A STUDY ON BLACK COTTON SOIL TO ENHANCE CBR VALUE OF SOIL SUB-GRADE USING COCONUT COIR FIBER FOR RURAL ROADS

Abstract

The (CBR) California bearing ratio Test is a test first developed by the California State Highway Department (U.S.A.) for evaluating and enhance the bearing capacity of sub grade soil for design of flexible pavement. Soft soils form problematic sub-grade for pavements due to its low bearing capacity and their strength. Pavement loads coming on the soft sub-grade soil may cause pumping actions when it is located in areas with high water table which causes both construction and in-service performance problem. The common solutions on en counting such problems include excavation and replacement of soil. Excavation and replacement of soil becomes very expensive especially when used as soils have to significant distance. Stabilization using various additives and different material can improve the properties of soils. Now-A-days recent trend in stabilization is to be utilized locally available industrial and material wastes to improve the properties of soils. In this procedure has the dual advantage of increase the strength of soil and a solution for the problematic disposal of such wastes. Coir waste consisting of coir pith and coir fiber is a by product of coir manufacturing industry obtained from coconut husk during extraction of coir fiber. The pollution is caused due to the poly phenol leaching and the resistance to degradation due to the stable lignin structure makes the coir waste a potential threat to the land resources. The permeability and the CBR constitute two important parameters in the design and assessment of long term performance of the pavement. In this project only strength aspects of pavement sub-grade have considered. It is very natural process. In laboratory investigations and experiment have been carried out on a number of soil samples procure from different roadwork sites. Starting tests, it provide a good strength.