Rolling Shear Strength of Laminae for CLT with Four Japanese Softwood Species Obtained by the Compression Method. Influence of species and moisture content

In order to investigate the rolling shear strength of CLT with Japanese softwood species, we carried out the rolling shear test by compression method with four major Japanese softwood species (Japanese cypress (Chamaecyparis obtusa), Japanese larch (Larix Kaempferi). Japanese cedar (Cryptomeria japonica) and Sakhalin fir (Abies sachalinensis)). In addition, in order to determine the effect of moisture content on rolling shear strength, the test specimens were humidity-controlled under three different humidity environments (40% RH. 65% RH, and 80% RH at 20 degrees C). Results from the tests were as follows: (1) the rolling sheer strength was higher in the order of Japanese cypress. Japanese larch. Japanese cedar and Sakhalin fir. (2). There was no significant difference in the rolling shear strength due to the difference in moisture content. (3) There were correlations between the rolling shear strength and the air-dried density of laminae in Japanese cypress and Japanese cedar. However, there were no correlations between the rolling shear strength and the air-dried density of laminae in Japanese larch and Sakhalin fir.