Basic Mechanical Properties of Laminated Flattened-Bamboo Composite: An Experimental and Parametric Investigation

Abstract

To reduce carbon emissions in the construction industry, more and more researchers have paid attention to engineered bamboo, a natural and green material. This research focused on laminated flattened-bamboo (LFB), a new bamboo composite produced by the advanced non-notched flattened-bamboo technology which can improve the utilization rate of bamboo and reduce production costs by reducing the use of adhesive compared with the gluing process of conventional bamboo laminates. The basic mechanical properties under compression, tension, three-point bending, and shearing of LFB in three orthogonal directions were mainly studied. Experimental results showed that compressive and tensile strength (modulus) along the grain direction were 56.2 MPa (9,542.7 MPa) and 106.9 MPa (10,151.1 MPa), respectively; in the radial direction were 43.1 MPa (580.9 MPa) and 1.8 MPa (1,459.6 MPa), respectively; in the tangential direction were 19.0 MPa (1,124.5 MPa) and 4.3 MPa (5,112.5 MPa), respectively; the mean bending strength (modulus) was 80.8 MPa (8,076.8 MPa), and the shear strength (modulus) was 17.3 MPa (1,878.8 MPa). The measured properties were comparable to that of other structural bio-based materials, showing LFB has the potential to be an alternative to timber in future construction applications. The modulus and Poisson’s ratio was analyzed, and the result showed that LFB could be regarded as orthotropic material approximately. The failure types under various loading conditions were summarized. Based on the Ramberg Osgood relation, the stress-strain models of LFB composite under compression, tension, and shearing were proposed, and the characteristic value of ultimate strength and elastic modulus was determined by parametric analysis.