Stabilization of High Sulfate Soils with Nontraditional Additives

The engineering properties of base course materials play an important role in the overall stability of a pavement system. The stabilization of sulfate-rich base course materials has been a challenge using traditional calcium-based stabilizers (i.e., cement, lime, and fly-ash) because soluble sulfates present in soils can induce chemical reactions between cement or lime and residual soils, resulting in significant loss of strength and heaving. Introduced as a non-traditional stabilizer, polymer-based products have become popular due to cost efficiency, ease of application, and fast curing times. To explore the feasibility of using polymer-based products for the stabilization of high sulfate soils, a series of unconfined compression strength tests were performed. A sulfate concentration of 20,000 parts per million (ppm) was used in the laboratory testing program. As compared to the strength without soluble sulfate present in the soil, the results revealed a loss of strength in cement, and lime treated specimens but an increase of strength in polymer treated specimens.