Durability of technical textiles embedded in mortar for cathodic corrosion protection

摘要

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 Carbon textiles embedded in mortar, which provide high mechanical properties and are also conductive, have already been studied. The results show, that Carbon textiles are suitable as an anode material for the CP. Deterioration of Carbon is likely to take place in CP systems using carbon as anode material. Therefor behavior of Carbon Textile by typical CP current densities of less than 20 mA/m2 should be considered.