Investigations on the incipient anode phenomenon following patch repairs for reinforced concrete structures

Patch repairs are a common repair technique for corrosion-damaged reinforced concrete structures. However, this repair method is sometimes associated with limited durability and in many cases further corrosion damage has been noted around the repaired patches, a phenomenon known as the “incipient anode” effect. The aim of this work was to examine the onsite performance of patch repairs from a full-scale reinforced concrete structure in order to identify the factors affecting the formation of incipient anodes. The results indicate that even after 250 days following application of the repair, the steel within several of the repairs investigated retained more negative potentials than the surrounding steel in the parent concrete, indicating that the formation of incipient anodes is not necessarily attributed to an electrochemical imbalance.