Use of Bagasse Ash and Coconut Fiber in Stabilization of Black Cotton Soil

Abstract

The black cotton soil is known for its expansive behavior which makes it unfit for taking up any type of construction activity without proper treatment. In this research investigation, initially bagasse ash was blended with black cotton soil in a mix percentage varying between 0 and 20% to analyze its engineering properties. After obtaining optimum strength of the mix, it was further reinforced with coconut fibre in a ratio between 0.5 and 1.0% to explore the possibility of reduction in bagasse ash content for the same strength. Different laboratory tests, viz. liquid limit test, plastic limit test, free swell index and unconfined compressive strength test, were done on various mix samples to determine its strength characteristics. It is observed that with the addition of bagasse ash, the liquid limit, plastic limit, and free swell index of the mix specimens had decreased. The maximum strength of this soil–bagasse ash mix is observed at 15% of bagasse ash which was then further reinforced with coconut fiber resulting in a decrease in the quantity of bagasse ash to 10% with 0.5% of coconut fibre. Bagasse ash and coconut fiber are abundantly available waste materials, and as such use of these materials may be an economical solution in improving strength properties of black cotton soil.