Characterization of fresh and landfilled cement kiln dust for reuse in construction applications

Significant quantities of cement kiln dust (CKD), a by-product of the cement manufacturing process, are generated every year in the US. Despite improvements in kiln operations and efforts that have gone into finding reuse applications, considerable amounts of CKD continue to require disposal through stockpiling or landfilling every year. Due to the variability in the chemical and physical properties of cement kiln dust, its utilization in construction has been to this day quite limited. In addition, the work performed so far has been for the greatest part focused on freshly generated CKD, while the issue of reusing stockpiled or landfilled material remains mostly unexplored.The paper presents the preliminary work performed to characterize both the freshly generated CKD produced by a US plant as well as the material sampled from the adjacent landfill facility. At this disposal site, more than 400,000 tons of CKD have been accumulated over a period of 12 years. The results of the characterization tests are compared to an extensive database collated from the literature and are used to discuss potential applications being considered for both fresh and landfilled CKD.