Rehabilitation of the L53 bridge in Carinthia, Austria

摘要

The L53 Bridge is part of the A10 Tauemautobahn highway in Austria and stretches over the Lieser canyon near Spittal an der Drau in Carinthia. This arch bridge, which was built in 1971, suffered from chloride-induced corrosion due to a failing drainage system and the intensive use of de-icing salts during long winters. After more than 25 years, a general overhaul of this bridge structure was required. Part of the rehabilitation concept included cathodic protection of approximately 2400m~2 of concrete surface. The government of Carinthia, which pioneered the use of cathodic protection (CP), issued the tender in summer 2000. Corrosion was already evident through rust spots on the surface and delamination of the concrete. There are ten bridges in Austria that have been cathodically protected using the conventional CP method of embedding titanium mesh into sprayed concrete. The L53 Bridge has been predominantly protected by the conductive coating, Emaco CP30. The cathodically protected areas include the arches, cross-beams, columns and cantilevers.