Optimizing Durability of Concrete Made with Calcium Carbide Waste and Lateritic Soil Using Response Surface Methodology

This study optimizes the durability performance of concrete by utilizing lateritic soil (LS) and calcium carbide waste (CCW) as partial replacements for fine aggregate and cement, respectively. A statistical method was employed to design the experiments and develop prediction models for key characteristics, including density, water absorption, and resistance to sulphuric acid attack (as measured by weight loss and compressive strength), using Response Surface Methodology (RSM). A central composite design (CCD) was employed to investigate the effects of CCW (0–20%) and lateritic soil (0–40%) on the properties of concrete. According to the results, higher CCW and laterite replacement levels reduce the durability of concrete by increasing its porosity and water absorption. Significant correlations were found in the responses that were successfully predicted by RSM-generated quadratic models. The ideal combination of 13.13% CCW and 18.7% LS was identified through multi-objective optimization, which maximized acid resistance while minimizing weight loss (8.84%) and water absorption (4.17%), resulting in an overall desirability of 75.4%. The experimental validation of this result revealed that the discrepancy between the predicted and experimental results was less than 5%. This indicates the potential of CCW-LS concrete for affordable, environmentally friendly construction in areas with limited resources.