2023 Volume 69 Issue 3 Pages 134-139
When out-of-plane loads are applied to cross laminated timber (CLT), shear stress occurs. If CLT results in shear failure, rolling shear in the transverse layer may occur because rolling shear strength is lower than that parallel to the grain. It then becomes important to evaluate the rolling shear strength of the lamina. However, how cross section size of laminae affect the rolling shear strength on Japanese larch (Larix kaempferi) has, to date, not been well examined. Therefore, we conducted compression type rolling shear tests on Japanese larch laminae with a thickness of 30 mm and widths of 60, 80, 100, and 120 mm. Laminae specimens comprising two pieces with a width of 60 mm were also tested. Results from the tests were as follows. The rolling shear strength was higher with increasing lamina width. In this study, the regression line of ratio of width to thickness and rolling shear strength was almost consistent with available data on Japanese larch lamina. The rolling shear strength of the specimen with two laminae was lower than that of specimens with 120 mm width.
