Study on Improvement of Black Cotton Soil by Using Fines of Concrete Cube & Brick Demolition Waste

Abstract

Subgrade soil is a primary part of a road crust which gives considerable strength and support to the whole pavement structure from below. If the subgrade soil exhibits a weak soil then improvement of load-bearing strength properties of that subgrade soil is done by soil-stabilization technique. This project aims to conduct a study to check the improvements in properties of Black Cotton (BC) soil by adding Fines of Crushed concrete cube and Brick waste separately. By varying percentage of Fines of Concrete Cube Waste (FCCW) at 0%, 20%, 40% and 60%, the soil parameters such as Compaction characteristics, CBR and Shear Strength were studied. These values are compared to that of a untreated BC soil. Similarly, the varying percentage of Fines of Brick Demolition Waste (FBDW) at 0%, 20%, 40% and 60%, the soil parameters only considered was Compaction characteristics. The first approach of BC stabilized using FCCW, the Maximum Dry Density increased from 1.504g/cm3 to maximum 1.708 g/cm3, decrease in Optimum Moisture Content and later increase, CBR value increased from 2.05%to maximum 7% and Shear strength increased from 377kN/m2 to maximum 1390 kN/m2 at 20% FCCW respectively. The second approach of BC stabilized using FBW, the Maximum Dry Density increased from 1.565g/cm3 to maximum 1.702 g/cm3 and decrease in Optimum Moisture Content at 20% FBDW respectively. However, in the light of studies conducted, the 20% of FCCW and 20% of FBDW are considered as the optimum proportion of the FCCW and FBDW resulting in maximum strength and performance as observed from UCS test results in the first approach.