A Study on Improvement and Cost Effectiveness of Pavement Subgrade by Use of Fly Ash Reinforced with Geotextile

The performance of a pavement is directly related to the characteristics of the soil subgrade, which provides base for the whole pavement structure. Therefore it is essential that the performance of pavements to be enhanced by adopting suitable design and proper construction methods. Now-a-days huge amount of fly ash produced from various thermal power plants is low unit weight, nonplastic, very fine and disposed in slurry form into ponds covering large area. The ash acquired from ponds gets directly air-borne and thus constitutes a serious pollution threat to the society. These materials have a low load carrying capacity, degraded settlement distinctiveness and their utilization in civil engineering works is a tough assignment. On the other hand the performance of these materials can be improved by using soil reinforcement procedure. It can be used as a pavement sub grade with the help of Geotextile sheets as reinforcement. In this study, samples of fly ash compacted to its maximum dry density at the finest moisture content is organized without and with Geotextile layers in the CBR mould. Geotextile sheets equal to the plan dimensions of CBR mould is placed in four distinct layers of different locations in the CBR mould. The CBR (California Bearing Ratio) values of each arrangement of Geotextile, are evaluated in the laboratory and compared with the results of CBR values without and with Geotextile layers.