Search for: All records

Thin-strand composite panels and subsequent mass timber beams were produced using thermally modified wood strands in a pressurized system. The effects of thermal modification (TM) temperature and dwell time on the mechanical, moisture, and decay performance of panels were studied. TM reduced moisture sorption and increased decay resistance. The thin-strand composites were evaluated in flexure and benchmarked against commercially available structural products. Moreover, the mass timber beams’ out-of-plane bending was accurately predicted with traditionally used laminated beam theory. The study shows that TM, under controlled conditions, enables the production of high-performing wood-strand panels with improved dimensional stability and decay resistance. 

Mass timber construction is rapidly growing in North America, given its versatility and performance. In addition, wood has a high strength to weight ratio and low environmental impact in contrast with other construction materials. Nevertheless, durability is a significant concern that needs to be addressed for the advancement of mass timber construction. Extreme care is required to protect members from exposure to high moisture environments while ensuring long-term durability. This project thus focuses on improvements of wood's longevity by combating two main issues: dimensional stability and decay resistance to biological organisms. At the same time, a sustainable approach is considered while utilizing small-diameter logs, which optimizes forest industry products. This is all achieved with the fabrication of Cross Laminated Strand-Veneer-Lumber (CLSVL) out of thermally modified wood strands. State-of-the-art concepts and technologies are implemented in the treatment process, fabrication, and assessment of the material. At first, wood strands are treated at different temperatures to understand its implications. A look at wettability, water sorption, and wood structure is used for this analysis. Furthermore, a series of macro-level mechanical benchmark tests in thin plies are conducted, such as internal bonding, bending, and tension. Later, accelerated decay tests are done to assess the improvement of wood's resistance to rot fungi. Finally, these analyses are used to systematically optimize the thermal treatment to obtain the best performing material to be used in the fabrication of mass timber as CLSVL.