Characterization of Granite Sludge Dust and Zeolite for Stabilizing Lateritic Road Soils

Abstract

Lateritic soils are widely used in Nigerian road construction, but their high plasticity, moisture sensitivity, and low strength often lead to pavement failures. This study investigates the characterization and stabilization of lateritic soil with granite sludge dust obtained from a marble company and commercially available zeolite as sustainable alternatives to conventional stabilizers. Lateritic soil, zeolite, and granite sludge were characterized, and blended mixtures with varying proportions were tested for compaction, California Bearing Ratio (CBR), and unconfined compressive strength (UCS). The characterization results showed the soil as highly plastic clay (CH, A-7-6), granite sludge as a granular material with 24.6 percent fines, and zeolite as an extremely fine powder with a specific gravity of 2.78. Furthermore, chemical analysis confirmed that all three materials are predominantly siliceous, with quartz as the dominant crystalline phase and silica contents of 46.24 percent (soil), 58.66 percent (granite sludge), and 69 percent (zeolite). The stabilized mixtures reduced plasticity, increased maximum dry density, lowered optimum moisture content, and significantly improved strength, with soaked CBR rising from below 10 percent to above 35 percent and UCS increasing from 180 kN/m² to over 450 kN/m². The findings enhance engineering performance of lateritic soils, making them suitable for subgrade and sub-base applications in Nigerian road construction