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|Last Updated||August 30, 2017|
Improvement of expansive soil properties used in earthworks of highways and railroads using cement kiln dust
Ahmed Mancy Mosa1,*, Qais Sahib Banyhussan2, Rana Amir Yousif2
- Cement Kiln Dust (CKD) was used to improve soil properties.
- Different CKD contents were adopted.
- The effects of CKD on engineering properties of soil were studied.
- Mineralogical and morphological properties of improved soil were analyzed.
- Interaction of CKD with soil particles generates CSH and CaCO3.
Expansive soils exhibit swell potential, compressibility and low strength especially in the presence of water. These soils, if used in highways and railroads earthworks where its unavoidable, can cause several damages in the structure of these major transportation facilities. Therefore, improvement of this type of soil is necessary. Using commercial admixtures in improvement encounter supplementary cost. Therefore, using of by-product material is economic and effective alternative. Cement kiln dust (CKD) is generated in huge quantities as a by-product material in Portland cement plants. Therefore, this study aims to use CKD to improve expansive soil properties. This study involved series of laboratory tests on sets of untreated samples and samples treated with different doses of CKD to investigate their effects on the properties of expansive soil. The investigation includes classification tests, compaction tests, permeability tests, compressibility tests, shear strength tests, swelling tests, and California Bearing Ration (CBR) tests. In addition, chemical tests were performed to determine the changes in pH values of control and treated soils. Furthermore, SEM and XRD tests were performed to explore the mineralogical and morphological properties of the original and the soil treated with 14% CKD and to investigate the generation of new products. The results exhibited significant improvement in treated soil properties; the optimum CKD dose was found to be 14% of dry weight of soil. As percentages of values determined for untreated soil, the values of liquid limit, plasticity index, compressibility coefficient, expansion coefficient, and swelling ratio of soil treated with 14% CKD decreased to 57%, 14%, 21%, 11%, and 9%, respectively whereas CBR value increased to 828%. Moreover, the tests revealed the generation of calcium silicate hydrate (CSH) and calcite (CaCO3) which are responsible of creation of great bond among the treated soil particles increase its tightness and decrease its expansibility.
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To cite this article: Mosa AM, Banyhussan QS, Yousif RA. Improvement of expansive soil properties used in earthworks of highways and railroads using cement kiln dust. Journal of Advanced Civil Engineering Practice and Research 2017;4:13-24.
To link this article: http://ababilpub.com/download/jacepr4-3/