Development of Small-scale Evaluation Methods for Wood Adhesives at Elevated Temperatures

摘要

Full-scale fire resistance tests on wood-frame wall assemblies carried out by the wood industry in 2006 demonstrated that end-joined (finger-joined) studs may not perform on par with equivalent solid-sawn studs, as had long been accepted by Canadian and U.S. building codes. The test results were found to vary significantly with the type of adhesive used, and more importantly, walls constructed with finger-joints made with some adhesives did not exhibit acceptable fire-resistance ratings. Although no problems have been reported with fire performance in the field, the wood industry recognized that it had to address this issue in order to ensure the continued safety of wood structures constructed with these products. In February 2007, the American Forest & Paper Association (AF&PA) released a qualification procedure for adhesives to be used in fire-rated assemblies that is based on full-scale ASTM El 19 fire resistance tests. This procedure has since been adopted by both the American Lumber Standard Committee (ALSC) and the Canadian Lumber Standards Accreditation Board (CLSAB). Although the full-scale test is now accepted, there are obvious advantages to developing a small-scale test procedure for use as an alternative to the full-scale procedure. This paper reviews the current small-scale tests available and presents a new elevated temperature adhesive tension test that builds on the current methods.