Effectiveness of Pulverized Oyster Shell (Ostreidae) as Partial Replacement of Cement in Concrete Exposed in Coastal Conditions

The production and use of cement are significant sources of greenhouse gas emissions. This project aims to utilize aquacultural wastes to reduce cement usage while enhancing the quality of the concrete. We assess the characteristics of concrete when pulverized oyster shell (POS) is used as a partial substitute. The main objective was to compare the physical characteristics of various mixtures containing 5%, 10%, and 15% pulverized oyster shells as a replacement material. This analysis focused on evaluating the workability and permeability of the mixtures. Additionally, the study aimed to determine the compressive strength of the different mixtures before and after coastal exposure. Lastly, a cost analysis was performed to identify the most effective treatment for the concrete mixtures. The results indicated that the workability of the mixture is inversely correlated with the proportion of powdered oyster shell substitution. However, the partial replacement of 5% and 10% of POS to cement has a higher compressive strength than pure concrete. Ultimately, the substitution of 5% and 10% of the concrete mixture results in reduced production expenses while maintaining the same level of strength as pure concrete.