Evaluation of Califonia Bearing Ratio and Permeability of Stabilized Clay Soil with Cement Kiln Dust

Abstract

Soil stabilization refers to the process of changing soil physical and chemical properties to improve strength and durability. It has been used for many years to improve the characteristics of the subgrades with problematic soils. Pavements with stabilized base and sub-base layers have been proven to deliver better performance during their service life. Clay is a type of soil with particles of certain minerals giving plastic properties when mixed with water. Soil has an important role in a construction, besides as a building material in a wide variety of civil engineering works. Basic properties of clay are rock-solid in dry and plastic with medium water content. In high water content, clay becomes sticky like (cohesive) and soften. Therefore, clay stabilization is necessary to repair soil’s mechanical properties. Cement industry is arguably regarded as the second largest producer of the greenhouse gases that cause global warming phenomenon, which contributes by 5–8% of the worldwide CO2 emissions (Mehta, 2004). The major challenges facing the cement manufacturing industry is the reduction of CO2 emission into the atmosphere during the manufacture of Portland cement. Cement production also results in massive quantities of solid waste material called Cement Kiln Dust (CKD), where the quantity of CKD is estimated by 3–4% of the total produced cement (Najim, Mahmod, & Atea, 2014). In this study laboratory experiment was conducted to evaluate the performance of CKD on clay soil. Presently, disposal of industrial waste products have been a global problem. Their disposal are costly as well as they are harmful to environment. Owing to these problems some researches are being conducted to utilise these waste products in ground construction and modification. To achieve this, a number of mixtures with different CKD contents were used as a stabilizer in improving the properties of clay soil in terms of California Bearing Ratio (CBR) and Permeability test. The Atterberg limits and compaction characteristics were also determined for the Clay soil and stabilized clay. The results indicates that the clay soil used has liquid limitation (LL) value of 32%, plasticity index of 13.4% and CBR value 9.25%. The results further shows that the 15% CKD gives the un-soaked CBR value of 11.33%.