EVALUATION OF PREFABRICATED FRP STRUCTURAL FORMWORK BRIDGE DECK SYSTEMS

摘要

This paper will discuss the investigation of a hybrid fiber reinforced polymer (FRP)-concrete bridge system, where prefabricated composite panels act as both the formwork and reinforcement for the deck of a box girder bridge. Large scale two cell box girder specimens utilizing FRP stay-in-place structural formwork have been designed and tested using both quasi-static and cyclic loading. The design of this test system allows for a direct performance and integrity comparison between the prefabricated FRP structural formwork bridge deck system and a traditional steel reinforced concrete system. The first test specimen contained connection detailing representative of new bridge construction and was loaded monotonically until failure, which occurred at loading in excess of nine times AASHTO factored service load. An epoxy injection technique was implemented using "field friendly" repair methods in order to reinstate proper load transfer between the concrete and the composite panels. The repaired specimen exhibited excellent performance characteristics with a similar ultimate capacity to the original test. The second test contained connection detailing that more closely modeled field construction conditions and was tested with both monotonic as well as cyclic loading. The composite system exhibited comparable performance to the reinforced concrete system under quasi-static loading, with slightly higher center deflections. Under cyclic loading, the composite exhibited superior integrity as compared to its reinforced concrete counterpart in terms of deflection response, stiffness, and residual deformations. The maximum strains in the composite were well below the maximum allowable values, and the overall behavior of composite system showed a stable response with significant reserve capacity within the FRP panels.