Eggshell as a fine aggregate replacer with silica fume and fly ash addition in concrete: A sustainable approach

The increasing demand for natural sand has proportionally influenced the industry for alterna-tives that can perform better in construction. Hence, this study was conducted to investigate the eggshell potential as a fine aggregate replacer in a concrete mix due to its high calcium carbonate content. The experimental plan was developed by substituting sand by volume in sustainable concrete (SC) replacement with 5 %, 10 % and 15 % eggshells. Primary concrete features that were studied were slump, water absorption, unit weight, compressive strength, splitting strength, flexural strength, modulus of elasticity and microstructure at age of 28 days. Results demon-strated that with the eggshell inclusion, the compressive strength was increased by up to 29.62 % in comparison with the control mix. The mechanical component of the bond was enhanced with the additional fly ash and silica fume with replacement ratios of eggshell sand. The replacement percentage of 10 % was beneficial for the acceleration rate of compressive strength. This study recommends that eggshells can be used for producing SC having a lighter weight than natural sand concrete.