Delamination of Cross-laminated timber and its impact on fire development | Focusing on different types of adhesives

Sammanfattning: In the recent decade, the interest of building taller all-timber structures using engineered timber materials such as cross-laminated timber (CLT) has increased substantially. On the other hand, there’s also a significant resistance and fear concerning the fire safety of buildings with wood-based load-bearing structures. In this report, the aim is to investigate the potential deviations of the fire performance of CLT. More specifically the occurrence of losing entire layers due to fire exposure, delamination, and how this might affect the fire development. Fire tests were performed in a standard testing furnace with specimens of CLT manufactured with five different adhesives. For these tests, the fire conditions of a previous full-scale test were attempted to be replicated. After evaluating the results, it was concluded that the type of adhesive used, could have a significant impact on whether a CLT-element delaminates or not. Furthermore, delamination also has a severe impact on the fire development, increasing the temperatures and extending the duration of the fire. CLT as a future building material still faces a lot of challenges, and further research is needed to optimise the composition of the material and investigate complications other than fire performance as well.