NBS TECHNICAL NOTE 706

Structural

Performance Evaluation

of Innovative

Building Systems
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards1 was established by an act of Congress March 3

1 1901. The Bureau’s overall goal is to strengthen and advance the Nation’s science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation’s physical measure-! ment system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materialsi Research, the Institute for Applied Technology, the Center for Computer Sciences andi Technology, and the Office for Information Programs.

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o

Structural Performance Evaluation

Of Innovative Building Systems

Felix Y. Yokel and Norman F. Somes

Building Research Division

Institute for Applied Technology

.National Bureau of Standards

Washington, D.C. 20234

tcchv' oj? e )4© > 0 (o

U.S. DEPARTMENT OF COMMERCE, Peter G. Peterson, Secretary

NATIONAL BUREAU OF STANDARDS, Lawrence M. Kushner, Acting Director,

Issued August 1972
National Bureau of Standards Technical Note 706

Nat. Bur. Stand. (U.S.), Tech. Note 706, 16 pages (Aug. 1972)

CODEN: NBTNAE

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 25 cents Stock Number 0303-1010
Structural Performance Evaluation of Innovative Building

Systems*

Felix Y. Yokel and Norman F. Somes

Considerable attention has recently been focused on the development of performance criteria. Per- formance Criteria are presently used in the U.S. by the Building Research Division of the Institute for Applied Technology, National Bureau of Standards, to evaluate innovative building systems. While building codes and design standards are usually related to specific building materials and

design solutions, performance criteria are derived from user requirements and are independent of

specific technological solutions. Many attributes inherent in traditional building systems which are acceptable to the user may not be present in untried innovative systems. The Performance Criteria therefore address themselves to many aspects of structural performance which are not considered in present codes and design stan- dards.The successful application of performance criteria depends on the feasibility of evaluating compliance. Performance can be evaluated by analysis by judgement based on past experience, or by physical

simulation. Deterioration with time must be considered, and performance criteria are viewed as minimum requirements which should be met at any time during the service life of a structure. An example is presented where physical testing was used to evaluate the performance of a high rise housing

system.

Key words: Building; connections; housing; neoprene; performance criteria; performance evaluation; performance testing; reinforced concrete; standard tests; structure; testing.

1 . Performance Criteria Versus Design

Standards

Considerable attention has recently been focused on

the development of performance criteria [1, 2, 3]. 1 Performance criteria, which are presently used in the

United States by the Building Research Division of the

Institute for Applied Technology, National Bureau of

Standards, have been discussed in a paper presented

I at the 5th CIB Congress in June 1971 [4]

Performance criteria define the required attributes

| of a building in terms of the functions the building has

j to perform. More specifically, attributes are defined in terms of the user requirements of safety, activity support, acceptable maintenance cost, absence of stress

and anxiety (comfort) and visual acceptability.

I

l

l —

: Presented at the 1st CIB Symposium on Tall Buildings (S—41), Moscow. U.S.S.R..

October 1971.

I Figures in brackets designate literature references.

The structural attributes thus defined can be

identified within broad categories of limits for strength,

stiffness and rigidity, and resistance to local damage.

These limits can be related to the required perform- ance which is entirely independent of any particular

design concept and material application.

Because of this independence from specific hard- ware solutions, the criteria cover many aspects of

structural performance not considered in present building codes and standards. These additional provisions

are necessary, since many attributes which are in- herent in traditional systems are not necessarily

present in untried innovative systems. Included are requirements for load capacity which take strength

variability into account, provisions for strength under

cyclic loading and prevention of progressive collapse,

criteria limiting vibrations and criteria for resistance to local damage under various concentrated and impact

loads. Also, now under consideration, are criteria for structural ductility (the ability to undergo large ir- recoverable deformation without fracture) to be applied

in particular in seismically active regions.

1
2. Methods of Performance Evaluation

The successful application of performance criteria depends on the feasibility of determining compliance

with the criteria. This determination is made by a per- formance evaluation which is carried out using one or

a combination of the following methods:

(1) analysis;

(2) professional judgement;

(3) physical simulation.

Traditionally, structural adequacy is determined by

analysis which includes the use of previous design ex- perience. However, when innovative untried designs

are evaluated analysis by calculation alone is not al- ways possible. In particular, it is difficult to predict certain aspects of structural behavior, such as long-term

strength and deflections, ductility, damping of vibrations, and behavior under cyclic loading. In such cases, it may sometimes be possible to use

professional judgment and draw conclusions from past

in-service experience or previous test results.

If neither analysis nor professional judgment can

provide satisfactory answers, physical simulation must

be used to supplement the analysis.

3. Guidelines for Physical Simulation

Physical simulation is a test procedure designed to simulate the response of an actual structure to various

loading conditions. Since it is required that the struc- ture satisfy the performance criteria at any time during

its service life, physical simulation must be interpreted

to account for the effects of structural deterioration

with time. This implies that in many cases the per- formance of a structure during the early years of its life must exceed the performance level required by the

criteria. The margin, by which the required per- formance must be exceeded, depends in each instance

not only on the materials and the systems used, but also on the uncertainty in judging the aging effects on per- formance. This uncertainty tends to be greater for systems with little or no service record.

The criteria that were set for physical simulation

require:

(1) selection of critical subassemblies for testing;

(2) use of critical loading conditions;

(3) allowances for, or simulation of, the effects of

the service-life environment;

(4) consideration of variability in performance.

These four points need further discussion;

(1 ) Selection ofcritical subassemblies for testing.

If structural response is simulated by full-scale te- ing, it is usually not possible to test more than a suba-j sembly representing a small part of the structure. Su

j subassemblies should be critical in their configuratiJ

(e.g., using the largest floor spans or the least numbj

of shear walls that would be used in an actual strut ture). Where foundation and joint fixity tend to increaJ load capacity and stiffness, it is important to considd potential loss or absence of foundation fixity by settle ment or adverse soil conditions and a possible deerea- in joint fixity by system slack and loss of tightness, del ciencies in fabrication, repeated loading, materi; deterioration, or loss of composite action. Choice of critical subassembly is particularly important whc prefabricated building systems are evaluated, wherl variations in architectural layout may result in reduo tions in, or unsymmetrical arrangement of, shear wail available to resist lateral loads or other critical lod supporting elements. In such cases the introduction openings for doors, windows, ducts, or staircases it

critical locations may also result in weakening of sheaf walls and reduction of vertical-load and diaphragm fiii plane loading) capacity of floors. Consideration must also be given to the interact! I of loadbearing and non-loadbearing elements, such i the interaction between structural frames and n ip loadbearing partitions. In some instances, non-load bearing elements contribute to the strength and stiff ness of the loadbearing structure. However, the lack' compatibility in stiffness may cause severe damage

the non-loadbearing elements. If unaccounted for. tn stiffening effects of non-loadbearing elements mayals

reduce the energy-absorbing capability of the structu under seismic loads.

(2) Use of critical loading conditions.

Critical loading conditions do not occur only as a cm sequence of critical load combinations acting on ft structure at critical locations. Other considerations *'

also important. An example is the added moment if duced by eccentricities of compressive loads acting I

vertical members. Such eccentricities may be at gravated by incidental construction misalignment

well as by permissible tolerances of fabrication a

erection, by instantaneous and time-dependent deft

tions and by lateral drift caused by wind forces orfou dation settlements.

(3) Allowancefor, or simulation of, the effect of the

service-life environment.

The simulation of the effects of service life deterior

tion presents one of the most difficult problems it

2
performance evaluation. The effects are particularly

, difficult to assess when no service records are

i: available. j The main difficulty arises from the necessity of simulating in a test of reasonably short duration environ -

| mental effects that occur over the service-life period.

Examples of environmental conditions that cause

deterioration are moisture and freezing, temperature

changes, ultraviolet light, chemical reaction, long-term

(loading, and cycles of repeated loading. These conditions may cause deterioration of materials, loss of strength in structural composites (particularly when adhesives are used), loss of stiffness in

structural joints, weakening of members by fatigue, and

Toad transfer from one structural element to another by

differential creep, (i.e., transfer from concrete to reinforcing steel) and by effects of temperature and

moisture.

All the above effects are reasonably well understood

in conventional construction and can be predicted by

analysis. However, in innovative systems and material

.applications, frequently only performance testing can

-provide a basis for prediction.

W Consideration ofvariability in performance.

\ ariability must be considered, particularly in the

evaluation of strength (load capacity).

Recently, considerable research has been devoted to

(he introduction of probabilistic concepts into structural design [5], At the present time, the professional

concensus in most countries is that the state of the art

has to be further advanced before such a step can be

taken. However, when the structure considered is very different from conventional construction, particularly with

respect to the application of structural materials,

presently-used margins of safety which are associated

"ith particular construction materials (concrete, steel,

masonry, etc.) may not be applicable. In these cases,

due consideration of strength variability provides the

only rational basis for setting safety margins.

The criteria require:

(1) that the structure not fail under certain

required “ultimate” loads and load combinations, which are service loads2 multiplied by

load factors. The factors insure that these “ultimate loads” have a very low probability of occurrence. The requirement is satisfied if a

suitably large percentage of a population of

load is a maximum load likely to occur during the service life of the building

structures would not fail under the required ul- timate loads.

(2) that the least credible strength be sufficient to preclude failure under any combination of ser- vice loads. Those requirements, in general, are deemed to be

satisfied by structures which are designed by present

widely accepted design standards and which meet the

requirements of the safety margins contained in these

standards. However, in order to determine whether in- novative structures, which cannot be designed by

present standards, meet both requirements, some basis

must be available to determine or estimate their

strength variability.

Strength variability provides the basis for determining by how much the average or “design” ultimate load

capacity should exceed the load capacity required by

the criteria. A strength excess is required in order to in- sure that the probability be suitably high that any building actually constructed have at least the load capacity

required by the criteria. When performance testing

provides the basis for determining average or “design”

load capacity, allowance must also be made for the possibility that the test sample selected had higher-thanaverage strength. Thus, the average load capacity of the

test sample must exceed the design load capacity. The

margin by which the design load capacity must be ex- ceeded can be determined by sampling theory, and depends on the number of specimens contained in the test sample.

The above-discussed relationships are illustrated in a very simplified form in figure 1. In this figure it is as- sumed that the variation of strength in the population

of structures built follows approximately a normal dis- tribution. The coefficient of variation of single struc- tures with respect to the mean strength of the population of structures is v, and the coefficient of variation of

the mean of a test sample (which is larger than 1; sayn)

with respect to the mean of a population composed of FREQUENCY

FIGURE 1. Relationship between strength variability and required

load capacity.

3
I Figure 2. Effect of strength variability of components on the strength variability of the structure.

test samples consisting of n structures each is v

'

. The

relationship shown in the figure corresponds to the

requirement that approximately 95 percent of the population have at least the strength required by the criteria,

and that there be about a 95 percent probability that the

structures tested have at least the mean strength

required to meet the criteria. The effect of the strength variability of a component

or subassembly on the strength variability of the

complete structure is illustrated in figure 2 in a very

simplified form. If the coefficient of variation of the

strength of the single shear wall to the left in figure 2 is v, then the coefficient of variation of the assembly of

four shear walls, v'illustrated to the right in the figure

will be v/VT, provided the walls are ductile enough to develop and sensibly maintain their capacity before

failure occurs and that the strength of the floor diaphragm corresponds to the failure mechanism. On

the other hand, if load is transmitted vertically through

many successive loadbearing members, and the failure of one member constitutes a failure of the structure, the

probability of failure in the structure is greater than the

probability of failure in a single member, subjected to similar loading.

Examples where strength variability has been considered include evaluation of untried structural adhesives, various structural composites including glass

reinforced plastic or metal stress-skin structural components with paper honeycomb cores, and several in- stances of unusual jointing techniques or structural

configurations in precast reinforced concrete structures.

4. Standardization of Performance Tests

It is essential that a performance evaluation be ob- jective. Ideally, objectivity in the evaluation of com pliance with any criterion requires a measuremen method that cannot be influenced by the individual per forming the measurement.

In practice, such objective methods are difficult to develop, since frequently many variables contribute t< produce a certain attribute. All of these variables are not always measurable. A case in point is the previous!

discussed strength variability. Obviously, it would no be feasible to measure variability by testing a sufficien number of full-scale buildings to destruction. Indirect means must therefore be used which include not onb tests, but also estimates of the magnitude of variou- parameters that cannot be reasonably determined b' testing. In these cases, a set of guidelines takes the place of a standardized measurement method.

In other, more simple cases, efforts are now under way to develop standardized performance tests. Such tests have the advantage of being consistent and relia ble and providing guidance to developers of innovative systems. The importance of standardizing tests is illus trated by the following example. Figure 3 shows the ap paratus used for impact tests on floors. The leather bar was prepared in accordance with the standard procedure described in the American Society for Test ing Materials (ASTM) designation E-72 [6] , which specifies tests for floors and walls. However, since the criteria for impact load require a higher impact energy than that envisioned when the ASTM procedure was
Figure 3. Apparatus for impact tests on floors.

developed, the bag was strengthened and filled with a

mixture of sand and lead shot, rather than only sand as

specified in ASTM designation E-72.

Various experiments that were performed indicated

that the impact resistance developed by the floor

systems not only depended on the impact-energy applied but also varied with the weight of the bag and the

ratio at which sand and lead shot were mixed. The conclusion was that only a standardized test procedure

would yield consistent and dependable results.

Another effort is underway to develop a standardized

ttest for transient vibration. The criterion for transient

vibrations of floors is presently expressed in terms of

the rate of decay as a function of time, based on data

which indicate the vibration induced by human activity,

persisting at a perceptible level for less than 1/2

second, will not be disturbing to occupants [7]. However, further research has been initiated to consider

also the variables of frequency and of displacement amplitude.

Figure 4 shows a test set up that was developed to

measure floor vibrations. The equipment consists of a

25-lbm (11.34 kg) bag filled with sand and lead shot, a

hag-release device mounted on a tripod for releasing

the bag from a height of 3 ft (0.914 m) and a displacement transducer (linear variable differential transformer, LVDT). The LVDT is attached to a rigid beam

°f adjustable length which is positioned to span

between two opposite walls.

The output of the LVDT is recorded by a recording

oscillograph, presently equipped with a 600-Hz

response galvanometer. Traces of the response are

recorded on photosensitive paper fed through the oscillograph at a rate of 4 in (10 cm) per second. Figure 5

shows typical traces of displacement amplitudes ob-

’ ta*ned in a test.

Figure 4. Apparatus for measurement of transient floor vibrations.

Standardization of the above-mentioned tests is important, and efforts are also underway to standardize

many other test procedures, among them concentratedload tests on floors (fig. 6), impact tests on walls, en- vironmental conditioning of test specimens, evaluation

techniques for structural adhesives, and evaluation of

structural ductility.

5. A Case History of Performance Evaluation

Figure 7 shows a housing system consisting of lightweight concrete modules, constructed in a checkerboard pattern. Several structures up to 17 stories in height have been erected, and a 22-story structure,

using modules of different dimensions, is now in the

planning stage. The modules for the 22-story structure

are approximately 13 feet (4.0 m) wide, 52 feet (15.8 m)

long and 8 feet 7 inches (2.6 m) high and weigh approximately 92 kip (41,700 kg).

The modules consist of a monolithically-cast ceilingand-wall bent and separately-cast floor slab. The

ceiling-and-wall bent derives its support from four ribs,

each consisting of two columns with a horizontal beam

connecting the columns at the ceiling level. Between

these ribs there are three inch (76 mm)-thick infill rein- forced concrete walls, and a four inch (100 mm)-thick

infill reinforced concrete ceiling. The floor is also a four

inch (100 mm)-thick reinforced concrete slab. Figure 8 shows the assembly of the modules in more

detail. One individual module is shown in figure 9.

5
y||Vw\AA^r^

TIME (sec)

Q-5<

TIME (sec)

Figure 5. Displacement-amplitudes of transient floor vibrations.

Modules in successive stories are connected to each

other by connecting the columns of the stiffening ribs

in the modules. This is illustrated in figure 10. The

checkerboard pattern of modules is closed at the end

walls by inserting a special precast wall-column as- sembly which matches the sidewalls of the modules,

and which is inserted at alternate story levels. Figure 11 shows the connection details. In Figure

11(a) the reinforcement detail at the column end is shown. In this case, it is necessary to transmit the full

Figure 6. Apparatus for concentrated load test on floors.

column load through a plain concrete bearing, with onl one grouted dowel passing from one column to the next The bearing stress on plain concrete permitted in U.S. design standards used at the time of the evaluation (ACI 318-63 [8]) was 0.25 f'c , where f'c is the 28-da\ concrete compressive strength. The concrete stres- permitted for ultimate load in the proposed revision ot ACI 318-63 [9] was 0.7 X 0.85 f'c

. In either case, in a< cordance with these standards, only a small fraction n. the load that the column is capable of supporting couh; be transmitted through the connection. In order to in crease the concrete compressive strength at the con nection, additional reinforcement ties (loops), were proposed, as shown in figure 11(a). It was reasoned thail these ties will increase the compressive strength of the concrete at the column face by providing confinemenl

Figure 11(b) shows the detail at the connection. T< accommodate structural tolerances, and also to minimize local stress concentration, a 1/4-inch (6.3? mm) thick neoprene pad was proposed to be inserts between two successive columns (cast in place or grouted connections were avoided for reasons of ecom my and ease of erection.)

Since Poisson’s ratio for neoprene is higher and the modulus of elasticity is lower than that for concrete.il was anticipated that the neoprene pad would exert a radially tangential shear force on the concrete face causing tensile stresses and thereby counteracting the

beneficial effect of the confining reinforcement ties Quantitatively these effects could not be predicted b} analysis, and past experience with concrete bearings or neoprene was confined to stress levels below 1000 psi

(0.7 kgf/mm2

). Structural analysis therefore had to be supplemented by testing.

6
FIGURE 7. Modular reinforced concrete housing system.

Figure 8. Detail of stacking of modules.

Figure 12 (left) shows one of the test specimens used

jt consisted of two half-columns and a connection

between them. Load was transferred to the half- columns through steel plates which were welded to the

roain reinforcement. The reinforcing arrangement of a

(half-column is shown in figure 12 (right). Most specimens were loaded axially to failure in a 600-kip

; (272,000 kgf) testing machine. Some specimens were

,, oaded at a vertical-load eccentricity equal to 1/10 of

' 'e column thickness. The specimens were instru- mented by a dial gage to measure the compression of

i:

1 e beaii ng pad, as shown in figure 12 (left). The figure

,aso s h°ws a displacement transducer mounted horiFlGURE 9. Individual module.

FIGURE 10. Stacking of module-ribs.

7
(o) COLUMN REINFORCEMENT

AT CONNECTION

Figure 11. Detail zontally on the left column face. Two such transducers were mounted on mutually perpendicular column faces

to identify the onset of concrete cracking by measuring

the increase in the width of the column face. The following interface conditions were tested:

(1) a 1/4-inch (6.35 mm) neoprene pad as proposed;

(2) a 3/4-inch (19 mm) thick bed of non-shrink high

strength grout;

(3) a 1/4-inch (6.35 mm) neoprene pad, with lowfriction material inserted between the

neoprene and the column face (to limit the

transmission of radially tangential shear

forces);

(4) a 1/4-inch (6.35 mm) thick neoprene pad set between two 1/8-in (3.17 mm) thick stainless

steel plates;

(5) a 1/4-inch (6.35 mm) thick neoprene pad set between two 1/16-inch (1.58 mm) thick stainless steel plates.

The following table summarizes the average concrete

strength developed at the column face in each system

as a function of the unconfined compressive strength of

0.85 // as recommended in ACI 318-71 [10] with the </>- factor taken to be 1.0.

Connection system

Average

failure stress/0.85//

Number of specimens

tested

(1) 1/4 in (6.35 mm) neoprene pad.. 0.91 3

(2) 3/4 in (19 mm) grout bed 1.13 2

(3) 1/4 in (6.35 mm) neoprene pad

covered by low-friction material 1.20 2

(4) 1/4 in (6.35 mm) neoprene pad between 1/8 in (3.17 mm)

steel plates 1.32 5

(5) 1/4 in (6.35 mm) neoprene pad between 1/16 in (1.58 mm)

steel plates 1.02 2

Figure 12. Specimen for connection test.

Test results on System (1) indicate that the bearing strength of the concrete was considerably reduced b'j the neoprene pad. A typical failure is illustrated in- figure 13. Results for System (2) indicate that with a grout bed some benefit is realized from the confining reinforce ment loops. A typical failure is illustrated in figure U

Results for System (3) gives an indication of the order| of magnitude of the effect of the neoprene (about 30, percent strength reduction), since the low friction inter face limited transmission of the radially tangent^

shear forces from the neoprene to the concrete. The failure is shown in figure 15.

(b) CONNECTION DETAIL

of column connection.

-STEEL DOWEL

1 .

f

/

- GROUT CHANNEL

„ NEOPRENE PAD OR NEOPRENE- STEEL SAND

8
Figure 13. Failure of connection with 1/4 in neoprene pad.

Figure 14. Failure of connection with 3/4 in grout bed.

Results for System (4) show very good performance.

This is attributed to two factors:

(1) the steel plates resisted the radially tangential

shear force exerted by the neoprene;

(2) the friction force between the steel and the

concrete provided confinement additional to that provided by the reinforcement ties. A typical test failure is shown in figure 16. Note that

the main reinforcement bars left an imprint on the

concrete face. The concrete face was molded, but did

> not crack. This is taken as an indication that the

Figure 15. Failure of connection with neoprene pads and low

friction material.

Figure 16. Failure of connection with steel-neoprene-steel sandwich.

) 9
Figure 17. Test specimen with grouted dowel.

concrete was triaxially stressed, and thereby developed

high compressive strength. Test results on System (5) indicate that the 1/16 in (1.58 mm) steel plate had insufficient strength to fully

resist the tensile forces. The above test results were consistent with results obtained under eccentric vertical load. On the basis of

the tests it was concluded that System (4) could be used

in critical bearing pads, namely those of the lower-story

bearings. The concrete stress permitted under ultimate

load will be 0.7 X 1.1 f'c where 0.7 is a reduction ac- counting for strength variability and 1.3X0.85/1 = 1.1fe is the average strength achieved in the tests. Another feature of the connection shown in figure

11(b) is the steel dowel. In some cases these dowels will be ordinary reinforcing bars, in others, post-tensioning

strands. In most connections, the dowels are grouted

after erection. However, in the two end walls, dowels

are grouted progressively during erection. These

progressively-grouted dowels will yield during erection,

since the dowels alone do not have the load capacity to support the dead load. Yielding will proceed until the

neoprene pad is compressed to the point where the load

in the neoprene is equal to the applied load less the

yield capacity of the dowel.

Figure 18. Shear-test specimen before grouting.

Several problems must be investigated:

(1) What is the effect of the dowel, and of the yielding

of dowels, on the compressive-load capacity ofthe column connection?

This problem will be investigated by testing colum connections with grouted dowels which will be pre loaded to the full dead load before grouting, and con

| paring the results with test results from simila' specimens which were not pre-loaded before groutin. the dowels. One of these specimens is shown in figur

17. The dowel, the main reinforcing bars, as well as tin reinforcing ties providing confinement to the concre: at the connection, are instrumented by strain gage-j The instrumentation of the dowel will give an indicate of the length over which the bond between the dem- and the grout breaks as a result of yielding. This w: give some indication of the magnitude of the strai: which occurs after yielding. The strain gages on the confining ties will give an indication of the contributi" f of these ties to the strength increase in the concrete

a'

the connection.

(2) What is the shear capacity ofthe connection, and

will there be ductile behavior after a shearfailure occurs ?

10
To investigate shear capacity and ductile behavior

specimens will be subjected simultaneously to shear

and vertical loads of various magnitudes. A shear test specimen being prepared for grouting of the dowel is shown in figure 18. These tests are considered critical,

since the shear strength of the connection is necessary

in resisting seismic forces as well as in providing the

structural continuity required to prevent progressive

collapse. A third series of tests planned for this system will measure ductility available for resistance to seismic

loading. In these tests, complete bents will be subjected to reverse cycles of lateral loading. First, several

cycles of load will be applied, each large enough to

cause a deformation of twice the yield deformation.

Then, several additional load cycles causing a deformation up to five times the yield deformation will be applied. Finally, the frame will be laterally loaded to its

full load capacity.

The previously discussed case is just one example of many performance evaluations now in progress at the

National Bureau of Standards. The Bureau of Standards is carrying out these evaluations as the technical

arm of the U.S. Department of Housing and Urban

Development under the Operation Breakthrough program which has been discussed elsewhere [4]. It ini volves the construction of a number of selected industrialized housing systems on several demonstration

’ sites. There were other cases of evaluation by testing

where environmental conditioning had to be used, particularly in the case of structural adhesives. In addition

to the present stage of performance evaluation, which

precedes initial construction, the in-service performance of buildings constructed at the demonstration

sites will be investigated. This investigation will be part

of the overall performance evaluation, prior to volume

production of the systems.

6. References

[1] Eberhard, J. P., Project Director, “The Performance Concept:

A Study of its Application to Housing” National Bureau ol Standards, U.S. Department of Commerce Clearinghouse Document PB 184458, Washington, D.C., June 1969.

[2] Mainstone, R. J., Bianco, L. G., and Harrison, H. W., “Per- formance Parameters and Performance Specification in Architectural Design” Current Paper 23/69, Building Research Station, Ministry of Public Works, U.K.

[3] Schirayama, K., “Conception of Performance of Dwellings and

their Standards,” Building Research Institute Ministry of Construction, Japan, 1971.

[4] Yokel, F. Y., and Somes, N. F., “Performance Criteria for Tall Buildings,” Proceedings, 5th CIB Congress, Paris-Versailles, June 1971.

[5] Benjamin, J. R., and Weinberg, B. E.; Sexsmith, R. G. and Nelson, M. F.; Benjamin, J. R., and Lind, N. C.; Cornell, C. A., Series of four papers submitted by members of ACI Committee 348, Structural Safety, Journal of the American Concrete

Institute, 66, Nos. 9,10, 11, 12, Pittsburgh, Pa., USA, September-December 1969.

[6] American Society for Testing Materials, ASTM Designation

E72-68, Conducting Strength tests of Panels for Building Construction, Philadelphia, Pa., USA, 1968.

[7] Commonwealth Experimental Station, Human Sensitivity to Vibrations in Buildings, RF No. 12, Melbourne, Australia,

1966.

[8] American Concrete Institute, Building Code Requirement for Reinforced Concrete, (ACI 318-63), Detroit, Mich., USA, 1963.

[9] American Concrete Institute, Proposed Revision of ACI 318-63, Journal of the American Concrete Institute 67, No. 2, Feb.,

1970, Amended 67, No. 9, Sept. 1970 and 68, No. 8, August

1971.

[10]

American Concrete Institute, Building Code Requirements for Reinforced Concrete, (ACI 318-71) Detroit, Michigan, 1971.
'

-
FORM NBS-114A 11-71)

u.S. dept. OF comm. 1. PUBLICATION OR REPORT NO. 2. Gov t Accession BIBLIOGRAPHIC DATA NBS TN -706 Np* SHEET

3. Recipient’s Accession No.

4. TITLE AND SUBTITLE

i Structural Performance Evaluation of Innovative Building

Systems

5. Publication Date August 1972

6. Performing Organization Code

7. AUTHOR(S) „ Felix Y. Yokel and Norman F. Somes

8. Performing Organization

9. PERFORMING ORGANIZATION NAME AND ADDRESS

1 NATIONAL BUREAU OF STANDARDS

} DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No.

11. Contract/Grant No.

12. Sponsoring Organization Name and Address Same as No. 9.

i

13. Type of Report & Period Covered

Final

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.) Considerable attention has recently been focused on the development of performance

criteria. Performance Criteria are presently used in the U.S. by the Building Research Division of the Institute for Applied Technology, National Bureau of Standards,

to evaluate innovative building systems.

) While building codes and design standards are usually related to specific building

materials and design solutions, performance criteria are derived from user requirements and are independent of specific technological solutions.

Many attributes inherent in traditional building systems which are acceptable to the

user may not be present in untried innovative systems. The Performance Criteria

therefore address themselves to many aspects of structural performance which are

not considered in present codes and design standards.

The successful application of performance criteria depends on the feasibility of

evaluating compliance.

Performance can be evaluated by analysis by judgement based on past experience,

br by physical simulation. Deterioration with time must be considered, and performance criteria are viewed as minimum requirements which should be met at any

time during the service life of a structure. An example is presented where physical

testing was used to evaluate the performance of a high rise housing system.

words (Alphabetical order, separated by semicolons) Building ; connections ; housing ; neoprene;

Performance criteria; performance evaluation; performance testing; reinforced

^Iferete; standard tests: structure, testii iting. ! ' AVAILABILITY statement

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