Integrating industrial wastes into soils to enhance their properties is a potential solution to current waste management challenges. Since the current literature lacks systematic studies on the mechanical performance of mixtures of soil, ladle furnace slag (LFS) and fly ash (FA), this research investigated the chemical stabilization of two different soils (clayey or sandy soil) using a concomitant mix of distinct types of industrial wastes: LFS and FA. A design of experiments (DoE) methodology was employed to systematically generate distinct mixtures for each soil sample, utilizing a simplex-centroid design. The mixtures were subjected to unconfined compressive strength (UCS), California Bearing Ratio (CBR) and resilient modulus (RM) tests. The industrial by-products improved the mechanical properties of the soils, providing UCS, CBR index and RM increases up to 130.5%, 324.4% and 132.6%, respectively. Synergistic and antagonistic effects related to the combination of different wastes were discussed, based on mathematical models with coefficients of determination ranging from 0.760 to 0.998, in addition to response surfaces generated for each response variable. The desirability function was applied to identify the optimal component proportions. The best mixture proportion was 80% soil, 20% LFS and 0% FA, which improved the formation of cemented compounds that contributed to the enhanced mechanical strength. The use of industrial waste for soil stabilization has therefore proven to be technically feasible and environmentally friendly.

The waste materials from the manufacturing process were employed for the purpose of enhancing the strength of lateritic soil grade E, which exhibited the least suitable mechanical properties. The present study focused on the investigation of waste materials from the steel manufacturing process, namely electric arc furnace (EAF) slag and ladle furnace (LF) slag, as well as waste material from asphalt concrete plants, specifically asphalt waste dust (AWD). These waste materials were examined in relation to their potential utilization in combination with lateritic soil. The mixing ratio employed in this investigation was 10% by weight (wt%). A mixture of 5 wt% ordinary Portland cement was mixed with 90 wt% lateritic soil and 10 wt% asphalt waste dust to enhance the efficiency of lateritic soil stabilization. The efficiency of waste materials was evaluated by the California bearing ratio (CBR) test. The integration of EAF slag and LF slag, byproducts of the steel manufacturing process, significantly improved the CBR more than 5 times and 7 times, respectively, for EAF and LF mixes compared to natural lateritic soil. Furthermore, the CBR of lateritic soil blended with asphalt waste dust and Portland cement exhibited approximately 20 times higher than that of natural lateritic soil and cement-stabilized lateritic soil.