Improvisation in the Swelling Behavior of Expansive Soil Using Industrial Waste

Abstract

Due to rapid industrialization, geological characteristics of the landscape are disturbed to a greater extent, mainly contributing to the soil contamination by industrial effluents. Thus, it becomes mandatory to identify suitable treatment techniques for remediating contaminated sites with less effort and resources. This work focuses on identifying the optimized percentage of the industrial waste mix proportion with expansive soil associated with an aqueous solution to depict the soil contamination with heavy metals, specifically Lead, Copper and Iron. The study involves the characterization of the swelling behavior of expansive soil with and without the presence of heavy metals, thereby stating the effect of heavy metals on the swelling behavior of four different types of soil. From the experimental results, the percent increase in the free swell index of expansive soil was identified as 4% due to heavy metal contamination (Pb, Zn, and Fe). On further investigation by utilizing the industrial waste, i.e., Fly ash with these contaminated soil, earned a productive result, which results in stabilizing the swelling behavior in expansive soil, particularly at contaminated sites. Different proportions of stabilizing agents adopted in the study were 5% of Lime followed by 5%, 10%, 15%, 20%, and 25% of Fly ash, respectively. Out of which, the optimized percentage of mix proportion was found as 5% Lime and 15% Fly ash, which yields the maximum reduction in the free swell index. The optimized ratio becomes valid by attaining a similar trend in the plasticity index at a percentage of 5% Lime and 15% Fly ash.KeywordsHeavy metalsExpansive soilStabilizing agent