Laboratory Investigations on Stabilization of Soil with Fly-ash

Abstract

Fly ash is a waste by-product of the thermal power plants. Its disposal is not only problematic but also environmentally hazardous to the nearby habitations. Some fine grained soils are problematic due to their settlement, swelling and strength issues when used in road subgrade / embankment. High strength soil in subgrade is recommended by IRC:37-2012, the code for design of flexible pavement. It recommends the use of selected soil of minimum CBR 8% in the subgrade where the traffic is more than or equal to 450 Commercial Vehicle Per Day (CPVD) . Quite often, large areas are covered with highly plastic and expansive soil, which is not suitable for subgrade / embankment and the idea of replacing the whole soil is very uneconomical. As fly ash is freely available, for projects in the vicinity of a thermal power plants, it can be used for stabilization of fine grained soils for various uses. This paper brings forth the work of various studies carried out for the improvements in the properties of such soils with fly ash in varying proportions (10%, 20%, 30%) and its combined effect with cement (1%).