Comprehensive Assessment of Asphalt Pavement Layer Compaction Degrees Using GPR-Based Density Profiling

Accurate assessment of asphalt layer compaction is crucial during the construction process. Ground-penetrating radar (GPR) technology allows continuous measurement of the dielectric constant of the surface layer, enabling comprehensive mapping of compaction levels. However, its application can be challenged by factors such as surface moisture resulting from roller nozzle sprays and the necessity of calibration coefficients in the dielectric constant-density relationship model. In this study, GPR technology was employed to develop an evaluation method for assessing the compaction quality of asphalt surface layers. Compaction metrics were analyzed by continuously collecting dielectric constant data from the asphalt surface layer, with the compaction interval and coefficient of variation used as indicators of compaction level and uniformity, respectively. The proposed method accounts for the impact of water vapor between the antenna and the ground on GPR accuracy and incorporates a data stability correction technique to remove outliers. The dielectric constant-density prediction model was calibrated through laboratory and field core testing. Field trial results demonstrate that GPR technology is effective in evaluating the compaction quality of asphalt layers. Unmanned compaction machinery was found to achieve better compaction uniformity, with a lower coefficient of variation compared to traditional methods. Variations in compaction were observed at the edges of construction sections and between lanes, showing the importance of improved construction monitoring to enhance overall compaction quality.