^atioTal Bureau of Stanairai

Jbrary, £-01 ^^'^

^^^doirslG SCIENCE SERIES

Experimental Determination

Of Eccentricity of Floor Loads

Applied to a Bearing Wall

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards
Announcing—The Building Science Series

The "Building Science Series" disseminates technical information developed at the

Bureau on building materials, components, systems, and whole structures. The series

presents research results, test methods, and performance criteria related to the structural

and environmental functions and the durability and safety characteristics of building

elements and systems.

These publications, similar in style and content to the NBS Building Materials and

Structure Reports (1938-59), are directed toward the manufacturing, design, and construction segments of the building industry, standards organizations, officials responsible

for building codes, and scientists and engineers concerned with the properties of building

materials.

The material for this series originates principally in the Building Research Division

of the NBS Institute for Applied Technology. Published or in preparation are:

BSSl. Building Research at the National Bureau of Standards. (In preparation.)

BSS2. Interrelations Between Cement and Concrete Properties: Part 1, Materials and Techniques, Water Requirements and Trace Elements.

35 cents

BSS3. Doors as Barriers to Fire and Smoke. 15 cents

BSS4. Weather Resistance of Porcelain Enamels: Effect of Exposure Site and

other Variables After Seven Years. 20 cents

BSS5. Interrelations Between Cement and Concrete Properties: Part 2, Sulfate

Expansion, Heat of Hydration, and Autoclave Expansion. 35 cents

BSS6. Some Properties of the Calcium Aluminoferrite Hydrates. 20 cents

BSS7. Organic Coatings. Properties, Selection, and Use. $2.50

BSS8. Interrelations Between Cement and Concrete Properties: Part 3,

Compressive Strengths of Portland Cement Test Mortars and Steam-Cured

Mortars. 55 cents

BSS9. Thermal-Shock Resistance for Built-Up Membranes. 20 cents

BSSIO. Field Burnout Tests of Apartment Dwelling Units. 25 cents

BSSll. Fire Resistance of Steel Deck Floor Assemblies. 25 cents

BSS12. Performance of Square-Edged Orifices and Orifice-Target Combinations

as Air Mixers. 15 cents

BSS13. Shrinkage and Creep in Prestressed Concrete. 15 cents

Send orders with remittance to: Superintendent of Documents, U.S. Government

Printing Office, Washington, D.C. 20402. Remittances from foreign countries should include an additional one-fourth of the purchase price for postage.

[See mailing list announcement on last page.]
UNITED STATES DEPARTMENT OF COMMERCE • C. R. Smith, Secretary

NATIONAL BUREAU OF STANDARDS • A. V. Astin, Direclor

i

Experimental Determination of Eccentricity of Floor Loads

Applied to a Bearing Wall

I ^ D. Watstein and P. V. Johnson

Building Research Division

Institute for Applied Technology

National Bureau of Standards

I Washington, D.C.

I

j

I

j Building Science Series 14

Issued June 1968

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 15 cents
CONTENTS

Page

1. Introduction 1

2. Description of the compressive steel reaction strut for measurement

of eccentricities, and its calibration 1

3. Eccentricity of reaction of an I-beam bedded in gypsum plaster 3

4. Eccentricity of reaction of an I-beam supported on neoprene rubber, 4

5. Eccentricity of supporting force at the base of a bearing wall subjected to an eccentrically applied load 4

6. Summary 5
Experimental Determination of Eccentricity of Floor Loads Applied

to a Bearing Wall

D. Watstein* and P. V. Johnson*

The eccentricity of the loads appHed to a specially cahbrated compressive strut simulating a brick bearing wall was experimentally determined for a variety of bearing materials and conditions of contact. In one series of tests, an I-beam was bedded in high strength

gypsum plaster, bonded and unbonded. For the unbonded plaster bed the eccentricity ratio ' increased with the applied load to a maximum value of about 0.42, while for the bonded

plaster bearing this ratio decreased to an average value of about 0.24 at the maximum load. In the second series of tests the eccentricity was observed for an I-beam supported on

neoprene rubber pads, capped and uncapped, of different thicknesses, and of different bearing length. In general the eccentricity ratio increased slightly with the applied load. Lack of intimate contact between the I-beam and the rubber pad Ys in thick resulted in an

eccentricity ratio of about 0.40, or nearly the same as for unbonded plaster bearing. Intimacy

of contact produced by plaster capping resulted in a marked reduction in the eccentricity

ratio to about 0.29; the confinement of the bearing length of the rubber pad to one-half of that used in previous tests and placing it at the extreme end of the beam, further reduced the

eccentricity ratio to about 0.18, and to 0.13 for a rubber pad 0.25 in thick. Key words: Bearing pads, bearing walls, brick masonry, design of bearing walls, eccentricity of applied loads.

1. Introduction

Since exterior bearing walls are designed as

i eccentrically loaded compression members, it is important to know what the eccentricities of the

I applied floor loads are for different bearing

materials and different conditions of contact

between the supporting structure and the floor beams. Some recently completed exploratory

studies by the Structural Clay Products Institute

Research Fellowship at NBS indicated that it is feasible to measure the eccentricities of applied

: loads using a specially designed stress-sensitive

compressive strut calibrated under loads of known

eccentricities. The strut was assumed to simulate

a load bearing wall of brick masonry even though

the boundary conditions and the elastic properties

of the strut were different from those encountered

in an actual masonry structure. The exploratory study included an investigation

of such parameters as thickness and rigidity of

bearing materials, the intimacy of contact between the supporting structure and the flexural

members, and the effect of bond with the bedding

material on the eccentricity of the floor loads.

The feasibility of measuring the eccentricity

of the force supporting a masonry wall subjected

to an eccentrically applied load was also explored.

2. Description of the Compressive Steel Reaction Strut for Measurement of

Eccentricities, and Its Calibration

The compressive steel reaction strut was a rec- tangular steel tube 4 by 8 inches in cross section

having a wall 0.187 in thick. The strut was 18

1 in high and had a %-in welded steel plate insert

I at the top providing a closed end. The strut was

capped with a 1- by 4- by 8-in cold-rolled steel

j plate bonded to the top welded plate insert with

I epoxy cement. The whole assembly was then

I capped with a solid extruded clay brick which

1 served to receive the load, simulating the bearing

conditions at the top of a brick masonry wall.

•Present address: Structural Clay Products Institute, 1760 Old Meadow

Road, McLean, Virginia 22101.

' The eccentricity ratio is defined as the ratio of eccentricity to the overall thickness of the strut.

The open bottom end was machined normal to the axis of the strut and was supported on a machined steel plate 4 in thick.

The dimensions of the capping brick were 23^^ by 3^16 by 7% in and hence the brick did not

cover the 1-in steel cap completely. The brick was set flush with one side of the strut (designated as side H) and was centered with respect

to the 4-in dimension of the strut as shown in

figure 1. The strut was instrumented with bonded wire

strain gages at two different levels. The location

of the gages is indicated in figure 1.

1
Calibrating

load P

- epoxy

joints

3/8 welded

steel insert

I - I

®

39/16".

br ^ 7 7 ck , /8 ^

steel plate

bonde d wire

/

jes

t = 8"

®

2-2

Figure 1. Schematic drawing of instrumented reaction strut for measurement of eccentricity of load.

During calibration a load, P, was applied to the

strut through a hardened steel knife edge seated

in a suitable V block. Thus, the eccentricity of the

applied load could be measured with a steel scale

with an accuracy of about %2 in. Let (Jmax and Cmin be respectively the stresses on

the side of the applied load and the opposite side;

then the following expressions can be written

P Pec

and

where

P Pec

'A Ar'

Pec_P r ec]

Ar^ Al'^r'J (1)

(2)

A=th.e cross section area of the strut, in.^, c= distance from the neutral axis to the outer- most fiber, inches,

r=radius of gyration, inches. (Ar^^moment of

inertia of the section) , and

e= eccentricity of applied load, in.

Adding (1) and (2),

''max ~r ""mln ^

Subtracting (2) from (1),

'''max Cmln" 2 Pec

(3)

(4)

Dividing (4) by (3),

^max ^mln

c~i" mlD (5)

and solving for e,

t

O'max O'min I

''^max ~t~ "^minJ

Assuming that the stresses o-max and o-min are

,

within the elastic limit, the eccentricity e in terms

of strains e^ax and e^in is given by:

^ ^ r^max femiQ~j ^ L^max~l~ ^minj

(6)

For the reaction strut used in these tests, r7c=2.06, and (6) becomes

?=2.06('^5«i^^\

\fmax~r ^mln/

(7)

The theoretical relationship given by (7) and

the experimental curve determined in two separate laboratory setups are compared in figure 2. The experimental values of eccentricity e were

varied over a range of 3 in on each side of the center line of the strut. It should be added that

the strain values given in figure 2 were those

obtained from the lower set of strain gages, since

they yielded a more consistent relationship than

the top gages. The departure of the calibration curve from

the straight line predicted by eq (7) may possibly

be accounted for by the nonhomogeneous nature

of the welded steel tube used in fabricating the

strut, and the possible presence of slight irregu0.8 0.4 SIDE L

Figure 2. Calibration of reaction strut in terms of eccentricity.

( e VS. — 1-

ij
larities commonly found in thin walled extruded have it relatively free from the deficiences which

I steel shapes. In future work, it is intended to might have caused the deviation from theoretical

fabricate a strut of greater strain sensitivity and relationship shown in figure 2.

3. Eccentricity of Reaction of an I-Beam Bedded in Gypsum Plaster

One series of five tests was carried out with an I-beam 6 in deep and a flange 3K in wide bedded

in high strength gypsum plaster. As in all determinations of eccentricity described in this paper,

the end of the I-beam extended to the center line

of the supporting strut. The arrangement of supports and the load are shown in figure 3, along with

the device for measuring the rotation of the beam

end at the strut. This measurement was an ap- proximation based on the assumption that the

strut did not depart from its initial vertical position, and that the vertical displacement of the

point at which the micrometer dial assembly was

attached to the I-beam was negligible.

In Tests 1 and 2 the I-beam was bedded in unbonded plaster. The bond between the plaster

and the bearing surfaces was destroyed by confining the plaster putty between two sheets of

polyethylene. The variation of the eccentricity

ratio with the rotation of the beam end is illus- trated in figure 4. It is noted that at small rotations

of the beam supported on the strut simulating a

wall, the eccentricity ratio ejt ^ was about 0.35, or nearly the value usually assumed in design of

masonry walls. The eccentricity ratio increased

with the rotation of the beam and tended to reach

a constant value at large rotations. For Tests 1 and 2, the maximum values of ejt were 0.43 and

0.001 0.002 0.003 0.004 ROTATION OF BEAM END, RADIANS

Figure 4. Eccentricity of reaction for an I-beam bedded in gypsum plaster. Tests 1 and 2—unbonded plaster; Tests 3,

4, and 5-—bonded plaster, spans 24, 36, and 48 in, respectively.

gypsju

pla

6 - In, I- beam

Ing

0.001 - in. micrometer dial

Figure 3. Schematic diagram of test set-up for an I-beam

bedded in gypsum plaster.

1 1 is defined as the overall thickness of the strut.

0.40 respectively, with an average of 0.415. The

maximum center load applied in these tests was

25 kips and the beam span was 44 inches.

In Tests 3, 4, and 5 the I-beam was bedded

in bonded plaster and the span lengths were 24, 36

and 48 inches respectively. It is interesting to compare in figure 4 the effect of bonded and un- bonded plaster bearings on the behavior of the

I-beam. The unbonded I-beam showed an increase

in the eccentricity ratio with load, while that for the bonded I-beam showed the opposite. The value

of e/t for the bonded I-beam was about 0.32 for

low loads and decreased with the rotation of the

beam; the eccentricity ratio tended to reach a constant value as the rotation increased. The

average e/t for the three tests at the maximum

recorded rotation was about 0.24, and represents

a reduction of 42% as compared with the eccentricity ratio for unbonded plaster.

Although the use of high strength gypsum

plaster is not practical as a permanent bedding

material for floor beams, its effect as a bonding

bearing material was investigated as one phase of

the broad problem of load transfer to masonry

walls. It is possible that some other more permanent bedding material can be found which would

have the same favorable effect on the eccentricity

ratio as the high strength gypsum plaster.

3
4. Eccentricity of Reaction of an I-Beam Supported on Neoprene Rubber

Five tests were performed to determine the ec- centricity ratio for the previously described I-beam

supported on a neoprene rubber pad. The hardness of the rubber as given by Shore A. Durometer

was 65 (instantaneous value). The rubber sheets were Ke in thick and they were stacked to give

thicknesses of % and ji in. The test setup used in the tests with a rubber

bearing material was similar to that shown in figure 3, except that the rotation of the beam end was measured with two micrometer dial gages; one of these was clamped to the web of the I-beam

and measured the movement of the end of the

beam with respect to the bearing surface of the

strut, while the second one was attached to the

side of the strut and its stem was in contact with

the underside of the flange of the I-beam.

In Tests 6 and 7 the I-beam was supported on a neoprene pad Ys in thick over its entire 4-in bearing

length. The rubber pad was coated with gypsum

plaster putty on both bearing surfaces in order

to assure intimate contact over its entire area. The values of e/t obtained in Tests 6 and 7 are shown in figure 5. It is noted that e/t increased

with the beam end rotation as would be expected

in the case of an unbonded bearing which leaves the

beam end free to rotate without any restraint

0.5

< 0.4 O

<^ 0.3

-,0.2

0,1

TEST 10

TEST 7

0 0.001 0,002 0.003 0.004 0.005 0.006 0.007 ROTATION OF BEAM END, RADIANS

FiGUEE 5. Eccentricity of reaction for an I-beam supported on neoprene rubber pads. Tests 6 and 7—Ys in rubber pad

4 in long, coated with plaster; Test 8—Y» in pad, 2 in long, coated with plaster; Test 9—Yi in pad, 2 in long, no

plaster; Test 10—same as 6 and 7, but no plaster coating.

from the supporting wall. The average value of

e/t ranged from 0.27 initially to 0.30 at the maximum rotation. The beam span used in these tests was 44 in and the maximum applied load was 30

kips.

Tests 6 and 7 were two independent determinations representing as nearly as possible identical

support conditions. It is important to note that

in spite of all efforts to secure uniform and

intimate contact with the rubber bearing pad, the

two determinations of e/t varied from 0.28 to 0.31

at the maximum rotation. Perhaps this variability even between two supposedly identical tests will account for the very large difference in e/t values

between Test 10 and Tests 6 and 7. In Test 10

the carefully leveled I-beam was set directly on a rubber pad Ys in thick; however, it was noted

that the contact with the rubber pad was not

intimate, and that daylight could be seen under

the outer corners of the I-beam flange. In this

instance a large rotation was observed at extremely

small load. In this test the value of e/t was

initially 0.45 and it tended to become nearly

constant at 0.40 for the maximum rotation of

the beam end. The span length in this test was

44 in and the maximum applied load was 30 kips.

This comparison of otherwise identical tests (Tests 6, 7, and 10) points up the importance of

attaining intimate contact with rubber pads of limited thickness and large bearing area. It can be seen that the e/t ratio of 0.40 for Test 10 was

about the same as for unbonded plaster bearing

pads in figure 4. In Tests 8 and 9 the length of the bearing pad

was reduced to 2 in at the extreme end of the

beam. As would be expected, the confinement of

the bearing reduced the e/t ratio considerably.

For Test 8, with a capped bearing pad Ys in thick,

e/t ranged from an initial value of 0.17 to 0.185

at the maximum end rotation. For Test 9 in which

the rubber pad thickness was increased to % in

and no plaster capping, the e/t ratio was further

reduced to yield a maximum of about 0.15. It is ^ noted that in this test the minimum value of e/t' was 0.135, as compared with a theoretical value ^ of 0.125. This theoretical value would be expected

' from the assumption that the centroid of the

bearing stresses lies at the midpoint of a uniformly compressed pad.

5. Eccentricity of Supporting Force at the Base of a Bearing Wall Subjected to

an Eccentrically Applied Load

Two exploratory tests were performed to in- vestigate the feasibility of measuring the eccentricity of the supporting force at the base of a wall subjected to an eccentrically applied load.

An overall view and a closeup of the loading

fixture are shown in figures 6 and 7.

_ The wall used in these tests was essentially a

pier 3%6 by 7% inches in cross section built of

solid extruded clay brick laid in stacked bond with s extremely thin joints of high strength gypsum 3 plaster. The strut was used as a base for this f assembly, as shown in figure 6. The wall was built \ in two stages—the first was 24 in high and the

second was 48 in high; both dimensions are - nominal. The wall was subjected to two loads

at each height, a centrally applied load, and an 4
Figure 6. Overall view of test setup to determine the eccentricity of supporting force at the base of an eccentrically loaded bearing wall.

eccentric load applied on side H (see fig. 1) 2.5 in

from the center line of the pier.^ The values of eccentricity of applied loads and the measured

values of eccentricity of reactions at the base of the wall are given in table 1 for both the 24- and

48-in heights of waU.

It can be seen from the data in table 1 that the

calibrated reaction strut can be used to measure

the eccentricity of the reaction at the base of a bearing wall. The effect of the height of the wall on the possible decrease of eccentricity at the base

will be further explored in future tests using a calibrated reaction strut of sufficient capacity to accommodate a larger wall specimen.

Figure 7. Closeup of eccentrically loaded wall showing the loading knife edge.

Table 1. Measured eccentricities of reaction at the base of wall subjected to a load of known eccentricity

Wall

height

Eccentricity of applied load

Applied

load

Measured strains on strut € max —€ min Measui-ed

eccentricity

at base of wall

(from fig. 2)

€ max e min emax-htmin

in in kips 10-6 10-6 in

24 0 15 112 112 0 0. 15 24 0 20 151 149 .007 .16

24 2.5 10 155 1 -10 1. 14 2.45 48 0 10 69 77 -.05 0. 06 48 0 20 148 159 -.04 .06 48 2.5 5 83 0 1.00 2.20 48 2.5 10 157 2 0.97 2. 14

> Tensile strain.

6. Summary

The following comments appear appropriate to summarize the work reported herein

:

1. A test procedure was developed by means of which the eccentricity of loads applied to a strut assumed to simulate a bearing wall could be

measured. The device also was suitable for measI uring the eccentricity of the supporting force at the base of a bearing wall subjected to an eccentric

load.

- The center line of the pier was taken as the center line of the compressive

strut.

2. Both rigid and resilient bearing materials

such as gypsum plaster and neoprene rubber were

used to support an I-beam as a floor member.

3. For an unbonded plaster bearing, the observed eccentricity ratio increased with rotation of the beam end to a maximum value of about 0.42. For the bonded plaster bearing this ratio decreased

with rotation to an average value of 0.24 at the

maximum load.

4. Intimacy of contact was essential for achieving a favorable distribution of bearing stresses

5
with a neoprene rubber pad. Lack of intimate and

complete contact between the I-beam and the

rubber pad resulted in an eccentricity ratio of

about 0.40; this value was reduced to 0.29 by bedding the rubber pad in plaster. A 50 percent reduction of the bearing length of the pad and its con- finement to the extreme end of the beam further

reduced the eccentricity ratio to a minimum value

of 0.135.

5. The eccentricity ratio was not found to be

sensitive to substantial increases in the rotation of

the beam end in the loading range producing rotations on the order of 0.004-0.005 rad.

6. Because of the limited sensitivity of the ec- centricity measuring device, the values of eccentricity ratio observed for low loads and extremely

small rotations were not considered sufficiently

accurate for presentation.

7. Because of the limitation of the span lengths

and flexural rigidities of the floor beam and the

reaction strut used in these tests, the eccentricity

ratios reported herein may not be applicable to spans and rigidities of widely different values. It

is considered that additional experimental work

with greater range of parameters is needed.

8. In order to achieve a greater degree of similitude between the eccentricity measuring device

and an actual masonry wall, the boundary conditions with respect to sidesway at the top and

restraint at the base of the strut will need to be

observed both during calibration and the measure- ment of eccentricities.

6
NBS TECHNICAL PUBLICATIONS

PERIODICALS

JOURNAL OF RESEARCH reports National

Bureau of Standards research and development in physics, mathematics, chemistry, and engineering.

Comprehensive scientific papers give complete details

of the work, including laboratory data, experimental

procedures, and theoretical and mathematical analyses. Illustrated with photographs, drawings, and

charts.

Published in three sections^ available separately:

• Physics and Chemistry

Papers of interest primarily to scientists working in these fields. This section covers a broad range of physical and chemical research, with major emphasis

on standards of physical measurement, fundamental

constants, and properties of matter. Issued six times

a year. Annual subscription: Domestic, ^5.00; for- eign, $6.00*.

• Mathematical Sciences

Studies and compilations designed mainly for the

! mathematician and theoretical physicist. Topics in

I mathematical statistics, theory of experiment design,

j numerical analysis, theoretical physics and chemistry, logical design and programming of computers

land computer systems. Short numerical tables. Issued quarterly. Annual subscription: Domestic,

j 32.25; foreign, $2.75*.

• Engineering and Instrumentation

Reporting results of interest chiefly to the engineer

and the applied scientist. This section includes many

j of the new developments in instrumentation resulting

sfrom the Bureau's work in physical measurement,

idata processing, and development of test methods.

I It will also cover some of the work in acoustics,

'applied mechanics, building research, and cryogenic

'engineering. Issued quarterly. Annual subscription:

'Domestic, $2.75; foreign, $3.50*.

TECHNICAL NEWS BULLETIN

\|The best single source of information concernmg

'the Bureau's research, developmental, cooperative

and publication activities, this monthly publication

I is designed for the industry-oriented individual whose

'daily work involves intimate contact with science

I and technology

for engineers, chemists, physicists, research managers, product-development managers, and

company executives. Annual subscription: Domestic,

$1.50; foreign, $2.25*.

ij 'Difference in price is due to extra cost of foreign mailing.

NONPERIODICALS

Applied Mathematics Series. Mathematical

tables, manuals, and studies.

Building Science Series. Research results, test methods, and performance criteria of building materials, components, systems, and structures. Handbooks. Recommended codes of engineering

and industrial practice (including safety codes) developed in cooperation with interested industries,

professional organizations, and regulatory bodies.

Special Publications. Proceedings of NBS conferences, bibliographies, annual reports, wall charts,

pamphlets, etc. Monographs. Major contributions to the technical literature on various subjects related to the Bureau's scientific and technical activities.

National Standard Reference Data Series.

NSRDS provides quantitative data on the physical

and chemical properties of materials, compiled from

the world's literature and critically evaluated.

Product Standards. Provide requirements for

sizes, types, quality and methods for testing various

industrial products. These standards are developed

cooperatively with interested Government and in- dustry groups and provide the basis for common

understanding of product characteristics for both

buyers and sellers. Their use is voluntary.

Technical Notes. This series consists of communications and reports (covering both other agency

and NBS-sponsored work) of limited or transitory

interest. CLEARINGHOUSE

The Clearinghouse for Federal Scientific and

Technical Information, operated by NBS, supplies

unclassified information related to Governmentgenerated science and technology in defense, space, atomic energy, and other national programs. For

further information on Clearinghouse services, write:

Clearinghouse

U.S. Department of Commerce

Springfield, Virginia 22151

Order NBS publications from:

Superintendent of Documents

Government Printing Ofiice Washington, D.C. 20402

iXU.S. GOVERNMENT PRINTING OFFICE : 1968—O-293-520
I
Announcement of New Publications in

Building Science Series

Superintendent of Documents,

Government Printing OflBce,

Washington, D.C., 20402

Dear Sir: Please add my name to the announcement list of new publications to be

issued in the series: National Bureau of Standards Building Science Series. Name

Company

Address

City State Zip Code

(Notification key N-339)

\
i
THE NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards^ provides measurement and technical information services

essential to the efficiency and effectiveness of the work of the Nation's scientists and engineers. The

Bureau serves also as a focal point in the Federal Government for assuring maximum application of

the physical and engineering sciences to the advancement of technology in industry and commerce. To

accomplish this mission, the Bureau is organized into three institutes covering broad program areas of research and services: THE INSTITUTE FOR BASIC STANDARDS . . . provides the central basis within the United

States for a complete and consistent system of physical measurements, coordinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform

physical measurements throughout the Nation's scientific community, industry, and commerce. This

Institute comprises a series of divisions, each serving a classical subject matter area: —Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Physics—Physical

Chemistry—Radiation Physics—Laboratory Astrophysics'—Radio Standards Laboratory,^ which

includes Radio Standards Physics and Radio Standards Engineering—Office of Standard Refer- ence Data. THE INSTITUTE FOR MATERIALS RESEARCH . . . conducts materials research and provides

associated materials services including mainly reference materials and data on the properties of materials. Beyond its direct interest to the Nation's scientists and engineers, this Institute yields services which are essential to the advancement of technology in industry and commerce. This Institute is or- ganized primarily by technical fields: —Analytical Chemistry—Metallurgy—Reactor Radiations—Polymers—Inorganic Materials—Cryogenics^—Office of Standard Reference Materials.

THE INSTITUTE FOR APPLIED TECHNOLOGY . . . provides technical services to promote the use of available technology and to facilitate technological innovation in industry and government. The

principal elements of this Institute are: —Building Research—Electronic Instrumentation—Technical Analysis—Center for Computer Sci- ences and Technology—Textile and Apparel Technology Center—Office of Weights and Measures —Office of Engineering Standards Services—Office of Invention and Innovation—Office of Vehicle

Systems Research—Clearinghouse for Federal Scientific and Technical Information^—Materials

Evaluation Laboratory—NBS/GSA Testing Laboratory.

1 Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted; mailing address Washington, D. C,

20234.

- Located at Boulder, Colorado, 80302.

3 Located at 5285 Port Royal Road, Springfield, Virginia 22151.
U.S. DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20230

POSTAGE AND FEES PAID

U.S. DEPARTMENT OF COMMERCE

OFFICIAL BUSINESS