Electrical conductivity and rheological properties of asphalt binder containing graphite

Abstract

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.