Assessment of Bridge Decks with Glass Fiber-Reinforced Polymer (GFRP) Reinforcement

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Date Created
2023-03
Report Number
2023-13
Description
In 2018, the Minnesota Department of Transportation (MnDOT) constructed a pair of side-by-side bridges on TH 169 over Elm Creek, with glass fiber-reinforced polymer (GFRP) reinforcement used in one deck and conventional epoxy-coated steel reinforcement used in the other. To understand the behavior of GFRP reinforcement and compare the performance and durability of the GFRP- and steel-reinforced decks, the following efforts were undertaken: (1) collect structural behavior information and response characteristics of the two bridge decks under service loads; (2) examine the short- and long-term performance characteristics of the two bridge decks; and (3) assess the advantages of using non-conventional, corrosion-resistant deck reinforcement. From the outcome of this four-year monitoring program, both bridge decks behaved similar to each other and as expected. The GFRP-reinforced deck showed no unusual behavior or sign of deterioration compared to the steel-reinforced deck. Although similar patterns of surface and full-depth cracks were observed in both decks, the structural integrity of both bridges was found to be consistent with design specifications. The short- and long-term comparison of the decks indicated that the use of GFRP bars can be a promising alternative in bridge deck reinforcement.

Field Investigation of Bridge Deck Reinforced with Glass Fiber Reinforced Polymer (GFRP) Rebar

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Date Created
2020
Report Number
2020-05
Description
The Minnesota Department of Transportation (MnDOT) constructed its first glass fiber polymer (GFRP) reinforced bridge deck on MN 42 over Dry Creek just north of Elgin; Minnesota. Successful implementation of the GFRP reinforced bridge decks would eliminate the steel corrosion problems that often shorten the life of the deck. Although there has been wide use of GFRP reinforcement in bridge decks in some parts of Canada; there have been relatively few GFRP reinforced bridge decks built in the United States. The Canadian decks were primarily designed using the empirical design method in the Canadian Highway Bridge Design Code. This method differs significantly from thee design guidelines produced by AASHTO and ACI Committee 440 on fiber-reinforced polymer (FRP) reinforcement. To maximize the knowledge and experience gained in constructing this type of bridge decks; this research project investigates the performance of a case-study bridge deck focusing on key issues such as cracking; deck stiffness; load distribution factors; and GFRP rebar strains. The main goals of this project are: • Collect behavior information and response characteristics of the bridge deck under service loads ·Identify the load distribution characteristics; especially for the bridge girders supporting the deck • Examine the short- and long-term durability of the bridge deck in terms of formation and propagation of cracks • Assess the impact of using non-conventional; corrosion-resistant deck reinforcement on maintenance needs and life-cycle cost with a specific interest in including service-life design philosophies. The outcome of this project will directly contribute to the development of guidance and details for the construction of corrosion-resistant bridges with service lives beyond 100 years.