Assessment of carbon black modified binder in a sustainable asphalt concrete mixture

Abstract

Carbon black has been used as a modifier in conventional binders together with a relatively low percentage of SBS polymer. In addition, an Evotherm additive has been combined by the wet way with the aim of decreasing the manufacturing temperature of the asphalt mixtures. The impact of these two has been analysed with a DSR rheometer, showing an increase in stiffness. An Asphalt Concrete mixture was then designed using the experimental binder and the warm mix additive and compared with a reference mix, using a commercial polymer modified bitumen.

The final experimental mixture was manufactured 15?°C cooler than usual, showing good mechanical performance despite the low percentage of natural aggregate, which was mostly composed of reclaimed asphalt and slag. Its stiffness and fatigue resistance were also investigated. Finally, the mixture was laid in an experimental road section under real conditions as proof of concept of the technology.