Expansive clay soils are known for their high shrinkage and expansion properties due to moisture fluctuations, which can compromise construction stability. To address this issue, soil stabilization techniques using additives such as fly ash, lime, and cement are commonly employed. This study examines the durability of clay soil stabilized with fly ash geopolymers activated by alkaline solutions (NaOH and Na2SiO3) at molarities of 12 M and 14 M. The soil mixture consisted of 80% clay and 20% fly ash, with activator ratios ranging from 1 to 2.5. The results demonstrated that geopolymer stabilization significantly enhances soil durability. Specifically, the 12 M molarity mixture is higher than the 14 M mixture, while higher sodium silicate content was found to reduce durability. The slake durability index (Id) for the second cycle at 12 M molarity was recorded as 28.81%, 15.84%, 11.07%, and 3.28% for activator ratios of 1, 1.5, 2, and 2.5, respectively. Additionally, a strong linear correlation was observed between the Disintegration Ratio (DR) and the Slake Durability Index (Id).