Rehabilitation of Medium Expansive Soil Using Cement Treatment

Problematic soils such as swelling/shrinking soil are widespread in the Middle East and worldwide. This type of soil, upon wetting and drying, causes severe damage to structures built on such soil. Rehabilitation of swelling/shrinkage using cement treatment was studied in this work. Medium expansive soil (12 < PI < 24) was selected for the present investigation. Soil specimens were mixed with various percentages of cement contents (1%, 2%, 3% and 4%) and molded to a range of prescribed pre-wetting dry densities and moisture contents. It was found that 2% cement content cured for 28 days was sufficient to reduce the free swell percentage for medium expansive soil from as high as 7.4% to merely 0.4%. The potential swell pressure, however, was reduced from a damagingly high value (333 kPa) for the untreated soil to a tolerable value (20 kPa) for the same enhancement conditions. Swell potential versus time relationship for the natural and stabilized soil could be very accurately represented by a rectangular hyperbolic function.