Influence of graphite on the thermal characteristics and anti-ageing properties of asphalt binder

Hydronic asphalt pavement (HAP) is an emerging technology for the purpose of harvesting solar energy in the summer and deicing the pavement in the winter. Increasing the thermal conductivity of pavement material is a fundamental technology to improve the operation efficiency of such novel system. In this paper, the influences of graphite on the thermal characteristics and anti-ageing properties of asphalt binders were experimentally investigated. A control asphalt binder (CAB) sample was prepared by the same weight ratio of asphalt and mineral filler. Experimental results indicated that the thermal conductivity and diffusivity increased linearly with the increasing of graphite content, while the specific heat presented a descending trend correspondingly. Although the storage stability of asphalt binders with graphite were better than the CAB sample, binders with mineral filler or graphite showed bad high temperature storage stability. Differences between the physical and rheological properties of the original asphalt binders and the aged samples illustrated that graphite improved the anti-ageing properties of asphalt binders.