In reinforced concrete structures, once corrosion of the steel reinforcement sets in, the rate of deterioration accelerates and the cost of repair can rise significantly. In assets such as bridges, car parks, marine structures and industrial plants, ensuring the integrity of the reinforcement is vital for structural safety, service life and whole-life cost. Carbonation and chloride-induced corrosion can lead to reductions in structural capacity as well as falling object risks and other safety concerns. Straightforward concrete repair is often not successful in preventing further deterioration and whilst specialist coatings and corrosion inhibitors can be successful in lower risk environments, cathodic protection is the best solution for sites with high a corrosion risk posed by chloride ingress.
Want to know more about Cathodic Protection?
What is Cathodic Protection (CP)?
Cathodic protection reverses or halts the electrochemical corrosion process by making the steel reinforcement act as a cathode, thereby preventing it from oxidising. In practical terms, this means embedding anodes (sacrificial, two-stage or impressed current) within the concrete or its surface and passing a current from them to maintain the protective effect. Galvanic anodes provide this current by re-locating the corrosion reaction to the anode surface. Impressed Current Cathodic Protection (ICCP) uses a power-supply to drive a controllable current from an inert anode and two-stage anodes combine both techniques. The process effectively controls the “driving force” of corrosion, preserving and extending reinforcement integrity.
Cathodic Protection Products
When to apply cathodic protection
Consider CP when:
To mitigate ‘incipient anode effect’ when completing concrete repairs.
Where chloride concentrations are so high that other methods are precluded or insufficient.
Reinforcement corrosion is widespread, or the risk of significant corrosion is high.
Access to the structure is limited or costly, meaning that returns to re-apply other protective options must be avoided.
Long-term performance is required (e.g., infrastructure with 40+ year service life).
Surface treatments, inhibitors or coatings alone will not provide adequate risk mitigation.
Key benefits of our CP systems
Enables maintenance-free protection for long periods when correctly designed and installed (for example, Sika® FerroGard®-860 CP).
Minimises invasive works: Large-scale removal and replacement of concrete can be avoided.
Preserves the passivation layer on the steel reinforcement by controlling the corrosion mechanism rather than continuing a cycle of repairing visible damage.
Aligns with asset-management strategies for lifecycle cost reduction and risk mitigation.
Suitable for almost any reinforced concrete application: bridges, marine structures, car parks, water treatment, chimneys, swimming pools, paper mills, etc.
