The Role of Biopolymers in Enhancing Granular Media Shear Strength: A Comparative Analysis

This study aims to investigate the effect of various types of biopolymers, including xanthan gum (XG), guar gum (GG), and agar gum (AG), on the shear strength of granular media. The environmental impacts of using traditional materials, such as cement and lime, for soil improvement have led geotechnical engineers to consider using eco-friendly alternatives. Biopolymers, due to their low cost and abundance, have become an attractive alternative for soil improvement. In this study, biopolymers were introduced at a dry mass ratio of 1%. Consolidated undrained (ICU) triaxial tests were performed to examine the soil shear strength, while an Anton Paar MCR 302e rheometer was used to evaluate the rheological properties of the biopolymer gels. The results showed that increasing biopolymer yield stress resulted in an increase in the effective cohesion (c′) of the treated material, while soils treated with all biopolymers resulted in a decrease in the soil's effective friction angle (ϕ′). Furthermore, the study established a correlation between the yield stress, viscosity at a strain of 1 s−1 of the biopolymer, and the enhanced soil shear strength for different biopolymer types.