CEMENT KILN DUST (CKD) AS A POTENTIAL STABILIZER TO MITIGATE THE SWELLING OF CLAYS

Utilizing industrial waste, like CKD (cement kiln dust) to stabilize expansive soils is of paramount importance in reducing the environmental impact of waste and in alleviating the expansive soil-induced structural damage. More studies are needed to demonstrate that CKD is beneficial in lowering the potential of expansive soils to swell. Therefore, this paper investigates how CKD affects the swelling of the CKD-treated soil as well as other engineering properties like compaction, Atterberg limits, mineral compositions, and microfabric. Soil stabilization was achieved by adding CKD in amounts of 6 to 30% of soil mass. The study revealed that CKD reduced the liquid limit from 85 % to 75 % and the plasticity index from 46 % to 16 % and thus, improved the plasticity and workability of the soil. Moreover, CKD decreased the swelling potential from 11.2 % to 3.4%, and the swelling pressure from 108 kPa to 17.5 kPa. XRD patterns demonstrated the usefulness of CKD for reduction in the intensity of palygorskite, montmorillonite, and illite swelling minerals. The success of the stabilization mechanism was also confirmed by the SEM micrographs where condensed soil particles with a few numbers of small pores were observed.