Indoor Test and Evaluation of Asphalt Pavement Compaction Measurements Using Ground-Penetrating Radar-Based Density Profiling System

A density profiling system (DPS) based on ground-penetrating radar was tested simulating the in-place DPS measurement in an indoor setting. The test investigated two types of asphalt mixture commonly used in Japan. Eight 15 cm (6 in.) diameter gyratory pucks were made for mix calibrations, and ten 50 × 50 × 5 cm (20 × 20 × 2 in.) wheel tracking slab specimens were fabricated for simulating the DPS measurement at the job site. Observation of the data showed that puck heterogeneity might cause calibration errors when compaction is too low. Furthermore, the test illustrated that the surface texture influences the measurement, and a correction may need to be applied when it is significant. With careful treatment of data and the surface texture correction, the DPS achieved a mean error of approximately 0.1% or less in air void content with respect to that based on bulk specific gravity obtained from cores using the saturated surface dry method.