Bridge construction; Bridge decks; Bridge members; Cast in place concrete; Girder bridges; Precast concrete; Prefabricated bridges; Skew bridges; Ultra high performance concrete
In spite of the benefits of deck girder bridge systems for prefabricated bridge elements and systems (PBES)/accelerated bridge construction (ABC), their usage has been limited to relatively short span and low traffic bridges because of their long term performance of their connections, and difficulties in accommodating super-elevation transitions on bridge decks, pier skews, differential camber, shipping, and handling stability. Skewed girders cause bridge deck profile problems because the cambers in adjacent girders do not align. The diaphragms are then difficult to connect and/or quite big forces are induced if they are used to bring the girders into line. In order to optimize the decked bulb tee design, the longitudinal joint between flanges must have sufficient stiffness such that the same live load distribution factor can be used as for I-girder bridges with cast-in-place decks. There are a myriad of potential variables for the joint including width, bar size, bar spacing, bar detailing (straight, bent, or headed), and black or epoxy bars. The variable flange thickness (thicker near the web) will help the ultra-high performance concrete (UHPC) joint, by attracting much of the total static moment due to a wheel load toward the negative moment region at the web and away from the mid-span region where the UHPC joint is located. Research is needed to investigate design, fabrication, transportation, and construction of precast deck girder bridges. Other factors such as connections between adjacent units, longitudinal joints, live load distribution, continuity for live load, skew effects, and suitability of lightweight aggregates concrete need to be addressed by this research. The research should focus on optimizing the joint width. This project should address the constructability aspects and suggest methods of leveling the girders, how to determine the size of the leveling equipment needed, and means of holding the girders in the level position to allow the leveling equipment to be removed before the flange connections are fully cured. The objective of this research is to implement design, fabrication, transportation, and construction algorithms and to develop suitable details for the connection for prefabricated deck girders with UHPC for PBES/ABC.