不同树种木材复合交错层压胶合木的力学性能

Experimental study on mechanical properties of cross-laminated timber with different tree species wood

采用花旗松、辐射松和杨木,即将杨木置于芯层,花旗松或者辐射松置于表层,压制单一树种和混合树种交错层压胶合木(Cross-laminated timber,CLT),对材料进行顺纹抗弯、顺纹抗剪和横纹抗剪性能测试。试验表明,相比抗弯弹性模量最低的纯杨木CLT,花旗松与杨木混合CLT的性能提高35%;包含杨木和不包含杨木的不同树种CLT顺纹抗弯强度及抗剪强度差别不大。试件破坏形式与CLT材料和结构形式有很大联系,主要包含指接处破坏、胶层分层和垂直层滚动剪切破坏等。

Three different wood species, such as Douglas fir, Radiata pine and Poplar were used to make pure wood species and mixed wood species cross-laminated timber （CLT） by putting Poplar lumbers at the core and other two wood lumbers at the outer surfaces. The mechanical properties tested in this study were the bending strength in the major direction, modulus of elasticity in the major direction, shear strength parallel to the grain and shear strength perpendicular to the grain. The results show the CLT panels only made of Poplar had the least E0 value, which was about 35% lower than that made of mixed Douglasfir and Poplar. It was found that the mechanical strength of CLT panels containing poplar were similar to those made of non-poplar wood. The wood species and configuration of CLT significantly affected the failure mode. The main failure found were finger joint failure, delamination and rolling shear failure.