Improving swelling soils with polyvinyl chloride waste materials and cement kiln dust.

Swelling soils are found in many regions of the world, including Iraq. Swelling soil contains minerals that can absorb water easily, which leads to an increase in its volume, and this is the reason for swelling soil. The aim of this study is to improve the properties of swelling soils, reduce the cost of paving construction, and clean the environment from industrial waste by using waste materials in soil stabilization. Wasit Governorate in Iraq was selected as a study area because it contains swelling soil. Where the clay soil was soft, puffy, and looked like popcorn, after the free swell test, the soil swell rate was 70%. The material used is PVC waste of small dimensions (2-3 mm) mixed with cement kiln dust. 10% of waste PVC with 5, 10 and 15% of cement kiln dust was used to treat the swelling soil. The liquid limit is reduced from 66% to 42,34,27%, the plastic limit decreases from 34 to 29, 22, and 19%, and free swelling decreases from 70% to 55,40,32%, respectively. The results showed an increase in the dry density when adding the same percentages, as well as an increase in the optimum water content. Soil dry density of 1.48 g/cm3 became 1.75 g/cm3, 1.84 g/cm3, and 1.88 g/cm3 and 6,8,10, and 12% optimum water content, respectively. The CBR for soil was 2%. The test results showed the best ratio The results showed a 10% PVC with 10% CKD, which gave the best results during a different curing period. The results were 6.3, 7.5, and 10% with a curing period of 96 hours, 7 days, and 28 days, respectively, with the optimum percentages being 10% PVC and 10% CKD. [ABSTRACT FROM AUTHOR]