Bending performance of parallel bamboo strand lumber under high-temperature treatment

Parallel bamboo strand lumber (PBSL) is economical and environmentally friendly and has good mechanical properties, but as a combustible material, there is a lack of research on its bending performance at high temperatures. In this paper, specimens of moso-bamboo-based PBSL were prepared and three-point bending tests were conducted at 11 temperatures ranging from 20 to 270°C using a temperature-controlled box. It was observed that the modulus of rupture (MOR) and modulus of elasticity (MOE) were basically inversely proportional to the temperature. Meanwhile, the color changes, bending failure modes and load-displacement curves of PBSL at different temperatures were compiled. In addition, the mass loss of the specimens was calculated and the microstructure of PBSL was analyzed by electron microscopy scanning. The results showed that the high temperature had a significant effect on the moisture content of PBSL and its internal structure, which was manifested as the weakening of the MOR at the macroscopic level. Finally, the fitting equations for the temperature-dependent changes in MOR and MOE reduction factor of PBSL are proposed in this paper, which provide a reference for predicting the performance of PBSL components under high-temperature conditions.