Composite Bridge Decking: Phase I Design Report

3. AFTER-TEST REVIEW

On August 14, 2012, the research team provided the project Technical Advisory Panel with an update and summary of the testing that had been done. The presentation used for this is included in Appendix M.

The Technical Advisory Panel's comments are listed below, followed by the project team's responses:

• Question: How is the wearing surface repaired/refreshed?
  • Response: Since the second course of the wearing surface is only ¼ inch thick, a new ¼-inch surface can be applied if the additional 3 psf weight is not critical. Otherwise, the polymer concrete wearing surface can be milled off and resurfaced with a fresh course of the same material.


• Question: Will this be available in various panel sections/sizes? Will there be a table for design engineers to use as a design guide?
  • Response: The deck design is valid for a range of spans, and this can be tabulated to give designers the ability to pick the suitable deck type for their stringer spacing. Spans between 2 and 10 feet were tested. Sections were tested with various stiffening materials: empty, epoxy grout in the top only, and epoxy grout alternating between top and bottom.


• Question: What about dynamic loading?
  • Response: An impact factor was applied to the American Association of State Highway and Transportation Officials (AASHTO) design load. The field testing that is planned may provide additional information about the actual dynamic loading induced by truck loads.


• Question: Previous FRP decks have had trouble with the deck-deck joints, deck-steel connections, and the wearing surface. What has been done to prevent those problems?
  • Response: "Details" have been given a lot of attention in the design/analysis, material testing, and proof testing stages of the project. The modeling and subsequent testing assures us that the proposed details will function well in service.


• Comment: In the preliminary design stage, a reviewer's only concern had been about the type of grout used. He was pleased to see that we addressed that issue by selecting a low-modulus grout that will be compatible with the fairly flexible deck panels.