Stabilization of B.C. Soil by Using Chemicals and Fly Ash

Abstract

Black cotton soils are very susceptible to detrimental volumetric changes with changes in moisture. This behaviour of soil is attributed to the presence of mineral montmorillonite which has an expanding lattice. Black cotton soils because of their specific physical and chemical make are subjected to volume changes. In many countries including India, these soils are so extensive that alteration of highway routes to avoid the material is virtually impossible. Various remedial measures like soil replacement, prewetting, moisture control, lime stabilization etc. have been practiced with varied degrees of success. Extensive research is going on to find the solutions to Black cotton soils. Recent investigations on chemical stabilisation revealed that electrolytes like Calcium Sulphate, Calcium Carbonate, Zinc Chloride can be used in place of conventionally used lime, due to their ability to supply adequate cations. Fly ash is a waste by product from thermal power plants consuming thousands hectors of precious land for its disposal and also causing severe health and environmental hazards. This work presents the results of an experimental program undertaken to investigate the effect of Calcium Sulphate, Calcium Carbonate, Zinc Chloride and fly ash at different percentages on properties of black cotton soil. Atterbergs Limit of subgrade soil effect of addition of Fly Ash and Chemicals on CBR ,MDD ,OMC, From the results it is observed that 2% of Zinc Chloride and 12% of Fly ash improves the properties of black cotton soil as compared to Calcium sulphate & Calcium Carbonate. The conclusion drawn from this investigation is that a combination of 2% of chemicals and 12% of fly ash is more effective in improving the properties of black cotton soil.