Out-of-plane bending and shear behavior of cross-laminated bamboo and timber under four-point loading with variable spans

Abstract

This paper investigates the out-of-plane four-point loading behavior of cross-laminated bamboo and timber (CLBT) with variable spans. The experimental design involved CLBT specimens with spans ranging from 1800 mm to 3600 mm, and cross-laminated timber (CLT) specimens were used as the control. Theoretical calculations and finite element simulation methods were employed to analyze the out-of-plane loading performance. The results indicated that under the same span, the measured mechanical properties of CLBT specimens were higher than those of CLT specimens. For example, the CLBT specimens with a span of 3600 mm exhibited bending strength and global bending stiffness that were approximately 190 % and 70 % higher than those of the CLT specimens, respectively. Increasing the span reduced internal shear stress in both CLBT and CLT specimens and increased their strength and global stiffness in bending. Although the CLBT floor panel was heavier than that of the CLT floor panel, it exhibited lower mid-span deflection in the serviceability limit state, indicating better performance in safety and stability compared to CLT. The results of this study offer valuable insights into the design and application of CLBT floor panels.