=+little research has been done on the characterization of dielectric properties of asphalt mixtures. The article “Dielectric Modeling of Asphalt Mixtures and Relationship with Density” (J. Transp. Engr., 2011: 104–111) reported on the dielectric response with percent air voids for various asphalt mixtures at 7-GHz frequency. The following data, kindly provided by the authors of the cited article, compares y 5 dielectric constant and x 5 air void (%) for 18 samples having 5% asphalt content:

y: 4.55 4.49 4.50 4.47 4.47 4.45 x: 4.35 4.79 5.57 5.20 5.07 5.79 y: 4.40 4.34 4.43 4.43 4.42 4.40 x: 5.36 6.40 5.66 5.90 6.49 5.70