UNITED STATES DEPARTMENT OF COMMERCE • Maurice H. Stans, Secretary For sale by the Superintendent of Documents, U.S. Government Printing Office Certain proprietary and patented building systems, structural components, and building materials are identified in this report in order to adequately specify the test specimen and the experimental procedures. In no case does such identification imply recommendation or endorsement by the National Bureau of Standards, nor does it imply that the proprietary products identified are necessarily the best available for the purpose. This report does not account for possible variation in the performance of these proprietary products. The contents of this report are not to be used for advertising or promotional purposes. Library of Congress Catalog Card No. 73-602417 Structural Performance Evaluation of a Building System* Edward O. Pfrang and Felix Y. Yokel** A full-scale, first-story portion of a building system was tested in the laboratory in such a manner as to simulate the structural behavior of a three-story building under both service and potential ultimate loading conditions. Additional tests were performed on the system components to provide behavioral data needed for the evaluation of the system. Performance criteria for the evaluation of the structural safety and adequacy of certain building systems were developed. This report presents the results of the physical tests performed in the evaluation of the safety and structural adequacy of one such system, and discusses their significance. The report also presents data concerning the complex interaction between components which takes place in the building system. The primary conclusions reached were: (1) The system, as erected in the laboratory, satisfied the performance criteria which were set for its evaluation with a substantial margin. As a system, it exhibited strength and stiffness in excess of service and ultimate load requirements. (2) The walls of the system behaved as an integral part of the structure. They provided most of the stiffness of the system with respect to lateral loads, and provided a significant portion of the stiffness against vertical loads. Key words: Building systems; low-income housing; performance criteria; performance testing. 1. Introduction It is now recognized that the United States has a severe housing shortage, particularly in the area of low-income housing. This shortage is of such magnitude and urgency as to make questionable its solution through conventional means. It appears that only systems-type solutions taking full advantage of the innovative capabilities of our advanced technology will be capable of coping with this problem economically and within an acceptable time framework. Traditionally, structural innovations in building construction have been evolutionary rather than revolutionary and have taken place in small, carefully considered increments. Many of these incremental steps have been based upon extensive laboratory and analytical investigation. Progress has usually been based upon component testing and upon simplified and conservative analyses which do not fully account for system interaction. Because of these simplifications, the strengthening effects of so-called nonstructural portions of a building system are, in general, neglected and the complex interaction of components is frequently overlooked. As a result, in those few cases where tests on complete building systems. have been performed, results have been obtained which in most cases indicate strength and rigidity far in excess of that predicted either by component testing or by conventional * Work sponsored by the Department of Housing and Urban Development, Washington, D.C. 20410. **Associate Professor of Engineering, on leave from School of Advanced Technology, State University of New York at Binghamton, New York 13901. simplified analysis [1].' Strict reliance on these conventional concepts tends to inhibit innovative solutions to the building problem. One solution to this dilemma would be fullscale system tests coupled with mathematical analysis. However, full-scale tests of large building systems are prohibitively expensive and time-consuming and are also difficult to interpret unless they are performed under ideal laboratory control. In addition, the development of mathematical theories generally depends upon a trial-and-error feedback process involving numerous cycles of physical testing. A more reasonable approach appears to be the execution in the laboratory of large-scale subsystem tests which simulate total system behavior. If such subsystems are carefully chosen and are tested in a manner designed to simulate the performance of the total system, and if they are supplemented by critical component tests, then they can be used as a basis for determining the structural adequacy of proposed innovative solutions. This report summarizes the results of such an evaluative study. 2. Objective and Scope This report presents the results and evaluation of a structural performance test on an innovative building system. Criteria for structural performance and for performance testing are developed and are subsequently applied to system evaluation. 1 Figures in brackets indicate the literature references on p. 25. |