Abstract
Two types of mixed-species three-ply CLTs (Cross-Laminated Timbers) composed of hinoki-sugi-hinoki and akamatsu-sugi-akamatsu were manufactured in this study. The relationships between modulus of dynamic elasticity using frequency (Efr) of logs or lamina graded visually for knots, and modulus of elasticity (MOE) of edge-glued laminae were investigated. Moreover, mixed-species three-ply CLTs were examined by static bending tests to clarify the bending properties. The results are summarized as follows: Positive correlations were recognized between Efr of logs and MOE of edge-glued laminae for each species. When comparing average values of MOE of edge-glued laminae graded visually for knots, it was recognized that for sugi and akamatsu, MOEs of edge-glued laminae with none or fewer knots were significantly larger than those with few knots and loose knots. MOEs for mixed-species three-ply CLTs were clearly greater than those for sugi-only three-ply CLTs. When comparing mixed-species three-ply CLTs with hinoki or akamatsu single species three-ply CLTs, air-dry densities for mixed-species three-ply CLTs were significantly lower. However, differences of MOEs between mixed-species three-ply CLTs and hinoki or akamatsu single species three-ply CLTs were hardly recognized.
