Evaluation of the mechanical properties and chemical components of naturally aged glued laminated bamboo

This study experimentally investigated the mechanical properties of aged GLB. The material under investigation was obtained from an outdoor-exposed GLB frame that had been subjected to outdoor exposure for a period of ten years. In-depth discussions were conducted on the mechanical properties and failure modes of the material in tension, compression, and bending. The failure modes were identified as fiber fracture under tension, fiber buckling accompanied by delamination in compression, and a combination of tension failure and transverse shear failure in bending. In comparison to new materials, the tensile strength, compressive strength, and bending strength of aged GLB exhibited a reduction of 5.19-41.2 %, 11.5-26.9 %, and 6.6-40.1 %, respectively. The reduction in strength exhibited considerable variability across the various positions within the aged GLB component cross-section. The greatest reduction in strength was observed in materials located on the upper surface of the component, which were directly subjected to UV radiation and rainwater erosion. Furthermore, Fourier transform infrared (FT-IR) spectroscopy analysis was conducted. The FT-IR spectra demonstrate that the chemical components of bamboo, including cellulose, hemicellulose and lignin, have experienced severe degradation.