STRENGTH EVALUATION AND EXPERIMENTAL CHARACTERIZATION OF GMELINA ARBOREA TIMBER FOR STRUCTURAL APPLICATIONS
Keywords:
BS EN 338 Strength classification, Linear regression analysis, Engineered wood product (EWP)Abstract
The increasing demand for timber in Nigeria necessitates frequent investigation into less-known timber species to ensure a steady supply for construction. This study focuses on the experimental characterization of Gmelina arborea timber to evaluate its suitability for structural applications. The methodology involved tests following ASTM and BS EN standards to measure moisture content (MC), density, specific gravity and various strength and stiffness properties. Results showed a mean green moisture content of 141.28% and a density of 505.03 kg/m³. The mean shear strength is 7.65 N/mm2, tensile strength and modulus of elasticity (MOE) in tension are 63.74 N/mm2 and 7741.1 N/mm2, compressive strength parallel and perpendicular to the grain are 35.83 N/mm2 and 5.89 N/mm2 respectively. The bending strength and the corresponding MOE are 58.82 N/mm2 and 11980 N/mm2. Statistical analysis revealed that Weibull distribution best fits the experimental data for density and bending strength, while the normal distribution fits the MOE in bending. Characteristic values were determined as 416.71 kg/m³ for density, 33.24 N/mm2 for bending strength, and 11980 N/mm2 for the MOE in bending. Consequently, Gmelina arborea falls into C30 strength class according to BS EN 338, confirming its suitability for structural applications.
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