Augmenting bamboo strength and thermal stability for sustainable construction

Abstract

In modern timber structures, the prevalent use of metal fasteners for structural connections introduces concerns related to their high thermal conductivity, which can induce excessive charring of adjacent wood and compromise joints fire resistance. To address this, the exploration of high-strength bio-materials presents a promising alternative. In this study, an eco-friendly methodology was employed to augment the densification of bamboo, resulting in the creation of composite-modified bamboo without the use of organic thermosetting resin. Comprehensive investigations were conducted to evaluate its mechanical properties and high-temperature performance. Microscopic alterations were unveiled through Fourier Transform Infrared spectroscopy (FT-IR) and scanning electron microscopy, complementing each other in revealing substantial changes. The results of chemical constituents and FT-IR analyses corroborated the observed alterations. A noteworthy observation is that the modification of composite materials significantly increased modulus of elasticity, bending, and tensile strengths of bamboo, with a slight improvement in compressive strength. Additionally, it concurrently enhanced ductility. The thermal stability of composite-modified bamboo exhibited an initial increase followed by a subsequent decline over duration. The increased density induced by hot pressing facilitated the formation of a denser charring layer, effectively serving as a protective shield against external heat and oxygen. Consequently, this limited the degradation of bamboo constituents under high-temperature conditions. The optimal alkaline treatment duration for 9 mm thick bamboo was determined as 7 h based on the methodology established in this investigation.