Assessment of Populus tremuloides (Michx) mechanical characteristics for glulam production

Abstract

This project aimed to document the mechanical properties, the bonding, and joint performance of trembling aspen to improve its use in Engineered wood products. It also aimed to study the bending characteristic and investigate the failure behavior of full-size beams made of trembling aspen. Non-destructive and destructive tests were conducted on lamellae of trembling aspen (Populus tremuloides Michx) following the ASTM D198. Full-size beams were manufactured following the manufacturing principles outlined in the CSA-O122, the standard for glulam production in Canada, to evaluate the performance of finger jointing, block-shear and delamination, and to establish the glulam's bending strength. Mechanical tests on trembling aspen assessed a 5th percentile value of 13.8 MPa in tension, and 40.9 MPa in bending with a mean modulus of elasticity of 10,343 MPa. The relationship between dynamic and static modulus of elasticity was analyzed and showed a strong correlation, with low relative error, and its feasibility for machine stress rating. The test conducted on the finger joint shows a characteristic value of bending strength of 31.8 MPa. The block-shear and delamination align with the requirement from the standards CSA-O122. The investigation of the bending performance on the glulam made of trembling aspen achieved a mean strength resistance of 30.3 MPa, once modified to be compared with the values from the standard, is lower than the MOR value required from the standard. In addition to the mean modulus of elasticity determined of 9013 MPa, it is also lower than the value from the standard.