Dielectric mixing principle of asphalt mixtures towards intelligent transportation techniques

Heightened need for sustainable transportation infrastructure leads to growing tendency towards intelligent transportation electrification techniques. Dielectric mixing principle of asphalt mixtures plays crucial roles in intelligent transportation techniques (for instance, e-Road, microwave heating and ground-penetrating radar) towards asphalt pavement. In this paper, by solving electric polarization behaviour of ellipsoidal inclusions in the external excitation field, new dielectric mixing principles were established to compute the dielectric properties of asphalt mixtures based on effective medium approximation scheme (EMAS) and average field approximation scheme (AFAS). To validate the feasibility and accuracy of developed principles, laboratory dielectric tests were conducted using coaxial probe and waveguide cavity methods based on the vector network analyser platform. From the experimental observations, choices of background media (air, asphalt and limestone) to the prediction accuracy of dielectric mixing principle had been comprehensively explored. Moreover, depolarization factors d of different background media were assured, and it was concluded that the proposed ellipsoidal dielectric mixing principles had higher accuracy compared with classical models. Hence the developed dielectric mixing principle is much more appropriate for explaining dielectric properties of asphalt mixtures, which enhances technical knowledge of dielectric property modelling of asphalt mixtures in terms of intelligent transportation techniques.