Performance of Soil Subgrade with Reinforced Fibres in Pavement

This book studies the benefits of reinforcing the subgrade soils in flexible pavements where two different types of fibres (Jute and Polypropylene fibre) were used, and were randomly mixed with two different types of soil, then a series of Proctor test, Unconfined compression test California Bearing Ratio (CBR) tests and Triaxail tests were conducted to evaluate the compressive strength and shear strength of subgrade soil. Both the Fibres were added at various percentages (0.5% to 1.5%) by dry weight of soil were used for improving soil strength. The CBR value increases with increase in fibre content upto a certain percentage but decreases with further addition of fibres in both the soils. Unconfined compressive strength test was conducted to cheek the increase in compressive strength where confining pressure is zero. And found that the optimum percentage which gives the maximum CBR and compressive strength is 0.75% jute fibre and 1.0% PP fibre for both types of soil. Adding of fibre results in less thickness of pavement due to increase in CBR of mix and hence economy of the construction of highway will be achieved.