BEHAVIOR OF ULTRA-HIGH PERFORMANCE CONCRETE CONNECTIONS BETWEEN PRECAST BRIDGE DECK ELEMENTS

The Federal Highway Administration’s ongoing research program into the use of Ultra-High Performance Concrete (UHPC) in highway bridges has recently begun focusing on deck-level connections between modular precast components. In conjunction with the New York State DOT, researchers at the Turner-Fairbank Highway Research Center are investigating whether the exceptional durability, high strengths, and superior bonding characteristics of UHPC led themselves to the development of a new generation of connection details applicable to modular bridge components. A physical testing program has been initiated in which subassemblages of full-scale precast bridge deck panels are connected via UHPC closure pours then cycled under repeated truck wheel loadings. The test program has six specimens, with variables including joint orientation, slab thickness, reinforcement configuration, and reinforcement type. None of the specimens include any pre- or posttensioning. Test results to date, along with two NYSDOT bridges constructed in 2009, demonstrate the potential viability of using UHPC as a closure pour material.