A Study on Cotton Fiber Stabilize Soil and its Effect on CBR Value

For improvement of soil properties natural fibers can be used with great advantage because they are locally/ readily available, biodegradable, economical and eco-friendly as well. Soil reinforced with natural fiber is responsible for noteworthy improvement in its shear strength, tensile strength and other engineering properties. The use of randomly distributed synthetic and natural fibers over last two decades have gained remarkable popularity and success. In this study samples of locally available soil reinforced with cotton fibers were considered for experimental investigations. California bearing ratio (CBR) test was performed on samples with and without reinforcement for obtaining CBR values of soil by preparing samples at its maximum dry density (MDD) corresponding to its optimum moisture content (OMC). The cotton fiber content by dry weight of soil was taken as 0.3 %, 0.6 %, 0.9 %, 1.2 % and 1.5 %. Unsoaked and soaked CBR value corresponding to each cotton fiber content was determined in the laboratory as per specified procedure. From the test results it was observed that unsoaked and soaked CBR value of soil increases with fiber content up to 1.2 % and then a slight decrease was marked. It was also noticed that the increase in CBR value of reinforced soil was appreciable at cotton fiber content of 1.2 %. This increase is responsible for reduction in the pavement crust thickness and ultimately economy in the cost of construction.