Measurement of asphalt pavement layer thickness of road using ground penetrating radar

Thickness and moisture content of the asphalt surface are two important parameters, contributing to the assessment of road quality. Typically, these parameters are measured by drilling and sampling, causing structural damage, time loss and intermittent data acquisition. Ground Penetrating Radar is a geophysical method that uses electromagnetic waves at high frequency ranges to form pulses into the ground, so it has good resolution and accuracy. By measuring above the road surface, the data obtained can reveal the boundaries of shallow layers without causing destruction. Relying upon algorithms for wave impulse, we can calculate the value of earth wave velocity, characteristic of the wave propagation velocity in the first subclass. Therefore, the surveyor can accurately determine the thickness and moisture content of asphalt on the entire route, the accurate determination of layer thickness and defects of surface layer of plastic contributes to improving and restoring road quality. This paper presents the results of using 700 MHz and 1000 MHz frequencies to conduct field surveys and collect data, in order to verify the accuracy of processing algorithms, and evaluate the errors of initial calculation results. The use of Ground Penetrating Radar to measure the thickness of the plastic layer is a potenial method to increase the effectiveness of road quality appraisal in the future.