Chemical Treatment of a Highly Expansive Clay Using a Liquid Ionic Soil Stabilizer

Expansive soils for residential projects are often treated with liquid ionic soil stabilizer (LISS) using deep pressurized injection method. Liquid ionic soil stabilizers have a long history of application in practice. However, there is limited knowledge and experimental evidence of their stabilization mechanism and effectiveness. This paper summarizes the research that investigated the effects of liquid ionic stabilizers on key engineering properties of a highly expansive clay from Carrollton, Texas, through comprehensive physical and mechanical testing and microscopic observation of untreated and treated soils. Test results before and after treatment were analyzed for two different treatment ratios: 1:300 and 1:150, showing a 53% swell reduction for treated soil compacted at the optimum moisture content (OMC) for treated soil, and 25% swell reduction for treated soil compacted at the OMC for the untreated soil. There was no significant improvement in unconfined compressive strength; noticeable improvement in stiffness was observed. The microscopic analysis showed a marked change in morphology and quantitative element composition, thus suggesting the occurrence of a reasonable degree of stabilization.