Index properties of alkalis treated expansive and non expansive soil contaminated with acids

Abstract

In recent years attention has been given to the acidification and alkalization of the soils to understand physico-chemical and Engineering properties. The effect of Sulphuric acid and Orthophosphoric acid with Calcium Carbonate and Magnesium Carbonate treated soils is studied. The Optimum percentages of CaCO 3 and MgCO 3 mix were found for Black Cotton soil and Red Earth based on compaction test. Liquid limit is decreased with CaCO 3. and increased with MgCO 3. Plastic limit is increased with CaCO 3 and decreased with. MgCO 3. Shrinkage limit is increased with CaCO 3 and decreased with MgCO 3. Acidification of alkalis treated soils by one normal Sulphuric acid and one normal Ortho Phosphoric acid showed alteration and impairment in index properties. However, the effect of 1N H 3 PO 4 on the alkali treated soils has less negative effect than with 1N H 2 SO 4 on the index properties. It is evident that the index properties of soils are altered when compared with their initial characteristics. The reasons for the observed behavior of soils are addressed.