Building Technology Project

Summaries 1987

Noel J. Raufaste

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

May 1987

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

Research Information Center

-National Bureau of Standards

Gaithersburg, Maryland 20899

NBSIR 87-3565

BUILDING TECHNOLOGY PROJECT

SUMMARIES 1987

Noel J. Raufaste

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Gaithersburg, MD 20899

May 1987

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

FOREWORD

The building research program of the National Bureau of Standards, the Nation's

central engineering measurement laboratory, is conducted by its Center for

Building Technology (CBT) . CBT works cooperatively with other organizations,

private and public, to improve building practices. It conducts laboratory,

field, and analytical research. It develops technologies to predict, measure,

and test the performance of building materials, components, systems, and practices. This knowledge is required for responsible and cost-effective decisions

in the building process and cannot be obtained through proprietary research and

development. CBT provides technologies needed by the building community to

achieve the benefits of advanced computation and automation. CBT does not

promulgate building standards or regulations , but its technologies are widely

used in the building industry and adopted by governmental and private

organizations that have standards and codes responsibilities.

Construction is one of the Nation's largest industries. In 1986, new

construction put in place amounted to $375 billion, about 8.9 percent of the

Gross National Product. Over two-thirds of the Nation's fixed reproducible

wealth is invested in constructed facilities that shelter and support most

human activities.

CBT research provides knowledge for decision making. This knowledge includes

characterization of the environments in which buildings must operate (such as wind loadings), characterization and definition of the performance of buildings, components, and systems (such as the mechanisms for heat loss through a window or wall cladding element) , and methods of testing for performance

qualities that will apply equitably to a whole family of potentially

competitive proprietary materials and components

The CBT staff of 130 includes 84 professionals, of whom 30 are registered

professional engineers and 44 hold doctorates. The principal disciplines are structural, materials, mechanical engineering, physics, and chemistry.

Among the variety of special facilities and equipment at CBT are a large -sale

testing facility including a reaction buttress 45 feet high with a lateral

force capacity of 1.2 million pounds in conjunction with the universal testing

machine of 12 -million-pound capacity is capable of testing structural

components 60 feet in height; a tri-directional structural testing facility

with its associated computer control data acquisition and processing equipment

capable of applying forces of displacements in three directions simultaneously

to full-scale structural components and systems; seven environmental chambers,

including a 30x40x50- ft chamber, for developing thermal performance modeling

techniques required to predict human comfort and energy efficiency of

buildings; a guarded hot-plate that measures insulation performance of

thicknesses up to 15 inches; a calibrated hot-box to provide precise

measurements of heat and moisture transfer in full-scale building wall and roof

sections; a five-story plumbing research laboratory with high-speed computer

data acquisition system to study the performance of water supply and drainage

systems; daylighting laboratories; an illumination color laboratory capable of

presenting eight light sources independently; an outdoor solar-collector testmethod for development area, including a passive solar test house and

facilities for experimental solar heating and cooling systems; a network of

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outdoor material exposure sites; materials reference laboratories include the

Cement and Concrete Reference Laboratory sponsored by the American Society for

Testing and Materials and the AASHTO Materials Reference Laboratory sponsored

by the American Association of State Highways and Transportation Officials; and

a well equiped materials research laboratory with a scanning electron

microscope and many other instruments for materials characterization.

This report summarizes CBT's research for 1987, and is arranged according to

CBT's research programs. Each summary lists the project title, its activities,

point of contact in CBT, and sponsor.

*

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CONTENTS

Page

Foreword iii

Computer Integrated Construction 1

Expert System for Durable Concrete 2

Expert Systems for Air Infiltration Prediction and Control

in Buildings 3

Information Exchange Technologies in the Building Process 4

Knowledge Representation and Use in the Building Process 5

Assessment of Robotics for Improved Building Operation

and Maintenance 6

Economic Methods for Building Standards 7

Structural Performance 8

Structural Assessment of the U.S. Office Building in Moscow 9

NDT Methods for Concrete 10

Structural/Mechanical Design Criteria for Low Impact

Resistant Structures (LIRS) 11

Flow- Induced Vibrations of Bluff Bodies 12

Assessment of the Uncertainties and Risks Associated

with the Dynamic Behavior of Compliant Offshore Structures 13

Punching Shear Study of Reinforced Shell 13

Dynamic Characterization of Structural Networks 14

Strengthening Methodologies for Structural Members .... 15

Spread Footings for Highway Bridges 16

Reliability of Wood Structures 17

Pulse Probing and Deconvolution in the Dynamic

Characterization of Structural Networks 17

Earthquake Engineering 18

Technical Assistance and Engineering Expertise for

Seismic Construction Activities 19

Inelastic Performance of Steel Braced Frame Connections 20

Large-Scale Bridge Columns Subjected to Reversed

Cycling Loading 21

Cyclic Loading of Masonry Building Components 22

Secretariat for U.S. Side UJNR Panel on Wind and Seismic

Effects 23

Heat Transfer 24

Development of a High-Temperature Standard Reference Material 25

Experimental Evaluation of Dynamic Test Procedures 26

Thermal and Environmental Evaluation of Advanced

Technology Office Buildings -Phase II 28

Heat Loss Calculation Procedures for Shallow Trench

Heat Distribution Systems 30

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Page

Mathematical Model for Predicting Combined Flow of Heat

and Moisture 31

Indoor Air Quality 32

Measuring and Predicting Indoor Air Quality in an Office

Building 33

Infiltration/Ventilation in Large Buildings 34

Indoor Air Pollution Concentration Model 35

Micro -Modeling of Contaminant Concentration in a Space 35

Methods for Measuring the Efficiency of Devices for

Removing Gaseous Contaminants from Air Streams 36

Characterization of Volatile Organic Chemical Emissions

from Products Used in Buildings 37

Mechanical Systems and Controls ; 38

Building Operations and Controls Laboratory and Integrated

Building Services 39

Building/HVAC/Controls Dynamic Modeling 40

Thermal Modeling of Buildings 41

Inspection and Testing Procedures for Commissioning

HVAC Equipment and Systems 42

Thermal Analysis for Radiant Panel Systems in New/Renovated

VA Facilities 43

Advanced Building System Simulation * 43

Refrigerant Mixtures 44

Measurements of Modified HP Cycles Using Nonazeotropic

Mixtures 45

Non-Azeotropic Mixture Refrigerants for Heat Pumps . » 46

Two Phase Flow of Refrigerant Mixtures 47

Nonazeotropic Refrigerant Mixture Property Evaluation 48

Test Procedures for Major Energy Appliances 49

Furnaces, Boilers and Household Heater Test Procedures 50

Water Heat Test Procedures 51

Heat Pump and Air Conditioner Test Procedures 52

Refrigerators, Refrigerator-Freezers and Freezers 52

Lighting Research 53

Lighting/HVAC Interaction Computer Modeling 54

Lighting Environment Assessment 55

Interaction Between Lighting and HVAC Systems 56

Metamerism and Features of Secure Documents 57

Building Environment Impact on Office Productivity 58

Measurement of Luminous Backgrounds ; . 59

Sky Luminance Distribution 59

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Page

Building Security 60

Guidelines and Test Methods for Building Materials and

Equipment Used in Correctional Facilities 61

Coatings 62

Quantitative Characterization of Building Materials Surfaces

by Computer Image Processing 63

Organic Coatings 64

Performance Tests and Criteria for Coatings 64

Degradation of Organic Protective Coatings 65

Bond Strength of Organic Films on Metals During Service Using

Reflection/Absorption Fourier Transform Infrared Spectroscopy • • • • 65

Volatile Organic Content (VOC) . . • • 66

Test Method for Friability of Sprayed Fireproofing and

Insulating Materials 67

Roofing Systems 68

Quality Assurance of USPS Roofing Systems 69

Criteria for Modified Bitumen Roofing Membrane Materials • 69

Service Life of Single -Ply Roofing Membranes . . 70

Assessment of Exterior Condition of Metal Buildings

and Roofing Systems 71

Factors Affecting Initial Bond of Seams in Single-Ply

Rubber Membranes 71

Quality Assurance of DoD Roofing Systems 72

Concrete 73

Polymer Concrete Set Time 74

Influence of Interfacial Microstructure on Bonding in Concrete .... 75

Representation of Concrete Microstructure 75

Ultra-High Strength Concrete 76

Minimum Strength Levels for the Bond of Repair Materials

to Existing Concrete Pavements 77

Cement Hydration (Competence Project) :• 78

Quality Assurance of Laboratories 79

AASHTO Materials Reference Laboratory (AMRL) 80

Cement and Concrete Reference Laboratory (CCRL) 80

Calibration of Pavement Roughness Measuring Devices 81

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1 .&;' . . . .
COMPUTER INTEGRATED CONSTRUCTION
EXPERT SYSTEM FOR DURABLE CONCRETE

James R. Clifton, Building Materials Division, (301) 975-6707

Sponsor: National Bureau of Standards

The projects' objectives are to develop a prototype expert system to select

constituents for concrete (subjected to a broad range of service conditions)

and to document the development of the expert system which will help develop

other expert systems.

Expert systems can assist in decisionmaking for selection of construction

materials . They should give recommendations at or near the level of human

experts, thus facilitating and improving the selection process. Concrete was

selected for developing a prototype expert system because it is the most

widely-used man-made construction material and the knowledge for making durable

concrete is not easily accessible to all.

This project collaborative with several CBT groups and the professional

community. The ACI Guide to Durable Concrete, developed by ACI Committee 201

on Durable Concrete, is the prime source for the factual portion of the

knowledge base. An ACI subcommittee reviewed CBT's expert system and recommended improvements to the knowledge base. Other ACI documents have been used

to develop the knowledge base, e.g., guidelines on Corrosion of Metals in

Concrete and on Cements . The expert system will be submitted to ACI Committee

201 for consideration as a possible supplement to, or replacement for, the

Guide to Durable Concrete.

2
EXPERT SYSTEMS FOR AIR INFILTRATION PREDICTION AND CONTROL IN BUILDINGS

Andrew Persily, Building Environment Division, (301) 975-6418

Sponsor: National Bureau of Standards

This research focuses on developing an expert system for air leakage diagnosis

and infiltration characterization in residential buildings.

There are no adequate procedures to characterize building air movement,

diagnose air leakage problems, or determine appropriate retrofit procedures and

their effects. Predictive models of infiltration have been developed, but the

models require detailed descriptions of the building leakage characteristics

and other generally unknown information.

During FY87, CBT will further develop the prototype expert system produced in

FY86 for characterizing air infiltration and air infiltration related problems

in residential buildings. The FY86 prototype has concentrated on the diagnosis

of moisture related air leakage problems with additional considerations

regarding infiltration prediction and retrofit planning. The final system is

intended to use available information on the building and yield its infiltration rates as a function of weather conditions, identify heat loss, condensation, and indoor air quality, and recommend appropriate retrofit procedures and

anticipate their effects. The system will employ an existing predictive model

of air infiltration and a knowledge base of building construction details , a database of building component leakage characteristics, and a set of heuristic

rules

The FY87 effort will evaluate last years prototype system. The system will be

examined from a knowledge engineer's point of view to evaluate the

appropriateness of the production rule approach. Based on the results of this

evaluation, the prototype will be modified into a more correct and appropriate

form.

This effort also will expand the prototype to air leakage problems beyond the

current emphasis on moisture issues, including indoor air quality, heat

loss/gain, and thermal comfort. As the system is revised and expanded, the

process of evaluation by various domain experts will continue.

3
INFORMATION EXCHANGE TECHNOLOGIES IN THE BUILDING PROCESS

Kent A. Reed, Building Environment Division, (301) 975-5852

Sponsor: National Bureau of Standards

The aim of this project is to develop the technical basis for correct and

efficient information exchange standards for the building industry.

The many participants of the building process continue to be plagued with the

errors and inefficiencies that occur because information is not available when

needed, is incorrectly transferred, or is incorrectly interpreted. Rational

techniques are needed for developing and testing information exchange standards

if computer integration of the building process is to be achieved.

CBT will continue to serve as cochairman of the Architecture, Engineering and

Construction (AEC) Committee of the Initial Graphics Exchange Specifications

(IGES) Organization. CBT will work closely with the AEC Committee members to

define AEC- subsets of IGES entities and develop requirements for AEC -oriented

test cases. CBT will create test cases and organize an IGES-vendor round-robin

activity in which the current CAD-data exchange capability in the AEC- industry

will be demonstrated quantitatively. The results will be analyzed and

evaluation criteria will be proposed for consideration by the IGES Testing

Methodology Committee.

The building data protocols research will be extended. This research resulted

in the definition of the Modular Semantic -Application Layer Protocol (MS -ALP)

in FY86. An intelligent agent that simulates next- generation computer aided

design software will be developed using the Automated Reasoning Tool (ART) and

linked to the existing test programs that form the experimental test bed for

MS -ALP. The prototype semantic model for building information will be extended

and the protocol will be exercised and refined. Close coordination will be

maintained with the IGES Organization and with the ongoing activity of the

Committee on Advanced Technology for Building Design and Engineering formed by

the Building Research Board/NRC.

4
KNOWLEDGE REPRESENTATION AND USE IN THE BUILDING PROCESS

Kent A. Reed, Building Environment Division, (301) 975-5852

Sponsor: National Bureau of Standards

The purpose of the project is to develop principles for correct and efficient

representation and use of domain knowledge in computer-aided design,

construction and operation of buildings.

Construction projects in the building industry must deal with domain knowledge

in many forms . The representation of engineering data is reasonably well

understood, but the problems of representing and using other knowledge such as the intents of the participants, accepted practices, and the explicit and

implicit constraints imposed by building standards and codes are just now being

understood.

CBT, in cooperation with Carnegie -Mellon University (CMU) and the University of

Illinois (UI) , has developed systematic methods for representing and analyzing

construction standards, codes and specifications; for expressing their requirements in computer -usable form; and for interfacing them to computer-aided

design programs. This work has culminated in two software systems. The

Standards Analysis Synthesis and Expression (SASE) software system provides

standards -writers with an integrated set of tools for constructing, testing

decision tables, developing information networks, constructing and manipulating

classifier trees, and for developing scopelists, indices, and outlines. The

Standards Interface for Computer-Aided Design (SICAD) software system is an

experimental test bed that demonstrates how elements in a CAD -database can be

checked for compliance with the provisions of a standard when it is expressed

as an extended SASE-model.

During FY87, CBT will work with the Civil Engineering Department of CMU to

explore the use of logic programming techniques to replicate and extend the

core representation and analysis functions of SASE. CBT will complete development of a code checker program based on SICAD and the ACI-318 Building Code for

Reinforced Concrete Structures. Also working with the Civil Engineering

Department of UI , new principles for SICAD will be developed which resolve the

currently recognized problems with multiple databases and semantic

interpretations

5
ASSESSMENT OF ROBOTICS FOR IMPROVED BUILDING OPERATION AND MAINTENANCE

James E. Hill, Building Environment Division, (301) 975-5851

Sponsor: General Services Administration

The project's objective is to assess the potential for robotics in daily

operation and maintenance of GSA buildings and to develop guidelines and

performance criteria for the application of robotic devices to insure safe and

reliable operation within a building.

GSA is interested in potential applications of robotics for operation and

maintenance functions such as window cleaning, floor cleaning, trash compacting, and miscellaneous materials handling. Some of the robotics devices under

development have potential for use in these applications.

CBT will make a comprehensive assessment of the possible application of robotic

devices to a variety of building operation and maintenance functions . The

assessment will include a state-of-the-art survey of robot technology with

potential use in building operation and maintenance. The assessment will

include an analysis of operation and maintenance functions in building identifying those that are potentially promising for robotic application. The most

promising ones will be where the work must be done in dangerous or hazardous

conditions (e.g., window cleaning on the exterior of multi-story buildings),

where the environment is very structured and the tasks are repetitive and/or

where high quality and high skill levels are required and skilled workers are in short supply.

Potential barriers to the use of robotics within the buildings will be

determined. Recommendations will be made for changes in GSA practices so that

GSA can take advantage of the robotics age. A procedure for implementing

robotic use for selected applications will be developed.

6
ECONOMIC METHODS FOR BUILDING STANDARDS

Harold E. Marshall, Center for Applied Mathematics, (301) 975-6131

Sponsor: National Bureau of Standards

The building community needs sophisticated, practical methods and guidelines to

consistently evaluate alternative building technologies. The need for standardized, improved methods, and guidelines to help the building community

achieve affordable buildings that meet performance objectives stems in large

part from the rising costs of building materials, the high costs of construction due to safety/environmental regulations , the alleged decline in

construction productivity, and the uncertain costs of energy.

Economic methods and supporting analyses will be developed for application to

building problems. A special publication on handling risk and uncertainty in

the economic evaluation of buildings will be submitted to ASTM for use in the

development of a standard. The existing standard economic methods, including

the life -cycle cost, net benefits, internal rate of return, and savings -to

investment and benefit-cost ratio methods will be revised. This work provides

an integrated ASTM and NBS approach, resulting standards are formatted so consensus can be reached by ASTM.

The building community will benefit from building economics methods developed

at NBS and adopted as recommended practices through the ASTM process by

achieving target levels of building performance with lower life -cycle building

costs

7
STRUCTURAL PERFORMANCE

8
STRUCTURAL ASSESSMENT OF THE U.S. OFFICE BUILDING IN MOSCOW

Nicholas J. Carino, Structures Division, (301) 975-6063

Sponsor: Department of State, Office of Foreign Buildings

This effort focuses on conducting an analysis of the U.S. Office Building in

Moscow and providing recommendations and cost estimates for correcting any

structural flaws and construction defects.

In 1969, an agreement was signed between the U.S. and the Soviet Union to

construct new embassies in their respective countries. Construction of the

U.S. embassy in Moscow began in 1979, and built according to Soviet plans. The

building design is a mixed structural system of precast concrete and steel

members. Originally scheduled for completion in 1982, the project experienced

delays and increasing costs. In an effort to address the difficulties in

completing the project, Congress passed an amendment to the Continuing

Appropriations Act for Fiscal Year 1987.. The amendment authorizes NBS to

conduct an independent analysis of the office building. The analysis is to

include "an assessment of the current structure, recommendations, and cost

estimates for correcting any structural flaws or construction defects."

The investigation consists of four phases. The first phase is an assessment of

the building as defined by the contract documents. Potential failure

mechanisms will be identified, critical loading conditions will be considered

for each failure mechanism, and the distribution of forces will be determined.

The strength of the Soviet building components and their connections, as described in the contract documents, will be determined according to accepted

engineering practice, supplemented with available test data. Structural

integrity of the designed structure will be assessed for consistency with

accepted U.S. standards and practices.

The second phase will establish the as-built condition of the structure. Site

data for the project will be reviewed. NBS will perform a field investigation.

Representative samples will be secured to establish in-place material

strengths. Key structural components and connections will be examined using

available test methods. The non- structural system (roofing, brick facade,

glazing) will be investigated.

In the third phase, the structural integrity of the as -built structure will be

assessed. Attention will be given to the effects of flaws on the strength of

members and connections. Laboratory and analytical studies aimed at assessing

the influence of the flaws will be conducted as required. Based on a review of

design details, the materials used, and the workmanship, the ability of the

building envelope to function as intended will be assessed.

The final phase will involve recommendations for remedial measures that may be

required to provide the necessary structural integrity for members or connections , or to ensure performance of the envelope

9
NDT METHODS FOR CONCRETE

Nicholas J. Carino, Structures Division, (301) 975-6063

Sponsor: National Bureau of Standards

The objective of this research is to gain a fundamental understanding of the

interaction of stress waves with internal discontinuities in concrete structures and to develop test methods and proposed standards that use the impact

echo technique for nondestructive evaluation of internal condition of existing

concrete structures.

There is no satisfactory method for locating internal defects in concrete

structures. The impact-echo methods has the potential to fill this need. A

fundamental understanding of stress wave propagation through a heterogeneous

material, such as concrete must be developed.

The feasibility of the impact- echo method has been demonstrated under

laboratory conditions using controlled- flaw specimens. Dynamic finite element

analyses of plates containing disk- shaped flaws have been completed, and a field test system is under development. The FY87 research will evaluate the

performance of the technique for locating two common types of flaws in con- crete: honeycombing and delaminations in concrete slabs overlaid with asphalt

concrete. Analytical and experimental studies will be performed. In addition,

new experiments will be performed to verify preliminary successful results in

determining the depth of a simulated surface opening crack and detecting

ungrouted tendon ducts. Work on this project includes a cooperative effort

with NBS's Automated Production Metrology Division.

10
STRUCTURAL/MECHANICAL DESIGN CRITERIA FOR LOW IMPACT RESISTANT STRUCTURES

(LIRS)

Richard D. Marshall, Structures Division, (301) 975-6071

Sponsor: Federal Aviation Administration

This project will provide the FAA with test data, design criteria, and

analytical models to predict the response of low impact resistant structures to

aircraft impact.

The potential hazard of an aircraft colliding with approach lighting structures

during landing or take off operations has led FAA to investigate the

possibility of developing structural systems with low impact resistance. The

goal of designing low impact resistance structures (LIRS) is to impart minimum

damage to an aircraft in the event of an accidental collision. "Break- away"

mechanisms implemented in structural systems have been considered by FAA to

fulfill the goal. To ensure the effectiveness of such a system, the investigation of impact characteristics of structural systems, including components such

as the electrical conductors and the development of analytical models for

simulating impact phenomenon are needed.

The research consists of three separate activities. Activity one is to

investigate the behavior of electrical conductors by performing static and

dynamic pull tests on conductors of the type used for approach lighting LIRS.

Activity two involves the assessment of design loads and the analysis, erection, and testing of an antenna support structure. Activity three will be

devoted to development and validation of analytical models for predicting the

response of LIRS subjected to aircraft impact.

11
FLOW- INDUCED VIBRATIONS OF BLUFF BODIES

Richard D. Marshall, Structures Division, (301) 975-6071

Sponsor: National Bureau of Standards

This project will center on obtaining a basic understanding of the mechanisms

involved in the aerodynamic excitation of bluff bodies and the response of taut

strip models.

The taut strip model is simple and has ability to accommodate multiple modes of

vibration. It is an attractive alternative to other complex and expensive

models to study wind- induced structural vibrations. Recent wind tunnel studies

of taut strip models of rectangular cross-section and width to depth ratios

typical of engineering structures have shown that instabilities due to torsional flutter, galloping and vortex shedding are possible. Using carefully

conducted experiments on a series of rectangular prisms, the basic mechanisms

of excitation can be isolated. These experiments are needed to test existing

theories of flow induced vibration and to establish the validity of taut strip

models. The aerodynamic instabilities of the type to be studied in this

project include cases of instability referred to as "strange attractors". The

resulting body motions, although having the appearance of being random, are actually deterministic and are referred to generally as "chaotic" motions.

A series of rigid, spring-mounted, rectangular prisms will be tested in the NBS

Calibration Wind Tunnel. Emphasis will be placed on cross-sections having

width to height ratios in the range 0.5 to 4. Companion studies using taut

strip models covering the same range of width to height ratios will be con- ducted and observed instability boundaries will be compared with theoretical

predictions. The main thrust of the approach addresses excitation mechanisms

in smooth flow; the modifying influence of incident turbulence will be explored

as time permits.

12
ASSESSMENT OF THE UNCERTAINTIES AND RISKS ASSOCIATED WITH THE DYNAMIC BEHAVIOR

OF COMPLIANT OFFSHORE STRUCTURES

Emil Simiu, Structures Division, (301) 975-6076

Sponsor: Minerals Management Service

The purpose of this project is to study various aspects of the dynamic behavior

of compliant structures for identifying and reducing uncertainties and risks

associated with such behavior.

Compliant offshore structures are increasingly being used in various

applications, particularly in deep waters. Their hydrodynamic, dynamic and

structural behavior is complex, and little if any experience is available to

draw upon in evaluating their performance from a safety point of view.

This research includes an investigation on the effect of structural

amplification of wind- induced dynamic motions on response of compliant offshore

structures, and an investigation of the effect of Lighthill's nonlinear

potential flow term on estimation of offshore structure hydrodynamic dampling.

Consultations are maintained with the American Bureau of Shipping Det Norske

Veritas, Department of Navy, and other agencies with an interest in risk

assessment applied to compliant offshore structures.

This work will be used by MMS to establish research needs about the reliability

of compliant offshore structures and to verify reliability approaches implicit

in the design of such structures. The research will assist MMS in ensuring

acceptable risks to the public as far as the safe operation of compliant

offshore structures is concerned.

PUNCHING SHEAR STUDY OF REINFORCED SHELL

H. S. Lew, Structures Division, (301) 975-6061

Sponsors: Minerals Management Service, Department of the Interior and the

Oil Industry

The objective of the project is to develop a rational criteria for the design

of thick and heavily reinforced concrete shells, particularly of lightweight

concrete subjected to high intensity concentrated loads in the range of 100

tons/sq. ft. (10 MPa).

The performance of concrete shell elements subjected to high local forces will

be studied. The behavior of shell and plate elements will be evaluated using

small scale physical models. Tests will be made on 1/6 -scale and 1/3 -scale

models to study the size effects. The experimental program will be supplemented with analytical studies to predict the expected performance of the test

specimens. The analytical models will be simulate the multi-axial stress

states within thick members and will incorporate nonlinear material behavior.

The results of this study will be used to develop safety standards for the

Mineral Management Service and will serve as guidelines for design of thick

concrete shells.

13
DYNAMIC CHARACTERIZATION OF STRUCTURAL NETWORKS

Emil Simiu, Structures Division, (301) 975-6076

Sponsor: National Bureau of Standards

Structural systems are continually being developed which the dynamic response

must be determined with high accuracy up to frequency components of thousands

of Hertz. Such systems, which include orbiting space structures, typically

consist of networks with relatively simple topologies and with elements that

are relatively long compared with typical wavelengths of traveling disturbances. Recently, mathematics suggested that it is advantageous to characterize such systems dynamically by Greens function (the responses of the

various coordinates to unit impulse excitations). In practice, it is necessary

to evaluate Green's function experimentally for the actual structure, rather

than analytically for an idealized model. Work is aimed at developing computational and experimental capabilities allowing highly accurate identification of

dynamic response characteristics of structures of the type described above.

These capabilities will be based on recent mathematical research resulting in

the development of pulses of the inverse Gaussian type and generalizations

which allow the systematic and accurate solution of the inverse problem

described above. Numerical experiments will be conducted to assess the

accuracy with which it is possible to recover the exact Green's functions by

deconvolution of responses contaminated by noise. The research will be

conducted over a period of two to three years in collaboration with the Center

for Applied Mathematics.

A parallel effort will aim at the development of a testing capability

consisting of computer -driven rapid-acceleration actuators which reproduce the

requisite pulses to within the accuracy needed, and of devices for the synchronized measurement of the corresponding dynamic response.

The research will provide a useful application to structural engineering

technologies of mathematics, structural dynamics, and measurement sciences. It

will contribute to improved reliability of structural systems developed for

defense, communications, and industrial purposes.

14
STRENGTHENING METHODOLOGIES FOR STRUCTURAL MEMBERS

H. S. Lew, Structures Division, (301) 975-6061

Sponsor: National Bureau of Standards

This research will develop efficient methods to strengthen existing structural

members for vertical and lateral loads

Recently, an increasing number of old structures have been strengthened to the

levels of performance required by current codes and standards. There are no standard methods for strengthening structural members. This research will

evaluate the effectiveness of strengthening methodologies based on analytical

and experimental studies.

This multi-year effort will evaluate the effectiveness of various strengthening

methods for beams, columns, connections, and shear walls. The first year

effort includes establishing the research agenda and conducting exploratory

laboratory tests.

During FY87, an experimental study of the behavior of several strengthening

methods for compression members will be performed. The selection of specific

strengthening methods for experimental study will be guided by the results of

computer simulations.

15
SPREAD FOOTINGS FOR HIGHWAY BRIDGES

Felix Y. Yokel, Structures Division, (301) 975-6065

Sponsor: Federal Highway Administration

The objective of this project is to develop a comprehensive design procedure

and a draft standard for shallow foundations.

Two design limit states govern the geotechnical aspects of the design of

shallow foundations: (1) shear failure in the supporting soil leading to

rotation, sliding, or plunging of the footing; (2) excessive displacements

leading to failure or distress in the supported structure, pavement failures,

or alignment and drainage problems.

Data on settlement and structural tolerance to settlements, collected by FHWA,

and other available data will be carefully evaluated to determine the accuracy

and degree of reliability with which foundation displacements and displacement

tolerances of the superstructure can be quantified. As appropriate, stochastic

models will be developed from the data to facilitate the determination of the

reliability of predictions that can be made on the basis of available data.

Analytical methods of settlement prediction on the basis of data from in- situ

and laboratory measurements will be calibrated against the available data.

This information will be used to develop appropriate design procedures for

incorporation in a proposed design manual and draft standard.

The design manuals will be based on the principle of limit state design and

will contain quantitative criteria for allowable displacements for the characteristics of the superstructure and analytical approaches to settlement

prediction, tied to present methods of in-situ and laboratory soil exploration.

16
RELIABILITY OF WOOD STRUCTURES

Erik Henrickson, Structures Division, (301) 975-6067

Sponsor: National Bureau of Standards

The project will develop resistance criteria for probability-based limit states

design of engineered wood structures taking into account the statistical

variation in wood strength, the stochastic nature of loads, and the creep

rupture behavior in wood.

Structural codes governing the design of engineered wood structures do not

include probability-based limit states design. Probabilistic approaches to

wood design are complicated because wood is a natural material with large

variabilities in its mechanical properties and because wood strength is

strongly dependent on load rate and load duration effects.

The research is directed toward developing probabilistic design criteria for

engineered glulam and heavy timber structural elements. Statistical descriptions of the strength of wood will be determined using data from the in- grade

testing program and from other published sources. Load process models for wind

and earthquakes will be constructed using statistical data. Reliability

analysis methods developed at NBS that account for the effect of load duration

on wood members will be used to estimated limit state failure probabilities for

members subjected to wind and earthquake loads. This effort will be

coordinated with the ASCE Task Committee for LRFD for wood to prepare

recommendations for probability-based design for wood structures.

PULSE PROBING AND DECONVOLUTION IN THE DYNAMIC CHARACTERIZATION OF STRUCTURAL

NETWORKS

Emil Simiu, Structures Division, (301) 975-6076

Sponsor: Air Force Office of Scientific Research

This project will develop computational and experimental capabilities to

identify dynamic response characteristics of structures.

CBT will develop computational and experimental capabilities based on recent

mathematical research resulting in development of pulses of the inverse

Gaussian type which allow the systematic and accurate solution of the inverse

problem. Numerical experiments will be conducted to assess the accuracy which

it is possible to recover the exact Green's functions by deconvolution of

responses contaminated by noise.

The research will result in application to structural engineering technology of

new results of mathematics, structural dynamics, and measurement science

research, contributing to improved reliability of structural systems developed

for defense, communications, and industrial purposes. Potential spinoffs

include development of nondestructive testing methods for such members, as the

tethers of deep water compliant offshore platforms, and for active control and

damping of dynamic structural vibrations induced by as docking loads on

orbiting structures and seismic loads on buildings.

17
EARTHQUAKE ENGINEERING

18
TECHNICAL ASSISTANCE AND ENGINEERING EXPERTISE FOR SEISMIC CONSTRUCTION

ACTIVITIES

Charles G. Culver, Structures Division, (301) 975-6048

Sponsor: Federal Emergency Management Agency

This research will provide technical assistance to FEMA in connection with the

NEHRP activities related to new and existing buildings

The Federal government serves as an example for others to emulate for using

effective hazards mitigation measures in facilities. In recognition of these

needs, the Congress passed the Earthquake Hazards Reduction Act of 1977 (P.L.

95-124), and the President established the National Earthquake Hazards Reduction Program (NEHRP) the following year. The NEHRP established the Interagency

Committee on Seismic Safety in Construction (ICSSC) . The program also assigned

the National Bureau of Standards responsibilities to work in the Federal and

private sector to improve seismic design.

NBS provides the Technical Secretariat to the Interagency Committee on Seismic

Safety in Construction (ICSSC) . The Committee assists the Federal departments

and agencies involved in their ongoing programs.

NBS works with the Building Seismic Safety Council, an organization of

professional organizations, trade associations, and code groups. With NBS

technical assistance, the BSSC issued a set of seismic design provisions for

new buildings (NEHRP Provisions) . BSSC is updating these provisions to

incorporate the results of recent research and is working in the area of

existing buildings.

Results of this effort includes preparation of "code" provisions for seismic

design. These will be available for consideration by BSSC and others.

Examples of NBS work include technical assistance for developing typical costs

for seismic rehabilitation, technical assistance for handbook on rapid visual

screening of hazardous buildings, technical assistance for updating the NEHRP,

provisions, technical assistance for handbook on seismic evaluation of

hazardous buildings, and management of the ICSSC.

19
INELASTIC PERFORMANCE OF STEEL BRACED FRAME CONNECTIONS

John Gross, Structures Division, (301) 975-6068

Sponsor: National Bureau of Standards

This project will assess the behavior of gusset plates and the connection of

braced elements with columns and beams in steel frames.

AISC has identified the design of the bracing connection in steel frames as an

area of primary concern. The force distribution within the gusset plate used

in the connection is not well understood. Analytical studies have been

financed by AISC at the University of Arizona to study this problem, no experimental tests have been conducted to validate the results.

The NBS investigation will involve experiments on planar braced steel frames.

The selection of specific variables and specimen design will be coordinated

with analytical studies in progress at the University of Arizona. The experiments will provide information that is not presently available and will serve

as the basis for validating new mathematical models.

20
LARGE-SCALE BRIDGE COLUMNS SUBJECTED TO REVERSED CYCLING LOADING

William C. Stone, Structures Division, (301) 975-6075

Sponsor: National Bureau of Standards

The project will determine the influence of size (scale factor) on the seismic

performance of bridge columns and provide benchmark full-scale seismic behavior

data for bridge columns detailed in accordance with current design criteria.

A national workshop on earthquake resistance of highway bridges held in January

1979, identified research needs and established priorities in the area of

seismic aspects of highway bridge design. One of the highest priority research

needs was to determine the effects of scale factor on bridge column design to

determine whether the behavior of small sections can be extrapolated to large

cross-sections and to examine the performance of selected full-scale details.

Little information is available on the performance of large cross-section

bridge columns.

Research involves

O designing and constructing a Large-Scale Structural Testing Facility

capable of applying the vertical and lateral loads required to achieve

ultimate failure in a full-scale bridge column test specimen.

O performing full-scale bridge column tests involving one "flexural"

specimen, designed to develop high moments at the base of the column

with relatively low axial load and shear components, and two "shear"

specimens with high lateral load/moment ratio and varying axial loads

Construction details will be those in actual use in order to obtain

realistic performance data.

O conducting a parallel experimental program to obtain seismic

performance data for 1/6-scale replicas of the full-scale specimens,

and

O developing similitude models to predict the performance of full-scale

bridge columns subjected to seismic loads from scale model specimens.

The research will provide a technical base that is currently unavailable to

determine if there is scale effect for very large cross-section columns.

21
CYCLIC LOADING OF MASONRY BUILDING COMPONENTS

Charles F. Scribner, Structures Division, (301) 975-6069

Sponsor: National Bureau of Standards

This research will develop a rational procedure for determining the ultimate

shear strength characteristics of reinforced masonry shear walls for use in

structural design.

The process of developing tentative seismic design provisions for both

unreinforced and reinforced masonry building components reveals a scarcity of

information on ultimate strength characteristics. Since seismic resistance is

presently based primarily on ultimate strength considerations, the lack of such

information for masonry is detrimental to rational design in buildings

subjected to seismic loadings.

The investigation will involve experimental testing of failure modes to

identify their characteristics and the significant parameters affecting the

different failure modes. Analytical expressions for predicting failure as a function of key parameters will be developed.

22
SECRETARIAT FOR U.S. SIDE UJNR PANEL ON WIND AND SEISMIC EFFECTS

Noel J. Raufaste, Structures Division, (301) 975-9505

Sponsor: National Bureau of Standards and some member agencies

This effort provides for the U.S. Secretariat of the United States - Japan

Panel on Wind and Seismic Effects.

The U.S. Panel on Wind and Seismic Effects was created in 1969. Annual

meetings alternate between Japan and the U.S. The Panel is composed of 15

Federal agencies participating in 10 task committees. The task committees

focus on specific national issues, e.g., earthquake hazards reduction, buried

pipelines, and telecommunication systems; The results of task committee

workshops and conferences are shared at the annual joint meeting and published

as proceedings

The Panel's objectives are:

1) to exchange wind and seismic technology (including data, information,

measurement and test facilities and equipment, and researchers) between

appropriate U.S. and Japanese organizations;

2) to develop strong technical links between scientific and engineering

researchers of the government, industrial and academic organizations

from the two countries, and encourage exchanges of guest researchers;

3) to conduct joint research in areas of strong winds, earthquakes, storm

surge and tsunamis, publish findings from joint research efforts, and

distribute proceedings of annual joint meetings;

4) to conduct cooperative programs to improve engineering design and

construction practices and other wind and earthquake hazards mitigation

practices

The 19th joint panel meeting will be held in Japan during May 1987, along with

two workshops. Other workshops will be conducted during 1987.

23
HEAT TRANSFER

24
DEVELOPMENT OF A HIGH- TEMPERATURE STANDARD REFERENCE MATERIAL

Robert R. Zarr, Building Environment Division, (301) 975-6436

Sponsor: Department of Energy/Oak Ridge National Laboratory

The objective of this work is to establish a thermal Standard Reference

Material (SRM) with low thermal conductivity applicable for use over an

extended temperature range.

As better insulating materials are developed the need was identified for a new

Standard Reference Material with low thermal conductivity. Materials having

high thermal resistance values require special measurement considerations for

accurate determination of thermal properties. A low thermal conductivity SRM

is needed to calibrate instruments and as a base to compare thermal property

measurements

CBT will purchase 45 specimens , all from one lot of material manufactured by

Wacker-Chemie GmbH of West Germany. The specimens are 610 x 610 x 25 mm (24 x

24 x 1 in). From the 45 specimens, a smaller sample (10 to 20 specimens,

depending on the lot variability) will be selected. The thermal conductivity

of each specimen will be measured at 24 °C (75 °C) using the NBS 1-m Guarded

Hot Plate. Specimens will be tested as received with no high- temperature heat

treatment and at atomspheric pressure. Since the thermal conductivity of

fumed-silica depends on the barometric pressure, an attempt will be made to

modify the guarded-hot -plate (GHP) to control the barometric pressure under

test conditions to ±2 mbar (±0.06 in Hg) . Instrumentation will be installed to

automatically measure barometric pressure and control the new equipment.

If the pressure control modifications to the existing equipment are successful,

three specimens from the sample set will be tested at controlled atmospheric

pressure over the temperature range of the apparatus (approximately 0 °C to

60 °C) . At each temperature point the pressure will be changed allowing

thermal conductivity measurements at different pressure levels . This procedure

provides accurate data to calculate the thermal conductivity as a function of

mean temperature and barometric pressure for the lot of material.

Two other specimens, from the sample set, will be selected to study the effects

of high humidity on the specimens. The two specimens will be heated at 100 °C

until their respective weights obtain a steady value and then remeasured in the

NBS GHP. One of the specimens will be placed in an environment at 20 °C, 50%

relative humidity (rh) ; the other in an environment at 20 °C, 75% rh. The

specimens will be remeasured in the NBS GHP when moisture equilibrium is

achieved. Data from this study will establish the humidity levels which are acceptable for storage of the SRM specimens.

25
EXPERIMENTAL EVALUATION OF DYNAMIC TEST PROCEDURES

Douglas M. Burch, Building Environment Division, (301) 975-6433

Sponsor: Department of Energy/Oak Ridge National Laboratory

This work will develop an experimental procedure using a calibrated hot box to

characterize the dynamic thermal performance of building walls.

For many building types, the transient heat- transfer rate through the building

envelope comprises a significant portion of the total space heating and cooling

loads. Computer programs are widely used to perform hourly building energy

simulations which predict the building envelope heat- transfer rate. Building

designers, architects, and owners use these computer programs to size HVAC

equipment, to predict peak demands and to predict annual energy costs.

Moreover, such programs are used to minimize annual energy costs by investigating trade offs in the envelope design, selecting HVAC systems and equipment,

and analyzing various methods of building operation.

Many of these computer programs predict the transient heat- transfer rate

through the components of a building using conduction transfer- function

equations. Conduction transfer- function coefficients for selected building

walls are summarized in Table 29 of the 1985 ASHRAE Handbook of Fundamentals.

The mathematical algorithms that generate transfer- function coefficients

contain simplifying approximations such as an assumption of one -dimensional

heat transfer and constant heat- transfer properties. Moreover, these models do

not account for the heat transfer through thermal bridges such as metal ties in

masonry walls, and framing in wood walls, and other thermal anomalies. Very

little research has been conducted to verify the accuracy of these

mathetmatical models

There is need to develop an experimental procedure using a calibrated hot box

to provide a "general" characterization of the dynamic thermal performance of

walls. The procedure permits the measured thermal response under one set of

boundary conditions to be readily extended to different boundary conditions.

This provides a common basis for different laboratories to compare their

dynamic test results. This study permits those existing computer programs to

be used with greater confidence.

CBT will use the Stephenson Ramp Test on the masonry wall having known heattransfer properties. The National Research Council of Canada has developed a ramp test procedure with considerable promise and potential for determining

empirical transfer -function coefficients (TFC's) that are unique and closely

approach those predicted using an analytical model. A ramp temperature

waveform will be generated in CBT's climatic chamber. The metering chamber,

maintained at a typical indoor condition, will be used as calorimeter. The

specimen heat- transfer rate will be determined from an energy balance of the

metering chamber at hourly time intervals. From the measured transient

specimen heat- transfer rate, CBT will determine the poles and residues for a Laplace transform analytical solution. These mathematical parameters subsequently will be used to determine the TFC's. The TFC's derived from the

Stephenson Ramp Test will be compared with predicted TFC's determined from an analytical model. Also, CBT will conduct a different ramp test with the

climatic chamber temperature ramped in an upwards direction instead of a downwards direction to verify whether the thermal storage in the metering

chamber is being accounted for correctly.

26
A candidate masonry wall will be selected through a consensus process with

industry and government representative and installed in Calibrated Hot Box.

This masonry wall be exposed to excitation functions such as a ramp, a sol-air

diurnal waveform, and a four -harmonic diurnal waveform TFC's for this masonry

wall will be determined using both the CBT curve fitting procedure and the

Stephenson Ramp Test procedure and compared to predicted TFC's using an

analytical model. Each set of TFC's will be used to predict the transient

specimen heat- transfer rate for the other dynamic tests. Recommendations will

be made about a preferred dynamic test procedure for using a calibrated hot box

to measure the dynamic thermal characteristics of walls.

27
THERMAL AND ENVIRONMENTAL EVALUATION OF ADVANCED TECHNOLOGY OFFICE BUILDINGS

PHASE II

Andrew Persily, Building Environment Division, (301) 975-6418

Sponsor: General Services Administration

The projects objective is a measurement program that evaluates thermal and

environmental performance of advanced- technology office buildings. This

program will validate diagnostic techniques for evaluating building

performance

The design and construction of modern, advanced- technology buildings places

more stringent requirements on the buildings thermal and environmental performance. A better understanding of the thermal, environmental and operational

characteristics of advanced- technology buildings is essential to avoid design,

construction and operation errors that may result in a building unsuited to its

tenants. The inability to meet thermal comfort criteria and air quality

standards in buildings is due to 1) improper selection of building materials,

2) poor building design, 3) poor construction quality, and 4) improper operation of the building systems.

Previous studies have shown the value of diagnostic evaluations in assessing

building performance, and have revealed the importance of building envelope air

leakage in determining space conditioning loads. Many air leakage and insulation problems can be avoided by using diagnostic tests early in the construction stage and repairing the defects that are located. It is more economical

to correct these defects at this stage when the building is complete and

occupied.

There is an opportunity 'to establish and employ diagnostic centers in new

buildings to monitor critical parameters that determine the performance of the

building and the adequacy of its interior environment. Along with other on- site evaluations, these tests assure knowledge base relating building features

to performance and enable corrective actions if necessary. Of particular

concern are transient conditions associated with early occupancy.

CBT has developed design specifications for installing a diagnostic center, and

developed performance criteria and programming for installing diagnostic

centers. Diagnostic centers are expected to be installed in three federal

buildings: Portland, OR; Overland, MO; and Long Beach, CA. The evaluations

include thermographic inspection of building envelope; thermal resistance

measurements; pressurization tests of envelope airtightness; tracer gas

analysis of air exchange; and monitoring indoor levels of contaminants.

CBT performed a design review of the new Portland East Federal Building in

Oregon and installation of its diagnostic center. CBT also inspected the

building during construction to evaluate the contractor's installation of the

sensors and equipment to be used in the evaluations

In this phase, CBT will study cause and effect relationships between activities

in the buildings (e.g., cleaning, initial move-in, remodelling, pesticide use,

loading dock activity) and resulting indoor air quality conditions within the

building. Work also will include design review for installing diagnostic

centers in the Overland and Long Beach buildings. CBT will develop guidelines

28
for building operating procedures and servicing during building commissioning

and move -in.

- -

.

v

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29
HEAT LOSS CALCULATION PROCEDURES FOR SHALLOW TRENCH HEAT DISTRIBUTION SYSTEMS

Jin B. Fang, Building Environment Division, (301) 975-6417

Sponsor: Tri-Services Committee of DoD

The objective of this work is to develop a calculation procedure that predicts

heat losses from shallow trench heat distribution systems, and to estimate the

minimum life -cycle heat losses and the corresponding economic insulation

thicknesses

CBT provided assistance in developing a standard test method for underground

pipe insulation and heat loss calculation procedures for direct buried conduit

systems which are included in Guide Specification for Military Construction

FCGS-15705. A procedure based on life-cycle cost analysis was developed at CBT

for calculating the maximum allowable heat loss for direct buried conduit type

underground systems. CBT also takes part in the Interagency Committee on

Underground Heat Distribution Systems to review and approve product test

protocols and engineering brochures for use on federal construction projects.

The military installations currently maintain approximately 6,000 miles of heat

distribution systems. Some of these systems require repair or replacement due

to excessive heat loss resulting from deteriorated thermal insulation and

corroding pipes and conduits. An in-situ heat loss measurement technique such

as the thermal probe method being developed at CBT is needed to locate the

defective segments of a direct buried piping system. Field evaluation of a thermal probe method and comparison of its performance with a calorimetric

measurement are underway.

During FY86, a procedure was developed to calculate the rates of heat loss from

two insulated pipes installed in a shallow concrete trench using a finite

element computer program 'to solve a two-dimensional steady- state conduction

problem. Methods to determine the minimum life -cycle cost heat loss and the

economic insulation thickness were developed and sample calculations were

performed for a range of trench dimensions and pipe temperatures. The heat

loss calculation procedures for shallow trench systems will complement the

procedure already developed for direct buried conduit system. There is a lack

of field data to be used for validation of the predictive methods

CBT will modify the existing finite element computer program for calculating

the rates of heat loss from two underground pipes installed in a shallow

concrete trench, to account for the temperature dependency of the insulation

and soil thermal conductivities . The calculated results will be compared with

the available experimental data. Work will be performed to develop estimates

of material and installation costs for constructing various distribution

systems of different trench dimensions and insulated pipe sizes. A set of

tables will be developed listing the pipe heat losses associated with the

minimum life -cycle cost and the corresponding economic insulation thickness

based on a range of pipe sizes, fluid temperatures, energy costs, soil thermal

conductivities, and the undisturbed earth temperatures. Also, CBT will

continue providing technical assistance to the Federal Agency Committee on Underground Heat Distribution Systems, in reviewing product test protocols and

test reports submitted for acceptance on various heat distribution systems, and

participating in specific assignments as the scope of the tasks are refined.

30
MATHEMATICAL MODEL FOR PREDICTING COMBINED FLOW OF HEAT AND MOISTURE

Douglas M. Burch, Building Environment Division, (301) 975-6433

Sponsor: National Bureau of Standards

This research will develop a mathematical model to predict the combined flow of

heat and moisture through multi-layered retrofitted walls. This model will

consider the effect of moisture accumulation on the overall thermal resistance.

During FY86, CBT completed a mathematical model and computer program modeling

the effect of vapor resistance offered by paint layers, capillary transport of

moisture within a layer, and temperature -dependent and moisture -dependent

properties

During FY87, CBT will conduct:

1) Laboratory experiments to condition two walls specimens. Measured

profiles of moisture content within the wood siding of the two wall

specimens will be compared to corresponding values predicted using a mathematical model.

2) Complete the measurements of diffusion coefficients for specimen

materials. Thermal conductivity measurements will be conducted to

investigate the effect of moisture on the thermal conductivity of the

insulation materials.

3) Analyze moisture transfer found in a typical wall exposed to several

outdoor climatic conditions. A magnetic tape weather data processor

will be added to the mathematical model of moisture transfer (computer program) . A variation of parameters will be performed to

determine the relative importance of various building construction

and operating parameters on the amount of moisture that accumulates

in the typical wall.

31
INDOOR AIR QUALITY

32
MEASURING AND PREDICTING INDOOR AIR QUALITY IN AN OFFICE BUILDING

Andrew Persily, Building Environment Division, (301) 975-6418

Sponsor: U.S. Geological Survey

This project will demonstrate and refine' test methods to determine the

relationship between the performance of the building ventilation systems, the

interzonal movement of air and the effectiveness of various contaminant removal

and containment methods and the ability of NBS developed models and measurement

methods using the U.S. Geological Survey Complex as a test site.

CBT has developed measurement methods and analytical models to determine and

predict air movement and contaminant levels in multi-zone complex buildings.

To date little verification between the predictions of these models and the

actual level of indoor contaminants in complex buildings has been done. This

project will permit the study of a specific building complex which is well

characterized to evaluate how well the NBS developed measurement methods and

analytical models predict air movement and distribution. This technology when

validated also will provide information to assist USGS officials to determine

how ventilation systems should be designed and operated to ensure a good indoor

air quality.

CBT will perform an evaluation of the indoor air quality and ventilation system

of the U.S. Geological Survey complex in Reston, VA, to determine the

appropriateness of the NBS measurement and modeling procedures in this building

type and to assist USGS in investigating the type of ventilation problems in

this particular building complex. The tasks NBS will carry out are:

1) measure the ventilation rate and air leakage rate of the complex,

2) determine the ventilation effectiveness in several offices,

3) measure the entrainment of contaminants by the outside air,

4) measure the levels of indoor air pollutants including CO, C02 , radon,

particulates , hydrocarbons , N0X and volatile organic compounds

5) measure the interzonal air flow between various zones in the complex

and in particular from the laboratory and industry/printing areas,

6) determine operational and environmental conditions which could cause

adverse indoor air quality,

7) compare the data collected above and the multi -zone indoor air

contaminant model to the pollutant concentration obtained by the NBS

multi -zone model.

33
INFILTRATION/VENTILATION IN LARGE BUILDINGS

Richard A. Grot, Building Environment Division, (301) 975-6431

Sponsor: Department of Energy

This research will develop test methods for evaluating the movement of air into

and within large commercial buildings and determine the efficiency of the

ventilation systems of commercial buildings by providing a mechanism to remove

contaminants at minimum energy cost.

Insufficient data exist on the air leakage and air movement in large commercial

structures . Previous DoE/NBS research demonstrated that large buildings

experience under- and over -ventilated periods during their annual operation.

The design of the air distribution system and the placement of internal partitions may result in uneven distribution of an otherwise adequate amount of

ventilation air.

CBT test methods for measuring ventilation efficiency will be applied to the

Columbia Plaza building and two other office buildings. Measurements of the

distribution of contaminants in these office buildings will be made.

With NIOSH, CBT will analyze the relationship between the level of contaminants

and the operation and design of the ventilation system in the Columbia Plaza

building. NIOSH will measure the levels of micro-organisms and allergens in

the building. These data will be analyzed by CBT and NIOSH to determine

relationship between the performance of the ventilation system and the levels

of indoor contaminants. Two other office buildings to be studied. One of the

buildings selected will have no indoor air quality problems. These buildings

will be instrumented and data collection started during FY87.

34
INDOOR AIR POLLUTION CONCENTRATION MODEL

Richard A. Grot, Building Environment Division, (301) 975-6431

Sponsors : Department of Energy and

Environmental Protection Agency

The purpose of this report is to develop a comprehensive validated computer

model that simulates dynamic pollutant movement and concentration variations in

buildings

Most previous work reported for indoor air pollution modeling is based on a simplistic one-room dilution model which ignores the thermal effects and mixing

dynamics. A comprehensive analysis of pollution migration in buildings

requires accurate simulation of all processes affecting pollutant concentration. These processes are infiltration, generation, dilution, reaction,

removal, and exfiltration. CBT has recently developed a comprehensive dynamic

building simulation model called TARP. In addition to detailed thermal

conduction and radiation calculations , TARP computes infiltration and interroom

airflows by considering the flows through all openings (doors, cracks, etc.)

and requires a mass balance in each room. The flows are a function of wind,

stack effect, and forced ventilation. The TARP model automatically handles the

infiltration, exfiltration, and interroom dilution aspects of the contamination

equation which are the most computationally complex parts of the problem. It

can also serve as a framework for adding other components of the contaminant

equation.

During FY87, work will be performed to enhance TARP. Work will be concerned

with local air velocities, ventilation effectiveness, and removal of con- taminants which have localized sources . A more detailed model of the movement

of contaminants through HVAC systems will be developed that will include

situations where individual rooms are not well mixed and such concepts as ventilation efficiency. The model will be formulated so it will be compatible

with development of modern computer energy simulation techniques.

MICRO -MODELING OF CONTAMINANT CONCENTRATION IN A SPACE

Richard A. Grot, Building Environment Division, (301) 975-6431

Sponsor: National Bureau of Standards

CBT is developing models to predict the distribution of contaminants within

building spaces.

Many pollutants are released into a space from point sources and the

distribution of such pollutants within a space is not uniform. Some pollutants

may affect health when relatively high concentrations are inhaled for only a short time. Therefore, there is a need to predict areas where high concentrations will exist. Most modeling to date assumes complete mixing in a space or employs a two -compartment assumption with uniformity within each compartment.

There is a need for validated models for the short-term exposures to pollutants

which can result from such activities

This research will predict the distribution of contaminants in a space. This

information will be used as a basis for developing simplified micro-models.

35
METHODS FOR MEASURING THE EFFICIENCY OF DEVICES FOR REMOVING GASEOUS

CONTAMINANTS FROM AIR STREAMS

Bal M. Mahajan, Building Environment Division, (301) 975-5857

Sponsor: National Bureau of Standards

This project is developing measurement methods for filter efficiency to remove

gaseous contaminants from air stream.

Attempts were made to evaluate gaseous removal devices, however, no general

procedures are available for evaluating these devices . Methods are needed to

evaluate these devices so effective and economical control methods can be

promoted for improved indoor air quality.

CBT's is developing methods to evaluate the effectiveness of devices to remove

gaseous pollutants from air. These methods will employ a test duct system in

which a sample filter/device is challenged with several gaseous pollutants

introduced into the intake air. The gaseous pollutants will be selected

according to their possible adverse health effects, and their possible presence

in the indoor air. Methods will be developed to safely introduce metered

amounts of pollutants into the intake air of the test duct system. Methods

will be developed, utilizing mass spectroscopy, gas chromatography or other

feasible means, to measure the concentration of the gaseous pollutants in the

intake and outlet air of the test duct system. The gaseous pollutant removal

efficiency of the device can then be calculated from the measured data.

Also, methods will be developed to measure the capacity of such filters. It

will be possible to combine the removal efficiency of a device with its

contaminant load to provide information for comparison between filters and to

estimate system effectiveness and economic analysis of various alternatives.

CBT maintains close cooperation with ASHRAE technical committees on gaseous

contaminants and removal equipment to assist in providing a basis for promulgating a consensus standard.

36
CHARACTERIZATION OF VOLATILE ORGANIC CHEMICAL EMISSIONS FROM PRODUCTS USED IN

BUILDINGS

Samuel Silberstein, Building Environment Division, (301) 975-6420

Sponsor: National Bureau of Standards

CBT is developing procedures to identify and determine the amounts of volatile

organic chemical (VOC) emissions from products used in buildings. Such

products includes: plastics, underlayment , paneling, medium-density fiberboard, carpeting, wood, chemicals used in the treatment of these products,

pesticides, cleaners, glues, and combustion products from cooking and heating.

There have been increasing numbers of incidents of "sick building syndrome"

resulting from off-gassing of VOC from building materials as listed above. It

is often difficult to predict if building materials will emit gases and vapors

under normal or abnormal operating conditions. CBT will place products in

measuring chambers located in an environmental chamber where temperature and

relative humidity (RH) are carefully controlled. Pressed-wood products will be

tested. It will be determined whether VOC concentrations can be made high

enough, by minimizing air exchange rates in the measuring chambers, to permit

VOC to be analyzed directly without concentration.

Qualitative and quantitative analyses of VOC's will be made using analytical

instrumentation. Test protocols will be developed from the data for use in

characterizing VOC from building materials.

37
MECHANICAL SYSTEMS AND CONTROLS

38
BUILDING OPERATIONS AND CONTROLS LABORATORY AND INTEGRATED BUILDING SERVICES

George E. Kelly, Building Environment Division, (301) 975-5870

Sponsor: National Bureau of Standards

The objective of this project is to perform fundamental and applied research on

building controls, building system dynamics, whole building performance, system

optimization, and integrated building services for evaluating the performance

of building systems and controls.

About 25% of U.S. energy consumption is expended in heating, ventilating and

air conditioning residential, commercial, and institutional buildings.

Annually, a considerable amount of manpower and money goes into maintaining the

equipment and systems which service these buildings. Fire prevention and alarm

systems are usually completely separate and rarely make use of the advanced

technologies currently under development for energy control systems. Smoke

control in small buildings is usually nonexistent. Limiting electrical power

demand systems, transportation, and security systems are usually completely

separate and independent of all other services. Computer-based energy management systems are so complex that most building designers are afraid of them.

This list of problem areas indicates the desperate need of the building

community for information on how to design, control, and integrate the various

services provided in today's buildings. Guidelines and specifications are needed to fill these information gaps and to provide how- to -do -it manuals for

building designers, owners, and operators. Such information would greatly

improve the reliability of building systems and controls, reduce maintenance

requirements, and provide better services at lower first costs.

FY87 research focuses on performance of whole buildings using HVACSIM+

, whole

building simulation program, and the NBS Administration building, evaluating

building control strategies that involve dynamic interactions between the

building shell, the HVAC system and controls, and investigating the use of real

time building system models for optimizing whole building performance. A joint

research effort with the Center for Fire Research focuses on developing

procedures for commissioning HVAC systems and computerized building management

systems in fire control and smoke removal applications.

39
BUILDING/HVAC/CONTROLS DYNAMIC MODELING

George E. Kelly, Building Environment Division, (301) 975-5870

Sponsor: Department of Energy

The project's objective is to develop and verify building system models and a simulation program to evaluate the dynamic interactions among the building

shell, the HVAC system and controls.

None of the currently used building simulation programs (e.g., BLAST 2, DOE 2)

account for HVAC/control dynamics. As a result, there is little reliable data

on the amount of energy waste in buildings due to control dynamics and no information how to design and operate building control systems to optimize

dynamic performance.

CBT's recently developed building/HVAC/control system program HVACSIM+ will be

used to model NBS's 11 -story Administration building. Data on the performance

of this building will be collected using the energy management and control

system (EMCS) installed in this building as a part of CBT's Building Management

and Controls Laboratory project. This data will be used to verify and refine

the building shell portion of HVACSIM+ and the verified program employed to

study the dynamic importance of whole building systems. The results of this

work will be published to provide building researchers with essential

information on the performance of building/HVAC/control system dynamics

40
THERMAL MODELING OF BUILDINGS

George N. Walton, Building Environment Division, (301) 975-6421

Sponsor: National Bureau of Standards

This research develops modern modeling techniques for predicting the dynamic

performance of whole buildings.

Large buildings have complex interactions between the building mass, the air

and furnishings within zones, and the distribution/HVAC system. It is necessary to understand and to simulate these complex interactions and the heat

storage and transfer mechanisms to assess their effect on thermal performance.

Building energy performance models used by designers are usually single zone,

one dimensional heat transfer models that neglect these interactions. Little

theoretical work has been performed to identify the most desirable structure

for these simulation programs that will facilitate modification and future

updating.

CBT developed the Thermal Analysis Research Program (TARP) which predicts the

interzone heat transfer and interzone movement of air. During FY86, CBT

developed accurate and efficient models to predict radiative energy exchange

around a building and inside a building and incorporated modern adaptive

computer methods into building energy models. The algorithm development for

radiative energy exchange included methods for calculating view factors

shadows, and solar transmission.

FY87, research focuses on developing a theoretical basis in the modular

structure of thermal analysis simulation so modem computer methods as adaptive

computer language can be applied to the major general elements of thermal

simulation. These elements include formation of component response, description of the environmenal driving forces, assembly of the model equations,

solution methods for solving the equations and evaluation of the system

dependent quantities. This approach will examine the theoretical basis of the

analytical approach, the characteristics of the computational algorithms, the

nature of the data structures, and the necessity of developing and implementing

new methods. As a first step, the computer program ESP, developed by the

University of Strathclyde, will be obtained and adapted for an NBS minicomputer

or an engineering work station. Component models of building zones and HVAC

systems will be developed for use with the ESP program and the SPANK energy

kernel system being developed by the Lawrence Berkeley Laboratory.

This investigation is the beginning of a theoretical basis to develop a new

structure for building thermal simulation that can be easily modified to

accomodate future needs

41
INSPECTION AND TESTING PROCEDURES FOR COMMISSIONING HVAC EQUIPMENT AND SYSTEMS

James Y. Kao, Building Environment Division, (301) 975-3844

Sponsor: General Services Administration

The objective of this project is to develop comprehensive inspection and

testing procedures for commissioning HVAC equipment and systems in federal

buildings

The acceptance inspections of new buildings vary. The performance of the

building sub-systems and their energy consumption are contingent on the subsystems being installed, adjusted, and operated according to the intention of

the designers. Recent research has revealed the poor performance of many HVAC

control systems, even when the systems were newly installed.

The testing and balancing standards existing today for HVAC systems are inadequate for the monitoring necessary to guide long-term efficient operations. The responsibility of correcting deficiencies in operating performance

is not easily resolved. A considerable amount of attention has recently been

focused by ASHRAE, GSA, NBS , and others on developing commissioning procedures

for HVAC equipment and systems.

CBT is developing recommended inspection procedures for a variety of typical

HVAC equipment, systems, and controls, including refrigeration plant equipment,

heating plant equipment, air handling equipment and air handling basic systems,

building automation system fire safety system, and unitary heating and cooling

equipment. These comprehensive procedures will be used as the initial step in

evaluation of HVAC/control system. The purpose of these procedures is to

ascertain systematically that the equipment and systems are installed as specified and are meeting generally recognized good practices, so that known

and potential problems may be eliminated.

CBT is also developing measurement methods and performance test procedures for

the typical systems described above. The procedures will take into account the

system operating mode changes and the building load and environment conditions

at commissioning time.

The inspection procedures, measurement methods and test procedures will be

developed concurrently and the results compiled in a Manual on HVAC/Control

Commissioning Procedures having a format similar to the GSA "Quality Standards

for Design and Construction." Relevant industry standards of installing and

testing of these equipment will be reviewed and synopses included in the manual

to provide GSA commissioning personnel with relevant background information.

Fundamental measurement techniques and calculation equations will also be

included. Standard forms and sample worksheets will be developed and included

in the Manual to facilitate usage by commissioning personnel in the field.

42
THERMAL ANALYSIS FOR RADIANT PANEL SYSTEMS IN NEW/RENOVATED VA FACILITIES

George N. Walton, Building Environment Division, (301) 975-6421

Sponsor: Veterans Administration

The objective of this research is to evaluate the thermal performance of

radiant panels relative to two conventional heating and cooling systems in

typical VA facilities.

CBT research will modify CERL's BLAST computer program for thermal analysis of

buildings and building systems to incorporate system operating parameters and

control algorithms for predicting the performance and energy usage of radiant

panels

After modifying BLAST, the new program will evaluate the thermal performance

and energy use of radiant panels to conventional heating and cooling systems in

single building spacces as in typical VA facilities. Sensitivity analyses will

be performed for climate, occupant comfort, and building operating strategies.

This research will increase VA's ability of public domain energy simulation

models to include the performance of radiant heating systems

ADVANCED BUILDING SYSTEM SIMULATION

George N. Walton, Building Environment Division, (301) 975-6421

Sponsor: Department of Energy

The objective of this research is to develop dynamic HVAC system component

models as prototypes for a future Energy Kernel System (EKS) proposed by the

Lawrence Berleley Laboratory (LBL)

LBL proposed an EKG based on a prototype software system called SPANK

(Simulation Problem Analysis Kernel) . SPANK uses concepts from network

analysis and object-oriented programming to describe and solve whole building

simulation problems. The capabilities of SPANK have been successfully demonstrated for solving HVAC problems involving sets of steady- state , algebraic

equations. Research is required to determine if the SPANK approach can be

effectively applied to real world simulation problems involving dynamic,

nonlinear building systems.

CBT will develop dynamic component models for several different Variable Air

Volume (VAV) system designs and control options. These models, which will

include the "second-by- second" dynamic response of these systems to control

actions and changes in zone load, will be developed in formats suitable for use

with SPANK, HVACSIM+ (a simulation program developed at NBS) , and ESP (a

simulation program developed by the University of Strathclyde) . Simulation

studies will be performed using these three programs to evaluate the strength

and weaknesses of each approach. A technical paper summarizing the results of

this work and containing recommendations on how the proposed Energy Kernel

System should be developed for simulating nonlinear, dynamic building systems

will be published. Close communication will be maintained with LBL to

facilitate the exchange of information on the Energy Kernel System.

43
REFRIGERANT MIXTURES

44
MEASUREMENTS OF MODIFIED HP CYCLES USING NONAZEOTROPIC MIXTURES

David A. Didion, Building Environment Division, (301) 975-5881

Sponsor: Department of Energy/Oak Ridge National Laboratory

The objective of this research is to experimentally evaluate the thermodynamic

and operational behavior of modified heat pump cycles and systems hardware

using nonazeotropic refrigerant mixtures.

Interest in using nonazeotropic binary mixtures as a working fluid for

refrigeration systems has increased. It does not appear that new single

component refrigerants can be developed because of the limited number of

elements available for combination to produce volatile, nonflammable, non- poisonous, chemically stable compounds. Consequently, improvement in refrigerant performance is expected to result from the application of mixtures of

known refrigerants.

The theoretical potential for increased energy performance has caused the

initiation of studies dealing with the utilization of nonazeotropic mixtures in

heat pumps and refrigerators that require a wide variety of design changes in

both the refrigeration cycle as well as components. The intent of this work is

to experimentally evaluate in the laboratory the thermodynamic and operational

behavior of modified heat pump cycles and components using nonazeotropic

refrigerant mixture working fluids. Also it is intended to consider different

mixtures whose attributes may vary (e.g., increased efficiency or increased

capacity) and to determine their potential for different applications.

CBT developed a heat pump model for nonazeotropic mixtures, under EPRI

sponsorship, which uses a new hard- sphere equation- of- state . The new model

will be verified through comparisons with data obtained from hardware tests,

and also used to supplement the experimental data and help to design the test

program.

A criteria has been developed which establishes a method of rating a refrigerant mixture on the basis of a constant heat flux in the heat exchangers

and fixes the heat exchange fluid temperatures at the condenser and evaporator

inlets and outlets . Tests will be conducted for each mixture on this same basis to consistently compare their respective merits for particular, representative applications. In addition to the empirical characterization and

verification of the thermodynamic characteristics of the mixture above, CBT

will determine the heat exchanger characteristics that will best exploit the

mixture

The above empirical work will be used in gathering simultaneously the capacity

and efficiency of a traditional vapor compression cycle that is operating with

a mixture in counterflow heat exchangers. This focus is on the possibilities

of modifying the vapor compression cycle to take fuller advantage of the

performance benefits available when a mixture is employed. Another effort will

explore the advantages of incorporating a liquid pump to transmit refrigerant

from the evaporator to the condenser (around the compressor) to obtain independent control of the gliding temperature and gliding composition profiles.

45
NON-AZEOTROPIC MIXTURE REFRIGERANTS FOR HEAT PUMPS

David A. Didion, Building Environment Division, (301) 975-5881

Sponsor: Electric Power Research Institute

The objectives of this study are to develop a simulation model of a vapor

compression cycle operating with binary non- azeotropic refrigerant mixtures and

to perform a parametric evaluation of the energy performance advantages of

these mixtures for heat pumps.

Conventional vapor compression heat pumps employ single component refrigerants

or azeotropic mixtures (those which have a single boiling-condensing

temperature-composition phase diagram) as their working fluid. The use of non- azeotropic mixtures as the working fluid appears to offer potential energy

performance advantages without major changes in the manufacturing process of

existing heat pumps.

The development of the thermodynamic model (equation of state) will be done in

conjunction with NBS's Thermophysics Division. Selected mixtures will be

measured and a generalized equation of state will be fitted to the data, the

heat transfer modelling will be applicable theories of mixtures. The model

will be used to study the advantages of non- azeotropic mixtures as applied to

heat pumps. CBT will corporate a simulation of the ideal vapor compression

cycle with the generalized equation-of -stete model and evaluating the attributes of different mixtures as they might be applied to the ideal cycle. Of

particular interest is the potential for capacity at low evaporator temperatures, efficiency, compressor pressure ratio, and discharge temperature and

pressure. With the University of Maryland modifications to the heat pump cycle

will incorporate unique performance attributes offered by non- azeotropic

mixtures. A workshop of worldwide leaders in this field will explore the best

path for future research. This workshop will be held following the June 1987

ASHRAE meeting.

This study will quantify the thermodynamic performance of non- azeotropic

mixtures in today's heat pumps; and some new designs. Also this work will

establish the property data of selected mixtures which may be used in other

machinery systems.

46
TWO PHASE FLOW OF REFRIGERANT MIXTURES

David A. Didion, Building Environment Division, (301) 975-5881

Sponsor: Electric Power Research Institute

The objectives of this study are to determine if the degradation of the flow

boiling/evaporative heat transfer coefficient of mixture is caused by heat

driven nonequilibrium effects or flow quality and 2) to determine if a heated

glass tube test section can be developed to provide qualitative information as to the flow and boiling patterns.

The use of binary mixtures as a working media for power and refrigeration

cycles is being researched to improve the thermodynamic performance of current

systems. The nonazeotropic behavior of the two components allows for a system

design that will have a significant increase in capacity or efficiency or alteration to pressure ratio. The evaporator is an essential component

affecting the performance of the power and refrigeration cycles. Quantification of working fluid properties are essential for the design and operation of

the evaporator. The properties can result in oversizing the evaporator at the

design stage; while going too far in the other direction can result in flooded

conditions which can lead to liquid impingement on the turbine or compressor

during operation.

CBT will perform a series of calorimetric tests on a refrigerant mixture using

a two phase flow heat transfer loop (already constructed) . This series will

consist of tests which are capable of determining the local boiling/evaporative

heat transfer coefficient in annular two phase flow in four circumferential

positions at each of eight axial stations. This work will establish the

fundamental connections of mixtures

CBT's test rig will be modified so a heated glass test section can be installed

to visualize the annular flow in general and the ultrathin liquid layer in

particular. This effort will contribute to the two phase flow field in the

form of a new empirical technique. The refrigerants and mixtures evaluated in

this rig will be selected after the series of calorimetric tests have been

completed. The criteria for selection will address the nature of the fluid to

have its nucleate boiling suppressed (fluids which require the least and most

heat flux to establish the onset of nucleation will be of particular interest

to observe)

The refrigeration industry will use these findings to quantify the advantages

of binary mixtures in their future refrigeration systems design.

47
NONAZEOTROPIC REFRIGERANT MIXTURE PROPERTY EVALUATION

David A. Didion, Building Environment Division, (301) 975-5881

Sponsor: National Bureau of Standards

The objective of this project is to determine the values of the thermodynamic

and transport properties of nonazeotropic refrigerant mixtures necessary to

evaluate the impact these mixtures may have on the performance of refrigeration

cycles and determine the expected cycle performance of different refrigerants

and mixtures

The future of nonazeotropic mixtures in the refrigeration industry depends on

creating using new types of refrigeration cycles.

CBT is analyzing interactive coefficients already obtained from data and the

molecular structure of the components to determine if a pattern can be established. A new equation-of-state , one that models the components as two

separate substances, will be developed. It will be predictive in nature with

no requirements for experimental data. CBT's work on refrigerant mixtures will

be completed which will include recommended methods to predict mixtures. Also,

CBT will continue studying the degradation of two phase boiling heat transfer

coefficient for mixtures.

48
TEST PROCEDURES FOR MAJOR ENERGY APPLIANCES

49
FURNACES , BOILERS AND HOUSEHOLD HEATER TEST PROCEDURES

George E. Kelly, Building Environment Division, (301) 975-5870

Sponsor: Department of Energy

The project's objectives are to develop , testing and rating procedures for

determining the seasonal energy performance of central residential furnaces,

boilers, and household heating equipment; and to assist DoE by conducting

laboratory studies of furnaces, boilers, and household heaters and their

associated equipment.

CBT will use its HVACSIM+ program as the basis for modeling the performance of

furnaces, boilers, and household heaters, new space heating and domestic hot

water heating equipment on the market and new integrated appliances. This

simulation program, whose name stands for HVAC SIMulation PLUS other systems,

was recently developed by NBS as a research tool for whole building system

studies. It consists of a main simulation program, a library of HVAC component

models, a building shell model, and an interactive front end program. CBT will

develop HVACSIM+ compatible component models for furnaces, boilers, and boilers

equipped with tankless coils for domestic hot water heating. These models will

be dynamic models to fully account for the dynamic interactions that are important to integrated appliances. Experimental studies will be conducted to

verify these models and ensure the results are compatible with existing DoE

appliance test procedures.

After the component models are developed and verified, the HVACSIM+ program

will be used to study:

O The integration of space heating and domestic hot water heating using

appliances covered under ASHRAE's SPC-124P proposed standard.

O The effect of water draw schedule on boiler water heaters using

tankless coils.

O Regional heating and non-heating season fractions for determining

weighted annual efficiency of combination space/water heating

appliances

O The effect of rapid duty cycling on furnace and boiler performance.

Using the HVACSIM+ program and the component models developed CBT will study

the effect of furnace/boiler location treatment on system performance. If the

propose law specifying minimum national efficiency standards is passed, NBS

will provide DoE with the necessary technical assistance necessary to meet its

obligations under this law for future modifications of the furnace/boiler test

procedures

50
WATER HEATER TEST PROCEDURES

A. Hunter Fanney, Building Environment Division, (301) 975-5864

Sponsor: Department of Energy

The project's objective is to update, expand, and improve test procedures

applicable to conventional water heaters

DOE must establish test procedures which allow the accurate and repeatable

determination of energy efficiency for hot water heaters. CBT is providing

technical support to develop, maintain, and improve test procedures applicable

to water heaters. During FY 87 a state-of-the-art water heater laboratory will

be constructed at the National Bureau of Standards. The facility will permit

the testing of electric, gas, heat pump, oil, and instantaneous water heaters.

CBT will conduct tests in accordance with the current and proposed test

procedure on an oil , gas , and electric water heater to provide an opportunity

for the principal investigator to become familiar with both test procedures;

analyze comments received in response to articles on water heaters published in

the Federal Register and provide DOE with response recommendations; provide

technical support to DOE on Requests for Waivers and other matters that may

require technical analysis; and participate in the ASHRAE Standards Committee

118.1 which will develop an ASHRAE Standard for water heaters.

51
HEAT PUMP AND AIR CONDITIONER TEST PROCEDURES

David A. Didion, Building Environment Division, (301) 975-5881

Sponsor: Department of Energy

This research will provide industry, through DoE, with an equitable testing and

rating procedure for determining the seasonal energy performance of central

residential air conditioners and heat pumps.

DoE has been interested in verifying NBS's draft test and rating procedures for

air conditioners and heat pumps (1977 and 1978) and extending its scope to

include new designs coming on the market. CBT has developed a procedure by

which these mixed systems can be rated without testing complete systems.

Required input to this procedure Includes a DoE has directed NBS to develop

simplified methodologies by which the ratio of capacities of the mixed (new)

and matched (original) coil and ratio of refrigerant mass flow rate through the

respective expansion devices could be evaluated.

CBT will develop simplified techniques to determine the ratio of capacities of

mixed and matched coils, and the ratio of refrigerant mass flow rate through

respective expansion devices.

A computer model will be developed of the evaporator coll. It will be offered

to the industry to supplant or as an alternative to the catalog data. CBT will

develop a simple surrogate fluid test which could replace a more difficult and

expensive test with refrigerant for determining a refrigerant mass flow ratio.

The second part of this effort is to develop a rating procedure for variable

speed heat pumps that considers equitable test conditions for an intermediate

compressor speed test. Laboratory tests are planned to conclude in August; a draft evaluation procedure will be available in FY 88.

REFRIGERATORS, REFRIGERATOR- FREEZERS AND FREEZERS

Bal M. Mahajan, Building Environment Division, (301) 975-5856

Sponsor: Department of Energy

The project's objective is to provide DoE with technical assistance in

analyzing test procedures for refrigerators, refrigerator- freezers , and

freezers. CBT will:

O Participate and collaborate with the ASHRAE Technical Committee 7.1 in

the "Phase II A" of the research effort.

O Analyze the DoE test procedures to determine their ability to measure

the relative benefits of efficiency improvement features, particularly

solid state defrost control (i.e., ADC), that are incorporated in many

of the new products available in the market. Perform tests as appropriate

O Provide DoE with the evaluation of proposed test procedure changes

offered to DoE and evaluate manufacturers waiver requests to advise DoE

of the technical validity and to recommend an appropriate action.

52
LIGHTING RESEARCH
LIGHTING/HVAC INTERACTION COMPUTER MODELING

Stephen J. Treado, Building Environment Division, (301) 975-6444

Sponsor: Electrical Power Research Institute

The purpose of the research is to develop and validate a computer model that

simulates the interaction between lighting and HVAC systems.

A detailed computer model will be developed for simulating lighting and HVAC

interactions. The model will be based on fundamental principles and validated

empirical relationships. The initial model will be used to perform a sen- sitivity analysis to enable identification of the most significant parameters

to be varied during the measurement portion of the research program. Once the

measurement results are available, the computer model will be validated using

the measurement results, and any changes or modifications in the computer model

will be implemented as appropriate. Once validation has been achieved, the

model will be used to develop suitable algorithms for building energy analysis

programs

The lighting/HVAC model will be used by energy researchers and building

designers to evaluate lighting and HVAC design trade offs, to optimize performance through accurate analysis of lighting and HVAC performance.

54
LIGHTING ENVIRONMENT ASSESSMENT

Arthur I. Rubin, Building Environment Division, (301) 975-6445

Sponsor: U.S. Army Intelligence and Security Command

The objective of the research is an evaluation of environmental conditions in

Army intelligence and security facilities (physical conditions in selected

facilities and staff reaction to these facilities) and to develop standards and

criteria for improving new and existing facilities.

Many military and civilian employees work in environments characterized by

windowless spaces, highly automated equipment, and work tasks requiring

concentration. These conditions may lead to lowered performance and employee

health problems from lighting, air quality, thermal conditions and lack of view

to the outside. Integrated research is needed to identify existing problems

and to develop guidelines for environmental changes.

The project is performed in two phases. The first is a literature search,

interviews with experts and planning and conducting a pilot study at some field

sites. The purpose of this phase is to gain a better understanding of existing

environmental conditions and problems, and to develop, test, and refine data

collection methods and plan for phase 2 study.

The second phase is a comprehensive field investigation at additional sites.

The field studies include physical measures of lighting e.g., luminance,

illuminance, contrast, contrast rendering factor, glare. Other measures

include temperature, noise levels, indoor air quality, and user reaction.

This integrated research effort will result in improved understanding of

environmental conditions and will improve work place conditions in USA-INSCOM

facilities

55
INTERACTION BETWEEN LIGHTING AND HVAC SYSTEMS

Stephen J. Treado, Building Environment Division, (301) 975-6444

Sponsor: Department of Energy

The project's objective is to obtain the heat distribution characteristics of

various lighting systems in typical room thermal environments, to develop a database for detailed lighting heat transfer calculations, to analyze the

components of lighting heat transfer, and to evaluate the influence of wall and

floor construction and HVAC design on lighting and cooling/heating loads.

ASHRAE studies indicate that electric energy consumption in commercial

buildings constitutes as much as 50% of total building energy use. Since the

early 1970 's efforts have been made to reduce the lighting energy consumption

without reducing its illumination performance, such as the development of high

efficiency ballasts, high efficacy light tubes, and the use of daylighting.

This project is a combined, cooperative effort between the U.S. Department of

Energy (DoE) , the Electric Power Research Institute (EPRI) , Dubin-Bloom

Associates and Ross & Baruzzini, Inc. (DB-RB) , and the National Bureau of

Standards (NBS)

The thermal performance of lighting systems in actual room environments will be

examined using a calorimetric chamber and the large NBS environmental chamber.

The environmental chamber will be used to provide the "outdoor" condition for

the calorimetric chamber, in which various lighting system and room configurations will be tested. The NBS environmental chamber temperature can be

controlled to maintain either steady- state or dynamic outdoor temperature

cycles over ranges up to -50 °F to 150 °F. A calorimetric chamber will be

constructed within the large NBS environmental facility. This chamber will

emulate an office space with at least one wall capable of being exposed to the

equivalent of exterior conditions. The chamber will be designed by DBA and

R&B.

The use of the lighting/HVAC design and analysis procedures will enable the

design of energy efficient buildings, resulting in a minimization of building

energy requirements

56
METAMERISM AND FEATURES OF SECURE DOCUMENTS

Belinda L. Collins, Building Environment Division, (301) 975-6456

Sponsor: Bureau of Engraving and Printing, Department of the U.S. Treasury

The objective of this project is to determine features such as color, line

quality, design content, security devices, and lighting conditions.

The Bureau of Engraving and Printing of the Department of the Treasury prints

about 35 billion postage stamps annually. Also, several hundreds of billions

of dollars in paper currency circulate each year in the U.S. With improvements

in copier technology, counterfeiting is becoming more sophisticated yet easier

each year.

During FY 87 , further assessment will be made of those features which appear to

determine accurate identification of counterfeit and genuine banknotes and

documents. The first step in the research program will be to understand those

features most likely to serve as effective counterfeit deterrents. A detailed

review of the literature will be performed and set(s) of innovative currency

designs/devices for experimental evaluation will be developed. This assessment

will include measurement of spectral reflectance and luminance using a spectroradiometer , and a psychophysical determination of the visibility of the

test specimens. The latter procedure will include variation in lighting

conditions including luminance and SPD, and changes in currency characteristics

as color, OVD's and degree of wear. In addition, discussions on the

noticeability of banknote and document features will be conducted with other

researchers throughout the project and at the annual Document Security

Conference

This will be followed by determining common ink- source combinations most likely

to be effective metamers and which could serve as counterfeit deterrents.

Next, a computer analysis will be performed using the ink/light source database

to explore both common and innovative ink- source combinations toward the goal

of determining and developing spectra likely to be effective metamers under

defined lighting conditions.

This research is expected to result in redesign of the current system of paper

currency and ultimately in similar measures for other types of secure documents. Such measures are needed to reduce the threat posed by increasingly

sophisticated counterfeiting operations.

57
BUILDING ENVIRONMENT IMPACT ON OFFICE PRODUCTIVITY

Arthur I. Rubin, Building Environment Division, (301) 975-6445

Sponsor: General Services Administration

The project's objective is to develop design criteria for automated offices,

based on understanding the relationship of lighting and other environmental

conditions on productivity.

It is unclear if automation in the office environments has enhanced

productivity. Advanced systems are placed in settings where lighting and other

environmental conditions were designed to accommodate office tasks.

Research "tools" are not available to perform such studies under "real world"

conditions. The purpose of this research will develop, test, and refine such

tools for use in federal and other buildings. With this information it will be

possible to make more informed decisions about the design of workplaces that

best accommodate technological advances, thereby improving the productivity of

office workers. To accomplish this objective, it is necessary to develop work

productivity measurement procedures of managerial and professional tasks. The

first phase will develop and test appropriate field measurement tools and

procedures and test them in new GSA buildings such as Portland, Oregon and Long

Beach, California. The measurement techniques will be refined and used in full

scale field studies; e.g. sampling a larger number of buildings, activities,

environmental conditions . This work will be performed in several phases

linked to the delivery of new buildings by GSA. During each phase the measurement tools and findings will be refined over the previous one, leading to the

development of a predictive model relating environmental and other design

issues to productivity. This model will help in making improved cost-effective

design decisions.

The use of the procedures, guidelines, and criteria will provide an important

tool to decision maker to enhance productivity in high technology offices.

58
MEASUREMENT OF LUMINOUS BACKGROUNDS

James A. Worthey, Building Environment Division, (301) 975-6446

Sponsor: U.S. Coast Guard

The objective of the project is the measurement and spatial characterization of

the luminous intensity, color, and location of lights in New York City Harbor

at night from specified locations.

A serious problem facing mariners attempting to negotiate waterways at night is

the visual clutter created by numerous bright, colored, flashing lights. There

is need to increase the conspicuity of lighted aids and signals against the

background which they must be seen. The first step in increasing conspicuity

is to characterize the background lighting conditions in harbors through

detailed measurements and observations.

A two-part technical approach using photometric and photographic techniqes will

be used. Three locations in New York City Harbor were selected to perform

detailed photometric measurements of illuminance and luminance and a series of

color and black and white photographs . Frequency counts of the number of

lights meeting specific criteria for illuminance, flash rate, and color in

selected segments will then be made. The visual scene from the observation

point will be divided into segments 5° by 5° for the three sites. Information

such as illuminance, average luminance, color and histograms of illuminance

within these segments will aid in the characterization of the harbor.

SKY LUMINANCE DISTRIBUTION

Stephen J. Treado, Building Environment Division, (301) 975-6444

Sponsor: Naval Civil Engineering Laboratory

The project's objective is to characterize sky luminance distribution for

actual skies based on detailed measurements and analysis.

The calculation of interior daylight levels requires knowledge of the light

from the sky, typically the sky luminance distribution. Little information is

available about the luminance distribution of many classes of real skies

including partly cloudy and hazy conditions . This uncertainty in sky luminance

leads directly to uncertainty in predicting interior daylight levels , and

prevents the accurate evaluation of fenestration systems with solar -optical

properties that are directionally dependent.

The Naval Civil Engineering Laboratory (NCEL) will provide NBS with a sky

luminance scanning system. Measurements will be made of sky luminance conditions under various sky conditions and solar positions. Contour maps of

luminance levels will be generated and analyzed to explore the characterization

of luminance distribution in analytical form to be used for sky luminance

calculations. This work will extend the state of daylighting evaluation

procedures and lead to improved envelope designs and components.

59
BUILDING SECURITY

60
GUIDELINES AND TEST METHODS FOR BUILDING MATERIALS AND EQUIPMENT USED IN

CORRECTIONAL FACILITIES

Robert D. Dikkers, Building Environment Division, (301) 975-5863

Sponsor: National Institute of Corrections, Department of Justice

The project will develop guidelines, test methods, and the technical bases for

standards to assist in the selection, application, and maintenance of building

materials, hardware, and equipment for use in correctional facilities.

In 1983, more than $3 billion was spent on federal, state and local

correctional projects. In many projects, equipment and systems have not

operated properly and have required constant maintenance. In one survey,

respondents reported that security perimeter systems and window construction

(glazing, casing, framing) pose problems in one-half of the institutions.

During the first year of this project, CBT, in cooperation with various

agencies and associations (e.g., American Correctional Association, AIA

Committee on Architecture for Justice) , will identify and collect technical

data and information on the performance of building materials , hardware and

equipment used in correctional facilities. Collected data and information will

include: field successes, problems and failures; available standards and

standards under development; and available test data. At the end of the first

year, CBT will have compiled and assessed the data and information and

prioritized a listing for recommended research and standards development

activities

61
COATINGS

62
QUANTITATIVE CHARACTERIZATION OF BUILDING MATERIALS SURFACES BY COMPUTER IMAGE

PROCESSING

Jonathan Martin, Building Materials Division, (301) 975-6717

Sponsor: National Bureau of Standards

The project's objective is to advance the technology of surface

characterization of building materials using computer image processing and

photon emission properties of the surfaces of materials.

The service -life of building materials, like all engineered materials, is

determined by the chemical and physical properties of the material's surfaces.

Examples include incipient flaws in steel and concrete and the creation of

flaws in roofing membranes and stone surfaces resulting from the effects of

environmental factors. The surfaces of building materials must be

characterized to understand the causes and mechanisms of failures.

CBT developed a new procedure for characterizing the roughness of blasted steel

surfaces. With a thermal gradient imposed through the thickness of a material,

the infrared emissions from the material surface are detected by a thermographic camera; it digitizes the image and mathematically transforms it into a two or three -parameter description of the surface roughness.

CBT has characterized the roughnesses of a standard series of blasted panels

using fractal analysis techniques. Presently, CBT is mathematically modeling

the emissions from well -characterized roughness standards to demonstrate the

geometric characterization of blasted surfaces.

63
ORGANIC COATINGS

Mary McKnight, Building Materials Division, (301) 975-6714

Sponsor: Tri-Services Committee of Department of Defense

The objective of this research is to develop improved procedures for selecting,

using, and specifying coating systems and to transfer the technology to DoD

personnel responsible for maintaining coatings on structures.

The annual cost of organic coatings in the U.S. exceeds 10 billion dollars,

more than half of which stems from the use of protective coatings in buildings

and structures. If effective criteria for the selection, specification, and

use of protective coatings were available, as much as 25 percent of these

expenditures could be saved. An essential element of selection and use

criteria for protective coatings is service life.

CBT staff will visit military installations and attend coatings meetings to

learn about existing and potential problems; perform laboratory studies to

develop improved test procedures; provide leadership in standards activities to

solve these problems ; and implement the results by authoring manuals

presenting talks, and publishing papers.

During FY 87, CBT will continue development of the ASTM specification for

interior flat latex paint, VOC related problems will be addressed, the revision

of the Tri- Service Coatings Manual will be completed, and advisory and

consultative service, based upon laboratory and field tests, will be performed.

PERFORMANCE TESTS AND CRITERIA FOR COATINGS

Mary McKnight, Building Materials Division, (301) 975-6714

Sponsor: Federal Highway Administration

The program objective is to develop improved procedures to predict service -life

of coatings for steel.

This project addresses two needs. The first is for improved short-term tests

to aid quantitative service life prediction of coating systems for bridges.

Selection of traditional coatings usually has been based on in-service data.

For new coatings, there is inadequate in-service data available to make costeffective selections. Short-term tests that predict performance are needed to

select coating systems. The second need is for improved guidance for coatings

engineers to select coating systems based on the best available knowledge.

To meet the first need, three coatings will be exposed in a warm seacoast

environment and in controlled laboratory environments . Results from laboratory

and field tests and results of previous FHWA sponsored coatings work will be

used to further the understanding of the relative importance of degradation

factors and to develop reliable tests methods, evaluation criteria and predictive models. To meet the second need, CBT will develop guidelines for coating

engineers to select cost-effective systems.

54
DEGRADATION OF ORGANIC PROTECTIVE COATINGS

Tinh Nguyen, Building Materials Division, (301) 975-6718

Sponsor: National Bureau of Standards

The project objective is to develop improved methods to detect and quantify

blistering and corrosion under coatings, and to develop models to aid in

predicting the rates of formation and growth of blisters.

Corrosion-related problems in the United States cost more than $70 billion

annually. The use of polymeric coatings is an effective, economic, and widely

used means to prolong the life of corrosion-prone construction materials used

in the infrastructure. However, coatings are susceptible to degradation under

in-service environments.

Research will concentrate on 1) characterizing and quantifying molecular

behavior at the steel/coating interface of epoxies and other high performance

coatings before and after exposure, 2) proposing degradation mechanisms for

those materials and 3) characterizing coating reactions and properties that

control interfacial changes. The research builds on previous work by obtaining

knowledge about the fundamental mechanisms of interfacial degradation between

high-performance coatings and steel substrates, including identification of

chemical reactions which contribute to the interfacial degradation. Methods to

measure and understand the processes and factors which affect the permeation of

water, oxygen, and ions through protective coatings will be assessed. The data

will be used to develop and validate models that predict the service -life of

protective coatings. The research relies on Fourier Transform Infrared

Spectroscopy (FTIR-RA) to study the molecular behavior and changes at the

steel/epoxy coating interface. The method will provide new data on chemical

changes at the interfaces of high performance coatings and steel. Nondestructive methods to measure the pore size and pore size distribution of coatings

will be explored. Development of a method will permit data which are essential

for advancing the predictive modeling phase of the coatings research to be

obtained.

BOND STRENGTH OF ORGANIC FILMS ON METALS DURING SERVICE USING

REFLECTION/ABSORPTION FOURIER TRANSFORM INFRARED SPECTROSCOPY

Tinh Nguyen, Building Materials Division, (301) 975-6718

Sponsor: Office of Nondestructive Evaluation, National Bureau of Standards

This research will establish the relationship between reflection/absorption

Fourier transform infrared spectroscopy (FTIR-RA) band shifts with adhesion

(bonding strength) test data and using these band shifts, assess the durability

of a bond between a polymer film and a metal substrate. Two types of adhesion

tests, pull-off and scratch, will be performed following FTIR-RA analyses for

two different metal/polymer systems before and during accelerated testing

exposures

This research will provide a nondestructive procedure for use in quality

control and as a research technique to monitor the bond strength and durability

of thin and thick films on metal.

65
VOLATILE ORGANIC CONTENT (VOC)

Mary McKnight, Building Materials Division, (301) 975-6714

Sponsor: Air Force Engineering and Services Center

The project will develop a work plan for DoD to meeting the need to purchase

documents for volatile organic content (VOC) compliant coatings on military

facilities

About half of U.S. specifications currently used to purchase paints for

facilities use do not meet some of the Environmental Protection Agency's VOC

rules that take affect in 1987. With the possibility of even more restrictive

rules will be established, purchasing criteria for new compliant materials will

be needed. CBT is developing a work plan to help DoD respond to the need for

purchasing documents. The work will be accomplished by 1) examining federal,

state, and local rules governing VOC in paints, 2) determining VOC of government specification paints used for facility maintenance, 3) surveying commercially available low VOC products, and 4) listing needs for new specifications.

Input will be obtained from industry, trade associations, users, standardssetting organizations, and the literature to formulate the plan.

66
TEST METHOD FOR FRIABILITY OF SPRAYED FIREPROOFING AND INSULATING MATERIALS

Walter J. Rossiter, Building Materials Division, (301) 975-6719

Sponsor: General Services Administration

The project objective is to develop a field test method to measure the

friability of soft, loosely bound, sprayed- applied fireproofing and insulating

materials containing asbestos fibers.

The predominant use of asbestos -containing material in buildings has been

sprayed-on fireproofing and thermal and acoustical insulation on structural

members and on walls and ceilings. These friable materials may be readily

crumbled or pulverized which could release airborne asbestos fibers into the

building environment. No quantitative field test is available.

A two -phase study will be conducted. In the first, a test method for measuring

the friability of asbestos -containing materials will be established. Appropriate test methods (that have been used or have potential for use) for

friability of spray- applied fibrous materials will be reviewed. Key properties

that need to be measured to characterize friability will be determined.

Scientific principles that serve as a basis for development of test methods

that determine these properties will be identified. Test methods identified as having potential for measuring friability will be selected for evaluation.

Current tests such as air erosion and resistance to tumbling will be

considered. A proposed test based on the use of sound energy to determine the

ease of breaking loose friable materials will be evaluated. Preliminary

laboratory testing will be conducted on selected test methods to further assess

their potential for measuring friability. Recommendations will be made to

identify those test methods which are considered to offer the most potential

for the field measurement of friability.

In Phase Two, promising field test methods, identified in Phase One, will be

evaluated. In-depth laboratory and field studies will be conducted to determine the effectiveness of candidate methods to quantitatively measure

friability. Work includes preparation of a set of friability evaluation

samples, design and fabrication of field test equipment, and laboratory and

field evaluation studies to determine the effectiveness of the developed test

methods

67
ROOFING SYSTEMS

68
QUALITY ASSURANCE OF USPS ROOFING SYSTEMS

Walter J. Rossiter, Building Materials Division, (301) 975-6719

Sponsor: U.S. Postal Service

The objective of this project is to provide technical assistance to the U.S.

Postal • Service (USPS) in implementing NBS recommendations that improve the

quality assurance practices for USPS roofing.

Unacceptable roofing performance is a major USPS facilities problem. USPS

annually spends over $30 million for roofing repair, replacement, and new

construction. The work includes technical review of roofing documents prepared

by USPS, or individuals under contract to USPS, and failure analysis of

selected USPS roofing materials and systems.

CRITERIA FOR MODIFIED BITUMEN ROOFING MEMBRANE MATERIALS

Walter J. Rossiter, Building Materials Division, (301) 975-6719

Sponsor: Department of Defense

The objective of this research is to develop preliminary criteria for selecting

and specifying polymer-modified bituminous roofing membrane materials.

Criteria have not been developed to select and specify these membranes

materials . Although an ASTM task group was formed to meet the needs for

standards, the ASTM standards will not be available for at least four years.

Interim criteria are needed to provide the technical basis for voluntary

consensus standards.

CBT will perform a two-phase study. In the first phase, existing test methods

that characterize polymer-modified bitumens will be reviewed and summarized as

a starting point for the development of the criteria. Recommendations for new

test methods will be made. Laboratory testing will be conducted to obtain data

needed in preparating the criteria. Field visits to observe selected polymermodified bitumen membranes will be conducted to assess performance and identify

failure mechanisms . Recommendations on interim criteria for modified-bitumens

will be produced.

In Phase Two, laboratory and field research, based upon the needs identified in

Phase One, will be continued to develop the database needed for the final

criteria.

69
SERVICE LIFE OF SINGLE-PLY ROOFING MEMBRANES

Jonathan W. Martin, Building Materials Division, (301) 975-6717

Sponsor: National Bureau of Standards

The goal of this research is to provide the technical basis for developing an improved knowledge base for criteria and methods for predicting service -life of

single-ply roofing membranes.

In the mid-1970's, single -ply membranes were only 2 percent of all low- sloped

roofing membranes. By 1985, they were 25 percent, and they will be about 50

percent by 1990. The annual costs of installed single -ply membranes in 1986

were about $3 billion. The phase of this work include problem definition, pretesting, experiment and evaluation, analysis, and interpretation of data. The

service life of adhesively -bonded joints of EPDM single-ply membranes was

selected as the focus for this study. Factors considered in the selection of

this aspect of single-ply roofing were both economic and technical. EPDM is

presently used in approximately 60 percent of all single-ply applications.

Based on CBT field observations and on information from the NRCA and from

industry leaders, failure of bonded joints is the most prevalent mode of

failure. The key factors indentified as potential contributors to failure of

bonded joints were mechanical stress, temperature, moisture and application

parameters, such as surface cleanliness, application temperature, and force

applied to ensure bond contact.

Research will be performed through field inspections of single-ply roofing

installations (at time of installation and after installation) ; interactions

with consultants, manufacturers, researchers, other agencies, and standards

setting organizations for better knowledge of failure mechanisms; a Round Table

of industry leaders; and laboratory studies of bonded specimens with known

flaws and defects in the joints. The latter task will involve the pulse -echo

method to monitor flaw and defect growth.

Laboratory research will determine the effect of surface contaminants

particularly talc, on bond integrity and experimental results will be

incorporated into a probabilistic model. Computer image analysis will quantify

the surface contamination prior to creep -rupture experiments.

70
ASSESSMENT OF EXTERIOR CONDITION OF METAL BUILDINGS AND ROOFING SYSTEMS

Jonathan W. Martin, Building Materials Division, (301) 975-6717

Sponsor: Tri-Services Materials Committee of Department of Defense

This project's objective is to develop a procedure using computer image

processing for the quantitative assessment of the degradation state of a building for use as the basis for maintenance decisions.

This research builds on CBT's research to quantify the degradation state of the

exterior of metal buildings and roofing from visual or infrared pictures using

computer image processing techniques. The research expands on the previous

developed methodology for systematically assessing the condition of the

exterior siding of metal buildings. The procedure was based on the use of

visual standards. Products of this research include a detailed report on a semi -quantitative way of assessing the condition of a building.

FACTORS AFFECTING INITIAL BOND OF SEAMS IN SINGLE -PLY RUBBER MEMBRANES

Walter J. Rossiter, Building Materials Division, (301) 975-6719

Sponsor: Department of Defense

The objective of this project will determine the effect of application

conditions on the initial bond strength of adhesive -bonded seams in single-ply

rubber membranes as a function of time, application temperature, and surface

cleanness

Performance of adhesive -bonded seams in single -ply rubber membranes is

dependent on application conditions . Seams may be fabricated under a variety

of environmental conditions. Workmanship plays an important role for the

amount of sheet surface contamination, applied pressure, and adhesive thickness

and coverage. In spite of the number of parameters that may contribute to

improper application, criteria are not available to judge whether seams are assembled in the field as intended.

CBT is developing a test method to evaluate the quality of seams at the time of

fabrication. The test will assess the quality of newly-prepared seams; it will

be sensitive to detecting variations in bond strength due to application

conditions or workmanship. The combined effects of time, temperature, and

surface cleanness will be investigated. Seams, prepared from properly cleaned

and uncleaned (contaminated) rubber sheets, will be tested using a T-peel test

within hours after bond formation. Seam formation will be performed over a range of temperatures which are encountered during field application.

71
QUALITY ASSURANCE OF DoD ROOFING SYSTEMS

Walter J. Rossiter, Building Materials Division, (301) 975-6719

Sponsor: Department of Defense

The objective of this project is to provide technical assistance to the

Department of Defense (DoD) to improve the quality assurance of its roofing

practices

Unacceptable roofing performance is a major facilities problem. In the late

1970' s, the U.S. Air Force estimated its built-up roofs were lasting, on the

average, 12 years instead of the intended design life of 20 years or more. This project will provide technical assistance to implement practices that

improve roofing performance. The study will include: participating in

technical meetings of DoD's Tri-Services Roofing Committee to discuss inservice performance of roofing, field problems, and research needed to solve

the problems experienced, providing technical reviews of roofing documents

prepared by DoD and DoD contractors, and performing failure analysis of

selected DoD roofing materials and systems.

72
CONCRETE

73
POLYMER CONCRETE SET TIME

Robert G. Mathey, Building Materials Division, (301) 975-6709

Sponsor: Air Force Engineering and Services Center

The project will obtain set time data for a particular type of polymer concrete

(aggregate, resin, and catalyst) for a wide range of aggregate and resin

temperatures and investigate the effects of water and ice on set time.

The Air Force has been conducting studies for many years on the repair of

runways. Rapid repair of damaged areas of runway pavement is essential to

restore the operation of aircraft as quickly as possible. There is a need to

have available established means and materials for rapidly repairing damaged

areas of pavement.

This study will produce technologies that better characterize the material's

performance prior to use in the field. The set time of a particular type of

polymer concrete will be controlled and measured in the laboratory for a wide

range of aggregate temperatures and a corresponding wide range of resin

temperatures . Dry and wet aggregate and wet aggregate containing a range of

ice concentrations will be included in the study. The testing will be con- ducted to describe the impact of various resin and aggregate temperature

combinations on set time. Temperature measurements will be made during the set

time tests. A set time prediction model will be developed based on a simple

thermodynamic analysis. It will include materials properties, their initial

temperatures, their mass, and peak exotherm temperature. A limited number of

tests will be conducted to determine the impact of temperature variations on

the flexural strength of the polymer concrete. The flexural beam specimens

will be tested at age 30 minutes.

74
INFLUENCE OF INTERFACIAL MICROSTRUCTURE ON BONDING IN CONCRETE

Leslie Struble, Building Materials Division, (301) 975-6715

Sponsor: Air Force Office of Scientific Research

The objective of the research is to develop an improved understanding of the

relationships between the microstructure of hydrated cement paste in the region

of its interface with other concrete constituents and fracture of paste in this

interfacial region.

Concrete is a composite material, comprised of hydrated portland cement, coarse

and fine aggregate, and often reinforcing steel and occasionally constituents

such as steel or other fibers. The bonds that form between cement paste and

each of the other constituents are important to concrete strength and durability. At its interface with aggregate, and probably with other concrete

constituents, the microstructure of hydrated cement paste is known to be

different than in regions away from the interface. It is not understood how

this interfacial microstructure affects the fracture properties of the

composite, and thus the strength of concrete.

During this second year of a three year project, the microstructure of cement

paste near its interface with a number of other concrete constituents will be

examined, and the influence of the microstructure on fracture near the interface will be studied. The micros tructural examinations will concentrate on

determining the morphologies of the hydrated cement phases present, i.e., their

size, shape, and interrelationships. The principal technique for microstructure examinations will be scanning electron microscopy, using a backscatter

detector to examine specimens that have been impregnated with epoxy and

polished. Research will explore relationships between interfacial microstructure and mechanical properties of the bond, e.g., tensile strength, shear

strength and, possibly, fracture toughness.

REPRESENTATION OF CONCRETE MICROSTRUCTURE

Hamlin Jennings, Building Materials Division, (301) 975-6720

Sponsor: National Bureau of Standards

The project's objective is to develop a method for the symbolic represention of

the microstructure of cement paste and concrete that produces a quantitative

representation of microstructure suitable for standardization.

Microstructure is the key to connecting the physics and chemistry of the

hydration of cement to bulk properties of hardened cement paste and concrete.

The project has two parts: 1) developing microscopic techniques to resolve the

phases of interest including pores, aggregate, hydration products and anhydrous

phases and 2) developing algorithms which translate the digitized image into

mathematical representations which contain information about quantity, size,

shape, distribution and connectedness of the phases present. Using results

from analyzing air voids as a basis, algorithms will be developed to analyze

the complex fine porosity. Also, microscopic and mathematical techniques will

be developed for imaging aggregate.

75
ULTRA-HIGH STRENGTH CONCRETE

Hamlin Jennings, Building Materials Division, (301) 975-6720

Sponsor: Air Force Engineering and Services Center

The objective of this project is to determine the effect of various cement

mixtures on fracture mechanics parameters (strength, effective surface energy,

and Young's modulus) and the microstructure of the hardened material.

Advances in concrete technology have made possible the development of highstrength concrete with compressive strengths far in excess of 9000 psi (60 MPa)

usually considered high for conventional concrete. Concretes with compressive

strengths above 20,000 psi (140 MPa) have been prepared by the use of silica

fumes and high-range water -reducers in the concrete mixture. It is possible to

produce ultra-high strength concretes with compressive strength greater than

30,000 psi (210 MPa)

This research will apply materials science concepts to i) study the factors

which control the strength of ultra-high strength concrete, ii) form the basis

for establishing the upper limit of strength, and iii) study the feasibility of

developing ultra-high strength concrete (compressive strength greater than

30,000 psi (210 MPa) which can be cast under field conditions. The volume

fraction of porosity will be held at two constant values using pressure

compaction techniques . This will allow a series of experiments that can

separate the influence of a number of different variables on fracture mechanics

parameters, without having the difficulties of controlling the amount of pores.

The variables of interest are curing temperature and the nature and quantity of

aggregate, silica fume, and admixtures. The influence of shear mixing will be

investigated and, as far as possible, the porosity will be similar to the

porosity of the pressure compacted specimens. The microstructure of each type

of specimen will be analyzed with special attention being given to the size and

distribution of porosity. These results will be analyzed with a view towards

establishing the influence of each variable on the fracture mechanics parameters and therefore determining the upper limit of strength that can be

achieved for cement-based materials.

76
MINIMUM STRENGTH LEVELS FOR THE BOND OF REPAIR MATERIALS TO EXISTING CONCRETE

PAVEMENTS

Larry Knab, Building Materials Division, (301) 975-6712

Sponsor: Tri- Services of Department of Defense

The objective of this work will establish preliminary minimum strength levels

for the bond between repair materials and existing concrete pavements

The bond strength between a repair material and its existing concrete substrate

is a major factor in the repair of existing concrete pavements. The approach

to establishing preliminary minimum bond strength levels will be to determine

the bond strength of repair materials (e.g., new concrete or latex-modified

concrete) to existing concrete using the NBS uniaxial tension and slant- shear

tests concurrent with the direct shear test. Correlations between the test

results for the uniaxial tension, slant- shear, and direct shear will be sought.

The correlation will be used to establish preliminary minimum performance

levels for the uniaxial tension and slant- shear tests corresponding to the

direct shear minimum performance strength level of 200 psi.

77
CEMENT HYDRATION (COMPETENCE PROJECT)

Paul W. Brown, Building Materials Division, (301) 975-6708

Sponsor: National Bureau of Standards

The objective of this project is to improve: understanding of the physics and

chemistry of cement hydration, development of microstructure in pastes of

Portland cements; effects of chemical admixtures on these processes; and

development and validation of mathematical models based on physical and

chemical mechanisms

Over $4 billion each year is spent on cements used in concrete costing

approximately $20 billion. Concrete could be a much more predictable material

and a material capable of achieving higher levels of performance than are now

achieved. Investment in cement research has the potential of producing

significant benefits to the construction industry and the nation by providing

the technical bases to improve the durability of concrete structures. Recognizing the increasing importance of chemical admixtures in advancing construction technology, CBT's effort emphasizes the development and testing of

fundamental mathematical models based on conceptual models . Hydration and

microstructural models will be developed to predict the effects of chemical

admixtures. The chemistry and physics of the interactions between hydrating

cement particles and surfactants will be investigated.

CBT's work on microstructural development and the effects of particle size

distribution on hydration led to a model that simulates microstructural

development which occurs when a single phase reacts with water. The hydration

model developed for portland cements will predict, as a function of time, the

degree of hydration, concentration of ions in solution, heat release, interparticle porosity, and volume changes. This approach will be extended to deal

with the hydration of individual cement phases in the presence of surfactants.

Application of this knowledge will lead to improved standards for cements,

greater uniformity of cements, improved cements, more effective use of material

resources in concrete and other reaction- formed ceramics, greater productivity

in the cement and concrete industries, and more durable concrete structures.

Knowledge of the mechanisms by which chemical admixtures affect the rheology,

hydration rate, and microstructure of cement pastes will permit the design of

the microstructure of concrete to significantly improve its performance and

durability.

78
QUALITY ASSURANCE OF LABORATORIES

79
AASHTO MATERIALS REFERENCE LABORATORY (AMRL)

James H. Pielert, Building Materials Division, (301) 975-6704

Sponsor: American Association of State Highway and Transportation Officials

The purpose of this effort is to provide on-site inspection of public and

private construction materials testing laboratories and distribution of

proficiency test samples.

With the support of AASHTO Research Associates working under CBT supervision,

services are provided to laboratories testing soils, aggregate and bituminous

materials and frictional properties of highways. Procedures used in performing

conventional quality assurance tests are observed for conformance to applicable

national standards. Proficiency test samples of asphalt, soils, aggregates and

bituminous concrete are developed and distributed at regular intervals to

obtain information on laboratory performance

This work improves the reliability of test measurements; provides data to

quantify standard measurement techniques; and provides direct communications

between testing laboratories and standards -writing committees.

CEMENT AND CONCRETE REFERENCE LABORATORY (CCRL)

James H. Pielert, Building Materials Division, (301) 975-6704

Sponsors: American Society for Testing and Materials and

U.S. Army Corps of Engineers

This work provides on-site inspection of public and private cement, concrete,

aggregate, pozzolan and reinforcing steel, testing laboratories and the

distribution of proficiency test samples.

Roads, bridges, water supply and sewage systems, buildings, airports,

railroads, waterway systems, mass transit systems and other structures represent a substantial portion of the nation's wealth. Construction of such

facilities is one of the nation's largest industries usually amounting to about

10 percent of the Gross National Product. Over $4 billion of hydraulic cement

is produced in the United States each year. The productivity of the cement and

concrete testing laboratories can be increased by using correct procedures and

apparatus that reduce testing errors and provide a sound basis for acceptance

of cement on the basis of mill certificates.

With the support of ASTM Research Associates working under CBT supervision,

services are provided for on-site inspection of testing laboratories and the

distribution of proficiency test samples. Test apparatus is checked with

inspection equipment calibrated by NBS personnel. Proficiency test samples of

Portland cement, concrete, blended cement, and masonry cement are distributed

at regular intervals to obtain information on laboratory performance. Participation in the work of the ASTM technical committees by CCRL staff is a mechanism used to provide the standards community with information developed by

the inspection and proficiency sample programs. This work leads to improved

quality of testing in U.S., Canadian and Mexican cement and concrete laboratories by i) providing measures of the reliability of test measurement techniques; ii) data to quantify standard measurement techniques; and iii) direct

communications between testing laboratories and standards -writing committees.

80
CALIBRATION OF PAVEMENT ROUGHNESS MEASURING DEVICES

James H. Pielert, Building Materials Division, (301) 975-6704

Sponsor: Federal Highway Administration

The purpose of this project will be development of guidelines and criteria for

calibration of road roughness measuring devices in the field.

The NBS Center for Manufacturing Engineering has an FHWA funded project to

develop and demonstrate procedures that can serve as a basis for field calibration of inertial road roughness profilometers . The study involves the development and testing of procedures for calibrating the major components of the

profilometer , a determination of the overall uncertainty of the profilometer '

operation, and a field verification that this uncertainty is applicable to the

dynamic field operation of the system. CBT will perform field testing,

interact with state DoT's, and collect and disseminate data. CBT's AMRL staff

will attend training sessions to use the profilometers to obtain a familiarity

with the equipment, computer software and operating principles. AMRL will

provide a liaison with state DoT staff.

This program will have broad impact on the nation's transportation system by

providing data on the condition of the highway system and developing criteria

for the design, maintenance, and rehabilitation of highways.

81
NBS-1 14A (REV. 2»60

)

U.S. DEPT. OF COMM. 1. PUBLICATION OR 2. Performing Organ. Report No. BIBLIOGRAPHIC DATA

REPORT NO.

SHEET (See instructions)

3. Publication Date May 1987

4. TITLE AND SUBTITLE

Building Technology Project Summaries 1987

5. AUTHOR(S)

Noel J. Raufaste

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

7. Contract/Grant No.

I. Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City, State, ZIP)

10.

SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document Includes a significant

bi bliography or literature survey, mention it here)

The Center for Building Technology (CBT) of the National Bureau of Standards (NBS)

is the national building research laboratory. It works cooperatively with other

organizations, private and public, to improve building practices. It conducts

laboratory, field, and analytical research. It develops technologies to predict,

measure, and test the performance of building materials, components, systems,

and practices. This knowledge is required for responsible and cost-effective

decisions in the building process and cannot be obtained through proprietary research

and development. CBT provides technologies needed by the building community to

achieve the benefits of advanced computation and automation. CBT does not promulgate

building standards or regulations, but its technologies are widely used in the

building industry and adopted by governmental and private organizations that have

standards and codes responsibilities. This report summarizes the projects underway

in the Center during 1987.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) building research; building technology; criteria; measurement and test methods;

performance criteria; project summaries; standards; technical bases

13. AVAILABILITY

^] Unlimited

| | For Official Distribution. Do Not Release to NTIS

f 1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

89

15. Price

$ 13.95

U SCOMM'DC 6048-P 80