Experimental investigation on geometric, physical and mechanical properties of dendrocalamus giganteus in Sri Lanka

Abstract

Bamboo is a fast-growing, low-carbon material with strong potential for sustainable construction, yet its structural use in Sri Lanka remains limited by the absence of speciesspecific engineering data. This study experimentally characterised the geometric, physical and mechanical properties of Dendrocalamus giganteus to assess its potential for structural applications. Mature culms harvested from Balangoda were evaluated using international bamboo grading and testing procedures. Geometric properties, including external diameter, wall thickness, taper, bow, ovality and internodal length, were measured on 188 culm sections. Basic density, linear mass, compression, tension and shear parallel to the fibres, and tension perpendicular to the fibres were also determined. Moisture contents of specimens in all mechanical test series ranged from 9 to 15 percent at testing. The mean external diameter and wall thickness were 157 mm and 10.8 mm, respectively, while mean basic density was approximately 662 kg/m³. Mean compressive, tensile and shear strengths parallel to the fibres were 46.85 MPa, 153.04 MPa and 8.47 MPa, respectively. Tensile strength perpendicular to the fibres was substantially lower at 1.75 MPa, indicating susceptibility to longitudinal splitting. The findings establish a first-stage engineering property dataset for the sampled material and support further structural assessment, while highlighting the need for additional tensile testing and careful detailing against splitting. Application requires consideration of sampling limitations and material variability, together with appropriate derivation of design values.