Geotechnical behavior of clayey soils stabilized with cement kiln dust

Clayey soil can cause problems such as swelling and significant settlements during the geotechnical projects. In this regard, improving and reinforcing methods of weak soils can be classified into mechanical, chemical, and physical procedures. Nowadays, the use of available and waste materials is considered to prevent environmental pollution for soil stabilization. One of these materials is cement kiln dust, which is a by-product of Portland cement. In the present study, the possibility of stabilizing two types of bentonite and kaolin clayey soils is evaluated using cement kiln dust (CKD). For this purpose, cement kiln dust was mixed with clayey soils at 10, 20, 25, and 30% and then processed for 7, 14, and 28 days. To investigate the geotechnical behavior of stabilized soil, laboratory tests such as Atterberg limits, compaction, uniaxial compressive strength, direct shear test, and consolidation were carried out. The results show that the optimal amount of CKD is 30% during the processing time of 28 days, which are the most effective on bentonite. The results of bentonite stabilization show a 65%, 58%, and 75% of reduction in the plasticity index, compression index, and swelling potential, respectively. On the other hand, maximum dry unit weight, uniaxial compressive strength, and shear strength increased by 8.7%, 3 times, and 9.4%, respectively, compared to the unstabilized state.