Improvement of California Bearing Ratio (CBR) value of Steel Fiber reinforced Cement modified Marginal Soil for pavement subgrade admixed with Fly Ash
G. Praveen, Pandu Kurre, T. Chandrabai
Abstract
The existence of pavement relies upon on strength of the subgrade soil and traffic density. Most of the times, the subgrade soil properties may not be adequate. These soils are not directly suitable for the construction of pavement and are considered to be poor soils. In general, the poor soil subgrade have soaked California Bearing Ratio (CBR) value less than 2% and need to be replaced by proper soil for subgrade construction. These types of poor soils are known as Marginal Soils. Marginal Soil (in general Clayey Soil) often shows undesirable engineering properties along with low strength characteristics with regard to CBR value. To enhance the properties of these soils, the common technique adopted is admixture stabilization. The chemical additives are being used to improve the properties of subgrade soil. By means this process, the cost of construction of pavements increases. In this paper an attempt was made to evaluate the effectiveness of Steel Fiber reinforced Marginal Soil (Clayey Sand) modified with Cement and/or mixed with Fly Ash. The characteristics Steel Fiber reinforced Cement modified Marginal Soil mixed with/without Fly Ash was studied with respect to improvement in CBR value for the purpose of subgrade construction. It also offers a probable solution for proper disposal of Fly Ash. Hence, the study intended to provide a composite soil subgrade material for pavement construction . The results have shown adequate improvement in CBR value of composite Marginal Soil containing Cement and Fly Ash. Thus the stabilized composite Marginal Soil could be an alternative construction material used as subgrade soil for pavements. The composite soil mix could be suggested in rural areas with low volume of traffic.