EVALUATION OF GPR BRIDGE DECK SURVEY RESULTS USED FOR DELINEATION OF REMOVAL/MAINTENANCE QUANTITY BOUNDARIES ON ASPHALT-OVERLAID, REINFORCED CONCRETE DECK

Ground Penetrating Radar (GPR) was used to delineate deteriorated sections in a bridge deck located in New Hampshire. Recent developments in GPR technology provided high resolution images of the bridge deck structure that were used to create contour maps detailing different levels of deterioration. Because this was the first time this particular GPR method was used as a maintenance-level tool, and the decision database associated with the emerging technology was small, the appropriate contour level to use for concrete replacement was difficult to assess at the time by either Geophysical Survey Systems, Inc. (GSSI) or the New Hampshire Department of Transportation (NHDOT). The GPR interpretation suggested a contour level on the map that yielded a total concrete replacement area that exceeded the threshold for a cut-and-patch approach to rehabilitation. NHDOT decided to rehabilitate the deck within a tighter contour level, resulting in less initial concrete removal. This decision was based on a number of factors, including available project funding and the required life expectancy of the structure. If the initial rehabilitation-threshold contour level had been used instead, the entire deck surface would have been removed to at least the upper rebar level, then topped with new concrete and an asphalt overlay. As the asphalt was stripped in preparation for final overlay, it became evident that a significant amount of deterioration on the deck remained. Consequently, additional repair was required. A comparison/contrast between (a) the actual maintenance costs incurred on the project and (b) the originally estimated costs for completing the project could therefore be shown. This advanced GPR technique has been used effectively and accurately to guide the decisions for removal of deteriorated concrete prior to repair. With further refinements in methodology already addressed through discussions between NHDOT and GSSI, its judicious use can save a significant amount of money when decisions between various maintenance regimes must be made.

  • Availability:
  • Supplemental Notes:
    • This entry in the TRIS database is made from the hardback copy of the conference proceedings, which are also available on CD-ROM.
  • Corporate Authors:

    Technomic Publishing Company, Incorporated

    851 New Holland Avenue, Box 3535
    Lancaster, PA  United States  17604
  • Authors:
    • Romero, F A
    • Roberts, G E
    • Roberts, R L
  • Conference:
  • Publication Date: 2000

Language

  • English

Media Info

  • Features: Figures; References;
  • Pagination: p. 23-30

Subject/Index Terms

Filing Info

  • Accession Number: 00793100
  • Record Type: Publication
  • ISBN: 1566769493
  • Files: TRIS
  • Created Date: May 1 2000 12:00AM