Design Guidance for Point-Supported CLT Floors

Cross-laminated timber (CLT) has gained popularity in recent years as a sustainable and cost-effective alternative to traditional construction materials. The crosswise layup in CLT provides two-way resistance, which makes CLT a suitable choice for point-supported applications. In this system, the panels are directly supported by columns, eliminating the need for beams and their connections, resulting in an increased free story height. In such applications, CLT punching shear resistance is one of the key properties and is directly related to the rolling shear strength of the lamellas. The factors influencing CLT punching shear resistance are either material-strength related or support-condition related and should be accounted for when designing point supported CLT floors. This study provides the results of 164 punching shear tests conducted on CLT panels sized 1.7 × 1.8 m, 1.5 × 1.8 m, and 1.5 × 1.5 m, identifying the impact of column location; CLT provider, lamella species and grade; and support geometry. Adopting an appropriate shear stress distribution model is crucial for punching shear design of CLT floors; therefore, a comparison between the results from the plane beam equation, shear analogy method, and transformed composite section method is presented in this study.