Compaction and Permeability Characteristics of Biopolymer-Treated Sand

Traditional soil stabilization materials often cause environmental issues, prompting researchers to explore alternative, eco-friendly options such as biopolymers. This study examines compaction characteristics and permeability coefficient of poorly graded sandy soil treated with biopolymers, specifically Xanthan Gum (XG) and Guar Gum (GG), as sustainable substitutes for conventional stabilizers such as cement. The biopolymers were mixed with the soil in contents of 0%, 0.5%, 1%, 1.5%, 2%, 3%, and 4% of the dry weight of the soil. Furthermore, mixtures of both biopolymers were used, including 3% XG + 1% GG, 1% XG + 3% GG, 2% XG + 2% GG, and 1.5% XG + 1.5% GG, based on the dry soil weight. The study involved a series of experiments to evaluate the impact of different biopolymer contents on two key geotechnical properties of soil, compaction characteristics and permeability coefficient (k). Adding XG increased the maximum dry density (MDD) to 1.87 g/cm³ at 1% concentration, while GG peaked at 1.93 g/cm³ at 2%. Both biopolymers significantly reduced permeability, with GG being more effective due to its higher viscosity, enhancing particle bonding and pore blockage. Findings revealed that biopolymers significantly enhance compaction characteristics and reduce permeability of the soil. Based on the findings of this study, it is recommended to utilize XG and GG as effective agents for soil stabilization in dry conditions.