Experiments and Computations on Steel Bridge Corroded Beam Ends

According to recent estimates the number of deficient bridges in the USA is more than 50,000 and the rehabilitation of these structures is considered an enormous task. A common cause of deterioration of steel bridges in the Northern part of the country is the leaking water which develops after the use of de-icing mixtures on the bridges. The corrosion appears almost always at the ends of steel girders above the bearing leading to a reduction of strength. There have been several recorded cases where the phenomenon is extensive and the bridge has to be closed for safety reasons. This research focuses on unstiffened deteriorated steel girder bridges and aims to develop a new procedure to accurately evaluate their remaining strength. First, two loading tests are conducted to investigate the effect of thickness reduction on girders' capacity. The tested girders were removed from an in-service bridge, the need for artificial corrosion was precluded. Second, the experimentally obtained capacities are used to evaluate the current MassDOT procedures for beams with deteriorated ends. Finally, analytical procedure is developed to determine the impact of corrosion on the beams' capacity. The whole girder along with the bearing is simulated, and the model is calibrated using the experimental data. New procedures are expected to be based on this study, which could be incorporated in Bridge Manuals across the country.

View content