Comparison between epoxy-coated steel and glass fiber reinforced polymer bars in a concrete highway bridge deck

The use of fiber reinforced polymer (FRP) bars as reinforcement in concrete highway bridges potentially provides a means that can extend the useful life of the bridges in selected cases. Resistance of glass fiber reinforced polymer (GFRP) rebars to corrosion associated with the use of de-icing salts on bridges makes these bars particularly attractive to the transportation industry. However, questions concerning the bars' relatively low modulus of elasticity, bond slip properties, and in situ corrosion resistance must be answered prior to widespread implementation in highway bridges. The Sierrita de la Cruz Creek Bridge near Amarillo, Texas provides a means of making a direct comparison between the performance of an epoxy coated steel (ECS) reinforced bridge deck and a fiber reinforced polymer (FRP) reinforced bridge deck. Short-term comparisons are presented in this thesis, and the long-term monitoring potential of the two bridge sections is also discussed. With the exception of a longitudinal crack that formed in the cast-in-place bay in the GFRP-reinforced span, this thesis found that the GFRP-reinforced sections perform almost identically to the steel-reinforced sections. The research performed for this thesis also determined that the FRP may be exposed to internal temperatures which may cause long-term deterioration of the FRP bars. The data collected in the live load tests set a benchmark for any future live load testing performed on the bridge. Long-term monitoring of the bridge will be required to assess the durability of the GFRP bars in the concrete bridge deck.