Experimental investigation on the structural performance of two-storey cross-laminated timber shear walls

Rapid urbanization has led to an increasing demand for sustainable living and working spaces. In response, renewable materials like wood, especially in the form of Cross-laminated timber (CLT), have gained traction due to their sustainability, cost-efficiency, and versatility. However, there remains an insufficiency of experimental tests on multi-storey CLT structures, and the limited studies conducted so far have predominantly used conventional light frame connections. This thesis is centered on evaluating the performance of two-storey CLT shear walls with self-tapping screw (STS) connections, addressing a significant research gap. The research involves experimental tests conducted on two-storey CLT shear walls, with a focus on the effect of the shear connections between floors and tension strap connections as well as the effects of acoustic insulation layers and the presence of perpendicular CLT shear walls on the structural performance. Load-displacement curves showed linear behavior up to the intended lateral displacement, with STS-connected CLT shear walls meeting NBCC drift criteria of 2% height of the structure. Rocking was the primary factor influencing lateral displacement, with tension straps playing an important role. Strengthening shear brackets and adding dead load increased load-carrying capacity by almost 25%. Screw installation angle at tension straps had minimal impact. Also, test results showed that the addition of an acoustic layer had a slight adverse effect, while perpendicular shear walls boosted load-carrying capacities by 15%. In addition, Sliding contributed about 10% to lateral deformations. Panel distortion was minimal, affirming rigid body behavior, and CLT panels acted as rigid diaphragms. This study findings provide valuable insights into the behavior of CLT shear walls, highlighting the importance of appropriate tension strap connections and detailing.