SHRP-2 Nondestructive Inspection of VDOT Bridge Decks within the Districts of
Staunton & Hampton Roads, VA

Penetradar performed a nondestructive inspection of six bridge decks, including three bridges within each of the Hampton Roads and Staunton Districts in Virginia. The nondestructive inspection was performed using ground penetrating radar (GPR), infrared thermography (IRT), and high resolution imaging (HRI) of the bridge deck surface, all of which were performed at the minimum posted speed. The objectives of the GPR, IRT and HRI inspection were to provide an up-to-date assessment of the physical condition of the concrete decks, including the overall quantity of corrosion induced delaminated concrete within the bridges as well as cover over the top mat of deck reinforcing steel. The survey was conducted for the Virginia Department of Transportation, under the Strategic Highway Research Program Phase 2 (SHRP-2) research project.

The GPR and IRT data acquired during the survey were processed at Penetradar utilizing computer based signal processing hardware and software based on the AASHTO TP36, ASTM D 6087-08, SHRP C‐101 standards (GPR) and ASTM D4788‐03 (IRT). This provided accurate and objective location and quantity estimates of deteriorated concrete and depth to reinforcement. The results of our NDT inspection are presented graphically in a plan-view (top-view) format that shows the location and spatial extent of the detections.

Detailed results were presented in the report which include plan‐view mappings of (1) delaminated concrete (2) rebar cover and (3) visual imaging of the bridge decks at the time of the survey.  Inspection results summarizing the deck condition were provided for each bridge deck also.

A combination view of all the types of mapping are shown as a sample below.

The use of these multiple mappings provide a comprehensive package of information on the condition of the inspected bridge deck.  Quantities of delaminated concrete and depth to the reinforcing steel along with a detailed image of the deck surface at the time of the survey add invaluable information to the bridge owners without the need to close down any lanes on the bridge. This saves time and money and removes the inconvenience of traffic delays.