Moisture distribution in cross laminated timber (CLT) made from heat-treated wood

Abstract

Cross laminated timber (CLT), as a versatile and sustainable engineered wood product, holds significant promise in the construction industry. However, its natural hygroscopic quality presents challenges, particularly in managing moisture-induced stresses and dimensional changes. Heat-treated wood, known for reduced moisture absorption and increased stability, poses an intriguing prospect for addressing these challenges within CLT structures. As an objective, this study investigated the influence of heat-treated wood on moisture distribution and gradients within CLT panels. It aims to explore the potential of heat-treated wood to mitigate moisture-induced stresses, enhance dimensional stability, and improve the overall performance of CLT structures. Fir wood lumbers underwent hydrothermal treatment before being utilized to fabricate CLT panel samples according to specified dimensions. Conditioning involved wet-to-dry and dry-to-wet cycles, with moisture distribution analyzed through weight assessments and the utilization of statistical software for gradient calculations. The results indicated that the moisture distribution across various layers revealed significant differences between control panels and those incorporating heat-treated wood. Notably, heat-treated wood layers exhibited lower moisture contents, contributing to reduced dimensional changes and minimized risks of delamination. The study also highlighted the impact of heat-treated wood in promoting uniform moisture distribution and dispersion, thereby reducing moisture-induced stresses and potential structural defects. Generally, the incorporation of heat-treated wood led to lowered moisture contents, smaller moisture gradients, as well as reduced instances of delamination within the CLT panels.