Study Of Strenth Charataristic Of Black Cotton Stablizing With Fly Ash And Rice Husk Ash

Expansive soils also known as swelling soils or shrink-swell soils are the terms applied to those soils, which have a tendency to swell and shrink with the variation in moisture content. As a result of which significant distress in the soil occurs, causing severe damage to the overlying structure. During monsoons, these soils imbibe water, swell, become soft and their capacity to bear water is reduced, while in drier seasons, these soils shrinks and become harder due to evaporation of water. These types of soils are generally found in arid and semi-arid regions of the world and are considered as a potential natural hazard, which if not treated well can cause extensive damages to not only to the structures built upon them but also can cause loss of human life. Soils containing the clay minerals montomorillonite generally exhibit these properties. The annual cost of damage to the civil engineering structures caused by these soils are estimated to be ? 150 million in the U.K., $ 1,000 million in the U.S. and many billions of dollars worldwide. In this paper soil is treatd with different proportion of FA(5%,10%,15%,20%,25%) and RHA (,10%,15%,20%,25%,30%) and Optimum moisture content, Maximum dry dencity and california bearing capacity is evaluated. Test was conducted on BC soil and soil, Fly Ash, Rice husk ash mixtures prepared at optimum water content. Addition of Fly ash and Rice husk ash resulted in appreciable increases in CBR of soil. CBR value is used to reduce the thickness of pavement and increasing the bearing capacity of soil.