Evaluation of the Effect of Activated GGBS and Hydrated Lime on the Improvement of a Clay Soil Contaminated with Methyl Tert-Butyl Ether

In this research, the improvement of a clay soil contaminated with MTBE using GGBS activated by magnesium oxide and slaked lime was studied. Contaminated soil with MTBE was artificially prepared in the laboratory with a concentration of 2.25 g (MTBE)/kg (soil) and activated GGBS with slaked lime was added to it with different percentages. Experiments including Atterberg limit, compaction, uniaxial strength and SEM were conducted on samples of natural soil, contaminated and those which were mixed with the mentioned additives. The results showed that the used additives increase the strength of natural and contaminated soil and this improvement is a function of  percentage of the used materials and the curing time. In general, adding the used additives increases the strength by 14-22% by increasing the mixing percentage and curing time. In addition, the strength of natural soil with a same percentage of additives and the same processing time is about 3 to 7% higher than contaminated soil. Comparison of the effect of two additives clarified that lime has a greater effect in improving than activated GGBS. The SEM results also clarified that the hydration of the additives cause producing the cementitious materials which improves the mechanical behavior of the soil.