Exploring the Mechanical and Toxicological Properties of Concrete by Partially Replacing Fine Aggregates with Periwinkle shells Particulates

This study aimed to examine the impact of periwinkle shell particles (PSP) on the concrete compressive strength, and to assess the environmental risks associated with its leachates. In this study, different concrete samples were produced by partially replacing fine aggregates with varying proportions of PSP at levels of 0%, 5%, 10%, 15%, and 20%. The concrete specimens were cured using total immersion, and both their compressive strength and the physiochemical properties of the curing water were assessed on the 28th day.The concrete compressive strength results indicated an uneven decline from 26.3 to 13.17 MPa as the PSP volume integrated into the concrete inclined from 0 to 20%. Similarly, It was observed that as the quantity of periwinkle shell particles (PSP) increased from 0% to 20%, the pH values rose from 9.21 to 11.60, dissolved oxygen levels decreased from 7.70 to 3.63 mg/L, biochemical oxygen demand values increased from 2.12 to 9.30 mg/L, the total dissolved solids (TDS) levels rose from 69.00 to 85.85 mg/L, and the nitrate concentrations increased from 0.63 to 1.90 mg/L.Remarkably, the research findings revealed that incorporating a small amount of PSP (approximately 10%), as a partial replacement for sand during concrete production, can produce concrete with a reasonable compressive strength (greater than 17 MPa) and environmentally friendly leachates.This approach helps combat the negative effects of climate change by minimizing the depletion of natural sand and reducing the carbon footprint associated with conventional building materials.