Evolution of structural characteristics of bamboo scrimber under extreme weather

Abstract

With the rising frequency and severity of extreme weather events, the reliability of outdoor materials faces considerable challenges. Bamboo scrimber, an emerging outdoor material known for its excellent mechanical properties, lacks specific parameters for application in extreme weather conditions. Therefore, this study employed the hydrothermal-drying-hydrothermal cycle to simulate extreme weather events characterized by repeated heat waves, drought, and heavy precipitation. Its primary objective is to investigate the changes in the structural characteristics of bamboo scrimber at various scales in response to these extreme weather conditions. The results demonstrate notable changes in the structural characteristics of the bamboo scrimber: In terms of morphology, the width of the material experienced a swelling rate of 4.99%, while the thickness swelled at a rate of 18.68%. Additionally, cracks occurred on all surfaces of the bamboo scrimber, mainly concentrated at the bonding interface. In terms of pore structure, a large number of pores below 1.59 nm were generated in the cell wall, accompanied by the enlargement of cell cavities. These increased the porosity of the bamboo scrimber from 10.67% to 35.76%. The change in the porous structure accounted for 88.96% of the observed volume increase in the bamboo scrimber. In terms of chemical composition, bamboo scrimber extract was dissolved, and the hydrolysis of lignin and hemicellulose led to the formation of new CO bonds. The dissolution and degradation of the chemical composition causes an expansion of the pore structure, leading to the deformation and cracking of the bamboo scrimber. Ultimately, this study is expected to contribute to the effective use of bamboo scrimber.