Kathodischer Korrosionsschutz für Parkbauten mit carbontextilienbewehrtem Spezialmörtel

Cathodic protection for parking structures with carbon textile reinforced special mortar

Cathodic protection (CP) is a widely used method to protect steel reinforcements against corrosion. In the course of the last half century, it has been established as a proven system for repairing corrosion-affected reinforced concrete structures, which have mainly been damaged by chloride-induced corrosion. The impressed current anode system for the protection of steel in concrete is latest state of technology. The CP anodes can be embedded in mortar, as coating or distinct anode on the repair structure surface and exposed to external current. In this way, the potential of carbon steel is shifted in cathodic direction and the anodic dissolution of carbon steel is suppressed. The current densities on the surface of the reinforcement play a key role in the shifting of the potential in cathodic direction. Nowadays, Mixed Metal Oxide coated Titanium (MMO) is used as an anode material for CP due to its high durability under anodic polarization. Also other materials such as carbon fibers are being studied.
Carbon textiles in combination with mortar, which provide high mechanical properties and are also conductive, have not been studied systematically so far. In this paper investigations are described, which have been carried out in order to evaluate the capabilities of different carbon-textile anodes and different mortar mixtures for the cathodic protection of steel in concrete. In order to evaluate the polarization behavior of carbon-textile in mortar, galvanostatic experiments were performed. Based on these experiments, current density-potential-curves were derived.