Published Paper Details:

The stabilization of expansive soils, characterized by high plasticity, poses significant challenges in geotechnics due to their substantial volume changes and low strength. Recent advancements have introduced alkali-activated binders and geopolymers--derived from industrial by-products like fly ash, slag, metakaolin, rice husk ash, and zeolitic materials--as sustainable alternatives to traditional lime and ordinary Portland cement (OPC) for soil stabilization. This review consolidates both laboratory and field findings regarding the durability of geopolymer-stabilized expansive soils, examining their resistance to wetting-drying and wetting-soaking cycles, sulfate attacks, freeze-thaw cycles, leaching, long-term strength retention, and microstructural changes. We compare these mechanisms with conventional stabilizers, summarize the testing methods and durability metrics employed in existing literature, identify knowledge gaps (including standardization, long-term field monitoring, and the influence of local materials and activators), and propose research priorities for infrastructure applications. Key findings indicate that geopolymer stabilization generally enhances immediate strength, minimizes swell and shrinkage, and exhibits promising resistance to chemical and moisture cycles in contrast to OPC and lime. However, durability is highly dependent on precursor chemistry, Si/Al ratios, activator types and concentrations, curing conditions, and the presence of sulfates or chlorides. Evidence of multi-year field performance remains limited and necessitates coordinated long-term monitoring.