Effect on Characteristics of Expansive Soil by Inclusion of Lime and Polypropylene Fiber

Abstract

Expansive soils are often encountered in many parts of the world. Black cotton soil is found in Maharashtra, Madhya Pradesh, Karnataka and Andhra Pradesh in our country. Such kind of soils generally include active clay minerals in low water content, enlarge in volume by absorbing the water through the surface and cause a great harm to the light structures such as roads , airports, embankments and cannel coatings etc. The expansive soils were encountered on the path of road pavements in the villages of vidarbha region in Maharashtra. The research done in the area, it is predicted that the soil has swelling nature and need soil improvement. Instead of replacing the expansive soil with granular soil, by stabilizing it with lime and polypropylene fiber at its original place which will decreases its swelling percentage. In order to improve the characteristics of expansive soil stabilized by lime and recently proposed polypropylene fiber described and reported in this paper. To investigate and understand the influence of the mixture of polypropylene fiber and lime on the engineering properties of a black cotton soil, nine groups of treated soil specimens were prepared and tested at four different percentages of fiber content i.e. 0.5%, 0.75%, 1% and1.5% by weight of the parent soil and five different percentages of lime i.e. 2%, 4%, 6%, 8%,10% by weight of the parent soil. These treated specimens were subjected to California bearing ratio test and swelling percentage. It was found that fiber content and lime content had significant influence on the engineering properties of the fiber–lime treated soil. An increase in lime content resulted in an increase of CBR value. On the other hand, an increase in lime content lead to a reduction of swelling potential. However, an increase in fiber content caused an increase in strength and decrease swell potential.