Strength and Durability Modelling of Lateritic Soil Treated with Sustainable Pozzolanic Additives

Abstract

This study explores the effectiveness of Rice Husk Ash (RHA) and Cement Kiln Dust (CKD) as sustainable stabilizing agents for improving the geotechnical properties of lateritic soil from Guwahati, Assam. Laboratory tests were conducted to evaluate changes in shear strength, permeability, consolidation characteristics, and pH across different RHA-CKD combinations and curing periods (7, 14, and 28 days). The results demonstrated significant improvements in shear strength (up to 95 kN/m²) and substantial reductions in permeability (to as low as 1.69 × 10⁻⁵ cm/s), particularly with the 15% RHA and 9% CKD mix. The pozzolanic interaction between RHA and CKD led to the formation of cementitious compounds, which improved particle bonding and pore structure. pH measurements confirmed a shift from acidic to optimal alkaline conditions conducive to long-term stabilization. Durability tests, including wet-dry and freeze-thaw cycles, showed excellent retention of mass and strength, indicating the stabilized soil’s resilience under cyclic environmental loading. Comparative analysis with conventional stabilizers highlighted RHA and CKD’s advantages in terms of environmental impact, waste valorization, and contribution to the circular economy. The study concludes that RHA and CKD can serve as efficient, low-cost, and eco-friendly alternatives to cement and lime, with promising potential for application in sustainable infrastructure projects.