Thermal Spray Coatings for the Corrosion Protection of Steel in Concrete
Our thermal spray solutions help protect reinforcing steel within concrete structures from corrosion.
Long Term Corrosion Protection for Reinforced Concrete
Corrosion of reinforcing steel is one of the most common causes of deterioration in reinforced concrete structures. Over time, chlorides, moisture and other contaminants can penetrate the concrete and reach the embedded steel reinforcement.
Once corrosion begins, the steel expands as rust forms. This places pressure on the surrounding concrete, which can lead to cracking, delamination and eventually sections of concrete breaking away.
Thermal spray technology provides a proven method of controlling this corrosion without needing to remove and replace large areas of otherwise serviceable concrete.
A metallic coating, typically zinc, is thermally sprayed onto the prepared concrete surface. The coating can then form part of an Impressed Current Cathodic Protection (ICCP) or Galvanic Cathodic Protection system designed to protect the reinforcing steel within the concrete.
Rather than simply creating a barrier on the outside of the structure, cathodic protection addresses the electrochemical process responsible for corrosion.
The result is a practical solution for extending the service life of reinforced concrete structures, particularly where replacing the structure would be disruptive, difficult or expensive.
Zinc Thermal Spray
Zinc is commonly used as a thermally sprayed anode for the cathodic protection of steel reinforcement within concrete.
The zinc coating is applied directly to a suitably prepared concrete surface, creating a conductive metallic layer that can be used to deliver protection to the embedded reinforcement.
Impressed Current Cathodic Protection
With an impressed current system, the thermally sprayed zinc coating acts as an anode. A controlled electrical current is supplied to the system to reduce corrosion activity at the reinforcing steel.
This approach can be particularly useful for major infrastructure where long term corrosion management is required.
Galvanic Cathodic Protection
Thermally sprayed zinc can also be used as a sacrificial anode. In this type of system, the zinc corrodes preferentially, helping protect the reinforcing steel without the need for an externally supplied electrical current.
Metallisation can help you identify suitable thermal spray equipment and processes based on the structure, project requirements and cathodic protection system being used.
What Concrete Structures Can Be Protected?
Thermal sprayed cathodic protection is particularly valuable for reinforced concrete assets where corrosion has the potential to cause significant structural, financial or operational problems.
This includes:
- Bridges, decks and supporting structures
- Car parks and parking structures
- Marine structures and jetties
- Coastal infrastructure
- Concrete columns, beams and supports
- Tunnels and transport infrastructure
- Industrial concrete structures
- Piers and harbour structures
- Buildings with reinforced concrete elements
- Other ageing reinforced concrete infrastructure
For asset owners and infrastructure operators, thermal sprayed cathodic protection can provide an alternative to repeated patch repairs by tackling the corrosion process affecting the embedded steel.
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Got a Project in Mind?
Dealing with corrosion in a reinforced concrete structure?
Metallisation can work directly with contractors, asset owners and project teams to support major cathodic protection projects where thermal sprayed coatings are required.ย
From bridges and marine structures to car parks and major infrastructure, our experienced team can provide specialist knowledge, equipment and practical support throughout the project.
We can help establish the right thermal spray approach for the structure and work alongside your team through planning, preparation and application.
