Sustainable Stabilization of Loess Soils Using Marble Powder: Improvement of Mechanical Properties

Abstract

The instability of clayey soils poses a major challenge in geotechnical engineering, especially in arid regions where water infiltration causes a rapid loss of strength and cohesion. Due to the high cost and limited sustainability of conventional stabilization methods, this study evaluates marble powder (MP), a low-cost industrial by-product, as an effective stabilizer for collapsible soils in the Messaad region (Algeria). Soil samples were treated with 5%–20% MP and tested using unconfined compressive strength (UCS), direct shear, California Bearing Ratio (CBR), subsidence tests, and XRD/XRF analyses. The results revealed significant improvements with increasing MP content: UCS increased by 536.36%, CBR by 206.61%, and shear strength by 26.60%. Additionally, maximum dry density increased by 9.14%, while optimum moisture content decreased by 9.86%. XRF results showed higher CaO and lower SiO₂ and Al₂O₃ contents, while XRD confirmed the formation of calcite, which enhances bonding and soil stability. Overall, the study demonstrates that marble powder is an efficient, sustainable, and environmentally friendly material for improving the geotechnical behavior of collapsible soils.