Cathodic protection is a corrosion control system used to prevent steel reinforcement within concrete from rusting by altering the electrochemical process that causes corrosion.
Explanation
Reinforcement corrosion occurs when carbonation or chloride contamination breaks down concrete’s natural protection. Cathodic protection works by supplying a small electrical current or using sacrificial anodes to stop the corrosion reaction.
There are two main types:
- Galvanic (sacrificial) systems
- Impressed current systems
These systems are commonly specified for structures exposed to harsh conditions, such as:
- Car parks
- Bridges
- Marine environments
- Coastal buildings
Cathodic protection is often used where widespread chloride contamination makes traditional patch repairs insufficient.
Why It Matters
Without corrosion control, deterioration will continue even after local repairs.
Cathodic protection:
- Extends structural lifespan
- Reduces future maintenance costs
- Protects repaired and unrepaired areas
- Provides long-term corrosion mitigation
It is typically specified for large or high-value reinforced concrete assets across the UK.