Dielectric loss law of asphalt mixture under the condition of microwave heating

Abstract

In order to improve energy conversion efficiency of asphalt mixture during microwave heating, key characteristic parameters are researched. Attenuation law of electric field intensity and dielectric loss in asphalt mixture are discussed and conversion model between thermal field and electric field is built. Results show that: (1) electric field intensity attenuates with the increase of the measuring depth of microwave, and the utilization rate of electromagnetic energy increases with attenuation constant; (2) electric field intensity also attenuates with the increase of dielectric permittivity and dielectric loss tangent of asphalt mixture; (3) temperature of asphalt mixture can be significantly improved by enhancing intensity of internal heat source. The findings can provide the theoretical basis for selection of asphalt pavement material, establishment of microwave recycling theory and design of microwave heating equipments.