STRENGTH CHARACTERISTICS OF BITUMINOUS CONCRETE WITH DIFFERENT TYPES OF FILLER

Abstract

The performance of a pavement depends on the characteristics of the constituent materials, environmental condition, properties of soil support etc. It should he designed to resist the traffic load during its design life without excessive deformation. The strength property of a flexible pavement and particularly of bituminous concrete has been a major concern. Many approaches have been devised to improve its strength by adding materials into the bituminous mixes. Polymeric products and other modifiers can be added into bitumen to alter its property. Invaluable improvement has been observed by adding appropriate proportion of filler in bituminous mixes. Fillers serve to fill and control voids in the mineral aggregate, increase contact area and stiffness. They also improve resistance to rutting, shoving, thermal cracking, increase stability and durability, resilient modulus and resistance to water damage and other engineering properties of bituminous mixes. In the present investigation, an attempt has been made to study the effect of type and amount of filler on different properties of bituminous concrete. Three types of filler namely lime, stone dust and marble dust were used and various tests like Marshall stability test, unconfined compression test and indirect tensile tests were conducted. It was observed that maximum Marshall stability of 1531.2 kg was at 7.5 % lime filler. Higher compressive strength, modulus of elasticity and tensile strength was obtained with marble dust filler. The maximum compressive stress at 5 % marble dust filler was 73.39 kg/cm2. The modulus of elasticity and the maximum tensile strength of the mix at 7.0 % marble filler were 851.79 k g/cm2.and 18.2kg/cm2, respectively.