STABILIZATION OF PAVEMENT SUBGRADE BY USING FLY ASH REINFORCED WITH GEOTEXTILE

Abstract

The performance of a pavement is very responsive to the characteristics of the soil subgrade, which provides base for the whole pavement structure. For that reason of utmost significance the performance of pavements is enhanced by adopting proper design and construction schemes. Million tons of fly ash produced from various thermal power plants is low unit weight, non-plastic, very fine and disposed in slurry form into ponds covering huge area. The ash acquired from ponds gets directly airborne 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 distinct preparations of 1 st , 2 nd , 3 rd and 4 th layers at different locations (i.e. at different embedment ratio, z/d) in the CBR mould. Subsequent to each arrangement of Geotextile, the CBR (California Bearing Ratio) values are evaluated in the laboratory and compared with the results of CBR values earlier than including geotextiles.