Sustainable Improvement of Clayey Soil Using Marble Stone Dust: Experimental Analysis of Shear Strength, Compaction, and Load-Bearing Capacity

Soft clay soils, susceptible to deformation under load and known for their low bearing capacity, high compressibility, and weak shear strength, demand costly stabilization solutions.This study investigates marble stone dust (MSD)-a widely available industrial by-product as a sustainable, low-carbon alternative to conventional stabilizers (e.g., lime or cement), with a focus on shear resistance, stiffness, California Bearing Ratio (CBR), and compaction characteristics.Through systematic laboratory investigation, varying percentages of MSD (5%, 10%, 15%) were evaluated for their stabilizing effects on soft clay.The experimental results demonstrate significant improvements in key engineering parameters: shear strength increased by up to 51.6%, unconfined compressive strength rose 15.99%, and California Bearing Ratio improved by 22.5%, while optimum moisture content (OMC) decreased proportionally with MSD addition.Maximum dry density (MDD) showed consistent enhancement across all mixtures.These results position MSD not merely as a waste-derived stopgap but as a high-performance stabilizer that aligns with circular economy principles.By transforming problematic clay into construction-ready material, this approach offers a triple win: geotechnical resilience, environmental sustainability, and economic viability for infrastructure projects.