i
The program of research on building materials and structures, carried on by the

National Bureau of Standards, was undertaken with the assistance of the Central

Housing Committee, an informal organization of Government agencies concerned

with housing construction and finance, which is cooperating in the investigations through

a subcommittee of principal technical assistants.

CENTRAL HOUSING COMMITTEE

SUBCOMMITTEE ON TECHNICAL RESEARCH

Walter Junge, Chairman. A. C. Shire, Vice Chairman.

Federal Housing Administration. United States Housing Authority.

Sterling R. March, Secretary.

Albert G. Bear,

Veterans' Administration.

Pierre Blouke,

Federal Home Loan Bank Board (Federal Loan Agency).

Carroll W. Chamberlain,

Public Buildings Administration (Federal Works Agency).

Joseph M. DallaValle,

Public Health Service (Federal Security

Agency).

John Donovan,

Farm Security Administration (Agriculture).

George E. Knox,

Yards and Docks (Navy).

Vincent B. Phelan,

National Bureau of Standards (Commerce).

Edward A. Poynton,

Office of Indian Affairs (Interior).

George W. Trayer,

Forest Service (Agriculture).

Elsmere J. Walters,

Construction Division (War).

CHAIRMEN OF SECTIONS

Specifications Materials Maintenance

Carro)/L W. Chamberlain Elsmere J. Walters John H. Schaefeb

Mechanical Equipment Methods and Practices

Robert K. Thulman

NATIONAL BUREAU OF STANDARDS

STAFF COMMITTEE ON ADMINISTRATION AND COORDINATION

Hugh L. Dryden, Chairman.

Mechanics and Sound.

Phaon H. Bates, Gustav E. F. Lundell,

Clay and Silicate Products. Chemistry.

Hobart C. Dickinson, Addams S. McAllister,

Heat and Power. Codes and Specifications.

Warren E. Emley, Henry S. Rawdon,

Organic and Fibrous Materials. Metallurgy.

The Forest Products Laboratory of the United States Department of Agriculture

is cooperating with both committees on investigations of wood constructions.

[For list of BMS publications and how to purchase, see cover page III.]
UNITED STATES

NATIONAL

DEPARTMENT OF COMMERCE • Harry L. I lopkins, Secretary

BUREAU OF STANDARDS • Lyman J. Briggs, Director

BUILDING MATERIALS

and STRUCTURES

REPORT BMS39

Structural Properties ot a Wall Construction

of "Pteiier Units" Sponsored by the

Wisconsin Units Company

by HERBERT L. WHITTEMORE, AMBROSE H. STANG,

and DOUGLAS e. parsons

ISSUED JANUARY 31, 1940

The National Bureau of Standards is a tact-finding organization;

it does not "approve" any particular material or method ot construction. The technical findings in this series ot reports are to be construed accordingly.

UNITED STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I94O

FOR SALE BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE 10 CENTS
Foreword

This report is one of a series issued by the National Bureau of Standards on the

structural properties of constructions intended for low-cost houses and apartments.

These constructions were sponsored by indiistrial organizations within the building

industry advocating and promoting their use. The sponsor built and submitted the

specimens described in this report for the program outlined in BMS2, Methods of Determining the Structural Properties of Low-Cost House Constructions. The sponsor,

therefore, is responsible for the design of the constructions and for the description of the

specimens and method of fabrication. The Bureau is responsible for the method of test- ing and the test res^dts. Tliis report covers only the loail-deformation relations and strength of the walls of a house when subjected to compressive, transverse, impact, concentrated, and racking

loads by standarchzed methods simulating the loads to which the elements of a house

would be subjected in actual service. Later it may be feasible to determine the heat

transmission at ordinary temperatures and the fire resistance of this same construction

and perhaps other properties.

The National Bureau of Standards does not "approve" a construction, nor does it express an opinion as to the merits of a construction for the reasons given in reports

BMSl and BMS2. The technical facts presented in this series provide the basic data

from which architects and engineers can determine whether a construction meets

desired performance requirements.

Lyman J. Briggs, Director.

[n]
Structural Properties of a Wall Construction of "Pfeifer Units"

Sponsored by the Wisconsin Units Company

by HERBERT L. W H ITT E MOR E , AMBROSE H. STAN'G, and DOUGLAS E. PARSONS

C O ^ T II iN T S

Page

Foreword ii

I. Introduction 1

II. Sponsor and product 2

III. Specimens and tests 2

IV. Wall CU 3

1. Sponsor's statement 3

(a) Materials 3

(b) Description 5

(1) Four-foot wall specimens 5

(2) Eight-foot wall specimens- - 6

Page IV. Wall C//--Continued.

1. Sponsor's statement—Continued.

(c) Comments . 7

2. Compressive load 7

3. Transverse load 10

4. Concentrated load 10

5. Impact load 12

6. Racking load 14 V. Selected reference 14

ABSTRACT

For the program on the determination of the structural properties of low-cost house constructions, the Wisconsin Units Co. submitted 18 specimens repre- senting a wall construction of "Pfeifer Units." The specimens were subjected to compressive, transverse, concentrated, impact, and racking loads. For

each of these loads three like specimens were tested. The deformation under load and the set after the load was removed were measured for uniform increments of

load. The results are presented in graphs and in tables.

I. INTRODUCTION

To provide tecliriical facts on the performance of constructions wliicli might be used

in low-cost houses, to discover promising new- constructions, and ultimately to determine the

properties necessary for acceptable performance

m actual service, the National Bureau of Standards has invited the cooperation of the buildingindustry in a program of research on building

materials and structures suitable for low-cost

houses and apartments. The objectives of

this program are described in report BMSl,

Research on Building Materials and Sti'uctures

for Use in Low-Cost Housing, and that part

of the program relating to structiu'al propei'ties

in report BMS2, Methods of Determining the

Structural Properties of Low-Cost House Constructions.

Masonry constructions and wood constructions of types which have been extensively

used in this country for houses wei'e included

in the program because their behavior under

widely different service conditions is known to builders and the public. The reports on these

constructions are BMS5, Structural Properties

of Six Masonry Wall Constructions, and

BMS25, Structural Properties of Conventional

Wood-Frame Constructions for Walls, Partitions, Floors, and Roofs. The masonry speci- mens were built by the Masonry Construction

Section of this Bureau, and the wood-frame

specimens were biult and tested by the Forest Products Laboratory at Matlison, Wis.

The present report describes the structural

properties of a wall construction sponsored bj' one of the manufacturers in the bTiilding in- dustry. The specimens were sid^jected to compressive, transverse, concentrated, impact,

and racking loads, simulating loads to which

the walls of a house are subjected. In actual

service, compressive loads on a wall are pro- duced by the weight of the roof, second floor and second-story walls, if any, furniture and

occupants, and by snow and wind loads on the

roof. Transverse loads on a wall are produced by the wind, concentrated and impact

loads by accidental contact with heavy objects, and racking loads by the action of the

wind on adjoining walls.

[1]
The deformation and set under each increment of load were measured, because the

suitability of a wall construction depends in

part on its resistance to deformation \mder

load and whether it returns to its oiiginal size and shape when the load is removed.

II. SPONSOR AND PRODUCT

The specimens were submitted by the

Wisconsin Units Co., West Allis, Wis., and

represented a wall construction made of reinforced-concrete units marketed imder the trade

name "Pfeifer Units." The units are bolted

together with a steel reinforcing- plate in each

longitudinal joint, forming a masonry wall.

III. SPECIMENS AND TESTS

The wall construction was assigned the

symbol CH, and the specimens were assigned

the designations given in table 1.

Table 1.

Specimen desigjiations, wall CH

Specimen designation

CI, C2, CS. - ^ Tl, T2, T3 - TJ,, T5. TO. _. PI, PZ, PS

Pi, PB, P6

//, 12, IS U, 15, 16 Rl, m, RS...

Load Load applied

Compressive^

Transverse

do__.: Concentrated _ do Impact

.,..do Racking

Upper end.

Inside face. Outside face. Inside face. Outside face. Inside face. Outside face. Near upper end.

» These specimens were undamaged portions of the transverse speci- mens.

Except as mentioned below, the specimens were tested in accordance with BMS2, Metbods

of Determining the Structural Properties of

Low-Cost House Constructions, which gives the

requirements for the specimens and describes

the presentation of the results of the tests, particularly the load-deformation graphs.

The compressive loads were applied over the

entire thickness of each specimen along a line distant from the inside face by one-third this

thickness. The shortenings and sets were measured by means of compressometers at- tacked to the steel loading plates through which

the load was applied to the specimen, nnd not

attached to the specimen as described in BMS2.

Measurements of the laternl deflections under

compressive loads and the deflections under

transverse loads were made with a deflectometer of fixed gage length, which consisted of a light (duralumin) tubular frame having a leg

at one end and a hinged plate at the other.

The distance between the points of support was 7 ft. 6 in. A dial micrometer was attached

to the frame at midlength. The micrometer was graduated to 0.001 in., and the readings were recorded to the nearest tenth of a division.

The deflectometer was attached to the specimen in a vertical position by clamping the

''iGTJRE 1

.

Apparatus for concentrated load test. A, steel disk; B, crossbar; C, dynamometer; D, stand; E, dial micrometer.

hingetl plate to the upper end of either face. There were two deflectometers on each specimen, one near each edge. This method of

measurement was used instead of the taut- wire and mirror-scale method described in

BMS2.

The indentation under concentrated load and

the set after the load was removed were measured, not the set only, as described in BMS2.

The apparatus is shown in figure 1. The load was applied to a steel disk. A, to which the

crossbar, B, was rigidly attached. The load was measured by means of the dynamometer,

C. There were two stands, D, resting on

the face of the specimen, and each sup-

[2]
poitetl a dial inicroineter, E, the spindle of which was in contact with the crossbar 8 in. from the disk. The niicrometers were graduated to 0.001 in., and the readings were re- corded to the nearest division. The mitial

reading (average of the micrometer readings) was observed under the initial load, which in- cluded the weight of the disk and dynamometer. A load was applied to the disk, and

the depth of the indentation under load was

taken as the average of the micrometer readings

minus the initial reading. The load was then

renioved, and the set was taken as the average

of the micrometer readings minus the initial reading.

The deformations caused by racking loads were measured ^\•ith a dial micrometer which

was fastened to one end of a right-angle frame,

consisting of a steel channel and a steel angle,

])raced to form a rigid connection. In use, tliis deformeter was attached to the specimen by

resting the channel along the top of the speci- men. Two pins driven through the channel

into the top of the specimen prevented relative

motion between them. The steel angle was

then in a suspended vertical position in the

plane of the specimen, wdth the micrometer at

its lowest point and the spindle bearing du-ectl_y on the specunen. The gage length (distance

from the top of the specimen to the micrometer

spindle) was 6 ft. 8 in. The micrometer was

graduated to 0.001 in., and the readings were

recorded to the nearest tenth of a division.

This deformeter was used instead of the system

of taut wires and mirror scales described in

BMS2.

The tests were begun March 15, 1939, and

completed March 23, 1939. The units were made on or about December 14, 1938. The

sponsor's representatives witnessed the tests.

IV. WALL CH

1. Sponsor's Statement

The information for this statement was obtained from the sponsor and from inspection of

the specimens. The Masonry Construction

Section of this Bin-ea\i assisted the sponsor by

determining the physical properties of the concrete units.

(a) Materials

Concrete units. —The imits were thin rciii- forced-concrete slabs about 2 ft scjunre liaving

flanges along two opposite edges.

The materials for the concrete were Petoskey

Cement Co.'s "High-Early" portland cement,

Western Lime and Cement Co.'s "Pure-Cai"

lime, and The Wayhte Co.'s "Wayhte" aggregate.

"Waylite" ag-gregate is a lightweight mateiial

of cellular structure produced by centrifuging

and beating molten blast-furnace slag in an

atmosphere of steam. The sieve analysis of

the aggregate is given ui table 2 and the chemical composition in table 3. Table 2.

Sieve analysis of the "Waylite" aggregate

U. S. standard sieve number

Passing;, by

weight

Percent

i 100 8 93

16 68 30 20

50 7 100 2

Table 3.Chemical composition of the "Waylite"

aggregate

[Average of samples taken on different days by the laboralorv of the Youngstown Sheet and Tube Co., South Chicago, 111., December 1937]

Ingredient Content, by weight

SUica, Si02

Percent

38.5

12.0 45.0

1.7 0.4

.8 1.6

100. 0

Alumina, AI2O3 Calcium o.xide, Ca0__ _

Magnesia, MgO

Iron oxide, Pe203 ....

Manganous oxide, MnO... . Sulfur, S, as sulfide.

Total

The reinforcement in the units was welded

steel-wire mesh, openings 3-in. square, weight

0.25 lb/ft manufactured by the American Steel

& Wire Co. The wire was No. 12 Stl. W. G.

(0.1055-in. diam), having a tensile strength

ranging from 70,000 to 80,000 lb/in-. The

mesh for each unit was 1 ft 11 in. high and 2 ft 3 in. wide, having nine longitudinal and eiglit transverse wires. The ends of the longitudinal

wires projected 1 in. beyond the top and bottom

transverse wires, and the ends of the transverse wires projected Iji in. beyond the edge of the

longitudinal wii'es. Thei'e were chaii's in the
tliree central longitudinal wires, formed by

bending the wire into a V which projected

about ji in. from the mesh. The chairs were

spaced 6 in. and those in adjacent wires were

staggered.

A binder was embedded in the flange at each

edge of the unit. It was hot-rolled, openFiGURE 2.

Sheet-steel binder.

hearth, SAE lOlO sheet steel. No. 20 U. S. Std.

Gage (0.037 in. thick), formed as shown in

figures 2 and 3. The chemical composition of the sheet steel is given in table 4. Each binder was plated with cadmium, the thickness of the coat ranging from 0.0008 to 0.0010 in. The

manufacturer was the Milwaukee Stamping Co.

Table 4.Chemical composition of SAE 1010 sheet

steel

Element Content

Carbon Manganese

Phosphorus . Sulfur

Percent

0. 05 to 0. 15 .30 to .60

. 045 maximum

. 055 maximum

The units were made in horizontal cast-iron

molds, the mold forming the flanged face of the

units. After spraying the molds with a mixture

of heavy lubricating grease and naphtha, the

binders were placed at the sides of the mold

over plugs which formed the bolt holes in the

flanges. The mesh reinforcement was placed

in the mold. The concrete mix was 1 part of cement, 0.21 part of liydrated lime, and 5.84

parts of "Waylite" aggregate, by volume; the

lime being added to increase the workability.

The concrete was mixed in a mixer having a capacity of 9 ft^. The aggregate was first mixed with water for at least 2 minutes to insure

adecjuate surface moisture, the cement and lime were added, and the mixing continued for

Figure 3.Details of binder.

another 10 minutes. The amount of water was

adjusted until no excess water appeared on the

concrete when the mold was vibrated. The

mix was delivered to the mold and vibrated by

a jolt-vibrator, operated pneumatically at the

rate of 85 strokes per minute. A sliding steel plate then struck ofl' the excess concrete and the

mold was removed to a curing chamber. The

chamber was filled with steam at 5 lb/in. ^ pres-

[4]
sure for 3 hours and then at 50 lb/in. ^ for 6

hours, after whicli time the pressure was re- duced slowly and the units were ready for shipment.

The units, shown in figure 4, were 2 ft 0 in. high, 1 ft 11% in. wide, and 1% in. thick at midwiclth. There was a flange, in which a, sheet-steel binder was embedded, along each

longitudinal edge. There were four holes, %6-

FiGURE 4. —Concrete iniit.

in. diam, in each flange 2% in. from the outside

face of the unit and spaced 6 in. on centers. Along each edge of the unit were semicircular

grooves, %-m. diam. The distance from the

outside face of the unit to the outer edges of the

grooves was %6 in. The outside face of the unit was rabbeted % in. along each of the four

edges.

The physical properties of the units were

determined on two samples. The water absorption for 24-hr cold total immersion was 13.4 percent of the dry weight of the unit, or 13.0

lb of water per ft^ of concrete. Computed from

the weight of 162 units, the average weight of one unit, when dry, was 57.6 lb. Bonding plate.—Sheet-steel, SAE 1010, openhearth, hot-rolled, No. 14 U. S. Std. Gage (0.077

in. thick), 8 ft 0 in. high, 2^ in. wide. The

chemical composition of the sheet steel is given

in table 4. There were holes, /le-in. diam, at midwidth, spaced 6 in. on centers. Each plate was pickled in a 50-percent solution of muriatic

acid and then completely covered by one coat

of black as])lialtum 0.001 Id, thick. Milwaukee

Stamping Co.

Bolts. Machine, mild-steel, K-in- diam, 5^ in. long, 13 threads per inch, threaded I'oi' a Iciigtli of 1% in., Iieads and nuts square, unfinish(!<k

Machine, niikl-steel, }.^-in. diam, 2% m. long, 13 threads per inch, threaded for a length of

1 in., heads and nuts square, unfinished.

11 V/.s'A^T.s.- Sheet-steel, lli-iu. diam, No. 12 U. S. Std. Gage (0.1072 in. thick).

(b) Description

Wall OH consisted of "Pfeifer Units" and

steel bonding plates bolted together at the

Figure 5.Fo)ir-foot wall .sped men CH.

A, concrete unil; B, honding plale.

flanges of the units, forming a masonry wall

with a flat outside face and a ribbed inside

face. The price of this construction in Washington,

D. C, as of July 1937, was $0.44/ft^

(1) Four-Joot wall specimens.—The 4-ft spec- imens, shown in figure 5, were 8 ft 0 in. high.

4 ft 0 in. wide, and 4 in. thick at the ribs. Each specimen consisted of eight concrete

[5]
units, A, and three bonding plates, B. There

were two units in each course and a bondingplate on each longitudinal (vertical) edge and

one in the joint at midwidth. The units ;ind bonding plates were fastened by bolts through

the holes in the flanges and the plates. There

were eight 2%-in. bolts along each longitudinal

edge and eight 5/2-in. bolts along the joint at midwidth. The bolts were in the top and bottom holes in each unit. There were two washers on each bolt, one under the head and the other

under the nut. Each nut was tighteneil until

the torque was about 11 Ib-ft. These specimens did not comply fully with

BMS2, V-1 (c) Width. They were of the type

shown in figure 2, BMS2; and, if the bondingplates are considered to be load-carrying members, the plates on the edges of the specimen

should have been half-sized plates, thickness

0.0385 in. Each specimen therefore had the

equivalent of one excess bonding plate. It did

not appear practicable to machine half-sized

plates from full-sized plates; and, if they had

Figure 6.

Eight-foot wall specimen CH.

A, concrete unit; B, bunding plate.

been made from sheet steel of the required thickness, there was no assurance that the properties

would have any relation to the properties of the

full-sized plates.

Full-sized plates were therefore used on the

edges of the specimens. Furthermore, it appeared probable that, being restrained laterally on only one side, their strength would be much

less than that of plates in a vertical joint between units. Observations during the tests indicated that the edge plates might be considered half-sized plates as regards the properties of tliis construction. Through a misunderstanding on the part of the sponsor the

vertical and horizontal joints in the specimens were not sealed -with asphalt-saturated cotton

fabric tubing, as in a house, and the rabbets in

the units were not calked. It appears probable

that the seals and calking would have had Httle

eft'ect on the structural properties.

(2) Eight-foot wall specimens.—The 8-ft specimens, shown in figure 6, were 8 ft 0 in. Ivigh,

8 ft 0 in. wide, and 4 in. thick. The construe-
iiig, maiuil'iicl iiicd by tlie Aiiacorula Wire &

Cable Co. under tlie trade name "Duraduct,"

in tlie grooves in the sides and edges of each

unit. The joints are then calked by filling the

/4-in. rabbets along the edges of tlie units with

a plastic asbestos calldng com pom id. The flanged surface of the iniits may be

turned outward and brick \ eneer applied as the

outside face of the wall. Metal ties for the

brickwork are fastened to the bolts in the

flanges of the units. The flat insifle face jnay

be painted or plastered.

For floor and roof constructions the units

are bolted, with the flanges down, to lightweight steel joists. The ends of the joists are secured by bolting the webs of the joists to the

flanges of the wall units. If the floor is of wood-frame construction, a wood header is bolted to the flanges of the wall units by clip

angles. The floor joists are nailed to the

header. If the roof is of wood-frame construction, a 2- by 4-in. wood wall plate is fastened

to the top of the wall units by narrow clip

angles. The clip angles extend through holes

in the plate and are bolted to the flanges. In

addition, 12d nails are driven through the

plate into the ends of the flanges. The roof

joists are nailed to the wall plate.

2. Compressive Load

Wall specimen CH-Cl untler compressive

load is shown in figure 7. Tlie results for wall

specimens CH-Cl, C2, and C3 are shown in

table 5 and in figures 8 and 9. Table 5.

Structural properties, wall CH

[Weight, 15.0 lb/ft2]

Compressive load" Transverse load' Concentrated load Impact load

Rackinsr load

Specimen Maximum

load Specimen Maximumload Specimen Maximumload Specimen

Ma.x'imum

height

of drop Specimen Maximum

load

CI

'Kipsjit.

8. 76 6.50

9. 63

Tl

IblfP

43. 7

48. 8 45.0

PI

lbJ], 000

•iLOOO

•'1,000

II

ft 5.5 5.5

5, 5

'Kipslft1.05 0.88

1 21 a T2.. P2 12 R2

cs TS PS 73... RS

Average.. 8. 29 Average... 45.8 Average... •JLOOO Average.. 5.5 Average.. 1.05 T4 93

111 11?

Pi 765

785

800 U 9.0

9.0

•10.0 T5 P.5 15 T6 P6 16

Average... 105 Average... 783 Average

" Load applied 1.33 in. (onfi-third the thickness of the specimen) from the inside surface of the ribs.

i> Span 7 ft 6 in.

« A kip is 1,000 !b.

•* Test discontinued. Specimen did not fail.

" Test discontinued. Specimen damaged.

tion was similar to the 4-ft specimens except

that there were four units in each course and

five bonding plates.

(c) Comments

"Pfeifer Units" are designed for walls, partitions, floors, and roofs. Walls and partitions

are erected on a masonry foundation wall or a concrete slab. The walls are anchored by cli]) angles fastened by bolts to the flanges of the

units, and to the foundation by anchor bolts. At each comer of the house there is a special 4- by 4-in. corner unit having wing nuts embedded in two adjacent edges, to receive bolts

passing through the flanges of the adjoining

imits. The miits are made in half and quarter

sizes to provide greater flexibility in the dimensions of walls and openings. Door and window

frames are of conventional wood or metal construction. Lintels are supported on steel angles wliich are fastened to the flanges of the

wall units by clip angles. Jambs are fitted with

oak strips bolted to the flanges of the units at the opening.

If the flat surface of the units forms the outside face of the wall, the inside face may be

finished either by naihng wallboard directly to the ribs or by nailing lath to the ribs and coveiing it with plaster. The spaces between the

ribs may be filled with thermal insulation or serve as chases for pipes, ducts, and conduits. In actual house construction the vertical and

horizontal joints between the units are sealed

by placing asphalt-saturated cotton fabric tub-

[7]
Figure 7.- -Wall specimen CH-Cl under compressive

load.

The shortenings and sets shown in figure 8

for a height of S ft were computed from the values

obtained from the compressometer readings.

The gage length of the compressometers was 8

ft % in. The lateral deflections shown in figure 9 were plotted to the right of the vertical axis for deflections of the specimen toward the outside

8

(nCO

0'

—•-

«

c —o—

oo

o oo

0, 0

i 1 o o/ o

•

\ *•

o Cf o

•r

/

/

o cy o

o

/ T ,

» jf

cp

i

0 OM 0.08

shortening ln./8ff

Figure 8.Compressive load on wall CH.

Load-shortenins (open circles) and load-sot (solid circles) resull^ for spef- imens CH-Cl, C2, and CS. Load applied 1.33 in. (one-third the thickness) from the inside surface of the ribs. The loads are in kips per foot

of actual width of specimen.

8

In

8

8

4

2

oy.

1 •—

• o

• -<)

•

o

po

•

• o

9. LiJ3 1

•

• c

0

o \

• c • c —•—

• o

O • 0>| » • c -o—•—

o • CM •O

o • ob c

-0.^0-0.15 -0.10 -0.05 0 005

/afera/ def/ecflon in. Figure 9.

Compressive load on wall CH.

Load-lateral deflection (open circles) and load-lateral set (solid circles) results for specimens CH-Cl, C2, and C3. Load applied 1.33 in. (onethird the thickness) from the inside surface of the ribs. The loads are

in kips per foot of actual width of specimen. The deflections and sets are for a gage length of 7 ft fi in., the gage length of the deflcctometers.

[8]
face (positive deflection) and to the left for deflections toward the inside face (negative

deflection).

Although the load was eccentric toward the

inside face, the speciniens deflected initially

toward the inside face. Under loads less than

about 4 kips/ft on specimens Cl and C2 the sets were numerically little less than the deflections,

but under greater loads the sets were numerically greater than the deflections and the values were nearly constant. Under loads less than 7 kips/ft on specimen

C3 the deflections were small and the sets were

numerically greater. Under greater loads this specimen deflected increasingly tow ard the outside face, but the sets (toward tlic inside face) were nearly constant. Because tlie tliickness of the bonding plates was sjiiall (0.f)77 in), they

p]T)l)a,l)ly did not liave a, proiioiiiiccd clfccl on

the cojnpressive ])roperties of tlic specijnens, l)iit functioned princij)a]ly to join and aline tbe concrete units. Inspection of tbe specijnens

before they were tested showed tbat at the

horizontal joints the units were in contact only

at the flanges (which faced towai-d tbe inside of

the wall). As regards the lateral deflections

and sets under compressive loads, these speci- mens did not behave like elastic engineering

structures, and no reasonable explanation for their behavior was found.

Figure 10.—Wall specimen CH-T4

under transverse load.

[9]
3. Transverse Load

Wall specimen CH-TIf under transverse load

is shown in figure 10. The residts are shown in

table 5 and in figure 11 for wall specimens

CH-Tl, T2, and T3, loaded on the inside face,

and in figure 12 for wall specimens CIi-T4, To,

and T6, loaded on the outside face.

40

I

50

20

10

0 ^—:

» O 1 —oc>

I^ \j « o-t

1 i • op

« OTP • op

1 /

T / *L

fr

0 12 3

defleciion in. Figure 11. —Transverse load on wall CII, load applied

to inside face.

Load-deflection (open circles) and load-set (solid circles) results for specimens CH-Tl, T'2. and T3 on the sjian 7 ft 6 in.

The transverse load was applied to specimen

Tl in a horizontal position. The load due to the weight of the loading apparatus and the

specimen was 23.3 Ib/ft^, and the deflection

caused by this load was 0.77 in. The results

for specimen Tl are shown in figure 11 for

loads of 25, 30, 35, and 40 Ib/ft^. The trans- verse loads were applied to specimens T2, TS,

T4-, T5, and in a vertical position, as shown

in figure 10; hence there was neither initial load nor deflection.

Under a load of 35 Ib/ft^ on specimen 71, the

bonding plates at the longitudinal edges buckled

at midspan, and imder a load of 40 lb/ft- the

edges of the flanges of the units crushed along

the joint at midspan. Under a load of 32.5

Ib/ft^ on specimen T2, one unit cracked along

the base of the flange at midwidth, and under

a load of 45 Ib/ft^ one outer bonding plate

buckled noticeably. Under the maximum load on each of the specimens Tl , T2, and T3, the

flanges of the units at midspan crushed and

the bonding plates on the longitudinal edges

buckled. The deflection increased without an mcrease in the load.

Under a load of 70 lb /ft- on specimen T4

and of 65 Ib/ft^ on specimen T6 (applied to the

outside face) the edges of one unit crushed.

Under the maximum load on each of specimens

T4, T5, and T6, the units crushed along the transverse joints and the deflection increased

continuously without an increase in the load.

100

I

80

60

40

20

o o

• • » ( ) o

1

3 •: OC

ctoy

r o

o

CH-4

I 2

defleciion in. 5

Figure 12.Transverse load on wall CH, load applied

to outside face.

Load-deflection (open circles) and load-set (solid circles) results for specimens CH-Ti, TS, and T6 on the span 7 ft 6 in.

4. Concentrated Load

Wall specimen CH~P2 under concentrated

load is shown in figure 13. The results are shown in table 5 and in figure 14 for wall

specimens CH-Pl, P2, and PS, loaded on the

inside face, and in figure 15 for wall specimens

CH-P4, PB, and P6, loaded on the outside face. The concentrated loads were applied to the

inside face of specimens Pi, P2, and PS between the flanges of a unit, the outside (flat) face resting on a steel plate. After a load of 1,000 lb had been applied, the set in speci-

[10]
Figure 13.

Wall s-pecnm n CH~P^ uiuicr rnnci ni nii< n lno,l. Or

0.02 OM 0.06

ino/enfafi'on in. Figure 14.

Concentrated load on wall CH, load applied

to inside face.

Load-indentation (open circles) and load-set (solid circles) results for specimens CH-Pl, Pt, and P3.

600

5S

r

°n

^ o-c

•-H m u

Fttsyo f

0 0.05 0.10 0.15 deflecfion in. Figure 15.

Concentrated load on wall CH, load applied

to outside face.

Load-indentation (o!)en circles) and load set (solid circles) results for specimens CII-P4, PS. and P6.

[11]
men PI was 0.003 in., in specimen P2, 0.014 in., and in specimen PS, 0.004 in., and no other

effect was observed.

The concentrated loads were appHed to the

outside faces of specimens P4, P5, and P6

between the flanges of a unit, the ribs of the

inside face resting on a steel plate. After a load of 600 lb had been applied to each specimen, a longitudinal crack (parallel to the

flanges) was visible in the inside face of the

units. Under the maximum load, specimen

PJi failed by widening of this crack and speci- mens P-5 and P6 by punching of the disk

through the unit. The deformations were

greater than those for the inside face, because

they included the deflections of the web of the

unit xmder the transverse load.

5. Impact Load

Wall specimen CII I3 dining the impact test

is shown in figure 16. The results are given

FiGDKE 16. — Wall specimen CH~I3 during the impact test.

[12]

in table 5 and in figure 17 for wall specimens

CH-Il, 12, and IS, loaded on the inside face,

and in figure 18 for wall s])ecimens CH-I4, 15,

and 16, loaded on the outside face. The impact loads were applied to the center

of the inside face of specimens II, 12, and IS,

the sandbag striking the ribs at a vertical and

and a horizontal joint. The effects of the

impact load on specimens II, 12 and IS are shown in table 6.

Table Q.— Effects of impact load applied to the inside face of wall CII

Height of drop

for specimens

Description of effects

// 12 IS

First cracks in concrete at base of ribs of either one or // ft fl two units near midspan- .. _ 2. 5 1.5 1.5 Failure of specimen by opening of tlie transverse joint at midspan. ... . . . 2.5 1. 5 2.0 Xoticeable buckling of either one or two outer bonding

plates 3.0 3.0 2.5 Maximum height of drop; under load, specimen came

in contact with floor; deflection about 2 ft _ .. . 5. 5 5.5 5.5
defleciion in. def/eciion in. Figure 17.

Impact load on wall CH. load applied to Figure 18.

Impact load on wall CII, load applied to inside face. outside face.

Height of drop-deflection (open circles) and height of drop-set (solid Height of drop-deflection (open circles) and height of drop set (solid

circles) results for specimens CH-II, li. and 13 on the span 7 ft 6 in. circles) results for specimens CII I/,. IS. and If! on the span 7 ft fi in.

Figure 19.—Wall specimen

CH—Rl under racking load.

[13]
The impact loads were applied to tlie center

of the outside face of specimens I4, IB, and 16,

the sandbag striking at a vertical and a horizontal joint. The effects of the impact load on

specimens 74, IB, and 16 are shown in table 7.

1.2

1.0

^ 0.4

0.2

0^

1

B C

1 0-

M

—

« eo 0 »

<xy 0

Si

V

0.5 1.0 1,5 2.0

deformafion in./8ff

Figure 20.Racking load on wall CH.

Load-deformation (open circles) and load-set (solid circles) results for specimens CII-Rl, RS, and B3. The loads are in kips per foot of actual width of specimen.

6. Racking Load

Wall specimen CH-Rl under racking load is shown in figure 19. The results for wall speci- mens CH-Rl, R2, and R3 are shown in table 5 and in figure 20. The deformations and sets for a height of 8 ft were compiited from the values obtained from

the deformeter readings. The gage length of the deformeter was 6 ft 8 in. In specimen Rl under a load of 0.30 kip/ft

the unit in the top course adjacent to the loaded

unit cracked longitudinally (vertically). A

similar crack in the corresponding unit oc- curred in specimen R2 when the load was 0.24

kip/ft and in specimen R3 when the load was

0.23 kip/ft. In each of the specimens more

units cracked as the load was increased. Most

of the cracks were at the base of the flanges. All of the units in specimen Rl were cracked

when the load was 0.90 kip/ft and in specimen

R2 when the load was 0.80 kip/ft. Under the

maximum load the units in each of the speci- mens crushed and cracked at the base of the

flanges and the bonding plates bent.

Table 7.

Effects of impact load applied to the outside

face of wall CH

Description of etiects

First crack along base of ribs of from one to four units. Failure of specimen by crushing at the transverse joint at midspan and further cracking of units

All units cracked Buckling of either one or two outer bonding plates Rupture of central bonding plate near midspan

Maximum height of drop; under load, specimen came

in contact with floor; deflection about 2 ft

Height of drop

for specimens

U 15 16

ft ft ft 3.0 2. 5 2.5

3.5 4.0 4.5

5.5 5.5

6. 5 6.5 7.0 8.5 9.0 10.0

9.0 9.0 "10.0

* Tost discontinued. Specimen badly damaged, but did not come in contact with the floor. The description and drawings of the speci- mens were prepared by E. J. Schell, G. W.

Shaw, and T. J. Hanley, of the Bureau's Building Practice and Specifications Section, under

the supervision of V. B. Phelan.

The tests for determining the structural properties were made by the Engineering Mechanics^ Section, under the supervision of H. L. Wluttemore and A. H. Stang, and by the

Masonry Construction Section, under the su- pervision of D. E. Parsons, with the assistance

of the following members of the professional

staft": C. C. Fishburn, F. Cardile, H. Dollar,

M. Dubin, A. H. Easton, A. S. Endler, C. D.

Johnson, A. B. Lanham, P. H. Petersen, A. J. Sussman, and L. R. Sweetman.

V. SELECTED REP^ERENCE

Rock Products 41, No. 9, .59--61 (1938). Washington, August 9, 1939.

o

14
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BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 10^ BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions, . 10^ BMS3 Suitability of Fiber Insulating Lath as a Plaster Base 10^ BMS4 Accelerated Aging of Fiber Building Boards 10^ BMS5 Structural Properties of Six Masonry Wall Constructions 15^ BMS6 Survey of Roofing Materials in the Southeastern States 15^ BMS7 Water Permeability of Masonry Walls lOfi BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 10(5 BMS9 Structural Properties of the Insulated Steel Construction Company's "Frameless-Steel" Constructions for Walls, Partitions, Floors, and Roofs 100 BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Company 10(4 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 10(5 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

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(List continued on cover page IV)
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