Information on pavement layer thickness is crucial for estimating bearing capacity, assessing remaining service life, and strengthening planning. Traditionally, the pavement layer thickness is determined by extracting cores and digging test pits. These methods are destructive, require temporary road closures and subsequent repairs, and at the same time provide incomplete information as the data relates to a specific location. For this reason, ground-penetrating radar has become one of the most widely used methods for determining pavement layer thickness in recent decades. GPR is a non-destructive testing method based on the emission of low-power electromagnetic waves to obtain images of subsurface layers. The reflection and scattering of the broadband electromagnetic waves emitted by the radar occur due to discontinuities in the electrical and magnetic properties of the structure under investigation. The echoes detected in the structures or subsurface layers under investigation are then converted into images using signal processing and imaging techniques. The main advantage of the GPR application is continuous data acquisition at a steady driving speed without interrupting traffic, resulting in reduced cost and inconvenience to users. This study aimed to investigate the effect of data acquisition speed on the accuracy and repeatability of the GPR method for determining pavement layer thickness. Data acquisition was performed using a survey vehicle equipped with an air-coupled GPR system. The speed of the survey vehicle varied between 30 and 100 km/h (in steps of 10 km/h). After interpreting the GPR data, the pavement layers thickness was compared with the cores.

ground-penetrating radar; non destructive testing; pavement; layer thickness