Experimental Investigation on the Effect of Fly Ash on Mechanical Properties of Polymer Modified SMA

The main purpose of this paper is evaluating the impacts of fly ash additive on mechanical and functional properties of polymer modified stone matrix asphalt (SMA). Fly ash was used as a filler in various percentages as 0%, 2.5%, 5%, 7.5% and 10% by weight of aggregates. In this research to defining mechanical and functional properties of modified asphalt mixture, moisture sensitivity, Marshall stability, resistance to permanent deformation and resilient modulus were carried out on the SMA mixes. The results show that , use of fly ash as a filler has no effect on drain down of the mix and this property just improve by bitumen modifying (by means of fiber or polymer). The results of moisture sensitivity test show that the most positive effect was related to use SBS polymer as a modifier and in samples with 7.5%FA. Also results of dynamic creep test show that, the value of flow number for prepared samples with fiber is significantly lower than polymer modified samples.