Experimental Investigation on Crumb Rubber Concrete Reinforced With Sisal Fiber

The study investigates the mechanical and workability properties of crumb rubber concrete reinforced with sisal fiber as a sustainable alternative to conventional concrete. The research aims to evaluate how partial replacement of coarse aggregate with crumb rubber and the inclusion of sisal fibers influence the compressive, split tensile, and flexural strengths of concrete. Crumb rubber, derived from recycled waste tires, was incorporated at varying proportions (10–20%) as a partial replacement for fine aggregate, while sisal fiber (0.25–0.5% by volume) was added as natural reinforcement. Concrete samples were subjected to slump tests for workability and cured for 7, 14, and 28 days before undergoing mechanical testing. Results showed that the addition of crumb rubber reduced workability and overall compressive strength due to the hydrophobic nature and low stiffness of rubber particles. However, sisal fiber significantly improved tensile and flexural strengths by enhancing crack resistance and ductility through fiber bridging action. The findings demonstrate that combining crumb rubber and sisal fiber can yield eco-friendly concrete with improved toughness and reduced environmental impact, though optimization of mix proportions is essential to balance strength and workability. The study promotes the reuse of waste materials in construction, contributing to sustainability, waste reduction, and carbon footprint mitigation in the building industry.