COMPARATIVE STUDY ON DIFFERENT SUB-BASE MATERIALS

Abstract

The quality of pavement design is greatly dependent on the manner in which the material properties are evaluated. Statically testing of material does not stimulate the repeated loading caused by the traffic. The traffic type loading is defined by resilient response, which is important for the load carrying ability of the pavement and a permanent strain response, which characterizes the long-term performance of the pavement and the rutting phenomenon. India has vast material resources, if these locally available materials are used in the construction of roads. The cost of construction can be reduced and also economy can be enhanced. Present study is intended to utilize the locally available material in road construction in subbase layer. Four locally available material near Roorkee are chosen, the materials are river bed material, coarse sand fly ash and stone dust. To evaluate the material properties static and dynamic tests are conducted. It was observed that river bed material available near Roorkee as good CBR, modulus of elasticity, resilient modulus and low permanent strain. Stone dust is having more permanent strain, which is the indicator of rutting phenomenon. Fly ash has low CBR value and low permanent strain compared to stone dust. Out of the four materials RBM is best and can be used in subbase followed by coarse sand. The stone dust has highest CBR value when compared to other materials but it performance is very poor under repeated loading conditions.