Enabling the circular use of Cross-Laminated Timber by upcycling production waste

Over the past two decades, the use of Cross-Laminated Timber (CLT) has significantly increased in the building construction sector. The low-efficient production process of CLT requires 1.21 m3 of lamellae per 1 m3 of CLT, creating waste which is typically burnt and releases biogenic carbon. This paper presents a state-of-the-art literature review of the circularity of the CLT industry regarding production waste. First, despite a project-based variation, the level of waste generated is consistent between the Northern American and Danish contexts. However, the lack of information on its properties is a primary bottleneck in the structural reuse of this waste. Recent literature on the structural reuse of those CLT offcuts is presented and other possible applications are proposed. Finally, computational methods and tools supporting stock-constrained design are reviewed. None of the publicly available tools are suited
for stocks of CLT offcuts. Based on an example found in the literature, we present a computational method for designing flat reciprocal frame structures from reclaimed timber and propose conceptual modifications to adapt it to the specific requirements of CLT offcuts.