Mechanical Properties of New Bamboo and Bamboo–Timber Hybrid Composites for Sustainable Construction: Experimental Investigation

This article presents an experimental investigation into the mechanical properties of new laminated bamboo and bamboo–timber hybrid composite materials for construction. A total of thirty-six bamboo and bamboo–timber hybrid composite specimens were manufactured, which include a new configuration that integrates bamboo and pine strips in hybrid bamboo–timber composite members. An interleaved configuration of the hybrid bamboo–timber composites is proposed to enhance stress transfer and interfacial bonding. Such a design can mitigate global hygroscopic and thermal mismatch effects, including composites panel warping and continuous interfacial shear, through redistributing differential strains into small, localized scales. To minimize manufacturing energy demand, cold hydraulic pressing was used to prepare the specimens with bio-epoxy and polyvinyl acetate adhesives (PVAs). The list of experimental tests includes compression parallel to the grain, compression perpendicular to the grain, and flexure. The experimental results revealed that the developed bamboo and bamboo–timber composites outperform the reference materials consisting of commercial engineered bamboo and natural softwood. In particular, the average modulus of elasticity of the hybrid specimens bonded with bio-epoxy adhesive reaches 11.6 GPa (CoV = 13.8%), which is 40 percent greater than that of the tested commercial engineered bamboo specimens (CoV = 15.7%), emphasizing a stiffer and more reliable engineered bamboo. In the case of flexural testing, the hybrid bamboo–timber specimens reach the highest modulus of elasticity, while the engineered bamboo bio-epoxy test series exhibited a modulus of rupture that was 36% higher than that of the commercial engineered bamboo material with a CoV equal to 8%.