A Comprehensive Review on the Effect of Filler Materials on Engineering Properties of Asphalt Concrete Mixes

Abstract

The effect of filler materials on the properties of bituminous concrete was reviewed in this paper. Flexible pavement layer is made up of asphalt concrete. It is the commonest type of pavement in the world. Asphalt concrete contains aggregates, bitumen binder and fillers. The Asphalt concrete has voids which needs to be filled for better performance of its functions. Fillers help to fill voids and change the physical and chemical properties of asphalt concrete and bitumen combines with filler to forms mastic that holds the aggregates together. Asphalt Institute recommended 4-8% fillers for use. The recent developments in technology is geared towards the use waste materials as fillers in concrete production. It was revealed in this review that Marble dust and Calcium Carbide Residue (CCR) can be used in bituminous mix as alternative to conventional fillers in asphalt mixes. The waste bagasse and coconut peat fillers give mastic viscosity similar to limestone filler but higher than granite filler. Concrete dust and brick dust as fillers in bituminous mix improve flow value, Marshall stability and physical characteristic of bitumen. The conclusion of this review analysis shows that fillers in bituminous mix reduces the problem associated with waste disposal and high concentration of calcium carbonate in waste ash can help to reduce rutting and moisture damage potentials.