Abstract
In accordance with the “Japanese Agricultural Standard for Cross Laminated Timber,” the bending Young’s modulus of laminae and the bending strength of finger-jointed laminae are graded by a bending test in a flat-wise direction. When a Cross Laminated Timber (CLT) was loaded in an out-of-plane direction, laminae in the CLT are loaded in a flat-wise direction and this direction matches with the direction of the bending test for the laminae. In contrast, when a CLT was loaded in an in-plane direction, laminae in the CLT are loaded in an edge-wise direction and this direction does not match with the direction of the bending test for the laminae. This study assessed the improvement in the accuracy of in-plane bending strength of CLT and compared the bending strength in flat- and edge-wise directions. The results showed that the average of Young’s modulus of sugi finger-jointed laminae in the edge-wise direction was 7% higher than that in the flat-wise direction, while the average of the bending strength of sugi finger-jointed laminae in the flat-wise direction was 20% higher than that in the edge-wise direction. Using bending Young’s modulus and bending strength of laminae in the flat-wise direction, an equation for bending Young’s modulus and bending strength of CLTs was derived and verified. Consequently, the estimated value of bending Young’s modulus and bending strength was well fitted with that of the measured value, and this estimation was also validated.
