Improvement of expansive soil properties using metakaolin-based geopolymer

In a practical situation, the expansive soil is a highly plastic-type that undergoes changes in volume because of hydrophilic minerals such as montmorillonite. This type of soil usually creates serious problems in geotechnical engineering applications. The use of stabilizers like chemicals is necessary to reduce these problems. This study examined the effect of a metakaolin-based geopolymer on the stabilization of expansive soil. Metakaolin is added to soil in three percentages (0.3, 1, and 2%) from the weight of dry soil. The study concluded that the increase in the quantity of metakaolin caused rising in the unconfined compression strength and a decrease in both the swelling potential and swelling index. The best percentage of metakaolin is (2%) from the weight of dry soil, which caused increasing in soil strength to reach (80) times in case of (7) days of curing time. At the same time, the swelling potential was reduced by about 86 %.