Detection of Delamination in Concrete Pavements Using Ground-Coupled Ground-Penetrating Radar Technique

Abstract

The ground-penetrating radar (GPR) technique has been successfully used to identify some subsurface problems on highway projects. However, the technique (especially techniques that use ground-coupled GPR systems) has not been fully developed or widely applied to concrete pavement rehabilitation work because of the data quality and data interpretation associated with the use of GPR systems for such work, which are only fair. Hence, a study was undertaken to explore the feasibility and potential of using the ground-coupled GPR technique for the detection of shallow delamination in continuously reinforced concrete (CRC) pavements. This paper proposes a three-step analysis protocol for the detection of field delamination with improved quality and improved accuracy of data interpretation on the basis of field-collected GPR data and graphic output. The three steps of this protocol include (a) a preliminary evaluation, (b) the development of a site-calibration algorithm based on the GPR return waveforms, and (c) the establishment of a threshold amplitude difference. This approach was preliminarily evaluated through further testing in the field, and it was identified as a potentially promising and useful tool for assessment of the delamination of CRC pavements.