The effect of cement kiln dust on the collapse potential of compacted shale

The effects of wetting-induced collapse on compacted soil are well documented in the literature. Objectives of the current study were to evaluate the potential of cement kiln dust, a byproduct of Portland Cement manufacturing, to reduce the collapse settlement of compacted shale caused by inundation with water. One-dimensional consolidation tests were conducted on treated and untreated shales using two different testing procedures to evaluate the Collapse Potential over a broad range of vertical stress levels. Tests were conducted on three different shales and test samples were prepared using three different molding moisture contents--dry of, at, and wet of optimum moisture content. Standard Proctor compaction effort was utilized. Results of odometer tests indicate that kiln dust is a potentially useful additive for reducing wetting-induced collapse settlements and for reducing overall compressibility.