Non-Destructive Evaluation of Bridge Decks using Ground Penetrating Radar

Ground penetrating radar (GPR) data were acquired across several bridge decks in central Missouri in an effort to demonstrate the utility and cost-effectiveness of using a high-frequency (1.5 GHz) ground-coupled and air-launched (2 GHz) ground penetrating radar systems to assess the condition of bridge decks. Areas of degradation and the extensiveness of degradation were mapped based on the amplitude of the reflections from the upper and lower mats of reinforcing steel and the apparent embedment depth of the upper and lower mats of reinforcing steel. Hydro demolition was performed on several of the bridge decks as a part of the remediation process. LiDAR data were obtained before and after hydrodemolition to estimate the volume of removed material and to verify the reliability of the GPR interpretations. The utility and cost-effectiveness of both the air-launched and ground-coupled tools were assessed based on the usefulness of the interpretations to the Missouri Department of Transportation and the estimated cost of generating the interpretations