Abstract
This study investigates the effects of using crumb rubber as a partial replacement for dune sand in concrete mixtures. The incorporation of crumb rubber presents promising ecological and economic benefits, particularly for waste management and material sustainability. In this research, up to 5% of the dune sand was replaced with crumb rubber, and the resulting concrete’s fresh and hardened properties were thoroughly examined to evaluate the impact of this substitution on its mechanical characteristics. The findings reveal that concrete mixtures containing crumb rubber exhibit significantly reduced compressive strength, with a comparatively smaller decrease in tensile strength, relative to conventional dune sand concrete. Specifically, at a 5% replacement rate, substantial reductions in compressive and tensile strength were observed at 28 days, amounting to 66.15% and 48.72%, respectively. These performance limitations suggest that crumb rubber-modified concrete may not be appropriate for structural applications. Nevertheless, potential alternative uses, such as in highway median barriers, curbs, or decorative elements, could represent viable applications for these modified concrete mixtures.