Effect of lamination grade on bending and shear properties of CLT made from fast-growing Chinese fir

Abstract

In this paper, fast-growing Chinese fir lumber were used to manufacture cross-laminated timber (CLT). Firstly, the non-destructive testing method was applied to test and analyze the distribution of the density and dynamic modulus of elasticity of fast-growing Chinese fir lumber, and Kolmogorov-Smirnov (K-S) test was applied to examine the distribution. After that, the bending and shear properties of CLT assembled with different grade of laminations were evaluated. Finally, the Shear Analogy Method was applied to predict the mechanical properties of CLT made from fast-growing Chinese fir lumber. The results showed that, the distribution of density of fast-growing Chinese fir lumber belonged to lognormal distribution, while the distribution of dynamic modulus of elasticity belonged to normal distribution. Besides, using higher grade lumbers as the longitudinal laminations of CLT could significantly improve its mechanical properties including bending and shear properties, and could avoid the damage in the longitudinal layer. Additionally, the Shear Analogy Method was appropriate to predict mechanical properties of CLT made from fast-growing Chinese fir lumber.