Experimental study on tensile and compressive properties of neosinocalamus affinis-based bamboo scrimber

Abstract

Engineered bamboo has emerged as a promising material for sustainable construction. However, its mechanical performance varies significantly depending on species and manufacturing processes. Among these, neosinocalamus affinis-based bamboo scrimber (NABS) shows strong potential as a structural material, but its mechanical properties remain insufficiently characterized. This study systematically investigates the mechanical behavior of NABS through tensile and compressive tests along the longitudinal, radial, tangential, and 45° off-axis fiber orientations. Digital image correlation (DIC), video extensometer, and strain gauges are employed to capture the stress-strain responses. At the same time, macroscopic observations and scanning electron microscopy (SEM) are utilized to examine the fracture mechanisms. The experimental results reveal that NABS displays exceptional mechanical properties, particularly in the fiber-parallel orientation, achieving a tensile strength of 214.33 MPa, elastic modulus of 24.23 GPa, compressive strength of 110.50 MPa, and elastic modulus of 29.38 GPa. These properties demonstrate superior tensile performance, surpassing those of conventional timber and other engineered bamboo products of tensile performance two to three times, while maintaining competitive compressive performance. However, pronounced anisotropy leads to significantly reduced strength and stiffness perpendicular to fiber orientation. The extended Hankinson's formula is applied to predict off-axis mechanical properties, achieving strength and elastic modulus prediction errors below 10 %. To support structural design, characteristic strength and modulus values are derived using nonparametric and parametric methods, respectively. A direction-specific stress-strain model is also developed to describe the anisotropic behavior of NABS. These findings enhance the fundamental understanding of NABS mechanics and provide guidelines for optimizing structural design parameters, promoting the adoption of engineered bamboo materials in sustainable infrastructure.