First Tunnel Refurbishment with Cathodic Corrosion
Protection in Germany
Classical renovation methods did not turn out to be practical for redeveloping the Rendsburg Canal Tunnel in Germany. But cathodic corrosion protection (CCP) emerged as a long-term solution. This internationally tried-and-tested technology could well feature big in Germany in future.
After the Hamburg Elbe Tunnel dating from 1912, the two-tube 640 m long Rendsburg Canal Tunnel, which opened in 1961, was the second underwater tunnel built in Germany for road traffic. Now it is the first tunnel in this country to be equipped with cathodic corrosion protection. Particularly in the winter months, the thawing salt carried in by up to 50 000 vehicles per day via the drag water resulted in high chloride exposure on the tunnel walls and carriageway. Conventional redevelopment measures undertaken on the ferro-concrete reinforcement and reworking the concrete failed to provide a...