A study of artificial debond pavement under controlled traffic by Ground Penetrating Radar

This study utilized high-frequency Ground Penetrating Radar (GPR) with a center frequency of 2600 MHz to monitor the critical geometric changes of debonding in a road pavement. The pavement was under repetitive traffic loadings up to 80,000 cycles tested in the accelerated pavement testing (APT) facility inUniversité. Gustave Eiffel, Nantes, France. The debond zones (i.e. loss of contract between layers) were artificially made of sand infill, geotextiles and absence of tack coat between bitumen layers. GPR amplitude ratio test (ART) and time-frequency analysis (TFA) were adopted to study changes of each debond zone under an increment of loading cycles. The results show that an increase of the loading cycles leads to an increase of the normalized amplitude and the shift of the center frequency of the reflection to a lower regime. The analysis appears to be a good indicator to monitor the geometrical changes of debond zones undergoing various traffic loadings, and can be turned to be a useful tool for diagnosis of pavement debond behavior, and maintenance of the pavement before any damages become visual.