EXPERIMENTAL STUDY OF THE BEHAVIOR OF FIBER REINFORCED POLYMER DECK SYSTEM

The deterioration of the transportation infrastructures in the United States is proceeding at an alarming rate. Therefore, it becomes increasingly urgent to determine the feasibility of utilizing high performance composite materials for the fabrication of new structures as well as for the retrofitting of existing ones. It was estimated that almost 30 percent of 600,000 highway bridges in the US are either structurally deficient or functionally obsolete and repair costs are estimated to start at $90 billion [Dunker, KF and Rabbat, BG, 1993]. In 1997, Salim et al. reported that 42 percent of the nation's bridges are considered deficient.Fiber Reinforced Polymer (FRP) bridge decking holds out great promise for partially ameliorating this unsatisfactory condition. However, to be properly used in modern bridge decking application, FRP decks must be made to act compositely with underlying stringers (this work focuses on steel stringers). To behave compositely, a sufficiently robust shear transfer interface at the FRP to steel transition zone is required. While some efforts to achieve such interfacial shear transfer have been undertaken current understanding is weak and existing theories inadequate. The current research aims to contribute to our evolving understanding of this complex and important interface.The research reported herein find that FRP deck and the underlying steel beam on both specimens tested as part of this work are interacting in a partially composite way at large load; as evidence by the discontinuity in strain at the FRP-to-steel interface. This result means that there was observed to be significant slip between FRP deck and underlying steel beam. It is also noted that at service load (e.g. 0-30 kips), even though the strain variations are relatively small, the FRP deck and steel beam are not acting in a fully composite fashion. It appears from the results presented herein that effective width approaching 75% of beam spacing (the overall width of the FRP deck)