Mechanical properties of aged glue laminated bamboo for structural members

This research experimentally investigates the mechanical properties of aged unidirectional engineered bamboo (EB) laminate, pivotal in constructing glued laminated bamboo (glubam) structures. Investigations encompassed both outdoor exposure and artificial accelerated aging tests. In particular, outdoor exposure spanning three sixmonth intervals from July 2019 to December 2020. Complementarily, the Boil-Test (BT) method, as per the BS EN1087-1 standard, was employed for accelerated aging. The research examined tension, compression, bending, and shear mechanical characteristics of the aged bamboo samples. Notably, failure modes were predominantly influenced by fiber, matrix, and interfacial lamination layers. Findings revealed the superior anti-aging capacity of bamboo fibers compared with than that of bamboo matrix and lamination layer. Bamboo fibers maintaining over 75% of their original tensile strength. The BT accelerated aging method gave conservative estimations compared to outdoor exposure tests. Conclusively, the research yielded a novel tri-linear stress-strain model for analyzing the bending performance of glubam structures under varying aging conditions. This model incorporated strength reduction factors derived from the experimental data obtained from the corresponding compression and tension tests.