Performance of Cement Kiln Dust in Stabilizing Lateritic Soil Contaminated with Organic Chemicals

Accidental or deliberate operational discharges of organic chemicals or wastes containing organic chemicals induce geochemical reactions with resultant adverse effects on basic geotechnical properties of the soil. To utilize soil materials from such sites for engineering construction or as foundation soil, stabilization must be carried out. In this study, cement kiln dust (CKD) was applied to lateritic soil contaminated with three different types of commonly occurring organic chemicals namely benzene, ethanol and kerosene to evaluate the restoration and improvements in the engineering properties. Contamination was simulated in the laboratory by adding known quantities (2.5, 5, 7.5 and 10%) of each of the chemicals separately to lateritic soil samples and allowed to air dry for 14 days before stabilizing with 10% CKD. Performance was evaluated on Atterberg limits, compaction characteristics, strength properties and hydraulic conductivity of the contaminated soil. Strength and hydraulic conductivity specimens were compacted with British Standard Light (BSL) compactive effort at predetermined optimum moisture content. Results showed that the simultaneous effects of the cementing and pozzolanic action of the CKD rejuvenated the geotechnical properties of the soil, in most cases comparable to the properties at the original pristine condition. Studies on durability and long term competent performance of the stabilized contaminated soil specimens is in progress.