Asphalt generally behaves as an insulator. The addition of graphite can produce electrically conductive asphalt, which can be further manufactured as multifunctional asphalt concrete. The present study investigated the effect of graphite on the electrical conductivity and rheological characteristics of base asphalt. A novel electrical resistivity measuring method of asphalt binder was also introduced in detail. Various binder tests, including penetration, ductility, softening point, and dynamic shear rheometer (DSR) tests, were utilized to determine rheological properties of asphalt binder. Experimental results indicated that the conductivity of asphalt binder improved with the increasing content of graphite. Moreover, asphalt binder exhibited improved viscoelastic response and resistance to rutting due to the addition of graphite. However, the low-temperature performance of graphite modified asphalt was not encouraging from the ductility test. Therefore, asphalt binder containing graphite is promising to become novel road functional materials to meet both requirements of electrical conductivity and road properties.

Pyrolytic carbon black (CB _p ) from scrap tire pyrolysis is a potential modifier for the bitumen industry. Binders containing different contents of CB _p were prepared and experimentally investigated to examine the effects of CB _p on the electrical and thermal conductivity, conventional physical properties, rheological properties, high-temperature antirutting performance, aging resistance, and storage stability. Laboratory test results indicated that the incorporation of CB _p effectively improves the electrothermal properties, rheological properties, high-temperature rutting resistance, and aging resistance. It also increases the viscosity and decreases the storage stability of bitumen. The study confirms that CB _p -modified bitumen with proper selection of content can be a multifunctional paving material.