Umsetzung des Kathodischen Korrosionsschutzes an den Spannbetonüberbauten der Schleusenbrücke Iffezheim

Realization of cathodic protection on the prestressed superstructures of the sluice bridge Iffezheim

After 30 years of use the reinforced steel of the superstructures of the sluice bridge Iffezheim showed remarkable reinforcement corrosion caused by the ingress of chlorides inside the hollow girders of the bridge. Static investigations have shown, that the damages due to corrosion could be compensated by relatively simple measures of mechanical strengthening if the corrosion process could be stopped.
Due to the small measurements of the hollow girders, conventional repair, which means removal and replacement of the chloride contaminated concrete, was impossible. In case of the two hollow girders at the upstream side, in which large areas were affected by reinforcement corrosion, the only applicable rehabilitation method was the use of cathodic protection (CP) to avoid further corrosion. After carrying out a test installation in a small area of one hollow girder (described in detail in [1]), the CP method became part of a general rehabilitation of the bridge in the years 2010 and 2011. After planning of the CP-System, which was done by Ingenieurbüro Raupach Bruns Wolff (RBW), the installation works were supervised by RBW and the Federal Waterways Engineering and Research Institute (BAW). In this article, that has to be seen as a continuation of [1], details of planning and realization of the CP-installation as well as monitoring results after one and a half year of operation are given.