Evaluation of Cracks in a Spliced, Prestressed Concrete I-Girder Bridge

The purpose of the investigation reported in this paper was to identify the main causes of cracking that occurred in the Cross Florida Barge Canal Bridge, a three-span, continuous, spliced I-girder bridge that comprises spans of 77.7–86.9–77.7 m (255–285–225 ft) located in Citrus County, Florida. This paper briefly describes the bridge and the cracking. It then presents analytical models. Analytical results showed that the maximum vertical tensile force within a girder end zone from longitudinal prestressing strands was nearly 8% of the total prestressing force. The force was significantly higher than that prescribed by AASHTO specifications to determine the quantity of vertical reinforcement required at the ends of pretensioned members. Finally, the paper discusses some recommendations for end zone detailing. The results could help bridge designers provide better bridge detailing and further mitigate cracking in prestressed, spliced I-girders.