Geotechnical evaluation of laterite soil treated with tamarind gum biopolymer

The stabilization of laterite soil using sustainable and environmentally friendly materials has gained considerable attention as an alternative to conventional chemical stabilizers. This study investigates the effectiveness of tamarind gum biopolymer (TGB) as a natural soil stabilizer for improving the engineering properties of laterite soil. Experimental investigations were carried out by incorporating varying proportions of TGB, up to 3% (w/w) based on the dry weight of the soil, and evaluating its influence on Atterberg limits, compaction characteristics, shear strength, and permeability. The results demonstrated that the addition of 3% TGB significantly enhanced the engineering performance of laterite soil, resulting in a 17.48% increase in maximum dry density, a 73.33% increase in cohesion, a 19% increase in the angle of internal friction, and a 13.63% reduction in permeability. Furthermore, Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses confirmed improved interaction and bonding between the biopolymer and soil particles, leading to a denser and more stable soil matrix. These findings indicate that tamarind gum biopolymer is an effective, sustainable, and eco-friendly stabilizing agent with significant potential for long-term geotechnical and pavement engineering applications.