Compactness prediction of asphalt concrete using Ground-Penetrating Radar: A comparative study

Abstract

The compactness is an important indicator of quality control during the construction of the asphalt concrete pavement. The construction quality of asphalt concrete can be continuously, quickly, and non-destructively tested by establishing the correlation between dielectric constant and compactness through ground-penetrating radar. In this study, five compactness prediction models were established based on the relationship between volume parameters and the dielectric constant of each component of asphalt concrete. 18 samples of Sup20 asphalt concrete (Superior Performing Asphalt Pavement with the nominal aggregate size of 19 mm) were used to verify the established compactness prediction models. The results showed that the average relative error, maximum error, and root mean square error of the CP_Rayleigh model (compactness prediction model of Rayleigh.) were minimum, and thus the CP_Rayleigh model was selected for the following-up research in this study. The shapes of scatterers (aggregates and pores) were not spherical, and a shape factor u of 0.033 was introduced to modify the CP_Rayleigh model. The prediction accuracy of compactness can be effectively improved by the modified CP_Rayleigh model. Combined with field engineering verification, it was shown that the modified CP_Rayleigh model can be used to predict the compactness of asphalt concrete in the field.