Evaluation of the effects of oyster shell powder on mechanical properties of cement concrete

Abstract

This study evaluates the effects of partially replacing cement with finely ground oyster shell powder on the mechanical properties of cement concrete. The oyster shells were processed through cleaning, sun-drying, grinding, calcination, and sieving. Experimental mixtures were prepared with replacement ratios of 2%, 4%, and 6% by weight of cement. The results indicate that a 2% replacement ratio is optimal, improving early compressive strength and enhancing flexural tensile strength by up to 58% compared to the control, while the elastic modulus remained nearly unchanged. The findings suggest that oyster shell powder has potential as a supplementary cementitious material, contributing to emissions reduction and waste reuse in sustainable construction.