Investigation of Mechanical Properties of Sisal Fibre-Reinforced Epoxy Composites for Roofing Applications in Benue State

Sisal fibre is an abundantly available agricultural residue in the North Central region of Nigeria, yet its potential in polymer composite applications remains underexplored within the local construction sector. This study investigates the mechanical properties of sisal fibre-reinforced epoxy composites intended for roofing sheet applications, with fibres sourced from Benue State, North Central Nigeria. Fibres were subjected to alkali, silane, and acetylation surface treatments to evaluate their effect on interfacial adhesion with the epoxy matrix. Composite laminates containing 20, 30, and 40 percent fibre volume fractions were fabricated using vacuum-assisted resin infusion. Mechanical characterisation included tensile, flexural, and compressive testing following ASTM D638, D790, and D695 procedures. Impact strength was assessed using the Charpy impact method. Findings demonstrate that alkali-treated sisal fibres at 30 percent volume fraction produced optimum mechanical performance, achieving a tensile strength of 52 MPa and flexural strength of 68 MPa. Silane-treated composites showed superior water resistance, with moisture absorption reduced by 19 percent relative to untreated fibre composites. Density measurements confirmed the composites are significantly lighter than conventional corrugated iron roofing sheets. The study concludes that sisal fibre-epoxy composites represent a technically viable roofing material for rural construction in North Central Nigeria, offering environmental and cost advantages. Further research is recommended on long-term weathering resistance and flame retardancy for broader adoption. Keywords: sisal fibre, epoxy composite, roofing, mechanical properties, surface treatment