ABSTRACT
Aggregates play a major role in asphalt mixes. The asphalt mix is made up of approximately 80 – 90% of aggregates. It is thus important to evaluate the effect of aggregate gradation in asphalt mixes. This is due to the escalating rate of South African roads experiencing permanent pavement deformation, particularly in Butterworth (Eastern Cape). Rutting of the asphaltic layer contributes to a lesser service life road as per designed service life. The main factor that contributes to rutting of asphalt roads is aggregate gradation. The aim of this study is to determine the effects of aggregate gradation in asphalt mix in order to extend the service life of asphalt roads as a result of pavement deformation.The laboratory test will be Marshall Flow, Marshall Stability and air voids in mineral aggregates. Volumetric bituminous mixes will be used using the Marshall Design criteria for analyses of performance of aggregate gradation and Dynamic creep test.Through the evaluation of air voids, voids in mineral aggregate (VMA), stability, flow, resilient modulus and Elastic modulus, the outcomes indicate that asphalt mixtures of upper limit aggregate gradation band are the most suitable material to resist rutting and permanent deformation of asphalt roads.
