Strengthening Recycled Glass Sand Using Xanthan Gum: A Sustainable Approach

Biopolymer-soil technology has emerged as a sustainable and environmentally friendly approach to soil stabilization, gaining increasing recognition in geotechnical engineering. Concurrently, the growing demand for sand necessitates the exploration of alternative materials to reduce environmental impact. Recycled glass sand (RGS) offers a promising substitute, contributing to sustainable construction practices by mitigating natural sand consumption. This study investigates the mechanical behavior of xanthan gum-treated recycled glass sand (XRGS), with a focus on the effects of curing period, temperature, initial mixing moisture content, and xanthan gum concentration. The findings indicate that xanthan gum significantly enhanced soil stability, while the strength was strongly influenced by initial mixing moisture content, biopolymer concentration, and curing conditions. The unconfined compressive strength (UCS) of XRGS exhibited progressive enhancement with curing time under varying temperature conditions; nevertheless, biopolymer contents exceeding the optimal threshold attenuated the rate of strength development. Furthermore, dehydration played a crucial role in enhancing soil stiffness. Although XRGS exhibited a slight reduction in friction angle, a substantial increase in cohesion was observed (the cohesion increased by 35 kPa). Scanning electron microscopy (SEM) imaging confirmed the uniform distribution of xanthan gum, effectively binding RGS particles. These findings highlight the effectiveness of xanthan gum as a stabilizing agent for recycled glass sand, supporting its application in sustainable and resilient geotechnical engineering.