tests of Floors and Flat Roofs," E 196, American

Society for Testing and Materials, (1974).

41. Halmshaw, R., editor, "Physics of Industrial Radiology," Heywood Books,

London, 1966.

42. Vary, A., "Ultrasonic Measurement of Material Properties," in "Research

Techniques in Nondestructive Testing," R. S. Sharpe, editor. Academic

Press, London, pp. 159-204, (1980).

38
2.2 WOOD (STRUCTURAL TIMBER)

The practice of evaluating wood must focus on identification of those

characteristics of the wood (such as density, knots, moisture content, etc.)

that define its performance. This is because, as contrasted with man-formed

materials (such as concrete & metals), timber must be segregated into use classes (graded) according to predicted performance. This means that the

building industry's control over the quality of wood is limited to the proper

application of these use classes.

In existing structures, questions of performance of wood products must address:

1) the presence of the properly specified product grade and size, 2) the proper

joining of these products, and 3) evidence of degradation of these products by

the environment (e.g., moisture, temperature, chemicals, etc.).

One of the greatest aids available for evaluating structural timber is the

grade mark stamped on it at the mill. Because grade marks usually can be

related to a recommended design value (by reference to the National Design

Specification for Wood Construction, Ref. 16, or other relevant documents), it

is helpful in determining the quality and strength properties of the existing

timber structure of a building if they can be discerned. Doing so may require

removing the finish on the members, and this usually is not done because of

the considerable costs of such explorations compared to the benefits derived.

If, on the other hand, the grade marks are not discernible, it may be necessary

to engage an evaluator who is experienced in identifying and grading wood

products to make the evaluation of the quality and strength properties of the

in-si tu structural members in question. In order to accomplish this task, many

nondestructive and destructive evaluation procedures are available, the most

common of which are listed in Table 3. This table is arranged according to the

properties or parameters to be evaluated, the corresponding capabilities of the

test, and the advantages and limitations associated with the test methods.

39
TABLE 3

TEST

METHODS

FOR

WOOD I)A w • o o z z

bJ

oe:

u

Cd

O bb < U Ou

02 9 Cd Cd

CO rH rH •H 8 y CO •o 73 Cd Cd 75 • 75 9 73 rH O 9 c; u rH X CO rH CO 75 9 9 9 Xi U t4 O *9 9 4b CO 4b iH 9 9 X O >^ 4J 0) • 4b 0) o •H 9 •H 9 y • 9 y 4b X 0) u 0 M X 3 CO rH p9 Cd 9 U O

CO CO 8 9 4b Cdu 9 CO 4b CO Cd Mb rH 9 lb 6 z 73 «r< •H ^4 Cd > • 9 CO Cd 9 OO u X CO a o O 9 01 4J • o rH & B o 9 9 O 9 cr 9 9 •H Cd u M O ^ CO CO >v 4b •H 8 o 9 o •iH •H 4b 0 •H CO CO 9 4J Mb H •H O 01 CO 4J «rH 01 •H •H 4b 4b rH 4b CO 6 •H • < 4-» »- 0) •H T> •H •9 CO Cd 4b •9 O u Cd 00 9 CO 9 H O rH 00 rH o; CO 0) cd •H a a 9 9 9 75 9 •H rH y 4b CO 7J y M 0) o u CO 4J CO X ^ 9 CO 9 X O X Cd y o 00 lb Cd Z a. Mb d) cd •H 01 00 *0 X a. 9 T-) 4b .9 9 9 Cd 9 9 Cd Mb M CO Cd 6 CJ >> o 4b CO 9 o 4b 4J 4b 9 rH » lb 9 o •H y (B <*-i o •H 9 9 0 9 9 9 9 0 9 Cd 9 9 9 M 4J CO r4 (d S -H > M X y Cd 5 •H M 9 X o 9 •H CO co >mH 1-1 U

t-i (d o> <0

CQW *H 9 C 9 S O

•H 9

1-1

u

0) <u W CO o. c

•a -H O CO o a 0) OO CJ CO 4J CO < CO <dC iH

0) cd 6 u

CO o>

5>

O •CO U • 0) C >> -H

o> (d c.) 4J o 0) X Q> O.

bJ fi CO

fH

O

Cd 0) 9 a CO CO •H c > M

p

O

y CO 9 cd 4b 9 9 9 Ou CO O 1 CO CO N Mb O o 9 •o lb 60

•H CO

y 4b •t •HO 4b

O 9 Mb 9 73 9 CO 4b y Mb 9 9 60 Mb CO CO •H U 0 Mb 4b O •H y • y lb •H 4b o u 9 9 0 •9 4b Cd O 9 O 60 lb •H •9

H 9 o 4b 4b 9 •H CO

y 9 Cd

y

a 9 • •H 3 9 9 60 4bO

Ma mh CO

X rH 00O *o • c Cd 9 •H 9 9 8 9 /TN 4b rH •H 4b 9 CO

O

rJ CO •H 4b Cda bH

y 0 9 (d rH 73O rH 75 9 a 73 9 •H •H

M 9 X

U

y 4b 8 CO 4b •H CO 9 lb 9 y CdO

O CD 9 Cd •H P •H y 9 9 0 9 4J 9 O* 60 9 U > O O. rb Cd 9 *9 < u 4b (d a 9 y CO CC •H 9 9 > 60 9 Cd 8 a 9 4b 9

Ql, rH Cd

y

y >> V- Cd

A c 4b

U * Cd COu 00 9 y

y o COUy 9 < m 9 cd 9 4b 9 rH 00 «r •H Mb CO > CO o CO •H cd 9 y X Cd O o 9 CO lb •o Mb Cd X Mb 8 rH 4b 9 4b 9 Cd rH Mb •o X lb 00

CO Cd 9 Mb lb

y o 9 (d 73 0 •o

uy lb 9 rH

U *9 4b •9 Cd •H O X M4 U *H 9 9 o X 9 9 5 9 4b Cd 4b rH 9 9 Mb 9 •H 9 X Mb > 4b y o Cd 73 4b CO M cr cd Cd CO Mb 00 y fib CO o cd 3 Cd y O

00C 0)

(Uv< -o cd •U C

CO (d o

op

t-t CO 9

(d CO >H 9 0) 73

CO

M (d 4J M > CO o

vO

<r

lb

u Mb 9 o O 73 Mb

Mb • >» 9 0k 9 •H 9 9 y 1 9 • 9 4b lb S.X 73 O U Cd 9 CO CO y CO Cd Mb 9 •H 9 9 9 CO X 9 9 Cd Cd O

4b 4b 00 9" > 9 < y

O Mb Mb >* CO Mb

•H

y cd 9 9 y •H *HU Cd

y •H 9 9 9 9 9 *9 O •H 4b 4b 9 00 y •H 4b Cd 60 •

CO

a 8 Cdy 4b P y

y 00 •H 9 4b 9 Cd

COy c/o cd 9 •9 CO 9 9 4b 4b rH 9 Cd rH o cd < u 4b lb 4b •H 73 •H CO 9

rH •H Cd 4b lba 9 0 HH 73 Li •H 9 9 CO lb CL *9 73 Mb 9 9 9 73 8 5 60 9 9 73 9 60 cd 4b O U 9 a 9 73 4b 9 rH 4b 9 •9 71 • y 4b Cd y o

CO •H •H

y 4b Cd CL -H

O

O 0k Cd c rH

•H *9 > 9 cd 9 9 •9 o X cd >% Li >% 5n Cd 9

CdO lb rHOy Cd 60 4b

y CO Cd CO 9 > >

4b

u

u 4b 9 •H

y

u % 9 Cd

X Cd 73 9 M 60 Ob CO lb 4b Cd 60 < 8 *9 9 y 9 U Cd 73 C

0) Cd •u o X Mb 0) MOP

00

rH 9

Cd *H 9 P 9 O

cd lb Z M

V

40

See

more

detailed

description

on

page

indicated
TABLE 3

(Continued)

TEST

METHODS

FOR

WOOD

03 • O O z z ^ u u o CtN •< U Pu 02

*3 VI

0) • 0) o 0) • 0) rH

y

GO £ VIB 0) • Viy o u CO Vi •H 4J CO B *B >% 0) 3 O rH iH 3 >> y rH O oo Vi CO VI u CO Vi VI VI O. VI iH 3 • *3

0) c XU •H fM o 3 GOa >1 (0

a 00

y

y • U 0) •H B B 0) v> •H >. CO iH iH y • y 00 y y >> CL Vi rH CO o 0 *o CO O O rH CO y O • y ,c 5s O B B a CO cn VI (0 • CO 0) •H VI a > a VI VI y CO cn CO y o y y z <a CO 0 CO 0) M-i CO 4-1 0 CO 0) iH B y y y Vi 3 CO Li y o rH 0) O VI 6 VI B y y «« y VI o rH iH *3 M 0) CM 0) B CO Vi o o •H VI CO y CO 4H 5s *3 CO VI VI 4h >1 4-1 H TJ o .B B. 3 •o 3 CO 4-1 0> cn O iM X y 4h VI a B B X •3 < •H 6 Vi CO 0) 0 a 6 B 4H 0) p CO 1-4 Vi iH 8>e y iH r B H > B VI CO >% CO CO 00 O >. •H O u a CO O 5< VI >^ y y M o O CO CO CO 0) CO 0> VI Vi iH Vi >s y B O B y rH y £ •H 3 CJ B X VI 00 4-1 0) a 0) GO y y 0t V< y 0 Vi rH > A M a 4^ e B 0) •H CO B c^ U y iH Vi iH CO *3 y Q.X y (0 CO •H y

nJ CO s •tJ CO •H CO CO 0) CO CO VI CL VI lH VI VI 4J B CD o CO • no U •H a • > 4h VI CO B B CO y y VI CO B o •H 00 B 0) T3 0) 0) VI •H VI 1-4 Vi y 3 B 00 y y 5s VI B > y c B B w 0) u o y 00 M B VJ 3 CO y y B a a CO rH 3 CO CO Vi *3 U •H 3 0) CO B 3 0) Vi O 0) •H CO Vi iH •H iH 1-4 4J •3 B V) *3 4J y Vi

CO 0)

X CO 0 4-1 CO 4-1 iHO Vi VI CO 3 VI -o *3

y CO rHO

y CO CO

y

0) VI CO VI CO 0 Vi > 0) Oj VI

aB

B 0/

y

U

y CO

y

y

y iHyX

y VI o Oj 0) •H 0) 3 CO •H B. O 0) y CO M y B. Vi iH B o {B 3 Vi y Q 'O PS > s o. CO CO D 'O e CQ U C/0 u < a tx ei CO VI 5- iH a P CO a Vi o c ^ cO iH

CL <J 0> JC S V

CO •H *t> *H

•H CO 0 ^

(d >,

iJ •> ^ iH C 01 0) 0) fH 0) "O C S 0) C

O. CO jQ CO

O

•H 4J 05 3 (0 3 W ^

O*

O 3 0)

txj

a ^ 0) 4J H (0 • 0) «H 00 cue c a *H o o c

(0W «H

U CU CO

OJ O. t-i a. CO 4J I 0> CO .c 0) T3 M cO to CiO U

4J

C 0) 00

•H o> o o;

CO

Q

C

C 4J -o o

OJ cn

C ^ *H

Q

W CO

O *J

a pi o z z o H H M U H S z < z O « >1 C6 H H CO a H (/> U H o U Z c/o 2 H u w M M

P4H Oi pH

00

y 4-1

y ps 3 y

Vi o Vi B. y • • y 4-1 y O y y o y y iH • y B 4H y y B y y *3 y 0 •3 y 3 B y u y Vi iH y B a y 1-H y 4H C 00 iH 4-1 rH y

>v

O iH

y

X Viy 00 TJ

y

X VI VI y Li 3 a 3 Vi y

y

y iH 3 y B. Vi

B

X rH

y

X 5s

uy 4-1 iH •H iH iH •3

u

y

y >»

y

y 3 *3 rH

y

y o y X X iH 3* 6 y y > Vi pa y E-i B. *3 4J y iH y y 00

0)

CJC

u

(0

u

00 0) C V4

a

y >1y

O

B -B *3

y 4J iH 3

lH

y

B 3 4J iH VI

y 4H 3 4-1 VI

X Vi •H

B

B 4J B.B

y rH

y o 00 •• y O B y 4-i 8 o • 4H r-4 3 iH u y Vi y 3 3 y oo O iH 3 B •• O y y 0

CL Z •3

y oo 3" 4JBy Viy

a

B. 4-1 4-1

Byy

y

yyBB

a

y

y

B L4

y oo *3

yy Vi

u

B 3 y iH iH 4-1

y

y 4H

B

B

a pC 4h 3 0 3 B 3 y o B o y y y 3 4J 3 y y B y a r4 4h O

4-1 Vi

yB

y Vi 4J

yy

aO iH 4J

y 4H

y 3 y 0 iH 3 O iHyy

y

y

B

a

y

y • B *H o iH 3 y

y

y

y 3

iH iH 5s

y

y 4J

a Vi *3y -3

y o y *3 iH 0

VI 3 4J

y 4J

y

y 4J

O B. o VI

X rH

y 3 a 6 y 4J Vi 3 iH Vi rH o 3 O y Vt B VI 1 Vi 4J y y y iH y y 3 3 4-1 y 3 4-1 y Vi 3 iH y B. »3 y y iH i-H 3 a y y rH y a B O a y 3 y y y y y y VI » y B. > o y B Vi 4H y y y 3 iH X rH rH iH o y a y Vi a iH a o a £ o *3 *3 4-1 4J y y Pu £ y 4H

0)M 4J 3 C

4J 0)

CO 4J •H C o o

s:

u

0)M I 3 o <u •H CO U -H

4J

O

<J

X Oi

0)

U

•H 0> 0)

0) O. 4J •H >> 0» Q H S

0) 3

rH

O

a T3

CO

0^

u •

<U CO s: 0)

>% CO 00 C *H C

CO

u

Mh 0) o uoB

4J 3 C iH

0»

•H I }-i 03 3 *H

CO 03 CO Qi 0) u B

CO

0) • Xi u O ^0) U Xi a B

cox ou o>O 0)

0) 0)

0>

u •H *H a; 0) 3

4J

M

CO 0^ 0) •H N 4J O *H 0) S «>

0)Wi

U 3 a

4_) 0)

CO •H

C o o X o

<U (Ua

CO c u CO ou3u

0) CO CL *Ho

PS

H

r s

41

See

more

detailed

description

on

page

Indicated.
TABLE 3

(Continued)

TEST

METHODS

FOR

WOOD

wozu

oc

Ci3 u0^ oz o o f-H u iTt lA lA o<

CU 1 CO •9 rH t3 0> iH 0^ 9 9 A •

0) JC 3 Cd CVl 8^ • >1

CO OJ 0)

H o 0> lA VI *9 VI

y •9 9 z (0 z VI CO C 9 O CO C Cd 9

4J 9 CO <V( z 9 pO

O

y CO 9 ViG

CO

C • •H

O VI 3 Cd VI 9 iH z 0) m 9 0) c Vi VI C G VI VI C y od

O o 0) Z VI iH o; *9 • o Cd >% CO O pC 0 y Vi VI M y •H Xi VI CO y y «c •H e y y cd VI H Vi CO <0 UpI 0) •H Vi 9 rH < CO 1 C o E CO CO 9 >%*9 9 9 00 9 oo CO 9 • H 0) c o •H 9 iH Vi VI 9 VI Vi Vi c 9 C 9 M c CO •H *H CO VI Vi 9 •H VI y Cd 9 iH Vi c VI Z o 0) U 01 9 9 VI y y Cd CO VI y •H 0 Cd M Vi 0) CO jO &0 VI 00 CO 0 9 Vi VI 3 (0 9 9 <0 u

nJ CO

V 0> o C CO

G •H «VI (d Cd Cd 1-( *9 9* Vi 9

(0C

O 9 M o >> Cd o 9 «vi pC pC o 9 9 9 a z •H u-i cr a iH X Vi E > Cd y VI CH S Vi Z a o

o; VI 4J >% c O i“I • fH *9

0) <0 S -H 0) iH • y 0) 9 *9 9 CO • 9 M .A 5 Cd «H >v VI 1 VI

CO VI 9 CVI fH

G VI CO CO >s 0) y Vi 9 9 pC o

CO •H 09 pO ,£) 9 Vi > E OO

y

u o C CO *9

O 9 iH E cd -O C VI 1-1 G U-i VI Vi rH 3 < Z oj (d CO Cd cd 9 O H E y M a VI 9 »H CO 0k rH z c 9 0) C 9 ^ 9 Cd 9 5 0) 4J CO z 9 fH pO pd 9 rH 0k > c <d • VI E pC Cd E pO VI Q 1 0) 0) CO a Cd VI Cd pC < 00 VI E C o 1-1 VI CL • VI VI OO c c <d VI 9 Vi Cd 9 00 Vi •H 0 o 01 0) e cr O •c CO 9 o 9 y pO E iH Z O. (d 9 4.1 3

44

CO CO 9 O 9

iH 9 Vi Cd 9

iH VI CD CO 9 rH

VI 9 VI CO

y

y *9 9 f-4 CD

Cd 9 • Vi Cd 9 c B •H 9 C 9 C 9 rH CD > e VI CO o O p9 U iH O y > 9 44 Cd rH 9 > 9 lH Cd 9 44 •9 VI VI OO Vi 0 Cd VI 44 a *9 9 VI pC •9 y «H 9 G 9 VI 44 rH 3 CO Cd >k E O Cd VI 9 1-i VI 9 Vi >% *9 CO • 9 •H VI Cd E X z 4J •9 «H E 9 VI «H pC *9 > CO CD >mH CO VI VI C 1-1 C 9 1-t 9 CO •9 •H 9 CO VI O CO G CD CO CD OO c 1-1 C VI > Cd 9 y VI CO oo O U 9 O B G Cd c c

0)

G •H Cd 9 VI •H Cd Cd c 3 o Vi

y 9 *9 9 o

0) tH CO

O

C VI

G 3 E cd VI E 9 VI

G VI *9G rH

u e d Cd c o c O ^H CO iH o V *9 c CO iH <d iH 9 VI •9

a; >mH V» cd o -H

O •H CO CO Cd VI VI VI

G 0 pC 9 lH c/3 9 u *o Cd $ 01 E O •H Cd VI y CO Cd iH G fH CO CO 9 iH 9 X VI XI Os CO >* G y p2 •9 CO 9 VI • VI Cd CO CO G cd 9 9 •9 0 VI CO pO H VI CD H O *o •H o pfi G 9 cd IVI 00 *H •H •H c V4 G 00 CO Cd Vi *9 iH O • X »- a 0) V y Vi Cd O iH 1-1 o Cd *9 E *9 o VI 44 O cd G 00 9 •9 0 y VI >s

Vi VI

y VI Vi

a Via CO 9 1-»O VI •H 44 Cd > 9 0 • o VI 9 M 0) 9 y c y G Q.*9 E Cd >» O 9 c VI VI G >% c 0 CL CO y 3 pC rH *9 1-1 U

CC

u CO

y Cd 9 O 9 Cd > VI Vi fH Cd iH Cd 9 CO *9 Cd iH o C c VI 9 9 y Cd < 9 Cd rH VI rH G VI CO •H CVpO V4 00 oo X 9 9 y a CO u Cd 9 9 00 > U iH p 0^ y 01 CO (V w 9 Vi Vii y •H VI G cd VI rH CO 9 u 9 Cl Vi 9 pC c 9 VI CO < CO e iH 9 »9 9 VI 0 o 9 00 O Cl 9 9 •9 9 rH VI rH VI 9 9 CO CO G

CJ •H 01 CO o y

O CO (0 > 00 9 rH

O •9 *9 VI pO 9 44 Vi > CD Cd 0 o CO Z 0) cd O c 9 Cd 9 Cd o V4 G O CO 44 9 Cd Xi 44 e c VI Cd 9 rH iH z 1-1 VI u VI M-l 3 •H VI Z > 3 a P Cd a cd S iH o *9 VI H o iH iH CO 3 E 9 VI

VM >» 44 5S

A

O VI 0k o VI

u 0) pC iH p9 iH H V4 V) VI CO y VI CO y u 9 C 00 9 iH oo 9 lH z 4J 01 c rH VI G rH VI

CO v» 9 9 CO 9 9 CO QC •H c Vi *9 cd Vi *9 Cd o o 4J O fH VI O rH

Cu z o C/3 z Z C/3 Z u

P»-S

Q 1 c 9 c o 01 y VI 9 o > o z cfl y 1-1 y VI 1 > iH Cd iH VI c >- G Cd >v G 9 cd VI Z VI G u •H « o a •9 VI 9 VI Z cd Cd 9 z 1^ VI M CO B 9 iH £ iH oo CO 00 B U CO 01 U O cd IH y 9 y a 00 rH Cd CO Cd a H O •H pO C/3 o Vi 9 CO o iH C 9 a 9 00 iH CO 0) CO o VI *9 •9 rH rH 9 o c o V o 9 u 0> v» Z u iH C 9 9 9 o- nJ *H Vi VI u cr H z CU > z cd •H Z > 'w' *9 Cv c/3 CU W

42

See

more

detailed

description

on

page

indicated
iIi aoo

:so

u*

COaosHU£H

COuH

•O

0)3CCo

CJ

w • 0 o

01

M

u o bb

taJ OU

0^

ceS 0t

01u

cuo

OC

cu

i-H 3 g 3 y rH

y CM 3 • •H 44 E y IH 44 •M y MH c 3 y y 3 o • CO CO y •H o V- Z

CO 44u Z y z y o o y • c y •H y Uj 44 y 3 o *o 0) 3 CO 44 • 3 y M <0 a •H y y y 44 y •H a H l-J a CO y Z M >s C y y •H < H c c 44 y y y y H CO 3 o o c 44 M pH a y y y M Oj cr y •H y y c y o. y 44 a £ <u 44 PO 3 *H 3 o y •pH y M •H CO • CO M a rH y s 4J y y •H O z y y y o M

cr CO ^ a 3 3 Z a > > a

y

QJ 4) CO *H

y 0 C «H iH

yya

y

pc:

u

H 4J z 44

y z H 3 z o 44

44c c y 44 o y • c G •M •H

(0 44 CO

y 44 • o LM C a a y 44 e

0) o y

ua 3 44

y

M 3 44 44 y •H z y o

CO COy c a 3 0) 60

H M-l

u 0) 0)

y 0 O* > *H

u

O

w o. > y CO z y

y

y < X y • a H 0) 0) iH y CO 3 44 y Z u t-i y • o z rH O < CO y >s 3 3 3 O Z Z 44 > p .A e 44 •M P 3 *H y q 3 CO CO > O 44 o c •H O y M M y o <0 44 O u y o y 0 y < y y a CU V4 M-t *H a y

44 PO y 3 c c C •H y • • •H o y y

fc4 rH 1 M •H 44u 3

COy 1-4

u PO 3 44

G

y 3 O

•o Z COyy c COy

y az

y rH •H o a a *H 44 •H y •M y z y o y 44

H o o y 44

y

y o >»

y t4

w

y o «H 3 y

M

u

a c 3 Uh

M

ay

y

M ^ z U •H

hJ U4

y 3 y 3 > az 44 • y

M

M r-A

U

O 44 «M 44 /-N 44

y

PQ o c CO

y

u CO P o y Vi

y z y 3 t> < y t-i CM •H y y 3 Z »H y rH •H

CO 3 U4 3 O 44M

y

y o y

y

G

y < 0) CO 44 «H y a c CM r4 c «M c •tH *H •H 44 44 iH 44 y 3 z y y Xi z •H M V4 y •H

O. 3 PO

y 44

y

y

M

y ^ yy

y

ay

M 3 f-l e e 3 a «Hy CNi 44 44 44 3

CO V4 44 c y •H o Gy z > y c y

y

y

CO CO CO CO

a

y CO CJ 44 o ^ aa 3 3 c c M y 44 O o y * Vh y *H

•M

y

y 3 y 44 i-H 44 •H 44 44 y y y rH y 44 •H y G y CM 5 y •H f-H *M •H O O 3 3

Pti

M c. o rH •H

Ed 0) •H

y

y

a

A

y

u

H S-i 44 3 44 •*

N

y o 3 c 3 * «> 3 y iH ».< s u 0) C PO >% y y PC y y u

CO 44 •Myy 44 44 CO z o

•H c y

y o c a 3 a o o o M u y c o y 3 y rH

a* z CJO •H 3 Z y 3 ya <M

CJ>

Q PO

M o C z z z •H z o H >> < M M U z H s H 3 CJ < Z 1 o Z H O H G M

COM CO

y o < u U Ed > H :s H 6 P5 z

•o

0)

*cc

(U

0) T3

0)Wioe

0)

0)

43
2.2.1 Visual Tests

A. Test Method - visual Inspection

Material - Wood

Parameter - Extent of Decay

Discussion

Visual inspection and probing with a sharp instrument are usually the first

and most comprehensive test methods employed when Inspecting wood structural

members. Decay is mainly the result of fungus associated with moisture

accumulation. Characteristics of decay to be noted in different types of

structural components are given in the following table.

Component Characteristics of Decay

Siding

Foundations

Roofs

Porches

Abnormal coloring (deeper than normal brown color);

Cubical checking (indicates an advanced stage of decay);

Bleaching (with or without the presence of fine black

lines); Softening (especially where siding ends butt

against trim or each other).

Fanlike fruiting bodies of fungi (located between

subfloor and finish floor, and between joints and

subfloor).

Cubical checking, warping, softening, shredding, breakage

(location of all these deficiencies may be underside of

roof sheathing).

Same as siding (check especially concavely worn areas

that may trap water).

Windows & Doors Brown or black discoloration near joints. Stains on sash (from condensation). Softening and mold growth

(from accumulation of condensate).

Advantages and Limitations

Visual inspection is the preliminary step in evaluation of a member's strength

properties. An estimate of the in-sltu surface condition obtained in this

manner gives a first estimate of the presence of decay (any such evidence

suggests possible serious strength loss at that point). Since this a subjective type of test, the accuracy of the results is dependent on the skill of

the Inspector. The results are not indicative of structural capacity if there

is any suspicion of internal decay.'

REFERENCE - 1

44
B, Test Method - Visual Stress Grading

Material - Wood

Parameter - Strength and Grade

Visual stress grading Is a non-destructive method of Identifying and categorizing lumber according to Its defects which can assist In placing It In

broad categories of anticipated load bearing capacity by: 1) the formulation

of grading rules; and 2) the application of successive reduction factors to

the strength values obtained from small clear tests to take into account the

different strength-reducing Influences involved. In this manner, an estimate

can be made of the percentage of the test specimen’s strength compared to the

strength of perfect material of the same size and species (e.g., 50 percent,

75 percent, etc.). The characteristics that determine a visual stress grade

include size and frequency of knots, checks, splits, and pitch pockets; slope

of grain; density; and wane.

A test specimen often will have several characteristics that can affect a particular strength property. Consequently, only the characteristic that gives

the lowest strength ratio is used to derive the estimated strength.

When using the visual stress grading method, the modulus of elasticity assigned

to a grade is an estimate of the mean modulus of the lumber grade. The average

modulus of elasticity for a clear wood of the species is used as a base and can

be obtained from reference 2. This clear wood modulus of elasticity is multiplied by empirically derived "quality factors" to obtain the reduction in

modulus of elasticity that occurs by lumber grade. See reference 13 for a description of this procedure.

Advantages and Limitations

Visual stress grading: 1) provides an assessment of the conformance of lumber

grades in a structure to current practices (ASTM/ALS), and 2) permits an

assignment of design values based on current practice. When applied to in-situ

lumber, the procedures are limited to assessibility and may possibly deface the

test pieces (damage to paint, etc.). When properly applied, it yields an approximate, and generally conservative, estimate of a member's strength due to

the fact that: 1) there is little allowance made for specific gravity of the

wood, and 2) only the surface is available for inspection. It has to be assumed

that a defect has the maximum effect that can be deduced from a surface

examination. It has the limitation that it cannot differentiate the modulus

of elasticity for different grades which means that, where deflection is a limiting factor, there is little advantage given to the higher grades. Actual

modulus of elasticity for individual pieces of the grade probably will vary

from the mean assumed for design. The properties derived from visual grading

criteria should be modified for design use by considering the influence of

size, moisture content, and load duration. A discussion of these adjustment

factors is given in references 13 and 14 (chapter 6). The test requires a trained grader (or careful attention to both grading and stress assignment

45
procedures). Both hardwoods and softwoods can be assessed with this technique,

but many hardwoods will require interpretation for development of stress values.

REFERENCES - 2, 13, 14

C. Test Method - Manual Probing

Material - Wood

Parameter - Extent of Decay

Discussion

Prodding or probing a suspected piece of decayed wood with a sharp tool and

observing the resistance to marring gives an idea of the stage of decay. A

loss of hardness can be determined by comparison with sound wood of the same species. Sound wood tends to lift out of the stock as one or two long slivers

with splintery breaks when jabbed with a pointed tool. Decayed wood tends to

lift out and break off squarely across the grain with little splintering and

little resistance.

Advantages and Limitations

Manual probing will yield an accurate assessment of in-situ surface decay if it

is extensive, but it must be used in conjunction with other test methods as described in table 3 to determine the internal quality. The probing method is

best suited to framework, siding, and fences. Penetrometers often are used

to determine the quality and uniformity as well as strength properties of wood

(see also Pllodyn Penetration Device).

REFERENCE - 1

2.2.2 Penetration Test

Test Method - Pilodyn Non-destructive Wood Tester (Penetration)

MATERIAL - Wood

PARAMETER - Degree of Degradation and Associated Reduction in Strength,

Density, and Shock Resistance of Structural Wood

DISCUSSION

This test is based on the principle that the degree of penetration of a steel

pin into wood is dependent largely on the nature and extent of decay present

In the wood. In other words, the pin will penetrate deeper into a decayed

wood than it would into healthy wood. Research indicates that there is an Inverse proportionality between penetration (density) and amount of energy

required for the penetration, and a parabolic relationship between penetration

46
(density) and pin diameter. Research further indicates that there is a correlation between density and strength of the material.

Some of the applications for which this test method is best suited are:

1) Estimate the strength of bio-deteriorated wood.

2) Estimate the condition of wood foundations.

3) Assess the degree of chemical or thermal decomposition on wood.

4) Assess the residual strength of poles decaying from the outside.

5) Estimate the density (strength) of sawn timber (stress grading of high

quality timber).

The test is conducted by loading the penetrometer device, pressing it firmly

onto the wood surface to be tested, and pulling the trigger to release the

striker mechanism. The degree of penetration for a known constant energy and

pin diameter then is measured by a scale reading from 0 to 40 mm (0 to 1-1/2

in). The instrument measures the fracture surface area created by a constant

amount of energy. As an example, the "impact work" of a typical test might be

of the order of 80 kJ/m^ (5,484 ft.lbf /sq.ft. ).

The test should not be made on cracks, fissures, or areas of excessively rotted

wood since the results would not be indicative of the overall sample.

Advantages and Limitations

The equipment is portable and easy to use with limited amount of training, and

its weight is only about 1.2 kg (2.6 lb). It can be used either on unimpregnated or salt impregnated wood. Unreliable values may result from the test if

the wood is frozen or in an extremely dry condition.

The correlation between depth of penetration and the associated effective

reduction in the strength of the structural wood member is affected to some degree by: (1) type of wood, (2) moisture content, and (3) the normal

variations in density. For this reason, it is advisable to calibrate the

scale readings by means of comparative tests on known samples of wood.

The test is reliable if used under uniform moisture conditions. It is known

that moisture content influences the penetration, but further research is

necessary in order to establish a fully reliable relationship. Research has

shown that this device is suited best to use on wood where the strength loss

due to degradation occurs on or near the specimen surface.

REFERENCES -3,4,5

47
2.2.3 Metered Tests

A. Test Method - Dielectric-type Moisture Meter

Material - Wood

Parameter - Moisture Content

Discussion

Capacitance-type moisture meters use the principle that the frequency of an oscillator changes according to the effect the specimen has on the circuit

capacitance or, in other words, according to the dielectric constant of the

specimen. A frequency discriminator generates a signal, which can be read on a meter, that is proportional to the changes in frequency. Using the relationship

between the dielectric constant and moisture, the meter then can be calibrated

to read moisture content in-situ.

Radio-frequency power-loss moisture meters use the relationship between moisture

content and power loss factor as a measure of moisture content. The wood speci- men is penetrated by the electric field radiating from an electrode that is

coupled to a low-power oscillator. The amplitude of the oscillation is indicated by a micro-ammeter. As the wood absorbs power from the oscillating field,

the amplitude of oscillation is reduced, which results in reduced meter current.

Because of the correlation between moisture and power loss factor, the meter

can be related to percentage of moisture content. The calibration is empirically

related to the average density of a given species of wood. Readings should be

taken near the middle of the widest surface at least 500 mm (20 in) from the

end of the specimen.

Advantages and Limitations

Dielectric type moisture meters are relatively easy to use. The useful range

of the measurement of moisture content is from 0 to 25 percent. Measurements

are less accurate, however, when moisture gradients exist in the wood since

they are very sensitive to surface moisture. The accuracy of readings can be

affected by: (1) calibration of the meter, (2) the species of wood being

tested, (3) temperature, (4) operator skill, (5) chemicals in the wood, (6)

specimen thickness, (7) moisture distribution, and other factors. Species and

temperature correction factors must be applied if the species or temperature

of the test sample are different from those of the material used for calibrating

the meter. Treatment of the wood with salt preservatives or fire retardants,

or long time exposure of the wood to seawater, will give unreliable meter

readings.

REFERENCES - 6, 7, 8

48
B. Test Method - Resistance-type Moisture Meter

Material - Wood

Parameter - Moisture Content

Discussion

Generally, resistance-type moisture meters are portable, battery operated,

wide-range ohmeters. The meters are of a direct reading type, calibrated for one species of wood with correction tables provided for other species. For the

resistance-type meter, penetration of the wood specimen by metal electrodes is

necessary to measure its electrical resistance. The method of contact must be

reproducible to provide consistent and meaningful results. The points of

contact are pin-type electrodes that penetrate the surface of the specimen to

a specified depth. The most common types of electrodes are: two-pin, fourpin, and insulated-pin. The insulated pin is useful because it allows testing

of lumber that has a high superficial moisture content (such as is caused by

rain or dew). One of the major differences between the electrode types is the

depth of penetration. The four-pin penetrates approximately 8 mm (5/16 in),

the two-pin penetrates approximately 25 ram (1 in), and the insulated pin

penetrates approximately 25 - 76 mm (1-3 in). Two nails may also be used for

electrodes and calibration data for two-pin electrodes applied. Measurements

on wood 6 mm (1/4 in) or less in thickness are made with an electrode consisting of approximately 6 to 12 short fine needles. Readings should be taken

near the middle of the widest surface at least 500 mm (20 in) from the end of

the specimen.

Advantages and Limitations

The instruments are relatively simple and rugged, and are especially useful

for in-sltu evaluation of structural wood members. The useful range of the

resistance-type moisture indicator is from approximately 7 to 30 percent

moisture content with an accuracy of + 10 percent. Electrolytes from

preservatives or fire retardants can produce erroneous readings, and this can

be a serious limitation to its use. It should be realized that meters read

only the wettest material in contact with the electrode. Thus, an uninsulated

pin type test on wood with a high surface moisture content would give

misleading readings. Species and temperature corrections must be applied if

the species or temperature of the test sample are different from those of the

material used for calibrating the meter. Needle type electrodes must be used

(surface contact electrodes are not useable). Insulated electrodes are preferred because of the possibility that unknown moisture gradients may exist

in the wood.

REFERENCES -6,8

49
C. Test Method - Electrical Resistance Probe

Material - Wood

Parameter - Moisture Content

Discussion

An electrical resistance probe has been developed by the U.S. Forest Products

Laboratory using wooden elements as the moisture sensor. The principle is the same as for the other types of resistance measuring devices but the probe

construction is unique. The probe consists of a rectangular element of wood

having two of its opposite faces coated with an electrically conductive silver

paint. Two silver painted electrodes are connected to a resistance-type

moisture meter by two lead wires and measurements are taken based on the

principle that the electrical resistance between the two electrode faces

changes in response to change in moisture and temperature. The probe can be

calibrated and located in remote areas and wired back to the meter for readout.

Advantages and Limitations

The wooden probe offers the advantage of reflecting the temperature and relative

humidity conditions which influence the moisture content of the wood products to

which it is placed. The probe will seek equilibrium of the material nearby and

long-term moisture content changes can be indicated by remote means. It can operate over a moisture content range from 7 to 35 percent. The major application for this type of probe has been in research involving in-situ evaluation

of structural wood members. These probes often show substantial long-time

drift, hysteresis, and slow response to changing conditions.

REFERENCE - 9

2.2.4 Miscellaneous Tests

A. Test Method - ultrasonic and Impact -induced Longitudinal Wave Pulse Velocity

Equipment

Material - Wood

Parameter - Mechanical Strength, Defects and Decay, Density, Modulus of

Elasticity.

Discussion

This test method operates on the principle that discontinuities (as well as other factors which affect modulus of elasticity) in wood will attenuate the

velocity of longitudinal wave propagation through it. Major variations in

the velocity at various time Intervals would indicate irregularities in the

wood such as knots, cracks, voids, etc. (This has not been quantified in

practice.) The apparatus measures transmission time of longitudinal wave

50
pulses from one piezoelectric transducer to another, both are attached to

opposite surfaces of a piece of lumber. The frequency of the pulse is a function of the commercial equipment and usually varies between 150 and

1,000 kHz. (Frequencies above 500 kHz do not penetrate dry wood well.)

The transmission time is translated into an estimate of strength and grade.

Advantages and Limitations

The properties derived from this test method should be modified for design by

considering the influence of size, moisture content, and load duration. A

discussion of these adjustments is given in references 13 and 14 (Chapter 6).

Certain defects have not been studied enough to know if they can be detected

reliably using this test method. The equipment requires specially trained operators. Although it is most applicable as a production-type lumber scanner, it can

be adapted for field use. It can sense defects in boards and laminated beams

up to 51 mm (2 in) thick and has a potential for locating surface and internal

defects in lumber of all species, green or dry, and rough-sawn or surfaced.

REFERENCES - 2, 5, 10, 11, 12, 13, 14

B. Test Method - Stress Wave Propagation Equipment

Material - Wood

Parameter - Strength, Modulus of Elasticity, Presence of Mechanical Flaws

and Decay

Discussion

This test method is based on the principle that the velocity of stress waves

through a material depends on the density of the material and increases as density increases. Voids and decay in wood cause a reduction in the velocity

as compared to the velocity in a healthy, denser, wood.

Stress wave propagation testing is somewhat similar to the ultrasonic vibrational method in that it is a dynamic test, but the frequency of. excitation is

approximately 1,000 times higher than the sonic vibration methods. The modulus

of elasticity, E, is calculated by measuring the period of time that it takes

a stress wave to cover a given distance in the wood (wave velocity, C),

measuring the density, P , and applying this equation of approximate

relationship;

E = pc2

The simplified test procedure is as follows; (1) a high frequency stress

wave is induced on a wood sample by an excitor mechanism, (2) the propagation

time of the stress waves is measured between two electron sensors that are a standard distance apart, (3) the piece of lumber is weighed to determine its

density, and (4) test results are entered in the equation and a value of

modulus of elasticity is determined. The modulus of elasticity then can be

interpreted further into strength properties and grade of the wood.

51
The modulus of elasticity assigned to a grade is intended to be an average

value for that grade. Stress grading machines can be adjusted so that the

modulus of elasticity for a grade varies less than it would in a visual stress

grade. It has been demonstrated that strength ratio and modulus of elasticity

used together provide a more efficient strength prediction than either by

itself. Two types of stress waves are useful for grading lumber, namely:

1) the longitudinal stress wave induced in the end of a piece of lumber, and,

2) the flexural wave. Research on dry wood indicates that the longitudinal

stress wave typically yields a higher estimate of E than the flexural stress wave. Although the various techniques yield somewhat different values of

elasticity, the moduli determined with dry lumber have been shown to

correlate well.

Advantages and Limitations

The propagation of the stress waves is influenced by the mechanical and physical

properties of the timber sample and somewhat by the shape of the piece. The

cited equation for stress wave analysis generally assumes the medium to be

isotropic and homogeneous, which is misleading—due mainly to natural inconsistencies in the wood. It has been found that the modulus of elasticity decreases

with increasing moisture content up to fiber saturation, which is about a 25

percent moisture content. Thus, a false value of elastic modulus could be

evident for data taken on wood above fiber saturation. It is necessary to

consider this in interpreting results since moist wood could produce a short

stress wave time, even though voids or decay might be present. The electronic

measuring equipment is very sensitive and has been refined to the point of

measuring only the wave movement pertinent to the needed results. The properties

derived from mechanical stress grading criteria should be modified for design

by considering the influence of size, moisture content, and load duration. A

discussion of adjustment factors is given in references 13 and 14 (Chapter 6).

Modulus of elasticity calculated from the basic longitudinal stress wave formula

is much more dependent on moisture content than E calculated from the basic

flexural stress-wave formula. The longitudinal stress wave method of stressgrading may overestimate the static E of incompletely dried lumber. More

importantly, when used to grade on the basis of stress-wave speed over short

spans, it may cause dry lumber containing wet pockets to be downgraded. Flexural

wave stress grading may also be affected by wet pockets, depending on their

position as well as their moisture content. The device can be used in relation

to either calibrated standards or a heavy degree of technical interpretation.

Lightweight, low-cost units are available. The test usually requires two

persons to operate the equipment. One of them should be knowledgeable about

the pathology of decay in wood and should understand the stress wave technology

well enough to know when the readings are appropriate to the known conditions

and be able to determine the properties of normal wood. Although this test

is most applicable as a production-type lumber scanner, it can be adapted for

field use.

REFERENCES - 2, 5, 13, 15

52
C. Test Method - Oven-dry Test

Material - Wood

Parameter - Moisture Content

Discussion

For this test method, the moisture content of a wood sample is calculated from

weight values obtained before and after drying it in an oven which is maintained at 103 + 2“C (217.4 + 3.6®F).

To conduct the test, a full cross-section specimen is cut or core drilled from

the host sample so that it is no less than 25 mm (1 in) along the grain, or longer as needed to provide a minimum volume of 33 cm^ (2 in’). The specimen

is weighed immediately after cutting (or protected in a vapor-tight container

until it can be weighed). Weighing must be to an accuracy of +0.2 percent.

The maximum delay for weighing after cutting is 2 hours. Then the specimen is

dried in the oven until it reaches a constant weight and is weighed again after

removal from the oven. The moisture content then is calculated in percent as [(A-B)/B] X 100, where A*= original weight and B = the oven dried weight.

Advantages and Limitations

The greatest advantage to this test method for measuring moisture content in

wood is its accuracy and time-tested reliability. Accurate results can be

expected at all levels of moisture content. The major disadvantage is that it

must be performed in a testing laboratory (not on-site).

REFERENCE - 8

D. Test Method - Radiography

Material - Wood

Parameter - Grain Direction, Internal Discontinuities, Moisture Content

Discussion

Radiography is the imaging of a radiation beam that has passed through an object under study. The test is based on the principle that radiation

attenuation is caused by density variations in the test specimen. In

the case of wood, it can be used effectively to determine changes in grain

direction (as around knots and other irregularities), to detect internal

discontinuities and gross density variations (such as, mineral streaks,

decay, insect damage, splits, etc.), and detect changes in moisture content.

It also can be used for "mapping" studs, joists, bracing, posts, and other

structural elements of a wood frame building for the purpose of determining

the strength of wall or floor systems.

53
To conduct the test, x-ray radiation is emitted from a source (e.g., x-ray

tube, radioactive isotope, etc.), penetrates the specimen, and exits the opposite

side of the specimen where it is recorded on a sensitive film as a radiograph

(picture) or viewed on an electro-optical imager (screen). Voids or relatively

low-density areas of the specimen allow a relatively higher rate of passage of

the radiation which will appear as dark indications on the film (as compared

to the relatively lighter background). Areas of higher density will provide

the opposite effect on the film.

Generally speaking, the energy level used for x-radiation should be the lowest

consistent with a reasonable exposure time. This allows detection of small

changes in the test material thickness or density.

Advantages and Limitations

Radiographic evaluation techniques offer the advantage of providing a permanent

record of the condition of wood specimens on film or a "live" image on an electro-optical system for greater speed of evaluation. Equipment for x-ray

inspection of wood is available which is lightweight and readily portable. The

test is relatively easy to perform. Radiographic sources are harmful to organic

tissue, so the test environment must be shielded (or isolated) as necessary to

prevent radiation hazards. Drawbacks to the use of radiographic evaluation

equipment are the high initial cost of the equipment and the film, the time

delay necessary to develop the film, and the requirement that access to both

sides of the test specimen is necessary to set up and use the equipment.

For inspection material thicknesses up to 12.7 mm (1/2 in), thickness variations

of about four percent are detectable. But, for thicknesses of 25.4 mm (1 in) or more only thickness variations of 10 percent or more are detectable.

REFERENCES - 17 , 18

2.2.5 References

1. Sherwood, G. E., "New Life for Old Dwellings," Forest Products Laboratory,

USDA, Agri. Handbook No. 481, pp. 8-9, (December 1975).

2. "Standard Methods for Establishing Clear Wood Strength Values," D 2555,

American Society for Testing and Materials, (1976).

3. "PILODYN Wood Tester, Operating Instructions," Proceq SA Zurich, Switzerland.

4. "PILODYN, A Non-destructive Wood Tester," manufacturer's literature, Carl

Bechgaard, Hovegaden 26, DK 2970 Horsholm, Denmark.

5. "Proceedings of the 4th Nondestructive Testing of Wood Symposium," Aug.

28-30, 1978, Vancouver, Washington, p. 47, p. 109, published by the

Engineering Extension Service, Washington State University, Pullman,

Washington.

54
6. James, W. L., "Electric Moisture Meters for Wood," USDA, Forest Service,

General Tech. Report FPL-6, p. 10, (1975).

7. Mackay, J. F. G., "Effect of Moisture Gradients on the Accuracy of Power

Loss Moisture Meters," FPJ 26(3):49-52.

8. "Standard Test Methods for Moisture Content of Wood," D 2016, American

Society for Testing and Materials, (1974).

9. Duff, J. L., "A Probe for Accurate Determination of Moisture Content of

Wood Products in Use," U.S. Forest Service Research Note FPL, 0142, (1966).

10. Elvery, R. H., "Strength Assessment of Timber for Glued Laminated Beams,"

Symposium of Nondestructive Testing of Concrete and Timber, London,

p. 106, (1969).

11. McDonald, K. A., "Ultrasonic Location of Defects in Softwood Lumber,"

USDA, Technical Article in the TIMBER TRADES JOURNAL, (January 1973).

12. McDonald, K. A., "Lumber Defect Detection by Ultrasonics," FPL, USDA,

Research Paper FPL 311, (1978).

13. "Standard Methods for Establishing Structural Grades and Related

Allowable Properties for Visually Graded Lumber," D 245, American Society

for Testing and Materials, (1974).

14. "Wood Handbook, Wood as an Engineering Material," Forest Products Lab,

USDA, Handbook No. 72, (1974).

15. Gerhards, C.C., "Stress Wave Speed and MOE of Sweetgum, Ranging from 150

to 15 percent MC," Forest Products Lab, USDA, FPL Journal, Vol 25, No. 4,

(1974).

16. "National Design Specification for Wood Construction," National Forest

Products Association, Washington, D.C., (1977).

0 17. Berger, H., "Radiography as a Tool of Nondestructive Testing," FOREST

PRODUCTS JOURNAL, pp. 290-292, (July 1964).

18. Hart, D., "X-Ray Inspection of Historic Structures: An Aid to Dating

and Structural Analyses," TECHNOLOGY AND CONSERVATION, Vol. 2, No. 2

(Summer, 1977).

55
2.3 METALS

2.3.1 Nondestructive Evaluation of Metals

Unlike bridge structures which are subjected to cyclic loadings, buildings

generally are subjected to static loads (except for such conditions as seismic

disturbances and vibrational loadings due to mechanical equipment). Consequently, flaws (such as cracks) in structural steel components of the building

generally are not subject to progression from fatigue, and it may not always

be critical to evaluate them. If, however, it has been determined that a structural component (a weldment, a splice plate, etc.) is suspect of degrading

the structural integrity of the building, nondestructive evaluation methods

can be extremely useful to evaluate the component. On the other hand, it is

important to evaluate flaws other than cracks (such as corrosion, voids, pits,

fabricating discontinuities, porosity, etc.).

Most NDE methods offer more than just a superficial examination of the surface

conditions of metals. It now is possible to reveal facts concerning overall

properties, quality, and dimensions of both the surface and the internal

regions of many metal test specimens.

Although nondestructive evaluation is used primarily on structural steel, some

of the evaluation methods available are applicable to other types of ornamental

and structural metals (e.g., cast-iron, aluminum, etc.) as indicated in Table 4

under the column heading "Typical Applications."

The following is a list of factors to consider in selecting the appropriate

test method to use:

1) What is the material to be tested?

a. Is it magnetic or nonmagnetic?

b. Is it electricity conductive?

c. Does the metal have a nonconductive or nonmagnetic coating?

2) By what method was the metal fabricated (cast, wrought, powder metallurgy,

welded, soldered, etc.)?

3) What is the geometry of the metal (surface condition, thickness, and

shape, etc.)?

4) What types of defects are possible or expected such metal?

5) What degree of sensitivity and resolution is required from the test

equipment?

6) What costs are involved?

a. How much does the equipment cost?

b. What are the operating and material costs of conducting the test?

7) Accessibility of the metal (e.g., behind a wall, pipe, or wiring,

concealed by ductwork).

56
Table 4 indicates the most commonly used NDE methods for testing metals, cites

examples of typical applications with their advantages and limitations, and

describes the appropriate materials on which the test is used. A more detailed

description of several of the most commonly used NDE methods follows.

REFERENCES - 1-12

57
TABLE

4.

TEST

METHODS

FOR

METALS

H<H2OM < tl u <

OuM< auwz o

Cx3U

cn !D

CO CO w < M b3 H r u

cu o o0^

04 c •H 3 o 3 >>

U 3 3 u 3 3 3 3 c e A 3 0 > 4J 3 pH 3 a 3 u C a O H 3 *H 3 Vi 00 92 3 c 3 0 3 M o 3 o M a 3 3 a 3 c a 3 3 »3 CM 0 4H CM • •H Vi •H •H M •H •H

JJ

U 3 3 0 3 3 Vi 4J 3 c >% 3 3 *3 CM

M 3 a 4J 3 3 4H 3 •3 4J 3 • 3 U 0 M 4J 3 •H Vi o 3 3 U •H c » 3 3 >% 3 pH •H a U 3 c 3 pH

4J MH

a o 3 rH 3 3 •H 3 4J 3 3 C •H

a 3 3 3 o •H •H pH pH Mh 3 3 •3 3 c •H 3 3 3 3 a > 3 A *3 iJ 1-3 M 4^ •H 3 3 C 3 3 3 (M Vi a M 3 3 3

IS *3

U

a •H on *3 3 V

O

M 3 •3

U •3 T3

CC 3 • •H 3 3 3 a *3 CM 3 a c • 3 *3 •H • a a 0 3 0. X •H /-s 3 0 > a 3 3 3 C 3 C c •H 3 • 3 •H iH •H •H 0 3 3 3 CM 3 4O CM •H C 0 rH

M)

O 3 3 3 3 0 3 3 4J 3 4J •H 3 3 iH s 3 3 a 3 a c 4-i 3 •H 0 c a 00 Vi X M C 0 Vi 0 3 iH 0 3 c 3 3 3 Vi 3 •H 3 3 > »H •H X •H a c 3 0

Op 4J 3 3 3 < M 3 3 0 M 04

aoXHu£

>» ^ Io

0) 0) 4J O

Q) CO

O (0 pH

CO <0

0) 4J V 0)

(0 £

4-t rH s

CO «3

H 3 /-s p, 0 3 Pk • U 3 Pk 3 M 3 3 a 3 3 3 U 3 73 3 3 •H 3 00 a 3 3 H •H 3 •H a •H 3 pt a 3 3 •H

Cz3 3 0 00 00 4J 4J 3 3 0 rH 3 00

M 0 rH > a c a * •H U c 00 Vi a a

<M 0 •H c a Vi V> 3 0 Pk

M •H

a

W 00 4J •H 0 3 3 •H pk >k 3 M •H

V- 3 3 3 4J •H x: rH 3 M 00

U Pk 3 M 0 3 M 3 c 3 u a 3 c •H Pk 3 3 a u 3 3 3 •H 0 0 0 00 3 c •H 3 3 pX •H 0

Cm CM 3 3 3 U 3 CM •H 'd 0 a 3 Vi 3

CC Vi Vi »H .0 3 u 73

V Vi

a c Vi 3 3 pO 3 o 3 0 3 •H 0 C Vi a 3 0 0 3 Vi 3 •H

C/) >»/

X CM •a 3 3 •H C/3 pH pO Gu 3 3 4-i 73

cd

CO 4J

O o

CO

0)

u

4J CO

CO

X

r

0)

CJCO

C CH

0)

U

a :o O CO 3 3

pC 4J 3 3 0 tH 4J a 3

Cm 3 /r«S 0 3 M • aM 3 3 M 0 3 Pk • M 3 3 3 3 >% Vi >> 0 3 z •H Pk 3 3 CM 3 >% 3 3 a pO M •d u 3 u U 0 > 3 3 M •d Vi iH 3 M 3 3 a «M 3 M 3 3 •H 3 3 a pO 3 3 a • a 00 •H 3 •H

Om

H •d CL

M 3 3 3 •H *d

u •d 0 3 3 3 a 73 pH

M < 0 a *H Pk

a 3 3 3 0 3 >k

a •pH

a 0 K rH 3 0 a 3 3 3 pX •H 0 4J 3 3 a s 3 •H • z Cx3 3 3 3 3 3 a 3 3 CM 4J *d •H 3 3 a a M Op •H 3 Vi u Vi Xi •H 3 a •H 3 3 •d •H 3 Vi 3 3 0

0^ 0 3 Vi 3 0 3 a 3 a •d s Z 3 a

M *d IM 3 •H

PL4 3 0 pO

a

aa 3 3 3 00 3 3 pX cr

a

V

U

a Xi •H 3 3 3 X

a pC 3 3 pH 0 3 •H 0 3 a >k 3

to MH

a 3 3 3 •H

M £ a ^•4 4J

a rJ 3 •H 3 3

rH CO (0 O 3 -H

(0 4H •H a. > o I CO c •

0)a o

0)

4J 0)

0> Ui u D

O. iJ

ki CO 0> u

4J 0) CO c a

v> «H

a I0) • c V 0) a

O. <H

*oc oo <u <0 C u Xi

*H -O 01 ^ C 'O 4-* CO CO d CO o •o

CO

O 3 a a

TJc

CO

4J

C

4J ^

CO 60 00

C 0) c c <u c

0) “H »H

a c *3 -U 00 *3 3 00 0) CO V4 fH

CO CO CO COO 3

3)a ^3 3 UH 3

iJ

O

U 3 3 3 - O 3 00 CO O. -H 3 3 a pO JJ U CO O 3 <0 4J 3 CO CM CO 3 Co

rH «H 3 4H

*H 3 U U 3 3a 3 M 3 3 a 3 s 3 O CO e3

*3

U

•H 4-» 3 3

cr

C

•H 3

hJ 04

58

controlled

carefully

to

get

true

Indications.
TABLE 4

(Continued)

TEST

METHODS

FOR

METAI.S • c g o g o 4J g u 3

>> »H c 3 g 1 00 >» g iJ 3 o r M B

0) *o •g •H

g •H

g «H • g g g c g 4J g g

CO CO s 00 0) e g •H

u

g • 3 g z •H o g rH 4J 4J *g a o u M a •H g g u e o g g M CO o a g g g 3 H a g g CM g CM • < •H Xi g • * a g u o H > •Oft.*© g u u o •o u M •H g g u g o o g g s 0) g ^ g u 4J 4J 4J c g g g 3 M y g g •H g g e o X iH g CM

CO 3 «-• 1 3 u •Hu CL CM

g c g O* g g 'V 3 u u

0) 0) 3 g o.

a o c CM

O 3 g

CO

u

g

Og on o o 4-»g o g

g

g

QO iH 1 • o g 2 V4

4-1

u

g 3 M 1 M

gg

g •M CiO

g

gB

g

g *3

g

g 2

4J pH • g 3 o .3 •M E CM

g • X g g t CM •H M jO g g E 5s g •M 5s Vi 3 3 g u Q Vi g 4J g g 3 O 4J g 3 g 3 3 g

•H

g •M

g

g •M • 3 4J

O

g

u

O

O

g

•H 3 M

g

M

g CM Vi

a • •H •H

g

CL

g £ rH

gg > o g o g

g 4JM

g

a 2 u 3 Vi

u

g •3 4J 4J 4Hg

gg

g s g

g CM

g *M pH

g 3 g 3 pH

N

g

g 1 B •H g a 3 g 3 g Vi •H 3 •H 3. 3

4-> 3 Vi

g cr

u 0 a

gg 4J

g o O u M g Vi g Vi •H g CL O g g 3 g z 3 o M eg a Vi M 4J Q o M 3 •H • g z g • g u g g g g 4H 3 3 g

pHg pHg • •pHgg

pH •M 3 g

g

A

g

g CM

COg 4Jg

g

g

g

g Vi

UB 3 g E g > g ^ CM 3 o g 3 • V4 3 •pH pH pH Vi g < •H g g Z g CM 3 H g M pH 4H M g A 3 o g g Z g 3 3 g •H g g g M g • 4J O g g u z pH a g 3 g > g g 4J 4J 3 M a X g 3 O pH 3 Q g g Vi g g E g 3 3 ^ pH g < O *H O 3 g CM •H 3 g o £ S

p-i pj *3 CL M < O CO •pH g -3 CM

COZ g • *3 O 3 bO g 3 g 3

-jMg

O 3 A 3 gg o g 1 • < H g pH •H •M g 3 g •H g > g 3 a < g • g 4J M bO •pt • g iH CM M M *H 3 O M O 3 00 •H g g 3 g pH g g 4J Vi g ^ M bO hh

CLM •iii 3 Vi

g

g •H 3 g pH

g Z 3 g

g •H 2 4J >• g mh g CL g bO Vi g CM bO g CL CL g g g

CL •H 00 4-1

g Vi *3 4H Vi 4J •pH z g 3 X

Oi z g

g 3 CM o 3 X o g 3 pH 3 3 CM

g

O •H < H CO s •M O CM g g Cb E CO g g •H o g M M Q Vi td * o • g o pH A g a a pH g •3

Es3 •3

g •H S A 3 H •pi pH A Z •3 g g g • Ed o »3 g Vi 4J 3 g g *3 g O > • g 3 o o g g g •H - 3

5s 4J

O • z g • o 5s

O

CO P M

g •H bO bO

g CM

g

A > U *H

H

g «H bO

g 3 3 u

g Vi

M

g •Hg

eg

g

g 3 •H •H

g

g 3 g Z A

g 3

Edg o Vi pHN •3

g CM

g

gg

g 0 »H

Cb

g Vi bogg 3 4J Vi z CM

g CL Vi

g

Ed Vi

O

g 3 Vi

Og 3 3 g Vi

gO 3 a eg O. g •H X «Q z g g •3 ej pH CL •H

QU •3

CO pH z o 3 3 g •

Cx3 Ed •H •H •H

g

CO oC • CM CM pH s g g g o CL

CO CO

g

gg

g

g E u < •H »H 3 •H •H M g g M iH M g iH 4H g g g H 2 g g •3 g g g

QC S 3 g E 3 X CM 4H

Cx3 Qd o o a

O bo 3 Vig

Ou o 3 g 6 3 2 pH S g O < g •M < E CM g M K

3d

g

g

g CM »3

g

g • pH

O

O 3 Vi > O g g 4J g 3 O o M g •H g •H CM

Cm <; 3 • •H 4J •3

g

g

O

g Vi •Hg Vi 5s 4J Vi

g 3 g

g CM z g rH o Z •M g 4J •H Vi Z O

Sx3 o g -3 & 3 CLg fH

O

g

pJM 3 N

g s g •3 •3 3 g CM

g

g

Eh o z gg

M

gg •Hg Vigu

g

M •M 3 g

g 4J ViM •H 4J •H

g Z 3

CJ os 4J

O •3g

g 3 4J 4HM bO •H • z Ed g o O pH g g 4J O g g g g 0) pH Vi M O. Vi o U g g pH 4J g 3 3 z Vi 3

qc

O

X

p

M 4J > CM

gg bOg bo

ggg

g

Cm •H

O 3 gg

g

g •H

g Vig

g z z g > eg 6 s Vi g •3 r g E 3 o g

•H CM 3 g g

aO •H 2 g M

g z g g •pH H Vi 3 M

Ed 4-t bO Vi S g g z z CL

0)^ 4) W XA

«—* CN

59

page

61

for

more

Information

page

65

for

more

Information
TABLK 4

(CONTINUED)

TEST

METHODS

FOR

METALS

rH

<9 44 4) • • 4J pH > G CO >» • o X 3 o *d IH >H c 4J 4) y 44 pH Vi C9 > 0 s

41 pH •H

y 44 C9 00 >s 1 <Q aJ 4) Z a. vu 3 • (9 »d « pH y

c/3 0) • u Z 44 E <4-1 •d >> V< c V c 3 z z ^ 0> 4J O e rH 44 <9 y 0 u .2 o lu > 00 CJ •d o c « 44 y 1 44 A ii

H4 CQ «p4 00 <44 0 • y 0 c CO

B

y 44y • A 44

H • N 4J

V 0 a;

d 4) 44 6 > B

yy

A 0 < cc •H 00 • u N C CO a y y 3 92 pH 0 •d y 3 44 H CO £ CO X OC c <9 O pH y Vi ^H 8 44 A 6 8 O c CO CM 4) pH C9 3 e (9 0 y A pH A •H •d • 3: O Z 0) 4J c 8 00 pH pH o y CO Vi 44 u •rH A y y •0

4J CO

y 4J z H

VC 3 W pH ViB z 3 pH

A ^H > y Z iH 0) 3 y y a (9 <44 4> pH y y <9 CO p< a 44 y CL 0 44 OO (6 aj <44 O •r4 4> 4» 44 <9 <44 44 C9 A 6 A > 6 8 A —' Oj 0 4) z z a z O CD d z y <4ri 0 y 3 0 y •*H A y y Z Z z -d C9 44 CO CO 44 Z S cc z 0 z 6 U' y H 44 A u 44 • *d » 44 y z (9 00 <4-1 44 •d c • o •rH a y at B

c/3

O (0 <44 C9 S y • <9 > 44 <4H

A pH

Ca: z • 44 c •d • 44

y •d •rH • A 0 A c pH V CO e o 4^ 4) 4; c pH <9 44 A A y pH y < CO <0 <9 rH 41 « <44 44 >s 44 rH y z • >% A y <4H 44 A A •H

EC c Z •d c *d « pH S z c *d C9 •d

y

B

U

A

A 44 •J

B z CJ ^ u «0 •fH L4 >» V4 ^ 6 (9 y iH rH y z A A >s A h pH •H A < 0) 0) V 4J > 6 o (9 01 *o O 44 S 0 •d 8 a pH y 3 3 A Z > iJ aj u u 0 L4 y U *d (9 44 u u y (9 y B 6 A > *J A >% y a 0) C X 0 u 4) 4) 1 O 4) 3 0 y y > y <9 0 0 B •H y y z y < C 0» a. a. a u X r z (9 a* z v< A B 0 4J y A c A u a. 6 1 A

pH

M •d z 00 e A s

CO 1 OC e o y

A 1 0 pH •d CO

uU 44 ft 0 z 4J C <0 4J •p4 00 «9 pH rH *rH <9 y QQ 0 X 0 >N y A b o 00 «p4 z c <9 C9 44 y pH 00 y z fH fH 6 z •H H4 (0 OC «k CO 44 •H <44 > ^ 0 <4H (9 z B pH y pH c rH < H CJ w CO 4) u 00 44 4) *d pH 0 44 Os Z A > A y •H • A y < 0 4J •H o St 3 pH O e A

92 0 • y • y pH

y pH 44A Vi pH

C (4^ c <44 4) C9 <9 b. • 0 o 4)

A CO 6 pH 00 •H 00 <rH 44 pH z A Z 3 p z

a. h-4 o d z 3 00

C 00

uy |4 00 6 pH

B z c Ipy 44

AA e 44

AA

A s E M oo

u pH •H c 0 44 (9 pH 44 •H 44 3 y

y

y •Hyyy

H a. •c CO •d o;

y •*H CO 9) • (9 •d

y 3 •p«y 44 00

y •dB 6 Z 3 CL p-< Ow 0) OC pH CO 4; 44 00 44 y 44 41 44 z Z y •d ki u 3 y B 00 U y U Ih A pH < CO C V CO Z «9 y e 44 a 2

<4rf 3 y z B 0 c A pH 0 § s.

pH 0 44 z s (0 y <44 c «H 4) 9 o 44 Vi CO <9 CO <44 Z y y c <4H a A 6 o

CaJ * A z

t- >. -o

p 9) at 44 CJ 4J C Z 4) A 1 z z

bs •vH « CO *H CO

C pH 44

B

t- CO «r4 44 8 •Pl CO 44 OC • y

b2 0 • C -H

A <9 0 c9 e 44 fcn

p

O

U (0 pH 3 CO

y 00 z y • y

C 44 c <44 o c <4-1 e c CO c 8 z 44 1h •H A 0 0

V3 CL o •rH 0 0 0 B 44 0 pH

C.W • y 44 •rH

A •rH

y v<

y

A c.

y 44

A

b P (0 (0

y c 00 CO 44 0 8 pHA 3

Ca3 CO s (9 0 c Z *9

X 44 •d *d pH Z pH

b« •d pH

y <4-

yV

y pH 0 B C9 pH pH

A

B 3

b]

y (0

W 00 8 C9

U pH 0 y

yy c 0 •d

O o e Wi 3 •rH

b C9 pH •rHu •rHy pH 0 > -H y C/3 "C •d y > (9 44 u >- X 44 y i

u:

c/3 CO z 0^

A • u & •w A CO • B

c/3 Ca: Li CO • c X

y >» •H

of •H COu c •rH 44 CO 44

A

C/3 3 o; o> c o •H <9 •plU

Cx2 c/3 c c •H 00 > y pH 44 < o> ^ * U 4> y y «rH A

00

y •H •fH 44 c •rH Z 1 z C <H 4J (0 pH U y 44 (0 A

CiJ e z o C9 44 3 y

y

A

a. 0^ o W CO o. i y •d at c i y O o z e § 0 4> B *d 00 C 1-1 cd c c 0) 0 C pH 0 c A y HJ Qu -1 *H •d y < 9) y C9 e z C/3

<9 1 •d c y

(9 • y

y

y 4J z <44 4) >> y 8 B y 44 e 41 • 0 8 (9 Z (9 y pH

b. o Z 4) • c e 44 44

y •d v« 3 •d

O •H 4J Z c 00 o « CO 6 a •pH 0)

y pH

B e • z 4-> CO 4J

9il 0 C9 z pH

y «rH (9 3 a & *d

ay

A pH

a bJ o <P X B pH y u CO <44 e 44 0 CD 8 pH rH 44 • A «H

B 3 z <44 «H Ls (9 c <9 pH OO pH 44 pH B z <44 A B A in Z Vi 0

a.

H

C « O

y

W (9 •d o *d •H c y pH pH CD •rH

y

yB 44A 0 pH

M < o» >> *d 4) 0 •H <9 Q>

O 0 pH (9 (9

B

y pH 3 0 A

B

A

CJ <9 4»

X o.

X CO 44 l-i Q,

y

y pH 44 44 pH « 0 y

A 44 4J pH 1 0 c A z Ci3 4J 1.1 u 4J CO A 4J <9 (9 1 a 0 B y 0 y •*H a *H kl pH 44 A PH 0 y •

t-t cu <9 1 y CO •rHy

X -i! •dy 0 8 y 00 44

A V4y 44

A

A 44 pH 4h

A

0^ o X 0) CO 44 •d CO p4 « y

B <9

y

aA pH

yA

A C. 44 a« ot <44 c CO e O •d 9> 4» O Vi y y y 5

rH

y 44 0 B Vi iH pH

B 6 A z <44 4) OJ o 4> z c Z Z Vi 3 z c z z y z A u 0 A 44 y y 0 y H O C9 •d 44 > *d CO •H 44 P o. 00 H pH U H y Vi 44 a 0. y > c/3 Vi H y 44

44 r>

Q c B o >^ A CM 4> 0 X <9 s X U a H Q •d w 3

Cd CO <9 •d 3 0 Z X o o u U3 CJ CJ

01 a; o; u u o o o E e 6 u u u ^ 00 ^ o >0 0» 01 0) 00 00 oo

(Q <9 <0 a a c.

OJ 0) 0^ 0) 0> 0) to c/^ cn

60

elasticity,

powdered

compressive

metals,

strength.
Test Method - Ultrasonic Pulse Velocity

Material - Metal

Parameter - Internal Flaws (Depth of cracks and their rate of propagation,

non-bonds, inclusions, corrosion, interfaces, etc.).

Discussion

Detecting flaws in metal by the use of ultrasonics is based on the principle

that the velocity and amplitude of vibrational waves of acoustic energy

propagated through a test specimen are affected by the elastic properties

of the material being tested. To conduct the test, an ultrasonic pulse is

generated by an electroacoustic transmitting transducer and is received by a receiving transducer. The pulse is amplified and its amplititude is displayed

for analysis on a cathode-ray oscilloscope. If the wave of acoustic energy

encounters a discontinuity in the test material (such as a crack or a void),

it will be diffracted around the discontinuity thus increasing the distance and

time of its travel from the transmitting transducer to the receiving transducer

(which, in turn, decreases its amplitude). Therefore, all other conditions

being constant, the travel time of the wave in sound material will be less than

that for a material containing discontinuties

There are three commonly used methods of introducing ultrasound into a specimen:

1) STRAIGHT BEAM (uses longitudinal waves)

The transducer is placed directly on a specimen and sends a straight

perpendicular beam of acoustical energy into it. Signals appear on the

cathode ray tube (CRT) at the receiving transducer end (on the far end)

which can be read and interpreted by an experienced evaluator. Any flaws

large enough to intercept the sound beam will show as abnormal patterns on the CRT. Detection of defects may be either by the pulse-echo method or

by the through transmission method. In the pulse-echo method, a transducer

emits short pulses of sound and receives the reflections of these pulses

resulting from discontinuities in the intervals between pulse emissions.

For the through transmission method, two transducers (a transmitter and a receiver) are positioned on opposite sides of the specimen. Any significant

reduction in amplitude of the signal received is an indication of the

presence of flaws. If no signal is received, this is an indication that

the flaw is large enough to block the sound beam completely. This twotransducer method is used where the shape or internal condition of the

specimen does not allow the reflection of the beam back to the same transmitting transducer.

2) ANGLE BEAM (uses transverse waves)

The transducer is mounted on an angle which causes the sound to bounce through

the specimen until it strikes a flaw and reflects back to the transducer.

This is used on specimens where mounting the transducer directly above the

flaw is impractical. The CRT display is similar to the display produced by

the straight beam method mentioned above.

61
3. SURFACE-WAVE (uses Rayleigh or Lamb waves)

When the transducer is mounted so that the angle of the sound emission is about

63® to the surface of the test material, all of the ultrasonic energy that enters

the specimen does so as surface waves (which penetrate only to a depth of about

one wavelength). Therefore, this method is useful only for detection of surface

or near-surface discontinuities. An advantage to the use of this method is that

surface waves will follow the contour of the test specimen.

Advantages and Limitations

Ultrasonic testing is one of the most popular nondestructive test methods for

metal evaluation available today for many reasons, some of them are:

1) High sensitivity permits detection of defects about the size of a wavelength.

2) Ultrasound can penetrate thick materials and measure thickness.

3) It can determine position and approximate size of internal defects with

accurate and fast readout of results .

A) It can be used with automated testing equipment.

5) It allows specimen testing when only one side is accessable.

6) There are no major hazards to personnel which require special shielding

for safety.

7) It is portable and versatile.

8) It is well suited for detection of laminar type defects that are oriented

perpendicular to the energy beam.

Ultrasonic waves do not travel through air effectively. Therefore, a liquid

coupling material (such as oil, grease, or glycerine) must be used between the

search unit and the test specimen. In immersion testing, a few i-nches of water

is used between the search unit and the specimen.

Certain test conditions may limit the effectiveness (or prohibit the use)

of ultrasonic testing; the most common of which are: 1) unsuitable geometry,

and 2) unsuitable internal structure of the test specimen. Specialized

training of an operator to interpret the results of this test is required,

which makes the test very operator dependent.

Standard calibrated reference blocks must be used to determine operating

characteristics of the instruments and transducers to established reproducible

test conditions.

REFERENCES - 1, 6, 7, 10, 11, 12

62
Test Method - Radiographic Evaluation (X-ray)

Material - Metal

Parameter - Internal structure and thickness of metal.

Discussion

X-ray evaluation techniques are based on the principle that x-ray attenuation

is affected by the density, chemical composition, and thickness of the test

specimen. Equipment of various types is available for x-ray evaluation. The

main ones use photographic emulsion, fluorescent screen, semiconductor

conduction values, ionization of a gas or an electron multiplier (or combinations thereof) as the means of detection of the test parameters. Selection of

the particular equipment to be used is affected by the following factors:

1) Density and thickness of the test specimen.

2) Number of radiographs required per unit of time.

3) Geometry of the material.

4) Whether the test specimen can be brought to the test equipment or must be

conducted in place.

In nondestructive testing of the quality of metal materials, x-rays are used

mainly to: 1) inspect for interior soundness; 2) to locate porosity, slag

inclusions, incomplete penetration, cracks, icicles, burn-throughs , and other

defects in welds; and 3) to detect defects within castings, pressings, and

worked or formed metallic parts. Voids measuring 0.5 to 1.0 percent of the

thickness of steel or aluminum alloy can be detected when using this technique

of nondestructive testing under carefully controlled conditions; however,

sensitivities of two percent are relatively easy to obtain and are used as the

commonly accepted minimum variation.

Advantages and Limitations

X-rays offer the advantage of providing a high resolution picture on a permanent record (film) or a "live" image on an electro-optical imaging system.

It is especially useful for detection of laminar type defects if. they are parallel to the energy beam. Since the equipment is heavy and costly, it is

used mainly in laboratory evaluations. X-ray sources are harmful to organic

tissue, and the test environment must be shielded (or isolated), as necessary,

to prevent radiation hazards. Another drawback is the high initial cost of

the equipment and film, the time delay required to develop the film, and the

requirement that access to both sides of the test specimen is necessary to

conduct the test. The user should be aware that there are many films from

which to choose; careful selection must be made of speed and resolution in

order to obtain the desired results. The entire process of selecting the

equipment, operating the equipment, and interpreting the test results requires

a high degree of technical training.

REFERENCES - 1, 6, 8, 9, 10, 11, 12
Test Method - Eddy Current

Material - Metal

Parameter - Surface Flaws, Variation in Alloy Composition or Heat Treatment

Discussion

Eddy current testing is one of the most widely used of nondestructive

testing methods. The test is based on the measurement of changes in the

impedance of a coil due to changes in the flow of eddy currents induced in a conductor. Test material properties and constituent variations that affect

the flow of the induced eddy currents sufficiently can be detected, measured,

and analyzed. The basic properties of conductors that influence eddy currents

are 1) electrical conductivity, 2) magnetic permeability, 3) mass, and 4)

discontinuities.

Since so many factors affect the flow of the induced eddy currents, this test

method can be applied to a wide variety of test situations. Typically, it is

used for thickness gauging; flaw detection; measuring coating thickness; alloy

sorting; monitoring hardness, grain size and heat treatment; and evaluating

the condition of wire, tubing, local regions of sheet metal, and welded pipe.

The basic operation is as follows:

1. A signal (10 to 250 kHz) is generated by a variable oscillator and is

applied through a modified Wheatstone bridge to a coil which is placed on a sound piece of material similar to the one being investigated.

2. The bridge is balanced.

3. When the coil is passed over a discontinuity of the test specimen, a change

occurs in the impedance of the coil due to the effect of induced eddy currents.

This unbalance is recorded on a microampere meter.

Many types of probes are used with eddy current testing equipment depending on the application. In some cases multiple coils are even used. For example, when

used for detecting surface discontinuities in ferromagnetic materials, two

driving coils are arranged around the pickup coil in the probe.

Advantages and Limitations

The advantages of using this test method are 1) high speed, 2) moderate cost,

3) it is readily automated, 4) the equiraent is easily portable, 5) a permanent

record can be obtained of the test results if needed, 6) the equipment is simple

to operate, and 7 ) it can be adapted to many comparative analyses. Limitations

to its use are 1) it is useful only on electrically conductive or magnetically

permeable metals, 2) it has a shallow penetration, 3) the use of reference

standards is essential, but, unfortunately, no generally accepted standards are available for ferromagnetic materials to establish the relationship between

physical properties and the eddy current data, 4) only a qualitative comparison

is possible rather than giving absolute measurements of the flaws, and 5)

because eddy currents are distorted at the edge or end of a test specimen, it

64
normally is not practical to inspect flaws any closer to the edge than 1/8 inch.

Practical experiments have shown that a fairly good correlation between eddy

current data and actual crack depth in ferromagnetic materials is available

only up to approximately 0,6 mm (0,025 in) maximum depth. The test normally

is not used to detect discontinuities deeper than 6 mm (0,25 in).

REFERENCE - 1

Test Method - Magnetic Particle

Material - Metal

Parameter - Surface and Subsurface Discontinuities

Discussion

The magnetic particle test is a convenient in-situ method of detecting surface

and subsurface discontinuities in metals. To perform the test, an electrical

current is used to induce a magnetic flux into a specimen which then produces a patterned magnetic field in the specimen. An indicator made of colored magnetic

particles is applied to the test specimen where they form visible patterns

around the discontinuities according to the magnetic leakage fields formed by

the discontinuities.

The surface indicator buildups which are caused by surface discontinuities

are thin and sharp, while buildups near subsurface discontinuities appear

broad and less well ‘defined.

Various types of electrical currents are used to produce the magnetic fields.

Table 5 summarizes them and describes their uses, advantages, and disadvantages.

65
Table 5

TYPES OF MAGNETIZING CURRENTS USED IN MAGNETIC PARTICLE TESTING

Current Use Advantages Disadvantages

Alternating

Current

(ac)

For detecting

surface

discontinuities

Gives best sensitivity

for detecting surface

discontinuities

Relatively easy to

demagnetize. No

penetration of flux

into specimen. Best

for detecting fatigue

cracks in ferrous

structural members.

Particle mobility is

good.

Inefective for

detection of

subsurface

discontinuities.

Direct

Current

(dc)

For detection

of both surface

and subsurface

discontinuities.

Best used

mainly for

subsurface.

Penetration of flux

into specimen permits

detection of subsurface

discontinuities.

Must use a fixed

voltage. Battery

maintenance is

required. Difficult

to demagnetize.

Half Wave

Rectification

(HWAC)

For detection

of surface and

subsurface

discontinuities.

Most sensitive

for subsurface

discontinuities.

High flux density.

Full penetration into

specimen permits

detection of subsurface

discontinuities. Some

ac equipment can be

converted by adding a rectifier and switch.

Particle mobility is

good.

66
There are many means for inducing a magnetic flux into a specimen and

producing a magnetic field, all of which are discussed in detail in reference

[1] for the reader who desires to learn more. Suffice it to say here that

the means should be selected to meet best the application and the nature of

the nature of the discontinuity to be detected.

The indicator particles are made of carefully selected magnetic materials of

the proper size, shape, permeability, and retentivity. Two classes of magnetic

particles are available for use with this inspection method - the wet method

particles and the dry method particles. Wet method particles use a liquid

vehicle, and dry method particles are borne by air. Particles used in the wet

method are suspended in oil or water and are available as a powder or thick

paste colored either black, red, or fluorescent. Fluorescent particles must

be viewed under a "black light" in a darkened room. Particles used in the dry

method are in the form of a dry powder in red, black, or gray color. In all

cases, color is chosen to give the best contrast on the metal specimen being

inspected. The powder is sprayed gently and evenly onto the metal surface

where it is free to be influenced by the magnetic leakage field and to form

indications of the discontinities.

The advantages to using this test method are:

1. It is relatively inexpensive.

2. It provides instant results.

3. It is portable.

4. It is easy to use with little training.

5. It is sensitive to surface cracks.

6. It is a nondestructive test method.

Limitations to its use include:

1. It requires external power supply.

2. It is limited to use on ferrous materials.

3. The evaluator must have a thorough knowledge of the test and be able to

evaluate and record test results with accuracy.

4. Sharp, angular types of discontinuities are more easily found than round

or streamlines types.

5. Surface discontinuities are more easily found than those located below

the surface.

6. Retained magnetic fields hinder cleaning of the specimen.

7. The specimen may require demagnetizing after the test.

8. Wet particles are best suited for detection of fine surface cracks

(such as fatigue cracks).

9. Dry particles are most sensitive for detecting subsurface defects and

usually are used with portable equipment.

10. Some surface preparation is needed.

11. Coatings can affect the ability to magnetize the specimen.

REFERENCE - 1

67
2.3.2 Destructive Evaluation of Metals

When evaluating metal structures to determine their ability to perform well

in a rehabilitation situation, the most important material properties to

determine are:

1. Yield strength.

2. Yield point.

3. Tensile strength.

4. Elongation (ductility).

5. Modulus of elasticity.

6. Compressive strength.

Using destructive methods of tension or compression testing of samples,

known as coupons, these properties are determined as follows:

Tension Testing

Yield strength

Yield point

Tensile strength

Elongation (ductility

Compression Testing

Yield strength

Yield point

Modulus of elasticity

Compressive strength

(for some materials)

Test Method “ Coupon Test

Material - Metal

Parameter - Strength, Ductility, Modulus of Elasticity

Discussion

To perform the coupon test, a test sample (known as the coupon) is removed from

the metal being evaluated and is tested for the important material properties

mentioned above.

The test machine must conform to the requirements of ASTM (Methods E 4),

Verification of Testing Machines.

Test procedures for tension or compression testing of coupons are described in

"Standard Methods of Tension Testing of Metallic Materials," ASTM E 8, and

"Standard Methods of Compression Testing of Metallic Materials at Room Temperature," ASTM E 9, American Society for Testing and Materials, (1977). The tests are applicable for use on 1) die castings, 2) forgings, 3) structural shapes,

4) malleable iron, and 5) powdered metals. Coupon shapes can include:

1. Plate-type specimens.

2. Sheet-type specimens (sheet, plate, flat wire, strip, band, hoop,

rectangular, etc.).

3. Round specimens.

4. Rectangular bars.

5. Pipe and tube shapes.

68
The test coupons can be substantially full size or machined, as prescribed in

the product specifications for the material being tested. The shape of the ends

of the specimen outside the gage length must be suitable to the material and

must be of a shape to fit the holders or grips of the tension testing machine

so that loads are applied axially. Figures 1 through 5 of ASTM E 8 describe

gripping and snubbing devices used with tension testing equipment, while

Figures 6 through 9 describe the shapes and dimensions to be used for tension

coupons. Similarily, a description of coupons and jigs used for compression

testing is provided in Tables 1 and 2, and Figures 1, 2, 3, and 4 of ASTM E 9.

Location of Coupons

Coupons are taken from locations in the metal material to be tested; and,

generally, the axis of the coupon is located as follows:

A) At the center for products 38 mm (1 1/2 in) or less in thickness, diameter,

or distance between flats.

B) Midway from the center to the surface for products over 38 mm (1 1/2 in)

in thickness, diameter, or distance between flats.

C) For forgings, specimens are taken either from the predominant or thickest

part of the forging; or, coupons may be forged separately as representative

samples of the forging being evaluated. Unless otherwise specified in the

applicable product specifications, the axis of the specimen should be

parallel to the direction of grain flow.

Surface Finish for Coupons

Particular attention has to be given to the uniformity and quality of surface

finishes of specimens for high strength and very low ductility materials since

they can cause variation in test results. Surface finish of the coupons is

described in applicable product specifications.

Procedures for Performing Test

Procedures for preparing and measuring test specimens and for conducting

tension or compression tests are described in paragraph 5 of ASTM E 8 and

paragraphs 5, 6, and 7 or ASTM E 9, respectively, and include a description of

the speed of testing (rate of separation or closure of heads, total elapsed

time, rate of stressing and straining, etc.).

Stress-strain diagrams for determining yield strength and yield point are provided in Figures 20 through 22 of ASTM E 8, and Figure 5 of ASTM E 9 for

tension coupons or compression coupons, respectively.

REFERENCES - 13, 14

69
2.3.3 References

1. "Nondestructive Testing," reference manual for a home study and extension

course, by the American Society for Metals, the American Society for Nondestructive Testing, and the Metals Engineering Institute, Metals Park,

Ohio, (1972).

2. "Fundamentals of Nondestructive Testing," by the American Society for

Metals and the American Society for Nondestructive Testing, reference

manual for an extension course by the Metals Engineering Institute, Metals

Park, Ohio, (1979).

3. DiGiacomo, G., Crisci, J.; and Goldspiel, S.; "An Ultrasonic Method for

Measuring Crack Depth in Structural Weldments," MATERIALS EVALUATION,

September 1970, Vol. XXVII, No. 9.

4. Dick, P., "Inttoduction to Nondestructive Testing," General Electric

Company, written for the Metals Engineering Institute, (1922), page 1.4.

5. "Nondestructive Inspection and Quality Control," Metals Handbook, 8th

Edition, Vol. II, American Society for Metals, Metals Park, Ohio, (1976).

6. McMaster, R. C., Ed., "Nondestructive Testing Handbook," Ronald Press,

New York, (1959).

7. Krautkramer, J., Krautkramer, H., "Ultrasonic Testing of Materials,"

Springer-Verlag, New York, 2nd Ed., (1969).

8. Halmshaw, R. , Ed., "Physics of Industrial Radiology," Heywood Books,

London, (1966).

9. "Radiography in Modern Industry," Eastman Kodak Co., Rochester, New York,

3rd Ed., (1970).

10. McGonnagle, W. J., "Nondestructive Testing, Pergamon Press, New York.

11. Sharp, R. S., Ed., "Research Techniques in Nondestructive Testing,"

Academic Press, London, (1970), (1973), (1976), (1980).

12. Vary, A., "Nondestructive Evaluation Technique Guide," National Aeronautics

and Space Administration, Washington, D.C., (1973).

13. "Standard Methods of Tension Testing of Metallic Materials," ASTM E 8,

American Society for Testing and Materials, (1977).

14. "Standard Methods of Compression Testing of Metallic Materials at Room

Temperature," ASTM E 9, American Society for Testing and Materials, (1977).

70
2.4 MASONRY

2.4.1 General

Since laany existing buildings being considered for rehabilitation are constructed of masonry » it is Important to know how to evaluate the condition

of the masonry and to determine whether it is capable of supporting the loads

imposed by the retrofit or rehabilitation work. This is especially true of

load bearing masonry assemblages which are expected to support new heavy dead

or live loads.

Several nondestructive evaluation methods have been used with various degrees

of success to determine the physical properties of masonry units and mortar.

However, these test methods have limited application and generally provide

Information only on the physical make-up of the masonry (continuity, location

of voids, reinforcement, etc.). In only one case (low frequency ultrasonics)

can an estimate of compressive strength can be obtained (by experienced operator’s and evaluators), but it is prohibitively expensive to use in routine

investigations. One manufacturer claims to be making progress in the development of a penetration device known as the Densicon Penetrometer which is based

on the same principle as the Windsor Probe for concrete evaluation, and it

might become an accepted test for measuring surface hardness (from which it

may be possible to estimate strength). As of this time, definite conclusions

concerning its effectiveness can not be drawn by the authors.

In contrast to the limited choice and undetermined reliability of nondestructive

methods for evaluating in-situ strength properties of masonry, there are a large

number of more thoroughly developed methods available for this purpose which

are termed destructive or which require testing other than in-situ. Depending

on the user's need for Information, the practicality of performing these tests,

funding availability, etc., these may be particularly applicable in rehabilitation projects.

To allow the reader the opportunity of selecting the most appropriate test.

Table 6 shows a reasonably complete listing, and summary description, of the

commonly used nondestructive and destructive test methods available to evaluate

masonry. Test methods are grouped in the table according to the parameter

being tested. A more complete reference list follows the table of ‘commonly

used evaluation methods. The reader's attention also is directed to two

destructive methods which were described previously in the concrete section

2.1.2 of this report which are particularly applicable to masonry: 1) core

testing, and 2) petrographic analysis.

REFERENCE - Fattal, S. G., and Cattaneo, L. E., Evaluation of Structural

Properties of Masonry in Existing Buildings , NBS BSS 62 (Washington,

D.C.j National Bureau of Standards, March 1977), 127 pages.

71
0

Vi1

afO

b.

Vicog(13 X

ft

Viu

•J% MU2tdUw

b.SHW

abO

'S’S o ,c U 4J M s 09 Urf e o

0) CO •Hc ^e « § e Vi «H

00 9 C 9*0) 4J W •

(0« O H Kk3

OOe

•H*C CO « *H oM c0) •ki 0 e *H •H 'J O 0

Q.

a

cc •o

Vi •H • £ oo u Id .a «a b 4J <b b» b £ O

a

a « 4J •

0) <r) « - c e o o X V 'J 4-> a b fH i O iH

o. « M a 4J e 9 e <b « o u N OO >« ib d)

l-tb 4J o. o a X V ^ X « *0 4J « « u e « *H

to fb

Id o. 00 •b *0 *9 00 b

01 o « ^ o X *a Cb « bi flt a Cb

00

V o e 9 p a >b « 00 y • a. y 60 4J •9 r4 *9 y •9 0 m 0 y Vi y 0 e

,X 4Jy

u

y o tt 0 tt • •9 rH • u y o y o y •H .0 2 *9 VI o VI <r VI CA P tt VI 2 0 PS y < 0 K o •9 •9 y y 0 < (a 0 • 0 U rH u 4J y

a. • 0 r*^ 0 yy •9 Vi rH JZ N© r tt a 0 rH VI

H 0 u •9 *9 P 0 0 tt CA Vi 60 y cj y CA u •9 0 9 0 rH •H < 0 y o O H X y 9-^ 9- VI VI 60 0 y Vi B P a Vi f>4 tt CM 0 y

rHu S ^ 0 y o y •H

X Vu CA tt < 00 as VI u O tt 0) 0) -o

60 e

Id «

>* tb b X to

b

B

a 4-)

a

O 0) <b bJ

10 00

C

b

Id 10

B

O

X < ^ X

y

*9

y Vi ? 1 0 y

Vi

uM

Vi0 0 o • •0 *9 O •H • 4bi y

VI iH •rl 9 •9 • 9 4^ y 60 o p"j y o VI 9* y tt 0 O > fH

VI

a .0 0 y • tt Vi fH 0 VI VI 4H VI CM 9 fH •9 >>x • x:

tt 0 o 1^ 0 9 VI c 60

u

fH

u tt Vi

y 9 rH •H *9 fH o

10 ^ 0 tt

M .©

y

y rH VIy 4-1

X P o VIy 0 0 9 tt » 4h 0 /-N VI tt *9 0 fH 0. O 0 c y 0 *9 rH fH Sm/ 0 .0 y y y * *9 > 9

•9

O 9 > y tt pH .0

a

yyy

a «0

O 0 60 • VI fH

a 60

y Vi fH

O VI

X D. 0 ^ y *9 VI

y 0 0 a y y tt .H a > 0 0 4^ y

CM

y

r

Ua 9 0 0 0 CL • .© y o o. 60 tt o a tt 4= 4^ tt a .0 VI tt 0 0 0 Ufi 0 a 6«0 O y VI fH fH y y >^ *9 60 CM Vi X tt VI .X a 60 • tt tt tt y tt y *9 fH a 9 C VI O y

CM 0 y

y

y 0 yy 0 9 ViO o fH rH • VI M VI u H© 9

fH tt

y .0 o > Vi iH

r4 >> 0 O fH

a 0 O. tt tt CM «p4 o 0 U 0 mh y y Vi tt a >> 1 VI a 0 0 «H .0 .0 y 60*9 y VI fH X tt o a 0 VI VI tt VI •9 fH rH tt tt y y tt iH s y tt y y o. 0 0 0 fH y

tt 0 rH o 4H 0 u

y tt tt 0 yyy Vi ,0 0> a d» IQ O fH CV VI 0> D Vi CA pH tt X VI

>« 60 « X C X O iJ •o fb 0) Id X u Id X

00

C -b

01

O 60 » X «b B

00 >b 0)

V 00 00

b

b

U 9 9

Id

b Id lb

frU <b

00

a d) 0) o 00 IX

60

U 9

Od

X

B

lb

B

X

O

X xl -b a *00

01

a fb

B

00 01

a 0) oo X B X <0 X 0

60 lb

>< 60 «d

a

b e lb

B

B bH T)

O o <0 60 w a 0) Id « e B -b X •-* o •«

Bb

s.

«0

id s

O.f-4 0

CM

dO

O

C

•H 0 U O ^ y a 0

tt ki S’* y u 0

00 o

tt

u 0) ye«

•coyy

(d

tt u vo

tt

u tt2g4J CA

CO < y9

4Ja9

tt9

pH9

*9OS y0 • •9 ^Uo u yy *9 0 o c 5 M y X*» * yH V© y cj Igtt CA y < w&£“go

S’yu

i*oo I •H tt •9 «H co y u ^

o. •9 g y 0

4H CA 09 • 4J 4) 0 f-t tt o.0

•9 0 0 tt 0 4J

>s tt u y

*9 4J

60 <«-• 0 O

•H•C tt 60 0

•H

O

y» u oy

•900 0

tt 0 9 O O

tt

Vrf IT> • y tt B u u

0©

O 9 9 O

tt .0

>%y ^ 0© 4J CM 0

*9 9 y o

4J 60 U.4 0 0 u u 9 rH y U *H 4H 0 O 0

tt .© 9

o.

ViO

tt 6©<

Viy4J 0y

•Hy Uod •p4 O

U-i tW 0 y o o •H y 4J • y 0 *H >» O *9 iJ •H y oH

4J rH 0 C. -H

Vi Xi a u CO O Vi 0 4-19

C/1 *9

72

Freezing

and

Thawing —

Repetitive

cycles

of

wetting,

Test

Is

continued

through

50

cycles

resistance

to

freezing,

drying,

and

weighing.

of

freezing

and

thawing

unless

damage. '

specimen

breaks

or

loses

more

than

3%

of

Its

original

weight

as

judged

by

visual

Inspection.
TABLE 6

(Continued)

METHODS

FOR

MASONRY e

ss

(b«HZ

CdOUuH

CdS<HWuH • O 00 ^

(0 4-> ^

(0 ^ Id lA i-» *H O CM ffi

1-4 (0 • s ^ w O «H 9 ^ W H *9

<8 <« . *J U4 h

CO 60 (0

O c o. ^ *H «C

4J 60 60 ^

4^ c e 60

CO *H

C ^ U > 0)

CO ^4

b 0) ,£ 4j O i-i CO w (0 *0

'j e 60

'J CD CO

C

•H *H U CO /-S c u «Q •b

u

<DX 0) 9 a ij X b e

•b

y 9

rb

d

b 9 •H y y b •9

4J 0) CS

CO o. •

1-4

O

CO 0> y 9 U w cO o > y a; e o

60

C

0) 9 O CO (0 4^ O 60 C

0)9a

U *H C u o e

CO o ^ 9 • .A O ^. CO CO. 4J ^

0^ iH <H 9

r-4 »- e *9

CO CO 9 , u .c ^

CO CO 9 O ^ X ^ 0) u X 4J 60 4^ Md ^d 60

o> o e

CO

b 0) CD w H C y y U 0) X 9 X m ^ X 9 CO

CO CO

CO

O

b 0) AJ y g X *0 b «-H 0) •b 9 b y y 0) 4J X

0) CO e

CO 9 P (0 c b

b 0)b CO 9 9 b

AJ

b

C

b CO

a > CO 9 b

CO CO •b CO rH 0 y > CO CO CO 9 9 CO 60 60 b 60 •b X *9 b rb 60 d d d • c a b 9 a y d

•b •b •b 9 •b 9 •9 o •b d c CO b c X X d 5s b d

•b •b

a 9 •b

yb 9 b 9 •b P a b a •b b 9 CO a b b 9) CO b d X 4^ b

0) 9)Xb 9) -b 9 CO 60 9 b U 9 b CO b CO d b y o b a OJ b y 9 •b 9

*9 •9 CO

a •9

b CO

X

d *9 9 9) 9 b CO b c d a b d y d *9 a 9 C

•b •b •b o lb

b

y *b c /*—s

4-1

y 9 O c 9 9 • o a 9 •b O o 9 • 9 9 •b 0 9 d X y 9

fb fb 4Jb

C lb •b CD lb

b

CO (0 •b 9 CO CO 9 • *9 <0 •b > > rH rH > 4-1 9 60 CD 9 >

•H o o 9 6 db > •b o O X QQ b O CO 0 •b 9 b O X d d CO d 9 y ^4 O 9 c CO b 9) o 0 X CD b

4^ 4^ 9 X

X 4^ 9 o o X 4-1 9 o o *9 o X b o CA 0 c *9

y

60

COab

CO 3

60C9

COCOyc

CO9O

•r4>b

<VQ.ea

9}bOo o

•99 9 60 CO

0)d

N *H 0) y

coy *H *H

H CO *H

b

U.

H

M

i! *99

*9

b

1-4 (0 9 a o •b u y • d • X *0 b b

60 9 d C b O

0) CO CO

d 9 5S 1 O b 9 9 b

d 1 o d b 'd •9 9 •b d b X d 9 9 d b CO 9

60 9 • d

X

y c 9 b

Ob

b 9 O

b

OX 9 9 C O •9 lA CD CO b 9 o X 4h a C • y lA y b t- o 9 9 CO •b 4-1 9 9 acM b H 9 9 CO b b CO pH b 9 CO 4.1 9 d a

CD •b 4-t

b *9 4-1 COb 9 s b

X CO

b

O

a

b cc 9 60 X fb O 9 9 O 9 a o CO 9 CO 9 ax U-i cr- 9 • X b CD d y a d X b b • o.i<: 9 b b 9 9 y c. CD b

b

b •b CO

a 9 •b COd CO pHO CO

b CO 9 60 9 b 9 b (0

a 9 a

d

d

b CO

y

a CO «b 9 CO

b 9 4h 9 d

d • 60b 5 b • 0 9 b COy c 60 9 9 9 X CO CO b d 9 O X CO CO b C CO 9 CD c b X CO 0 C

Q

a

a (0 1 CO 4-( CA

b •b

O CO CO

XO

b 9 COb

y (0 1 CD 4-1

b

b

O 9 9 CO 9 •Hb CO CO 4-1 o Xb c b

y

b

N CO > CO 9 b 9 b

b

b

N

ae

b

b 9 9 9 b •b

O *9 1—4 o d 9 O CO

d CO 9 O 9 9 9 9 y CO'

H 9 9 a

X COO

b 9 fs 9 bb 9 b

y

b 9 b

b

X

bab

X CD 9 b

bS CD CO

X

d 4-1 9 0 d

a COC

b

a

b 0 y

a

y

a COa

Xd

a

y

s: CO CO

b •b *9

y 4-1 o a

b 9 9 b

b

bb

O cvi 9 b 9 CD 9 9 O b 9 00 CO •b b 4h O b 9 O 9 y 4J a -Sk. c b b 9 d

b

H

a

a

ddNd 4h •9

b *9

O 4-4 9 O • 5s > 9 9 CC 9 d

C

b

y

CO 9 9 9 CO 9 b 9 • b

b CO CO

A

b 9 CO

a CO 9 Xa 9 9 CC 9

rH lb • d

a fb

a 9 d

X

O CO CO

X

b

b 9 b

b

b CO

b CN

bO

d

a

b

b

b

H cO CO CO 9 <0 60 «b CO •b CO

a

b 9 u CO 9 9 CO 9 y

d CO

O <0 60 CO 9 9 9 y 60 P d y a •b X X O o O CO 9 b o b CQ O CD b s d 3 9

CO CO CO *9bM 9 9 9 CO

d 9 d

ya

X c (0

X

b CO

b

U

C

b

b 9 CD •H •b 9 9 CO X o. j; X •b d 9 c 4-1 a b b 9 9 9 d CD 9 O 9 CO b

C > > (0 a b b CO 6-1 9 4-1 px3 a b 0 o CO <A b > b C Eh b O. <N a b a. b b > b yy

•H

d

<0 CO y b

•H CO E -r4 0) CO X 9 O

0)

4-4

X

O-a ^ 9 9 • § o e 3x0 d CO *b

•b

b

a CO CO d b

CO o o

•H

a

b

b o

60dy

>>

60b

60d

C

C *H *0

O

C3 CO *b

y

C CO

b

y CO CO CO

COU 9 CO

a

r

bb

a

a

y

X 9 CD (0 9 >s 9 y •H b b b d b b b b 9 b b b b o d O c/5 cy E- PS c/: P

73
TABLE 6

(Continued)

TEST

METHODS

FOR

MASONRY • fp| • •o pH o <o OH 2 SI m

CM CM

pH

•9

M

.c 0 '0-

O 0 u 9 • 0 0 • H *9 0 m p M 1 •9

.A 9 • A Ou

O • 9 3 S' 9 « •H •9 oa <Vi 0 g *9 •9

Vi 0 W 9 9 Sk 0 0 •H «pH 0 0

4J sH 9 > Ou 9 0 <VI Vi pH 0 •

QO > 0 Vi 0 P pH

B Vi •pH 0 g pH

X 9 0 CO

p 0 •H

a *9 9 0 VI o

00 MHO 0 9 ^ O -H9 g 9 O Vi hH Vi CM c o P0 e 9 g e o

•H 0 O

C .0

p 0 a

g Vi 9 04 CJ e 9 <fH 9 VI (i3 0 0 9 0 Vi g 0 CV*H •9 pH H-I • 0 M • X 0 0 sH ? 0 9 >s 0 a 0 M O p u 0 9 0 0 Vi 0 e pH o M m CO

MV ^ B 9 9 9 0 0 0 •H 0 pH pH < H Vi 0 «H 00 Vi g pH O Vi CO M-I 0 *9 Vi 2 9 g 0 0 0 KJ 0 0 o 9 » 0 o CJ Vi 0. 9 ^ 0 w <H 9 HH 0 0 9 s a 0. 0 *9 B • 0 Sk X a s c • 0 0 9 9 ^ 0 VI •9 Vi Vi * M p O pH •0 O O 0 Uu O 0 Vi 0 as M CO 9 u 4J Vi 9 Vi g •H 9 o O 9 «H o < B

4) <H 0 X MH

g VI Vi 00 VI 0 Sk Sk •H

D pH «VI Vi 0 * 0 0 e 9 B CO HH Vi pJ pH ^ 0 g 0 o VI 0 6 9

<0 .o 9 0 9 •H 0 •H *H 0 o O 0 sk 9 a •9 > <0 9 o VI X vH I4H X hH 0 •H B 0 X 0. 9 u •H 0 VI •H H Vi Vi VI u Vi O 9 VI Vi Vi *9 0 0 0 g 0 •H 0 VI 0 0 6 *9 9 0 9 0 a<H 9 0 0 9 B Vi 9 Vi 9 O VI 0 • §

•P^ o 1 a 9 8 *9 ^ S X U 0 pH o VI 9 tH 0 >> 0 9 >s

O o H M-i Vi

g pj

u

M Vi VI •H

HD CJ

X 100 £ V VI 9

CB • « w Vi • Vi Vi S’ 9 >> haw 0 9 0 0 0 hH 9 9 a 0 u w u •H mh 9 VI 9 g M (0 sC Vi 0 Vi 0 9 0 5 X 0 VI 0 g 0 c Vi g •H •pl 0 VI •H 0 Vi Vi 0 0

•H 00 *

s. 0 0 0 0 9 pH 9 0 •9 e MH CD 00 VI 9 9 0 VI *H B 0 VI *9 Vi Vi e 0 0 9 o 0 *9 0 0 M X 0 Vi 0 B Vi 9 0 9 pH Vi •H 9 • 0 a VI .0 9 *9 pH 0 o a g a CB 4) 9 M pH 9 0 U Ou VI Vi MH •pH g g

00 0 0 •9 pH 00 9 0 g *9 .0 VI •9g 0 0 a CD •9 <4H 9 0 0 0 O ON «H 0 > 9 0 0 0 0 0 0

•H

C 9 8 g

U Vi 0 «0 0 «H 0 0 0 0

<B 9 •9 0 Vi

a

g ^ 9 •9 VI 0 0 •H •H

Vi e 9 u-» 9 pH 0 6 9 u

X *9 9 p Vi 0 •H Vi e -w ^ 0 a 0 •H 0. 9 0 Cu 9 VI *9 9 0 VI a 9 9 0 Vi g 0 a VI 0 •pH 0 0 VI 0 •9 9 9 O 9 9 e 0 U O Vi 0 «H • 0 9 9 g 0

O.Hh Vi 0 •H 0 9 9 *9 0 *9 0 X ^ » VI 0 K •H

a CDO

K 0 VI .CCH 9 VI ax » 0 0 0 9 6 o 9 0 .0 VI Vi 0 0 0 0 Vi *9 0 c

?!

U Vi Xi MH •H 0 0 9 0 O 9 X 9 P CB CD Vi i X <VI ^ 0 9 hH » X o • vH Vi VI VI pH 9 00 • •H g «M O pH Vi > 0 VI £ •9 0 0 •pH 9 S .9 Vi c 9 pH g *H O 0 o 9 9 9 Vi 9 0 > •9 • 9 0 0 9 X 9 00 0 .0 .0 g VI Vi 0 0 9 0 H pH 0 9 a » 0 g *H 0 VI 0 •H 9 IM •H Vi Vi —H 0 CO M 9 £ CM 0 0 6 0 Mu ^ Vi 0 a 0 ON H CM

?! pH Vi vH Vi 0 4h • 0 /"s 0 0 M-I tw •9 VI

a 9

.O 0 9 > 9 Vi cn Vi CM 9 0 o 9 VI o VI CJ VI CJ 0 0 U 0 w 0 VI B •9 Vi w VI 0 g • 0

Vi Vi 0 0 B VI 0 0 «VI hH 9 o a

g 0 X CM 9 X

cs <S •9 sH 0 0 CO CS

O '—. g 0 •9 3 0 0 •9O

p r^ VI

p

4) *9 SMi 9 0 ^ *9 0 9 M-i 9 0 00 9 *9 9 Vi hH CO 0 e 4i X 0 g 9 ^ Vi X & a 0 VI 3 0 9 0 VI < M 0 < 9 *H s 0 0 B • 0 •< &pH 0 H ^ 0 c 0 X •9 0 X g B M i Vi 9 0 9 Vi 9 w g 0 9 X X C a C 0 9 0 Vi Vi o 9 0 0 S. a 0 0 Vi Vi < Vi Vi « a o £ 9 0 •H pH X 0 O 9 0 s

VI 9 •H

M •H hH

Pu (Bm

C VI 0 9 p^ 0 P Nm/

g vh e •H CO Vi 00 < 9

ec /-s 9> 9 •pH St 0 P g 0 X o Sk u Vi 9 0 0 Vi hH VI 5c OO Vi 0 9 00 VI 0 2 O 0 9 9 Vi 0 Vi 0 9

flC « ^ Vi

a

a 9 9 9 VI 9. 0 0 C 6 Vi VI Vi Vi 0 •9

0U

O 9 3 9 0 VI 0 9 •HO 0

pJ ^ Ou CJ CO 3 OC < CJ 0

•• Os •9 «

4) pH 0 N U * a Vi & 1 <B 9 (J •H 9 Vi >t *9 pH pH pH •H 0 •9 0 E 0 Vi 0 O CD •9 S 9 O pH Vi 0 0 H m •H 9 0 •9 p9 Vi 0 CO < O 9

tr 0 .s 0 1 o 0 1 p

i-i <H Vi 00 00 o X 0 Vi

X .B Vi Vi ec B O 0 0 CO 0 Vi pH 0 X 0 0 u « 9 •H «H O 0 Vi Vi 9 9 9 VI H ^ Vi O c; •9 o O Vi E 0 *9 6 Vi < 4) 4J 0 0 0 0 CJ 0 o 9 0 0 9 o X O CO Ou Cv 0 X 0) Gu CJ CO 0 O X

74

EfflorSand

per

ASTM C

144.

escence.

Efflorescence

tendency

Is

determined

using

the

wlbk

test

described

In

BIA

Research

No

air

entrainment

or

antifreeze

Report

No.

13,

Sec.

4.4,

p.

14.

admixtures

shall

be

used.
TABLE 6

(Continued)

TEST

METHODS

FOR

MASONRY • o2

td 00 U •0* 2 rA is * 6 * • CD 9

Vi *9

y

y 9 ON AJ

X • • 0 C c o rH o rH AJ 9 CO Cd •9 CO • M-i o CO a) r-l •H 9 ij X rH 9 CO AJ *9 c •c B .n U CO CM CO AJ Cd x: Cd •H AJ rH 9 o u 00 Vj -h o 9 0 9 iH AJ CO 9 *9 y 0) C O <H (U >> Vi AJ >> U 9 •rl 00 Vi 9 CO 9 • 2C «H y "O *J Cd *9 9 rH 9 cd 9 H AJ 9 9 CO ij •9 y c V O AJ 09 AJ AJ AJ •pH U 9 oo

CO (U « Cd vj

y CO 9 Cdy Cd CO 9 Vi *9 9 9 0 01 y AJ 9 Cd Cd e 9 O Cd • 9 9 9 •H e 9 c c 9 9 AJ y AJ X M CO 9 £ AJ rH •9 *9

CO JO •H .« 0 Vi £ 9 9 9 •H

u ,9

y <d .9 9

CO AJ

O 9 Oj Xi AJ AJ 9 9 9 y Cd >\ *H

w 9 c U-i ta \o AJ * o 9 9 •H 9* O.O •H 9 Cd CM

|h

u o .H .«

y Vi c 9 M CO 9 O AJ AJ

O 6 A <0 e O 9 <d >> *r» > Cd 1 M •9 CO •H 9 o 4J ^ vO Vi AJ AJ Cd 9 9 9 9 9 •H AJ CO AJ S (d Vi CO y £ AJ trf •H AJ CO •H AJ y CO AJ *C CO 9 Cd s & -H 9 •H P o CO o rH M >% rH QQ 9 9 Cd CL 9 Vi *9 o CU 9 H U to £ •pH 9 rH cd CO 9 9 9 y O 9 0 •H o <d O" ^ < « • A .o y 9 •pH Cd Vi •rH CO •H (0 cr y rJ V o Cd 9 •X u Vi pH 9 Cd 4J u • 9 X y •H 9 iH 9 9 CD 9 *9 9 9 ,9 AJ >

CO C^ 4J «H rH AJ 6 iH 9.

O •9 AJ CO

0) o Cd •*-> Vi 9 CO 9 9 Cd

X 0 9 •H 9 o H iJ Ed M-i ^ *C u o oi •rH 9 B CO H 9 00 Cd 9 :» H AJ

*9 9 <U 9 w 9 *9 9 •C .C CO Vi Cd 00 9 »9

•o CO Vi AJ 9 Cd 9 9 -9 9 • Vi 0) 9 oo V) 9 •rH 9 9

cd > C .C CO

B CO

B cd *H

•9 •H (0 9 AJ 9 6 Cd •H

M 6 p-H

C OQ •H Vi «H ,C CO 9 9 A Vi AJ

Cd CO Vi > AJ •H AJ AJ CO 9 •H AJ

4-J 0) (0 CO Va 9 9 AJ AJ 9 ,9

CO

U

B AJ

C

a CO *9 CO 9 *9 9 0 OO g. (0 9 fH fj rH 6 9 ^9 O AJ •H 9 Q M B •H > -H AJ Cd 9 CO AJ X & er B J= • O /-s O U •H 9 *9 CO •H y •pH 9 AJ c AJ *9

SE

a CO ^ 9 9 W

u 9 9 9 9 Vi 9 H CO CO AJ 9 o • •C Cd £ O AJ > o 9 9

Cd Vi >> 9 >» 9 AJ CM /-N AJ •9 9 CO CO AJ 9 O S O V4 Vi Vi 9 Cd 9 CO 00 1 m X m •H < Cd •H CO Ed c CL 9 CO 9 s •H 9 9 00 y AJ g r4 9 o B O Cd U 9 •H 9 CM •H rH c 9 W y AJ CD O CO 9 Va AJ M CO 9 • Cd 9 x: e

CO Cd

y cd CO AJ AJ •9 9 X • *9 > AJ AJ CO 0) 6 6 fH tH O rH CO 9 iH 9 AJ U 9 9 9 < AJ 9 9 CAJ rH £ Cd Cd 9 y 22 9 •9 >v

CM c oo*»-t c AJ 9 *9 9 AJ o. 6 O *9 .9

VUl

O •H c W

M 9 > >» o Cd «0 Cd

B CO 9 O * o 6 9 B AJ • 6 •H Cd e T5 9 AJ cd y AJ 9

•C Vi AJ AJ 9 •H CO *9

M

H £ AJ 9 O

00 4J 9 CO (d s 6 9 AJ CO 1 9 O 9 9 9 •H *0 •9 OO Vi 6 9 •H AJ Q. 9 • y Vi fH Cd Cd •H rH AJ o O e 9 X C AJ •H 9 u 00 y 9 AJ 9 Vi •H s: 9 *9 9 9 & •H rH CO y 9* S 9 <d g £ £ O 9 Cd •9

4J 4J Vi s s B •H

XB

O 9 B bO

u CO CL 9

0) o V)

O «4J cd Cd 9 9 9 o MO 9 3 •H •H 9 X

O s 6 CO V> O CO CO < •iH o CM >4 •H £ M 9 y

»9 0 9 AJ CO 1 0 rH

T3 p9 •9 rH 9 9 9 9 «k Cd y O CO s CO AJ * CM

0) •H Vi •H • > rH 9 Cd »9 < •H Cd 9 AJ 9 9

Ou CO

MM 9 rH

(0 4J 9 CM 0 •H rH

H <D 00 AJ

O

B s •H

u

C

y Vi CM

U

a 9 9 CO £ 9 H B Vi M CO AJ AJ 9 O 4J AJ 9 •H 9 M u CO C/3 9 *9 cd 1 /—s • y c y iH A Vi 9

•H o 0 Cd 9 Cd OO 00

Vi 9 y i-l Vi rH AJ 9 rH <d < . >>.o B JO 9 •H Vi •H rH rH M v> •H «k AJ Vi 0 •9 9 »£ c y .X 9 y a 9 CM 6 u o y *9 y Vi 9 rH 9 H CO CO C •H <U Vi 9 •9 y 9 9

Cd (d Vi ^ AJ rH e c CO S £ CO ^ y CO y Cd fH AJ Cd

75

Location

and

Probe

Holes

Uniformity

of

the

Penetrate

the

area

of

investlgaSmall

holes

may

be

patched

inner

cell

grout.

tion

with a

small

masonry

bit

and

easily.

Surface

damage

is

and

wall

probe

the

hole

with a

stiff

wire.

only

minor,

thickness.
TABLE 6

(Continued)

TEST

METHODS

FOR

MASONRY

C/3 gCdU

U2H

Cd%

Om<M

CCtdI

>s

>>X

fH 00

iH 3

fCO 9 l-i CO ^ 9 4J

CO

(C o

4J

U >* d «-• d> Co -c

ce 3 u

CO Q) C O.

o; xj ij o u X ui ‘

Cd « o

pd 9 O

CO XJ CO U-I XJ XJ 9 U CO 03 00 C. 9 M C

XJ 9 d 0 XJ

MC 9 9 XJ

CO > -9 •M CM •M -H «M *c to E 9 •H 9 u XJ C d *9 • 9 9

XJ CO 1-1 CO 9 >> 9 9 CO •9 XJ 9 9 c •d CM o o M 9 C XJ C Vi •M 9 9 9 9 o c; Vi c >1 0 cd CO 9 O CM C pC XJ 9* •H CO Vi CM u 9 s CM CM

•pj XJ

X 9 •9 9 Vi CO CO e c • * M 9 c •H

XJ Cd IJ Vi 0 e o •9 0 9 9 9 -M •9 9 CM CO P CM X CO 9 CO X N CO M 9 O 0 • 9 N *9 9 S

•9 00 o .pJ

O

M 9

Vi *9 Vi Cd 9 9 9 E 9 • E Vi CO .9 U-i Vi XJ O o

pC ^ o> 5 JJ pC

O «H

H

CO 3 wO *0

CO •9

•H •9 O e > CO CMo * 9 C >

XJ CO 0 •H • •H -X *H CO pd 3 9 XJ CO XJ C Cd eg 9 00

•H Vi e Vi c

XJ 9 f-l CL 9 C Xi E U o Vi CO O XJ C9 O 9 9 CO

CO 00 •9 C C «H « *9

V4 1-1 9 c CO (d i-c O 4J XJ o

CO *H 1.1

d 9 CO

Cd c O

M ^ CO

Xpr

w xj <e9

<d pC • >

CO

X 9 XJ

Ui fH 9 CO *9 9 9 X

•J 9M 4J

=5CO pd O «H a-c X o 9 U

CO CO 9 XJ

CO 03

CO 9

T-> CO

CO XJ CJ M 0.1.1 •9 O

'J9U *9 9

pd

E- c M (d

XJ *9 9

.CC CO OO cc 9U

C O. 9 u XJ 9 •M XJ •H o 9 a 9 •0

yy •9 r-i

U fH XJ • C9 9 N •H 9 9 U pO 9 o u pd >> • N 9 9 9 9 0 d A XJ 9 •M 9 d d •H 00 XJ d o. XJ 9 9 CO •fj CO Vi 9 CM d 9 4^ Vi •H •d 9

9* .JO 9* 9 9 o pd •H 9 Vi

p XJ CO fH Vi c XJd

O o 9 u 9 <0 Cd 9 > •M CO o XJ (A £ >% o y 9 9 9 pd 3 9 9 •M 4.1 CO a

•M 9 Vi

u CO CO •H XJ XJ 9 •9 9 Vi •H CO

y

y 9 3 u

CO •M 9 9 a o. 9 9 y 9 g fH •ri

y XJC CO CO .H

U >V pd 9

•H CO 9 *9 •9 P- > y 9 CM 9 B 9 O 9 CO 9 CO 9 •9 r-( XJ 9 XJ > a d d 4-1 d y a 9 9 9 O U CL •H pd o pd CO d U-i d O Vi d P CO CD 9 9 9 o *2 < QO CO •9 00 y a CO *9 a a H .pj O 0 pd 9 •pj 9 XJ d 9 00 u 9 (0 o 9

Vi CO XJ 9 Vi 9 E 5 9 y 9 pd 9 Cd 1 9 •H .H 1 >> Vi 9 d 9 XJ fH O *9 •M y XJ

Vi CO > d CO •O pd > 9 .H pd CO 9 XJ

u •

(0

u 9 d •H CO 9 9 XJ •H XJ e 9 pd CM CO 9 CO 9 o d 9 /-s 9 pd 9 XJ U •9 CO 9 iH pd XJ 9 d 4. •pH X £

CO > XJ Vi 9 9 c a 9 >» CO pd • •M XJ 9 CO Vi CO jO 00

d XJ 9

Vi •M XJ

d •H

a XJ XJ 9 XJ *9 CM CM pd •9 9 » y 9 •M

d •fJ 9 9 CM 9 9 00 0 a •H Vi 9 CM O XJ •H fH O vj CO E 9 0 0 •d 9 9 0 d 9 Vi •M CO CJ i y a a XJ 0 0 9 pd XJ -J O U •M XJ 9

CO 9 9 9 Vi CO •H 0 a CO CO 9 9 p» > OO CO 9 Vi XJ

d E 9 *9 U CO 9 9 •9 y XJ o «H 9 Vi CO Vi CO 9 d d M f-* 9 •H

CO 9 9*d •9 9 • CO 9 y tJ XJ 9 9 9 U XJ • 00 0 9 9 •Hy

d e *9 •9 9 CO 9 9 Vi 9 > a

X •9 CO XJ • Vid s 9 •H Uw 9 U *o •H

a 0 cdC •H

U 9 XJ

y pd •H o 9 *9 •H E XJ XJ 9 9 XJ o CD u CO CO CM > XJ d 9 9 XJ u •9 CO a d 9 S «M 9 9 CO > y 9 X CO XJ 9 E •M Vi 60.0 CD iH o 9 d X •H 9 pX 9 CM 9 Vi 3 d

E-»

u

M 9 » » •H E 0 » > 9 9 9 E Viu

y 9 XJ CO 9 •d oo

Cd x» 0 9 XJ o XJ ce CO

d 9 CO >> XJ 9 Vi 9 CO Cl 9 9 d 9 £ XJ •H 1-2 •9 c CO 9 O. Vi 9 9 pd 9 •H U •9 •9 0 pd •H 0 pd 9 «H E p XJ XJ CO d 9 *9 9 y 9 Vi pd a y CO 9 9 d «M XJ XJ pd CO 1 H •M 0 9 9 U •H pd 4j u 0 XJ 9 Vi o XJ Vi 9 CO d Vi 9 y 9 *d C > *9 S cv • 0 > XJ O XJ pd O M y V4 9 Q. M-i 9 9 •H d 9 9 9 9 0 9 C CO a XJ (0 9 > XJ O a OQ O a < > *9 o XJ P CO y 9 d P e <0 d 0 U 4.1 d d s UJ 0 0 CO 0 9 9 a Cd 9 C.W *M 9 «d d 9 H 0 9 d O 0 u •H CO CO 9 U E «H fH 44 9 9 9 Vi d 9 •M • p^ 9 •H •9 CM *9 9 d • CO •H 9 9 C • y XJ 91 a H 0 d pd •9 9 Vi XJ d pd B 0 C Vi 9 CM • Vi XJ Vi d d •H y 9 0 X o • XJ 9 9 XJ 9 u •9 g 9 0 y CO 9 9

"y 0 •M 9 » •H

U 9 *9

u CO •9 00 Vi » CO fH 00 9 9 *9 E CM o 9 9 a 9 XJ

V

d XJ

U

Dl CO • 9 d 9 9 e 9 9 CO

d > 9 oo 9 E

Vi pd pd XJ 0 c.y c. 0 9 c

•M •9 9 o u XJ 9 CO 9 tJ XJ 9 0 B

yy

a XJy pd pd 9 c. XJd 0 > C 9 Cd (0 XJ XJ U 9 fH > Vi •H U a H 9 9 9 pH XJ OO y 9 XJ 9 E C oo CO Q 0 CO fH S

rH •9 XJ 9 •H •H 0 d XJ 9 9 a *H CO

d 9 •H 9 -c 9 pd 0 £ 9 9

c/3 9 a e 9 a CO S » CD

y 3 CO Vi

C P a CO 4J •H o a iH d. *9 *XJ

y £ E B

CO Cd *9 c

CJ *H 0 0 9

(d 9 c

CJ 9 *H O XJ 9

id CO i)

76
2.4.2 References

1. "Standard Methods of Sampling and Testing Brick and Structural Clay Tile,"

C 67, American Society for Testing and Materials, (1978).

2. "Standard Specification for Masonry Cement," C 91, American Society for

Testing and Materials, (1978).

3. "Standard Specification for Ceramic Glazed Structural Clay Facing Tile,

Facing Brick, and Solid Masonry Units," C 126, American Society for Testing

and Materials, (1976).

4. "Standard Test Method for Air Content of Freshly Mixed Concrete by the

Pressure Method," C 231, American Society for Testing and Materials, (1978).

5. "Standard Methods of Load Verification of Testing Machines," E 4, American

Society for Testing and Materials, (1979).

6. "Standard Methods of Conducting Strength Tests of Panels for Building

Construction," E 72, American Society for Testing and Materials, (1977).

7. "Standard Test Method for Young’s Modulus at Room Temperature," E 111,

American Society for Testing and Materials, (1978).

8. "Standard Test Methods for Compressive Strength of Masonry Prisms," E 447,

American Society for Testing and Materials, (1974).

9o "Standard Test Methods for Water Permeance of Masonry," E 514, American

Society for Testing and Materials, (1974).

10. "Standard Test Methods for Flexural Bond Strength of Masonry," E 518,

American Society for Testing and Materials, (1976).

11. "Standard Test Method for Diagonal Tension (Shear) in Masonry Assemblages,"

E 519, American Society for Testing and Materials, (1974).

12. "Standard Specification for Portland Cement - Lime Mortar for Brick

Masonry," MI-72, Tech Note 8A, Brick Institute of America, (Oct/Nov 1972).

13. "The Causes and Control of Efflorescence on Brickwork," Research Report

No. 15, Structural Clay Products Institute (now BIA), (August, 1969).

14. Snell, L. M. , "Nondestructive Testing Techniques to Evaluate Existing

Masonry Construction, (August, 1978).

77
other test methods for evaluating masonry products are available from the

American Society for Testing and Materials (ASTM) as follows:

C 413-75 Absorption of Chemical-Resistant, Nonmetallic Mortars,

Grouts, and Monolithic Surfacings

C 905-79 Apparent Density of Chemical-Resistant Mortars, Grouts, and

Monolithic Surfacers

C 321-77 Bond Strength of Chemical-Resistant Mortars

C 67-78 Brick and Structural Clay Tile

C 608-71 (1977) Brittle Ring Tensile Strength of Chemically Setting Silicate

and Silica Chemical-Resistant Mortars

C 619-71 (1977) Chemical Resistance of Asbestos Fiber-Reinforced Thermosetting

Resins Used in Self-Supporting Structures

C 267-77 Chemical Resistance of Mortars

C 868-77 Chemical Resistance of Protective Linings

C 396-76 Compressive Strength of Chemically Setting Silicate and

Silica Chemical-Resistant Mortars

C 579-75 Compressive Strength of Chemical-Resistant Mortars and

Monolithic Surfacings

C 140-75 Concrete Masonry Units, Sampling and Testing

C 426-70 (1976) Drying Shrinkage of Concrete Block

C 580-74 (1978) Flexural Strength and Modulus of Elasticity of ChemicalResistant Mortars, Grouts, and Monolithic Surfacings

C 341-79 Length Change of Drilled or Sawed Specimens of Cement Mortar

and Concrete (see Part 14)

C 531-74 Shrinkage and Coefficient of Thermal Expansion of ChemicalResistant Mortars, Grouts, and Monolithic Surfacings

C 307-77 Tensile Strength of Chemical-Resistant Resin Mortars

C 308-77 Working and Setting Times of Chemical-Resistant Resin Mortars

C 414-77 Working and Setting Times of Chemical-Resistant Silicate and

Silica Mortars

78
3. HEATING, VENTILATING, AND AIR CONDITIONING SYSTEMS (HVAC)

Several techniques have been developed which can help evaluate the performance

of existing HVAC systems and to determine their capability to support retrofit

systems; some of these are presented in this section* Also discussed are methods for evaluating the performance of the building envelope which contains

the conditioned space. Techniques for measuring air leakage, as well as heat

gains and losses, through the exterior of the building are valuable because

space conditioning without proper humidity control can cause serious problems

of condensation within the building structure.

A discussion of techniques for assessing the condition of the existing HVAC

system and the envelope of the building follows.

3 . 1 BUILDING ENVELOPES

3.1.1 Evaluating the Amount of Air Leakage Using Air Pressure

Test Method - Pressurization

Subject - Building Envelope

Parameter - Air Leakage

Discussion

Pressurization of the space within a building, either positive or negative with

respect to atmospheric pressure, is one means of gaining a quantitative measure

of the air leakage of a structure. A fan, a metering station to determine air

flow rate, and pressure sensors, along with temperature measurements, are needed

to make the determination of leakage rate for the given pressure differential.

Generally, a window or door opening can be fitted with a plywood partition

through which the air required to pressurize the structure is introduced. The

air is allowed to seek points of penetration in an effort to equalize the

pressure between the space and the surrounding atmosphere. The amount required

to maintain the pressure differential provides an indication of the overall

performance of the structure with regard to air leakage. It is possible to

isolate contributing points of leakage by selectively taping cracks and joints

during a sequence of tests. Internal air leakage paths can be identified

using a fan to generate negative pressures and infrared scanners to trace the

path through the construction.

Advantages and Limitations

The technique is rather simple and not necessarily expensive (expense does vary

with the complexity of measurements). The results using the air pressurization

technique are not necessarily transferable to gain an indication of infiltration rates under natural conditions. The results provide a relative measure

for assessing the structure to determine where within a range from "good to

bad” the structure falls. The technique can be used effectively as a quality

assurance procedure.

REFERENCES - 1, 2, 3, 4

79
3.1.2 Determining Air Exchange Using Tracer Gas

Test Method - Tracer Gas Technique

Subject Area - Building Envelope

Parameter - Air Leakage

Discussion

The actual air exchange rate within a structure can be determined through the

use of a tracer gas which is released into the space to be measured, then the

concentration of the gas is monitored over a period of time. The exchange

rate can be expressed through the following relationship:

I * -^/t In (*^/co)

I where: I = air volume changes per hour {

t = time i

i CO “ concentration of tracer gas at time zero (beginning of test) >

c “ concentration of tracer gas at a specific time within the

test period

When the natural logarithm of the relative concentration (^/co) is plotted as a function of time, the rate of infiltration (I) is the negative slope of the

best fit line through the data points. Several tracer gases, such as carbon ! dioxide, helium, nitrous oxide, ethane, methane, and others, have been used as

| indicators of concentration decay. Currently one of the most popular is sulfurhexafluoride. Samples of the air within the structures are taken and analyzed

on the spot or stored in sample bags during the test and later analyzed. '

Advantages and Limitations

The tracer gas technique is probably the best measure of natural infiltration

in that it does not introduce any unnatural constraints for making the determinations, other than some form of forced air circulation to maintain mixing

of tracer gas and air. The use of sulfur-hexafluoride (SF^) allows the use of

very small amounts of harmless gas, generally on the order of 10-50 parts per

billion, to be introduced into the space, thus altering to a negligible extent

the composition of the air. At infiltration rates of greater than three air

changes per hour, the tracer gas technique may give unreliable results because

of the introduction of large amounts of unraixed air causing significant scatter

in the data. At the higher rates of air exchange, the need for rapid sampling

rates may also pose a problem.

REFERENCES -1,5

80
3.1.3 Determining Paths of Leakage Using Thermography

Test Method - Thermography

Subject - Building Envelope

Parameter “ Heat Leakage

Discussion

Sources of high heat losses can be determined through the use of thermographic

techniques. Thermography is a technique of portraying an object using the

thermal energy radiating from the surface of the object. The energy radiated

from the object (infrared region of the spectrum) is displayed on a cathode ray

tube (either a black and white or color television monitor). On a black and

white monitor, the intensity of the gray scale is proportional to the temperature of the object - within a given range, colder objects appear dark and hotter

objects appear light. On a color monitor, the gradation of colors of the image

indicates the surface temperature variation. Thus, since heat loss or gain

leads to surface temperature variation, it is possible to detect areas of heat

leakage through observations of the building's surface temperature. A photograph can be taken of the image on the screen of the monitor and a record of

the thermal image can be obtained in the form of a permanent thermograph.

REFERENCES -6,7,8

3.2 BUILDING INTERIORS

3.2.1 Determining Humidity with Color Changing Agents

Test Method - Humidity Indication by Color Change

Subject - Building Interior

Parameter - Moisture

Discussion

A rather simple, yet inexpensive, method of monitoring relative humidity

within a structure is through the use of the color change humidity indicator.

One such indicator uses cobaltous chloride as the basic ingredient for indicating the relative humidity. Blotting paper is used as the holder of the

ingredients; and, as the cobaltous chloride is exposed to the atmosphere and

equilibrium is reached, the color of the ingredient changes. A range of

relative humidity indication from 10 to 80 percent can be obtained. There

are plug-type indicators that may be used to indicate the relative humidity

in wall cavities or enclosed roof ceiling cavities. The color change indicator can also be used to monitor the relative humidity of the occupied spaces.

81
Advantages and Limitations

The color-change type indicators are inexpensive and are relatively easy to use. The accuracy of the indicator can be affected by temperature changes and

long-term exposure to high humidity, high temperature, or direct sunlight. As

an indicator of acceptable levels of relative humidity in a space within a building or an unacceptable condition within a structural compartment, the

color change indicator should perform adequately. Direct contact with water

will cause the chemicals to leach out of the paper and thus lose calibration.

It is possible to obtain an indication of relative humidity within a 5 percent

range of the published equilibrium point. A 10°F change in temperature will

affect the indicator accuracy by 2-1/2 percent. A limitation is that the

equilibrium point varies with the specific chemical used, and it is a specific

point (not a range).

REFERENCE - 9

3.2.2 Determining Humidity with an Electric Hygrometer

Test Method - Electrical Impedance Hygrometer

Subject - Building Interior

Parameter - Humidity

Discussion

With a change in humidity, many substances absorb or give up moisture and

exhibit changes in electrical impedance. Sensors can be produced having dual

electrodes or windings which are electrically separated by a thin film of

binder material containing a salt solution (such as lithium chloride). Means

are provided for measuring the AC electrical impedance between the electrodes

through the salt film. The impedance through the salt responds to changes in

relative humidity and temperature, so that accurate indications of relative

humidity can be obtained.

Advantages and Limitations

The electrical Impedance hygrometer is relatively sensitive to humidity changes

and provides the capability for remote read-out. Precision on the order of

+1.5 percent RH can be obtained and elements can be produced to cover the range

from 10 to 90 percent RH. The electrical impedance hygrometer is susceptible to

damage by air contaminants and water. Frequent calibration checks are required.

The elements can be placed in remote places for monitoring changes in relative

humidity in an effort to gain information on excessively high moisture

conditions.

REFERENCE - 10

82
3.2.3 Determining Heating System Efficiency by Using Electric Co-Heating

Test Method - Electric Co-~Heating

Subject - Building Interior

Parameter - Heating Efficiencies

Discussion

Electric co-heating is a technique used to determine the net efficiency of a system consisting of any heating appliance (a furnace, for example) and a house.

Several portable, thermostated, and metered electric heaters are distributed

throughout the house. First, the furnace is turned off and only the electric

heaters are used to heat the house. Next the furnace is turned on and cycled

manually (for example, four minutes on and sixteen minutes off) for about three

hours. Throughout the procedure, the indoor temperature remains constant by

appropriate reductions in the heat produced (and power consumed) by the electric

heaters. Finally, the furnace is turned off and the electric heaters see the

full load again. The indoor temperature is recorded and periodic measurements

of the outdoor temperature are taken. Also, the air infiltration rate (through

cracks in walls, etc.) is monitored using tracer gas techniques. The following

steps are used to calculate the efficiency: First the heat load, including

air infiltration, is determined through use of the electrical heaters. Second,

the portion of the heat load supplied by the furnace is found from the difference

in the load and the measured electrical power consumed by the heaters. Third,

the efficiency is calculated by dividing the difference by the average furnace

fuel consumption rate. Further capabilities of the electric co-heating technique include an evaluation of fireplace efficiency and determination of the

fraction of the heating load needed for individual rooms in the dwelling.

Advantages and Limitations

Unlike some methods of efficiency evaluation, electric co-heating takes into

account the effect of distribution heat losses (through ducts, etc.); in other

words, the efficiency calculation includes only the heat that benefits the

living space. Also, this method distinguishes between heating efficiency and

the house's envelope performance. Electric co-heating, however, is still in

the development stage. It is not practical for structures with a large number

of rooms because of the difficulty in monitoring the infiltration losses and

the power of the heaters.

REFERENCE - 11

83
3.3 MISCELLANEOUS TESTS FOR HVAC SYSTEMS

3.3.1 Physical Inspection

Test Method - Physical Inspection

Subject - Furnaces and Boilers/Heating Systems

Parameter - Efficiencies

Discussion

The current trends toward energy conservation and the subsequent reduction in

heating loads in buildings have had an effect on the efficiencies of furnaces

and boilers; the older ones tend to be oversized and often yield lower efficiencies. In such cases, a replacement may be desirable. However, several

actions can be taken to increase the efficiency of the existing furnace or boiler. The combustion system should be carefully cleaned and checked for

leaks. The air should enter the combustion chamber at controlled rates.

To obtain optimum efficiencies, the oil nozzle size may need to be reduced

or the gas burner may need to be replaced if the system will accommodate

a replacement. The air-fuel ratio should be determined and adjusted for

proper combustion. The O2 and CO2 content can be determined from an Orstat

apparatus or other available analyzer such as the non-dispersive infrared

spectrometer for carbon dioxide or oxygen specific electrodes to determine

oxygen content. This, coupled with the stack temperature reading, will provide

data for determining system combustion efficiency. The final decision on system replacement is generally made on the basis of economics — the annual

savings that can be expected as a result of purchasing and installing a new

system.

Advantages and Limitations

This procedure gives only steady-state performance. In practice, most systems

operate far from steady-state; however, this inspection should be undertaken

for safety reasons whenever major retrofits of a building are planned. Physical

inspection offers the advantage of hands-on experience and an immediate sense

of condition of the furnace or boiler and the HVAC system. With physical inspec

tion, there is the need for knowledge and skill gained through experience.

The inspector carrying out the condition assessment inspection, should be

technically trained. Replacement of furnace or boiler components should be

made by qualified personnel only.

REFERENCES - 12, 13, lA, 16

84
3.3.2 Determining Wall Thickness of Containment Vessels

Test Method - Ultrasonic Thickness Gauging

Subject ~ Containment Vessels (heat exchangers, tanks, pipes, etc.)

Parameter - Corrosion and Wear

Discussion

It is possible to use ultrasonic techniques to determine the thickness of

materials to obtain an indication of wear and deterioration. The pulse-echo

ultrasonic thickness technique is recognized as an accurate method of measuring

product thickness when the velocity of ultrasound is known. Ultrasonic

transducers have been developed that allow the determination of piping and

tubing wall thicknesses (and other forms) without physically penetrating the

material. Ultrasonic pulses are generated and the time required for the pulse

to be reflected back from the opposite surface is very accurately recorded. By

knowing the transmission velocity of the material and using the appropriate

electronic circuitry, a digital readout can be obtained which is a direct measure

of the thickness of the material. The technique has been used to evaluate large

boiler installations for heat exchanger deterioration from corrosion.

Advantages and Limitations

Small transducers are available to determine thickness of closed materials

without physically penetrating the surface. By scanning the surface variations,

wall thickness can be determined, thus gaining an indication of deterioration.

Some distortion results from rough surfaces as the ultrasonic pulse is

scattered, with a resulting lack of sharpness in the return echo. As surface

curvature increases, the coupling efficiency between transducers and the

material to be measured decreases, causing some loss in accuracy. Some

materials have special acoustical characteristics and can cause scattering,

velocity variation, and attenuation, with a resulting loss in accuracy.

REFERENCE - 15

3.4 REFERENCES

1. Crenshaw, R. , Clark, R. , Chapman, R. , Grot, R. , and Godette, M., CSA

Weatherization Demonstration Project Plan , NBSIR 79-1706

(Washington, D.C.: National Bureau of Standards, March 1979).

2. Tamura, G. T., "Measurement of Air Leakage Characteristics of Home

Enclosures," ASHRAE Transactions, V81, Part 1, American Society of Heating,

Refrigerating, and Air Conditioning Engineers, New York, N.Y., (1975).

3. Strieker, S., "Measurements of Air-tightness of Houses," ASHRAE Transactions, V81 , Part 1, American Society of Heating, Refrigerating, and Air

Conditioning Engineers, New York, N.Y., (1975).

85
4. Kronvall, J., "Testing of Houses for Air Leakage Using a Pressure Method,"

ASHRAE Transactions, V81 , Part 1, American Society of Heating, Refrigerating, and Air Conditioning Engineers, New York, N.Y., (1975).

5. Grot, R. A., "A Method for Collecting Air Infiltration Rates in a Large

Scale Dwellings," Proceedings of ASTM Conference on Air Infiltration,

American Society for Testing and Materials, Philadelphia, Pa., (March 1978).

6. Grot, R. A., Harrje, D. S., and Johnston, L. C., "Application of Thermography for Evaluating Effectiveness of Retrofit Measures," Proceedings of the

3rd Biennial Infrared Information Exchange, AGA Corp., Lecancus, N.J.,

(1976).

7. Hurley, E. W., and Kreider, K. G., Application of Thermography for Energy

Conservation in Industry , NBS Technical Note 923 (Washington, D.C.: National

Bureau of Standards, October 1976).

8. Pettersen, B. and Paljak, J., "Thermography of Buildings," The National

Swedish Institute for Building Research, AGA Corp., Stockholm, Sweden.

9. Blinn, B. C., "Properties and Uses of Color Change Humidity Indicators,"

Humidlal Company, Colton, Ca.

10. ASHRAE Handbook of Fundamentals, Chapter 13, (1977).

11. Sonderegger, R. C., Modera, M. P., "Electric Co-heating: A Method For

Evaluating Seasonal Heating Efficiencies and Heat Loss Rates in Dwellings,"

Lawrence Berkeley Laboratory, University of California Berkeley, California.

(Draft Report - presented at the 2nd CIB Conference, Copenhagen, Denmark,

June, 1979).

12. Dubin, F., Long, G. G. Jr., "Energy Conservation Standards for Building

Design, Construction, and Operation," McGraw Hill Book Co., (1978).

13. ASHRAE Handbook and Product Directory, 1977 Fundamentals.

14. ASHRAE Handbook and Product Directory, 1979 Equipment.

15. Fowler, K. A., Elfbaum, G. M. , Husarek, V., Castel, J., "Applications of

Precision Ultrasonic Thickness Gauging," Panametrics, Waltham, Ma.

16. "Home Repair and Improvement - The Old House," by the editors of Time-Life

Books, (1979).

86
4. PLUMBING SYSTEMS

The implementation of a design complying with the code requirements in new construction is fairly straightforward since inspection and testing of critical

elements at key times is feasible as construction progresses and before the

elements are concealed. However, this is not possible in rehabilitation work

where evaluation of existing, largely concealed plumbing is required.

Frequently, this difficulty has resulted in the preference for new construction

or a tendency to totally replace aged plumbing rather than selectively rehabilitate. With modern techniques for evaluating plumbing systems, however,

total replacement may possibly be avoided in favor of supplementing the existing

system or replacement of only those components which absolutely require it.

The following is a description of some of the inspection and test methods

available for evaluating the condition of existing plumbing systems.

4.1 PLUMBING SYSTEM COMPONENTS

4.1.1 Determining Condition of the Plumbing System

A. Test Method - Physical Inspection

Subject - Plumbing System Components

Parameter - Safety Functions

Discussion

A thorough inspection of the plumbing system should be carried out by a quail fied plumbing Inspector to gain a professional opinion on the condition

of the system. The plumbing system is Intended to function in a safe manner

for the supply of potable water and the effective removal of waste products

through sanitary drainage.

Physical inspection should include the following observations:

1) CONDITIONS WHICH COULD CAUSE AN UNSAFE BUILDING ENVIRONMENT:-

a. Excessively hot water (absence, inadequate design, or malfunction of

temperature control devices).

b. Explosion hazard due to absence, or defectiveness of, temperature

and pressure limiting devices.

c. Plumbing wall construction which will allow fire spread and passage of

smoke or toxic gases in case of building fire.

d. Water or drainpipe leaks, or leaks around fixture connections which

could allow gradual deterioration of structural elements of the

building.

87
2) CONDITIONS WHICH COULD CAUSE AN UNSANITARY BUILDING ENVIRONMENT:

a. Leaks in sanitary drains and vents (these leaks can contribute to the

development of vermin, mold, odors, noxious or explosive gases, sewage

saturation, etc.).

b. Overflowing of sewage from fixtures onto floor or under/behind

cabinets, etc.

c. Emission of sewer gas or suds from fixtures.

d. Inoperative fixtures due to clogged drains or Inability to obtain water.

e. Inoperative water heater, or inadequate supply of hot water.

f. Poor flushability of water closet.

g. Absence of potable water supply, or supply of inadequate quantity.

h. Backflow hazard; (e.g., submerged fixture supply fitting outlets below

flood rim, WC ballcocks without vacuum breakers, flushometers without

vacuum breakers, dishwashers without air gaps or air breaks, etc.).

i. Absence or inoperability of essential plumbing fixtures and plumbing

services.

Advantages and Limitations

Physical inspection provides quick feedback on the identification of problems,

but the value of the inspection may be diminished in cases where major portions

of the system are concealed. Many of the features identified in the inspection

listing (1 and 2 above) are items that must be accessible, so inspection can

be made with little trouble. Accessibility will be difficult or impractical

in some cases. Personal experience will be of value in gaining an opinion on condition assessment through physical inspection. The individual who has

designed, repaired, and observed the dismantling of older systems should have an advantage in assessing the potential remaining useful life of the existing

system or its ability to accept modifications.

REFERENCES - 1, 2, 3, 4, 5, 6, 7

88
B. Test Method - Water Test

Subject - Water Supply Lines

Parameter - Leaks

Discussion

A simple method to check for the existence of any leaks in the water supply

lines of the building is as follows:

1) Close all the valves on plumbing fixtures on the supply line to be

checked.

2) Be sure the main water supply valve (or valves) is open.

3) Listen for a gurgling or murmuring sound in the supply pipe.

4) If no leak can be determined to exist in the interior supply line,

and a leak still is suspected, listen for signs of leakage in the

supply pipe leading from the water luain outside the building and call

the water company to check that line for leaks if gurgling sounds are

heard.

Advantages and Limitations

The method is fast and simple. The results are immediate when leaks are large

enough to be heard and when they occur in pipes which are not embedded or concealed.

REFERENCE - 19

C. Test Method - Water Test

Subject - Water Supply Lines

Parameter - Adequate Water Pressure

Discussion

Clogged water supply pipes often cause a reduction in the water pressure at

the faucets. One way to check the adequacy of the pressure is as follows:

1) Open the top floor sink faucets.

2) Open the bathtub faucets and flush the toilet. If the flow of water

in the sink slows to a trickle, the piping may be of inadequate size

or badly clogged with scale.

89
Advantages and Limitations

This Is a fast and simple test method with results that can be obtained

Immediately.

REFERENCE - 19

D. Test Method - Water Test

Subject - Water Storage Tank

Parameter - Adequacy

Discussion

If the water supply is from a well, turn on as many faucets as possible and

observe the water after letting it run for ten minutes. If the water becomes

muddy, the storage tank probably is undersized for the demand of the building.

The capacity and recovery rate should be Indicated on the nameplate mounted on

the tank. An electric heater should have a capacity half again as great as a gas fired water heater to compensate for its slower recovery rate. For either

type, check to be sure there is a pressure relief valve Installed for safety.

Advantages and Limitations

This is an inexpensive, fast method for determining in a very general way the

adequacy of the size of the water storage tanks.

REFERENCE - 19

A. 2 DRAINAGE AND VENT SYSTEMS

A. 2.1 Water Testing for Leaks

Test Method - Water Test

Subject - Drainage and Vent Systems

Parameter - Leaks

Discussion

The water test can be used to test for leaks in a drainage system. It can be

applied to the entire system or to sections. If applied to the entire system,

all openings in the piping should be tightly closed (except the highest opening)

and the system filled with water to the point of overflow. The same conditions

apply if the system is tested in sections, but no section should be tested with

less than a 10-foot head of water. The water should be kept in the system, or in the portion under test, for at least thirty minutes before inspection starts;

the system should then be tight at all points.

90
Advantages and Limitations

The water test for leak determination Is relatively Inexpensive. Leakage of

water, should a leak occur, could cause some cosmetic damage In the existing

building. Because the total drainage system seldom will be fully exposed

for easy inspection, the point(s) of leakage may be difficult to determine

accurately. The test method should indicate the general area of failure when

leakage occurs. Some exploration through the removal of building components

may be required to pinpoint the exact location and carry out repairs of the

pipe or joint. If severe leakage occurs, or leakage is In an inaccessible

location, consideration should be given to replacement of system components

or possibly the total system.

REFERENCES - 8, 9, 20

4.2.2 Air Testing for Leaks

Test Method - Air Test

Subject - Drainage and Vent Systems

Parameter - Leaks

Discussion

The air test can be used to test for leaks in a drainage or vent system; it

should only be applied to the entire system. An air compressor or other

testing apparatus Is attached to any suitable opening and all other Inlets and

outlets to the system are closed tightly. Air Is forced Into the system until

there Is a uniform gauge pressure of five psi or 10” Hg. This pressure is held

without introduction of additional air for a period of at least 15 minutes.

Any reduction in pressure indicates the presence of a leak in the pipe.

Advantages and Limitations

The air test for determining leakage is a rather simple and inexpensive test

and requires little skill. A source of compressed air and adequate controls

are required to assure safe operating conditions and to guard against over

pressurization of the system. The test procedure will give a quick indication

of system qtiallty with regard to leakage, but the source of leakage may

require additional testing (such as the soap and bubble test or listening for

escaping air at the point of leakage). It also is possible to charge the system

with gas so that leaks can be identified through the use of gas detectors.

Because most drain and vent systems are enclosed in non-accessible construction,

the source of leakage may be difficult to locate.

REFERENCES - 8, 9, 20 (See smoke or peppermint test, p. 31 of ref. 20).

91
4.2.3 Trap Tests

Test Method - Discharge Test

Subject - Drainage and Vent Systems

Parameter - Slphonage of Traps

Discussion

To test for slphonage of fixture traps, one or more fixtures should be filled

to an overflowing level and discharged, then measure the trap seal retention.

Trap seal retention should be at least 50 percent or 1 inch (25 mm), whichever

Is greater. In all traps when tested for self~slphonage or for cumulative

effects of Induced slphonage. The seals In the traps should be measured before

and after each of several repeated discharges. If excessive slphonage occurs,

the discharge pipes should be enlarged, cleaned, or otherwise modified. The

number of fixtures to be discharged simultaneously In testing for stability of

the trap seal Is dependent upon the number and type of fixtures on the drain

stack and their spatial arrangement. The discharge load can be determined

from the references listed below.

Advantages and Limitations

The Indicated procedures to determine trap seal retention have been used for

years and are a fairly good Indication of anticipated performance. Judgment

must be used In looking at alterations of existing systems which may be

required to carry unusual loading. Because of the health and safety Issue

of sewer gas emission with reduced trap seal, a conservative selection of

simultaneous loading (extra heavy load) should be chosen when future use conditions are uncertain.

REFERENCES - 10, 11, 12, 13, 14, 15, 16, 17, 18

GENERAL COMMENT

Where future stories are proposed to be added to a building, the water piping

systems should be tested to reflect the added static pressure anticipated to

be Imposed by the added height.

92
4.3 REFERENCES

1. "Basic Plumbing Code," (BPC) 1978. Building Officials and Code Administrators International, Inc., 17926 South Halsted, Homewood, Illinois 60430.

2. "National Standard Plumbing Code," (NSPC) 1978. American Society of

Plumbing-Heating-Cooling Contractors (NAPHCC) and American Society of

Plumbing Engineers (ASPE), 1015 20th Street, N.N., Washington, D.C. 20036.

3 . "Standard Plumbing Code (SPC) 1979," Southern Building Code Congress

International, Inc. (SBCC), 900 Montclair Road, Birmingham, Alabama 35213.

4. "Uniform Plumbing Code (UPC) 1976," International Association of Plumbing

and Mechanical Officials (lAPMO), 5032 Alhambra Avenue, Los Angeles,

California 90032.

5. Fala, M. J., "Principles of Residential Plumbing Inspection," 1st Edition,

American Society of Sanitary Engineering, (1973).

6. Manas, V. T., "National Plumbing Code Handbook - Standards and Design

Information," McGraw Hill Book Company, Inc.

7. "Uniform Plumbing Code - Interpretation and Inspector’s Manual," 1st Edition, International Association of Plumbing and Mechanical Officials,

(1971).

8. "Standard Plumbing Code 1979," Section 107.5a, Southern Building Code

Congress, International, Inc., 900 Montclair Road, Birmingham, AL 35213.

9. "Basic Building Code 1978," Section P-1802.5 la. Building Officials and

Code Administrators, International, Inc., 17926 South Halsted, Homewood,

IL 60430.

10. "Standard Plumbing Code 1979," Section 1602. lOe, Southern Building Code

Congress, International, Inc., 900 Montclair Road, Birmingham, AL 35213.

11. Performance Criteria Resource Document for Innovative Construction . NBSIR

77-1316, (Washington, D.C.: National Bureau of Standards, November 1977),

p. 123, 13.6.7.5, "Criterion: Hydraulic and Pneumatic Performance - DWV

Stack and Building Drain Assembly."

12. Orloski, M. J., Wyly, R. S., Hydraulic Performance of a Full-scale

Townhouse System with Reduced Sized Vents , Building Science Series BSS 60

(Washington, D.C.: National Bureau of Standards, August 1975).

13 . Konen, T. P., "The Evaluation of Several Plumbing Drainage, Waste and Vent

Systems," Report DL-74-1776, Stevens Institute of Technology, (1974).

14 . Jackson, R. , Konen, T. P., "An Investigation of the Adequacy of Performance

of Reduced-Sized Vents Installed in a Ten Story Drain, Waste and Vent

System," Stevens Institute of Technology Report SIT DL-1708, (July 1973).

93
I

15. Konen, T., "A Test Procedure for Evaluating the Capacity of the Building

Drainage Systems," Report DL-75-1841, Stevens Institute of Technology,

(1975).

16. Wyly, R. S., Rorrer, D. E., Field Test of Hydraulic Performance of a Single-Stack Drainage System at the Operation BREAKTHROUGH Prototype Site

In King County, Washington , NBSIR 73-161 dwashlngton, D.C.t National

Bureau of Standards, May 1973).

17. Maybeck, E., "Demonstration of Performance for a Solvent System Installed

at Townsend Towers Near East Side Urban Renewal Project, Syracuse, N.Y.,"

Barnard and Maybeck, Rochester, N.Y., (1972).

18. Performance Criteria Resource Document for Innovative Construction , NBSIR

77-1316 (Washington, D.C.: National Bureau of Standards, November 1977),

page 122.

19. "Home Repair and Improvement - The Old House," by the editors of Time-Life

Books, (1979).

20. "Tentative Guide Specification, Plumbing," GSA, Public Buildings Service,

Section 15410 T, pp. 30-32, (Nov. 1978).

94
5o ELECTRICAL SYSTEMS

Since taost electrical wiring is concealed inside walls, a complete inspection

of all the parts of the electrical system in a building may not be feasible.

Some general items, however, are easily checked which can aid in determining

the electric shock and fire safety aspects of the system, as well as detecting

functional and energy loss problems which may exist. Nearly all aspects of the

National Electric Code (ref. 1) in some way address the requirements for shock

and fire safety. In older buildings there are potential problems through

system overloads as new appliances and oversized fuses may be placed in the

circuits

.

The following are examples of evaluation techniques for assessing the condition

of an electrical system in an existing building. While the evaluation methods

mentioned in this section generally are recognized as being good practice, local

codes and local officials should be consulted to determine whether any specific

requirements apply to the individual geographical areas or type of building

being evaluated.

5.1 ELECTRICAL BRANCH CIRCUITS

5.1.1 Determining the Condition of the System

Test Method - visual Inspection

Subject “ Electric Branch Circuits

Parameter - Circuit Faults

Discussion

One of the best techniques available for assessing the condition of existing

electrical systems is visual inspection of the wiring system. This technique

helps to determine the condition of the insulating material and the methods

used in making connections within the circuit. When analyzing existing systems,

it is important to determine not only the condition of the system but also how

the system is used during normal operation. During inspection it is important

that the following items be noted (if they occur);

1) Overfusing ~ Check to see that the proper size fuse or circuit breaker

is used in the branch circuit. Frequently, a fuse having a greater

capacity than the original design capacity will be placed in the circuit

and will create a potential overload condition in the circuit. This

could result in ignition of material near the conductors.

2) Overlamping - Observe the wattage of lamps to determine if they are within the recommended limit. This is especially critical in confined

spaces such as recessed lighting fixtures. With oversized bulbs in

confined spaces the potential for overheating and resulting ignition

of nearby combustibles is greatly Increased.

95
3) Size and Number of Conductors - Knowing the anticipated load, it is

easy to determine If the proper size wire and fuse combination Is being

used. The National Electrical Code should be consulted to determine

If the existing circuit has the required capacity. Check for the

existence of an adequate number of circuits with the proper voltage and

current ratings for any anticipated retrofit equipment. Some common

symptoms of circuit overloading Include: (1) presence of many 20 or 30 ampere fuses; (2) the smell of burning Insulation near the panel;

(3) fuses that have glass tops that are warm; (4) discolored copper

contact points under the fuses; (5) overheating of wires as evidenced

by melted insulation, and, in extreme cases, fire around outlet boxes,

switches, etc., or wherever thermal Insulation is tightly packed

around wires; (6) fuses that blow frequently or circuit breakers that

trip frequently, and (7) presence of surface mounted lampcord extension wiring or multiple cords plugged into a single outlet.

4) Type of Conductor - Examining the conductor will indicate its type

(copper, aluminum, or copper clad aluminum), and the wiring

method (non-metallic sheathed cable, armored cable, electric metallic

tubing, rigid conduit, or flexible metal conduit).

5) Type and Condition of Insulation - Generally, the insulation around

the conductor will be either rubber or plastic. The insulation should

be physically examined to determine its brittleness. If there is any

flaking or if any of the insulation falls off when bending occurs, it

is deficient and should be replaced. An easy place to check for

deficient insulation is in the exposed areas of the basement, around

the circuit breaker or fuse box, and inside outlets or switches. Be

sure to turn the power off to the circuit before removing outlet or switch plates or before probing any wires.

6) Connectors - Check for poorly functioning connectors which could cause excessive power losses and which might be a potential source of

ignition. Power losses and low voltage can impair the functional

operation of appliances and shorten the life of critical components.

Advantages and Limitations

Visual inspection provides immediate feedback on the condition of those parts

of the electrical branch circuit that are accessible for inspection. To gain

the most benefit from visual inspection it is best to have an experienced

individual who has repaired or examined and dismantled older systems to gain

first hand knowledge of potential problem areas. Visual inspection may

detect only the most obvious defects because of the surface-only type of

evaluation. It is recommended that only experienced personnel conduct

electrical inspections.

REFERENCE - 4

96
Test Method - Megohm Test (Megger Tester)

Subject - Electric Branch Circuits

Parameter - Deteriorated Insulation

Discussion

If the insulation appears to be deteriorated (crumbling or cracking), it is

important to either replace the wiring or check the condition of the insulation

with a megohm test performed by an electrician. In this test, the wires for

each circuit are disconnected at the power supply end, and a Megger tester

applies a test voltage to the wires at the other end. Branch circuits should

read at least one megohm to ground. If lights or appliances are connected,

readings should be at least 500,000 ohms. (Feeders should be tested In

accordance with Article 110-20 of the National Electric Code). If there are any indications of shorts in the circuit, the insulation is faulty, and the

circuit wiring must be replaced.

Advantages and Limitations

This procedure for evaluating the condition of the wiring Insulation is relatively easy, fast, and inexpensive. It is recommended that only a qualified

electrician perform the test since high voltage is used and there are certain

hazards associated with the test.

REFERENCES -4,5

5.1.2 Determining Electrical System Efficiency

Test Method - Voltage Determination

Subject - Electric Branch Circuits

Parameter - Excessive Voltage Drops

Discussion

The measure of voltage drop in a branch circuit is a good indicator of

excessive Impedance (e.g., excessive length) of the circuit. Conductors in

branch circuits will provide a reasonable efficiency of operation if the

following conditions are met:

1) The voltage drop at the farthest outlet of power, heating and lighting

loads does not exceed 3 percent.

2) The maximum total voltage drop on both feeders and branch circuits to

the farthest outlet does not exceed 5 percent.

97
If voltage drops much In excess of these values occur, the circuit needs

replacement. Generally, available voltmeters can be used for making the

determination of voltage drops in the circuit.

Advantages and Limitations

The procedure for making voltage drop determinations is relatively easy and

inexpensive. The conventional, commercially available voltmeter can be used.

Measurements must be made under load with current also being measured. It is

suggested that only a qualified individual, knowledgeable of electricity and

branch circuitry, make the required measurements because of the danger of

electrical shock when untrained personnel work with these potentially dangerous

levels of electricity.

REFERENCE - 1

5.1.3 Circuit Analysis

Test Method - Circuit Analyzer

Subject - Electric Branch Circuits

Parameter - Circuit Faults

Discussion

A commercially available electrical device has been developed for analyzing

potentially hazardous circuits. The analyzer is designed to determine various

faults in existing wiring systems. It is Intended for testing newly wired

circuits, but also may be useful in assessing the proper performance of existing

systems. The circuit analyzer is said to be capable of checking the following

circuit conditions:

1) open ground

2) open hot

3) open neutral

4) hot/ground reversed

5) hot /neutral reversed

Depending on the type of analyzer, one or more test lights will be activated

if the outlet is functioning and safely grounded. If ungrounded outlets are discovered, they should be grounded by installing a ground wire (this is

especially important in kitchens and bathrooms). The manufacturer’s instructions for the particular receptacle analyzer being used should be consulted

for the detailed meaning of the lighter indicators. The analyzer can be used on old two-wire circuits with a special adapter.

98
Advantages and Limitations

Measurements obtained through the use of the circuit analyzer Indicate only

design or operating faults such as improper connections. This method of analysis will not help determine the condition of materials which make up the branch

circuit. The technique is simple and quick, and the analyzer is commercially

available.

REFERENCE - 2

5.2 ELECTRICAL CIRCUITS

Test Method - Circuit Breaker and Resistance Tester

Subject - Electric Circuits

Parameter - Condition of Circuit Breakers

Discussion

A commercially available Circuit Breaker and Resistance Tester is claimed to

provide the capability of evaluating circuit breakers by simulating an overload

condition and proof testing the circuit breaker. A component of the Test Set

allows evaluation of resistance of motor windings and other insulation

resistance in the range from 1 megohm to 1000 megohms. The current is limited

to five milllamperes short circuit current for maximum safety. The Test Set

provides for quick assessment of the condition of electric circuit breakers to

make sure that they operate in the intended range for overload protection. The

resistance tester is intended to Indicate potential problem areas relative to

breakdown in electrical resistance of insulating materials.

Advantages and Limitations

Testing of the circuit breakers requires that the circuit breaker be removed

from the panel. Because of potential danger in working with electric circuits

a qualified electrician should be engaged to conduct the tests. In older

buildings which may not have a master disconnect, the utility company may be

required to cut off service to the building during the removal of the circuit

breaker.

REFERENCE - 3

99
REFERENCES

"National Electrical Code 1978," Paragraph 210-19, Conductors - Minumum

Capacity and Size, National Fire Protection Association, 470 Atlantic

Avenue, Boston, Massachusetts 02210.

AMP, Incorporated, Harrisburg, Pennsylvania.

Multi-Amp Corporation, Dallas, Texas 75237.

"Home and Improvement - The Old House," by the editors of Time-Life Books,

1979.

"Inspection Guide, Electrical Systems," GSA, Public Buildings Service, PBS

P 3480.2, Section 1605.

"Draft Rehabilitation Guidelines," Department of Housing and Urban

Development, Federal Register Volume 44 - No. 215, Book 2: Rogers 63759,

November 5, 1979.
r<OS-ll4A (Kb.V. W-/b>

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 80-217.1 F

4. TITLE AND SUBTITLE

Selected Methods for Condition Assessment of Structural,

HVAC, Plumbing, & Electrical Systems in Existing Buildings.

7. AUTHOR(S)

Frank H, Lerchen, James H, Pielert. Thomas K. Faison

9. PERFORMING ORGANIZATION NAME AND ADDRESS

Z. Accession No,

5. Publication Date December 1980

8. Performing Organ. Report No.

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON. DC 20234

- iifi.i&i 11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS rsrreer. City, st^te. ZIP)

Department of Housing and Urban Development

451 7th Street, S.W.

Washington, D.C. 20410

13. Type of Report & Period Covered NBSIR/Final

15. SUPPLEMENTARY NOTES

I I Document describes a computer program; SF-185, FIPS Softw/are Summary, is attached.

16. ABSTRACT (A 200-word or leas factual aummary of moat aignificant information. If document includes a significant bibliography or

literature survey, mention it here.) This report was developed with the intent of assisting government officials,

designers, builders, code officials, and others involved with making technical

decisions relative to building rehabilitation to evaluate the condition of

existing buildings.

The report describes evaluation methods available specifically for use with the

structural material^ of concrete, steel, masonry, and wood, as well as, for use

with the supportive systems of heating/ventilating/air conditioning, plumbing.,,

and electrical. Both commonly used methods and other possible (but more technically complex) laboratory methods are described for the reader. Comparative

tables are provided, where possible, to aid the reader in making a quick selection of the evaluation method most appropriate for the particular parameter to

be tested. Considerably more information is included in the area of structural

systems than in the rest of the report because of the fact that this report

supplements a previous effort to develop a technical manual on structural

strength for rehabilitation of existing buildings.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the firat key word unless a proper name;

separated by semicolons)

Building rehabilitation; concrete; electrical; evaluation; HVAC;

masonry; plumbing; steel; structural systems; test methods; wood.

18. AVAILABILITY Unliitiited

[Xl For Official Distribution. Do Not Release to NTIS

r~| Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

I I Order From National Technical Information Service (NT!S), Springfield,

VA. 22161

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF

PRINTED PAGES

22. Price

USCOMM-DC
’ ‘K , . /

• *» I - . 44M03%9.r^9<i^,

1 : -oi SfcS^ *»•«

ii&-

, SjTRTpua j^.rriT > .

'Vli^ Jimt yreamn^ '

_

,.irt4 ‘ f » ew.au<itflct Hiiiftmt

^T'i<#»'tf 022|Q'^

moA <m #air^WA0f<' t>

‘^e»4«

, . . %^%P*• iOil*;llI»WkTf ^eUAtJIttf J^r,Wr*H ^

^ jL*>n'ntM0') *e^ t»*4, ti4i»a *

^ , v,im *r>.a

l*8t»fe«c >*)» ’ rft ^^au-r '^4 j#i'^»v'.- - ..:i']''^i

'''

;,.^ .’^ »i S <Vlt|!|!>K SHft

' ''^^'^JmL' 3»-

^ -B' '*8 •' • a^K ,S3f*^3 :«fe^^Mii; Mwwinao) i iirfh;wl^ v

) tCt'MMM taMfftOf «mi .'1)4'

,»i4*JC5li3'v W.I iii'J 4ait b*ti<aXwii a.l ^ ^

io uel.Tii>i.^^ r<\^' $titiiJtud o3 »v» |«iir 5«ij

'•.-3!^/ i. .;« .. ^'t. ^

•« Hgft' ,V)' j.»v #t tvtcti . .'icjoaiusi ,;»> )a ,»s«1£M30C' 3© aijUtt-U/wli

<#>»**]) »•*'•.**» bis oj

.V-ruJ-wvm ?it «(«4t Wts'.i?*

iV'sr^i 'M-wiUjijMl

'rti «.»*i3

i.-»i.vioT.f .? 4:^ i<,*jr»«« »»altt4a«3 -a ^l»v#fe »^f w0:» a^^wnif a

-•^5 ' To flai34 tJti4:<DM<at

•’

, .' a VA,' T ' in

.5 7

' /lablsj^wila

t (galfpioa .^Ifajiitl

-^r:} },

-Kf‘* *BfW<*1. i>» '**A tV •'•W “'*•*• <*%Ii».«* b>

^

I

'

' i-jV 4II

' '

. •-I‘'*lw;t’l** * ,,ov4»a»i ;Uai!’7^<a>4/’r ;aJ4x#o^ ;aat»a3t’tJtiA<ia» x.TJfci/'ua;

: :'1>A,. .>itl

«?

;W"'S (fw«*^*qIT5^' vrif,'

pI£

j -3

A<r4i>» $wMm fiH oO 3!t\f

f •'*.MW^i49>&t0f if Mvmn\~r, ^ X,U

,'3 ^'- r'y‘;‘r^

ll.ik^Hyll«'^ OiiMI) >i»f *0 <7 1 ' ‘5I

it

ii j

'i»f *0

'

1' ' .1 MaiiJ "f