Field Demonstration of GPR and UAV technologies for Evaluation of US75 Bridges

Asphalt overlay is increasingly applied on many Nebraska bridges. The asphalt overlay prevents visual inspection and many nondestructive evaluation (NDE) methods. Ground Penetrating RADAR (GPR) is currently the only proven NDE method that can be used to evaluate a concrete bridge deck with asphalt overlays (ASTM 2015). GPR can penetrate though the asphalt layer and the amplitudes of GPR reflection signals from reinforcing bars are used to evaluate the deck condition. In a previous Nebraska Department of Transportation (NDOT) project (M-065), the PI’s team developed a complete procedure of GPR data analysis for bridge deck evaluation, which has been used to evaluate bridge decks with various types of overlays (bare, concrete overlay, asphalt overlay).