Cement Kiln Dust for Improving Properties of Soil

Globally, most of the factories have some waste that can be regularly produced. Cement factories generate cement kiln dust (CKD) waste, releasing large plumes into the air. Accumulation of factory waste, such as CKD, is a serious issue that has been considered in much research for some time to find the best cost-effective methods to utilize CKD for various purposes in construction projects. In this study, clay soil (CL) that covers most of north Iraq is considered to characterize its geotechnical characteristics in the in-situ condition and as a soil-CKD mixture. CKD was utilized with percentages of 10%, 20%, 30%, and 40% as an additive to replace the dry mass of the in-situ soil sample. The study's experimental program involves conducting geotechnical experiments to determine compression index, expansion index, standard proctor compaction, compressibility, and hydraulic conductivity. CKD improved the compaction characteristics, increasing the maximum dry density (MDD) after adding 10% CKD, and the optimum moisture content (OMC) linearly rose. The reduction in the porosity value was noticed particularly after 20% addition of CKD. Compressibility parameters, compression index (Cc) and expansion index (Ce), settlement, and swelling were also enhanced for stabilization and their reductions were significantly noticed. CKD successfully reduced the hydraulic conductivity values of soil-CKD mixtures. The study indicates that CKD is a significant soil stabilizer, suggesting that its removal and use for soil stabilization could have positive environmental consequences