The temperature effect on the compressive performance of laminated bamboo lumber

Abstract

Abstract In order to study the temperature effect on the compression performance of laminated bamboo lumber (LBL), a total of 11 temperatures were set, and 198 specimens were tested in three loading directions: parallel to the grain, perpendicular to the grain in the flatwise and edgewise section. Based on the results, the color changes and failure modes at different temperatures were analyzed. The difference of the failure process under different temperatures was compared, and the changes of the microstructure such as the vascular bundle were observed, which was helpful to further discuss the influence of temperature on the failure mechanism of LBL. It was found that the compressive strength parallel to the grain is obviously greater than that perpendicular to the grain, and the compressive strength perpendicular to the grain in the flatwise and edgewise section was close. The results showed that the average compressive strength of the specimens in three loading directions at 20℃ was 45.07 MPa, 12.13 MPa, and 10.75 MPa respectively. Compared with that, the compressive strength in three directions increased by more than 80% at low temperature (-60℃), and the loss of compressive strength exceeded 70% at high temperature (200℃). Therefore, an empirical formula of compressive strength reduction (increase) factor was established by regression analysis.