Abstract:
The resilient modulus (MR) is regarded as an important stiffness parameter for pavement design. Determining the MR of expansive subgrades is critical because of their high swell-shrink potential. Lime stabilization has been adopted to treat expansive subgrade soils in North Texas for decades. Due to severe greenhouse effects of lime use and production, an alternative to lime stabilization has gradually emerged. A liquid ionic soil stabilizer (LISS), an environmentally friendly soil stabilizer can be used as an alternative soil stabilizer for its significant effect in enhancing soil stiffness and strength. However, engineers are still reluctant to accept the use of LISS because of the proprietary patent and limited literature review. In this study, the MR of expansive soils before and after LISS treatment was evaluated in the laboratory. The LISS used is composed of sulfuric acid, phosphoric acid, surfactant, and water. LISS was diluted in water to treat expansive soils and the soils were cured for 7 and 28 days. The experimental MR results of expansive soils treated with LISS were validated by comparing them with the results of the M-EPDG model and Ooi et al. (2004) model.