Improvement of geotechnical properties of sabkha soil utilizing cement kiln dust

Improvement of properties of weak soils in terms of strength, durability and cost is the key from engineering point of view. The weak soils could be stabilized using mechanical and/or chemical methods. Agents added during chemical stabilization could improve the engineering properties of treated soils. Stabilizers utilized have to satisfy noticeable performance, durability, low price, and can be easily implemented. Since cement kiln dust (CKD) is industrial by-product, it would be a noble task if this waste material could be utilized for stabilization of sabkha soil. This study investigates the feasibility of utilizing CKD for improving the properties of sabkha soil. Soil samples are prepared with 2% cement and 10%, 20% or 30% CKD and are tested to determine their unconfined compressive strength (UCS), soaked California bearing ratio (CBR) and durability. Mechanism of stabilization is studied utilizing advanced techniques, such as the scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), backscattered electron image (BEI) and X-ray diffraction analysis (XRD). It is noted that the sabkha soil mixed with 2% cement and 30% CKD could be used as a sub-base material in rigid pavements. The incorporation of CKD leads to technical and economic benefits.