Effect of Cement Kiln Dust on Some Properties of Soil

Abstract

In recent years, use of various waste products in ground construction and modification has gained considerable attention worldwide in view of increasing costs of waste disposal, and environmental constraints. One of these waste products is the cement kiln dust, which is a by-product of Portland cement manufacturing process. It is generated from burning the raw materials in a rotary kiln to produce clinker. The cement kiln dust used in this study was brought from Al-Kufa cement factory.In this study, the effect of adding different percentages of cement kiln dust on some properties of clayey silt soil was investigated. The results show that the plasticity index, liquid limit and activity of soil decrease significantly as the percentage of added cement kiln dust increases, while the plastic limit increase. The maximum dry density decreases and the optimum moisture content increases as the added cement kiln dust increases. Also, significant improvement in the performance of soil as a subgrade in a highway can be noticed with increase in CKD percentage, due to a reduction in value of the group index.