Flexural properties of bamboo scrimber under different temperature conditions: Experimental study and mathematical model

Abstract

Changes in ambient temperature significantly affect the flexural properties of bamboo scrimber. From the perspective of structural safety, temperature is one of the most important conditions to be considered when using structural components made of bamboo scrimber. This experimental study investigated the flexural performance of bamboo scrimber across a broad temperature range of −30 °C to 250 °C, providing essential data for its use as a structural member under different temperature conditions. Through a series of tests conducted at different temperature conditions with utilization of scanning electron microscopy, the damage modes and failure mechanism of bamboo scrimber were analyzed at both macroscopic and microscopic levels. It was found that the failure modes of bamboo scrimber under different temperature conditions were mainly categorized as simple tensile fracture damage, split tensile damage and brittle tensile fracture damage, in which the brittle tensile fracture damage only occurred in the specimens at a temperature of 250 °C. In general, the flexural strength and modulus of elasticity decrease with increasing temperature; when the temperature was increased from 20 °C to 250 °C, the specimens' flexural strength and modulus of elasticity decreased by 87.95 % and 90.25 %, respectively. Microscopic analysis revealed that these variations were correlated with alterations in the shape, structure and composition of the internal cells. Moreover, based on the Hognestad model, a mathematical relationship model between the load-displacement curves of bamboo scrimber and the temperature was derived, which can accurately predict the flexural load capacity of bamboo scrimber under varying temperature conditions.