The increasing use of cross laminated timber (CLT) panels in large multi-story buildings has highlighted the structural performance of CLT in fire as a critical issue concerning life safety and serviceability. It is well-known that wood material strength decreases when exposed to elevated temperature for an extended period of time. For CLT panels, another level of complexity lies in the mechanical properties of the glued interface under high temperature. In this study, the tensile strength of typical North American wood species and shear strength of the glued interface of commonly used adhesives in CLT production were evaluated at different levels of elevated temperatures. The researchers systematically tested glue interface and wood samples in a controlled temperature chamber and obtained the load-deformation curves of the specimens until failure was observed. A total of five temperature levels were tested, with three wood species and four wood adhesive types. The glued interface strength was also compared to wood material strength itself under different temperatures. For each test, multiple samples were tested to ensure statistical significance of the results. The ultimate objective of this study is to develop a mechanistic model for CLT panels that can take into account the effect of temperature. In this paper, only the design, execution, and results from the elevated temperature tests are presented.
