Author Description

The addition of chemicals into the subgrade has been widely used during construction to improve the soil properties. The chemicals, often Lime Kiln Dust (LKD) and Portland cement, are added to the soil to improve its workability, compactability and engineering properties. Many DOTs have been using chemical modification for more than 20 years. In fact, 90% of the current subgrade is treated. Despite the wide experience-based in treating subgrade soils, several problems still exist. The INDOT (Indiana Department of Transportation) design manual states that subgrade clays with low plasticity (PI