Innovative Methods for Evaluation of Precast Box-Beam Bridges

Full-depth precast and prestressed concrete slab panels offer an efficient alternative to traditional cast-in-place concrete bridge construction. Although utilizing the precast system makes the process of constructing much easier and faster, over time, damage at the longitudinal joints connecting the panels affects the bridge integrity and can reduce the load-carrying capacity of the structure. This study investigates the performance of a precast and prestressed box-beam bridge that has been in service for more than 50 years. A series of load tests were conducted on the bridge to evaluate the bridge's structural response. Moreover, a finite element model was developed to study the bridge behavior considering possible damages in the longitudinal deck joints. A comparison between load testing results and the finite element model showed that the longitudinal joints were significantly damaged, resulting in a reduction of the bridge load-carrying capacity. A novel bridge monitoring approach was also proposed for joint damage detection in these types of bridges.