Assessing the Compaction Quality of Dolomitic Asphalt Pavements Using Ground Penetrating Radar

The quality of newly constructed pavement depends mostly on compaction, which is essential for ensuring the pavement’s longevity and performance. Traditional methods of evaluating pavement compaction and density, such as core sampling and nuclear gauge measurements, are often time-consuming and invasive and provide only a limited amount of data at a low spatial resolution on the potential air void content of the asphalt layers. The present study aimed to assess the specific gravity (Gmb) of a dolomitic asphalt mixture at different degrees of compaction using GPR techniques. Relative density (RD) maps were generated to visualize the spatial homogeneity of the asphalt density. Nuclear density gauging was applied for the calibration, and cores were used to validate the results. The survey was conducted on two recently paved roads in Szeged, Hungary. After testing various approaches, it was found that applying horn antennas and the surface reflection (SR) method is the most feasible way to obtain reliable and accurate dielectric permittivity (ε) data. Based on the measurements, clear relationships were found between dielectric constants, Gmb, and aggregate size. The findings highlight that it is possible to indirectly determine the Gmb of asphalts composed of dolomite and limestone aggregates using GPR, with aggregate sizes ranging from 11 mm to 25 mm and Gmb values between 2.43 and 2.57 g/cm3. Consequently, a robust function was developed, which can be applied to other asphalts with similar compositions.