Soil treatment using fresh and landfilled cement kiln dust

A laboratory study was undertaken to evaluate two fresh and one landfilled cement kiln dusts (CKDs) for soil treatment. Only one fresh CKD (with free lime in 2–5% range) was found to be sufficiently reactive and showed potential to be used for soil stabilization. The results for the other fresh and the landfilled CKD (both with only traces of free lime) suggest that these materials may be used for treating wet subgrades or water-logged areas. In presence of 10–20% (by dry mass of the soil) of these CKDs, it became possible to compact soils outside their normal compaction range, and the further addition of 1% Portland cement produced mixtures of considerable strength. The results obtained highlight the importance of knowing the chemical composition of each batch of CKD collected and suggest that changes in plastic limit and pH may give insight into the suitability of a particular CKD for soil stabilization.