A new arrangement of galvanic anodes for the repair of reinforced concrete structures

• A new arrangement for galvanic anodes in the repair of reinforced concrete.
• Galvanic anodes installed in the parent concrete surrounding the patch repair.
• Galvanic anodes performance not affected by the properties of repair material.
• Close interval potential mapping is advantageous for performance monitoring.
• An alternative criterion, to that of 100 mV depolarisation, is proposed.

Discrete galvanic anodes are traditionally embedded in the patch repairs of steel reinforced concrete (RC) structures to offer corrosion prevention. This research investigated the performance of galvanic anodes installed in the parent concrete surrounding the patch repair, in order to explore the performance of such a new arrangement and identify its potential for wide-scale application.This arrangement was tested on a RC multi-storey car park and a RC bridge, both suffering from chloride-induced corrosion of the reinforcement. The performance of the anodes was assessed using close-interval potential mapping for 215 days after installation. The results indicate that the anodes polarised the steel at a significant distance away from the patch repair interface, up to 600 mm in some cases. It illustrates that such an arrangement may be advantageous when repairing RC structures as the corrosion prevention can be targeted at the steel in the surrounding parent concrete, which is traditionally considered to be at higher risk due to incipient anode development.