摘要: |
Minnesota Department of Transportation (MnDOT) is in the planning phases for its first glass fiber reinforced polymer (GFRP) reinforced bridge deck. Instead of using traditional steel rebar, the deck will be reinforced with GFRP rebar. The bridge deck is scheduled to be let in February 2016 with construction starting later in 2016. Successful implementation GFRP reinforced bridge decks would eliminate the steel corrosion problems that often shorten the life of the deck.
Although there is wide use of GFRP reinforcement in bridge decks in Canada, there have been relatively few GFRP reinforced bridge decks built in the United States (US). The Canadian decks were primarily designed using the empirical design method in the Canadian Highway Bridge Design Code. This method differs significantly from the design guidelines produced by American Association of State Highway and Transportation Officials (AASHTO) and American Concrete Institute (ACI) Committee 440 on FRP Reinforcement.
To maximize the knowledge and experience gained in constructing this bridge deck, a research project should be undertaken to investigate the performance of this bridge deck. Some of the key issues to be studied include cracking and crack control, deck stiffness, and FRP bar strains. Design of these decks using the US guidelines is almost always controlled by the crack control provisions, so monitoring cracking and bar stresses may allow less conservative designs in the future. The modulus of elasticity of GFRP bars is about one quart of that of steel bars, so deck deflection may also be of interest. |