Improving engineering properties of laterite soil using eco-friendly biopolymers: a study on strength and compressibility

In recent years, there has been a growing focus on sustainable and eco-friendly alternatives to conventional chemical stabilizers for improving problematic soils. This study investigates the stabilization of laterite soil using eco-friendly biopolymers xanthan gum (XG) and guar gum (GG) to enhance its engineering properties. Soil samples treated with 1% to 4% biopolymer dosages were tested after curing periods ranging from 3 to 28 days. Laboratory evaluations included Unconfined Compressive Strength (UCS), permeability, and consolidation tests, along with microstructural analyses using XRD. The results demonstrated significant improvements in strength, reduced permeability, and enhanced microstructural integrity, confirming the potential of XG and GG as sustainable soil stabilizers. Results reveal that 3% XG and 2% GG are the optimum concentrations, yielding maximum UCS improvements of 321.40% and 241.05% after 28 days, respectively. Permeability reduced significantly by 93.12% for 3% XG and 96.96% for 2% GG, while void ratio decreased from 0.807 to 0.4803 and 0.454, indicating enhanced consolidation. Microstructural analysis confirmed formation of cementitious products and dense matrices contributing to strength gains. The findings of this study provide practical insights into using biopolymers as green stabilizing agents to enhance the strength of laterite soils for sustainable geotechnical applications.