A STUDY ON COEFFICIENT OF PERMEABILITY AND MAXIMUM DRY DENSITY OF STABILIZED FLY ASH

Abstract

Energy is the key input to the alround development and economic growth which have a symbiosis with the availability of energy. Electricity, is the most convenient and versatile form of energy; demand for it has been growing at a rate faster than that for the other forms of energy. Out of total installed generating capacity of around 82,000 MW at present in the country about 53,000 MW is generated from coal based thermal power plants. Coal based Thermal Power Plants produce Fly Ash as a waste by prodct. The huge quantity o f Ash being accumulated over the years is likely to pose a problem for its disposal and cause environmental pollution leading to health hazards. To minimise all these effects abest alternative is to promote large scale utilization of coal ash which has potential for use in the country. The use of Fly Ash in India is the lowest where 95-97% of Fly Ash is still reported to be unutilised. However use of 20-45% of Fly Ash is reported for use as sustainable geomaterial for construction of embankment, subgrade layer of road,dyke and ash pond embankment depending on the type of local soil and the quality of Fly Ash. Compaction of soils increases their density, shear strength, bearing capacity but reduces their void ratio, porosity, permeability and settlements. And the quantity of stored water escaping through and beneath an earthen dam depends on the permeability of the embankment and foundations respectively. Shear Strength of soils also depends indirectly on its permeability, because dissipation ofpore pressure is controlled by its permeability. So, we can say that compaction and permeability characteristics are the most governing properties in geotechnical applications. The current work is an attempt to compute the Maximum Dry Density and Coefficient of Permeability of stabilized Fly Ash so that Fly Ash can be successfully used as fill/embankment material or subgrade layer of road.