This report describes progress achieved in 1993/94. It had been anticipated that those parts of this research program concerned with interior walls would be completed by March 31, 1994. Because NRC carried out more fire tests than required by the collaborative research agreements with the various "Partners", they were not able to submit a final report for the fire tests by March 31. That report will be available in May. The sound transmission tests were completed by December 31,1993. The last fire test was carried out on February 28,1994. The final report for the sound-transmission tests was submitted to the "Partners" on February 23, 1994.
This report describes a program plan required to develop dynamic performance criteria for the design of wood-based floors in commercial occupancies. The need for serviceability criteria for wood joist floor systems in residential settings had long been recognized. This recognition led to the adoption of new span tables for Part 9 of the 1990 National Building Code which indirectly limited vibration amplitude and frequency (NBCC 1990) based on the research conducted and the Eastern Laboratory of the Canadian Forestry Service (now Forintek Canada Corp.). The introduction of these additional criteria into Part 9 of the NBCC to limit dynamic effects was the beginning of a true systems approach to floor design. It is now in the best interest of the wood industry to extend the systems approach to the design of wood-based floors in commercial occupancies, where the floors are likely to use engineered type wood products rather than solid sawn lumber, and combined with concrete toppings of various types. No dynamic performance criteria can be applied to these applications, in part because the basic work required to instill confidence in any proposed criteria has not been done. Dynamic performance criteria are now needed to serve the interest of the wood industry and to provide reliable guidance to the design professionals.
The objective for this work was to prepare a project plan for the development of moisture management guidelines to maximize durability of wood-based building systems. Exploration of the complexity of the technical issues involved led the conclusion that access to the use of a reasonably accurate computer model was needed to explore the performance of systems we feel have shown good track performance. Essentially, parametric sensitivity studies are needed, both to confirm the suitability of walls built in the different regions of the country based on the current field experience, and to extrapolate limits to these systems that might also be used as a guide for unconventional systems. With this assurance, information of the performance of typical wall systems as a function of the variables noted in this report should be obtained by modelling. It should then be possible to develop or assist in the developing of simpler user-friendly design tools for the building industry which incorporate advice on good construction practices.
Under current ASTM D-3501 procedures, the only practical method of obtaining compressive properties of wood based panels is to glue two or more plies of the specimen together to provide a compact column cpapble of resisting buckling. It is thought, however, that this method may not provide representative compression strength and stiffness data due to load sharing.
The main objective of this research is to contribute to the stream of research under way in Canada at the present time on the performance of exterior wall systems. In the process, we will facilitate the continuing and appropriate use of lumber and wood-based panel materials.
