The use of Ground-Penetrating Radar in determining pavement layer thickness and void content in Latvia

This paper is focusing on the possibilities to determine pavement layer thickness and void content in pavement by using the ground-penetrating radar (GPR) owned by SJSC “Latvian State Roads”. The research reflects the analysis of results from three sites in the territory of Latvia. In the sites with the total length of 85 km GPR data was gathered after taking 86 core samples to determine pavement layer thickness. The void content in these drilled core samples was measured with laboratory methods. Void content was also measured with laboratory methods. The results show that dielectric permittivity coefficient (ε′), determined with the metal plate test, was equal to the one estimated from the drilling on sites if road pavement materials were similar in all layers. Void content test results have showed no correlation with the ε′ determined with the metal plate test.