Bridge Isarring

Task

The building authority of the city of Munich commissioned us to develop a repair concept after a percise condition survey.
Furthermore we were instructed to determine the repair locations and then evaluate and repair the exposed tendons next to the deformed hollow bodies.

Procedure

In addition to a visual assessment of the damage to determine the status of the bridge, investigations into the chloride content as well as concrete cover and potential field measurements of surface openings were conducted.

Furthermore, hollow locations were detected during the construction test. In the hollow locations there were up to six free tendons, the sheaths were  corroded through in places and directly on the sheaths adjacent to the tension wires extensive corrosion was found. However the inject status of the tendons was good. The wooden framework of the hollow body showed defects, which led to the damage of the construction.

The evaluation of these damaged points, the status of each exposed tendon was determined and appraised based on the remaining lifting capacity and the durability. Moreover the additional weight from the partially concrete-covered hollow body was determined. Based on these results, the mathematical verification for the superstructure could be conducted.

To prevent further corrosion and preserve the durability of the uncorroded bracing wires, a repair concept  was developed.

With additional measurements the area in need of repair was determined. The repair of the exposed tendons was monitored throughout the whole repair process.