Experimental study on compressive and tensile properties of a bamboo scrimber at elevated temperatures

Abstract

To understand the stress-strain relationship and failure mechanism of bamboo scrimber at elevated temperatures, both parallel and perpendicular to grain properties in tension and compression at temperatures from 20°C to 270°C were experimentally studied. A total of 90 tensile coupon specimens and 60 compressive specimens were tested during heating at temperatures ranging from 20°C to 270°C. The experimental results indicated that tensile stress-strain relationships of a bamboo scrimber parallel to grain at elevated temperatures were linear from the beginning of loading to failure, and the tensile strength and modulus decreased with increasing the temperature from 20°C to 270°C, except at 200°C. Perpendicular to grain direction, the tensile stress-strain relationships exhibited nonlinear behaviour, and the ultimate strengths were very small. Accordingly, it was observed that the modulus decreased to zero from 20°C to 180°C. The compressive stress-strain curves of bamboo scrimber exposed to elevated temperatures were divided into a linear branch and a nonlinear branch beyond proportional limit for both grain directions. The equations with reduction factors for strength and modulus of elasticity were established by regression analysis of the test data. Parallel to grain of a bamboo scrimber, the values from fitting formulas were mostly larger than those from Eurocode 5, and the maximum differences between reduction factors were 0.31, 0.04, 0.23, and 0.24. This study provides a valuable reference for potential application of bamboo scrimber in structural engineering.