Extend the life of concrete structures without demolition or disruption.
Concrete doesn’t corrode – but the steel inside it does. And when that steel starts to rust, it expands, putting pressure on the concrete from the inside out and leading to cracking, spalling, and eventually failure.
That’s where electrochemical repair systems come in. They don’t just patch the symptoms; they treat the cause.
These electrochemical systems offer a low-disruption, sustainable alternative to cathodic protection or rebuild, extending the life of ageing concrete structures without the need for extensive breakout or ongoing monitoring.
A better way to protect ageing concrete
At Contech, we now offer MCM GreenTech Shield: a surface-applied electrochemical system that restores the protective environment around steel reinforcement and removes the corrosive agents attacking it.
Using a methodology developed by Marine & Civil Maintenance (MCM), this award-winning technology includes two surface-applied systems that use a low-voltage current to either:
Realkalize the concrete
Restoring the alkaline conditions that prevent corrosion.
Electrochemical Realkalization (ER) increases the pH of carbonated concrete and restores the protective alkaline environment around steel reinforcement. By halting the carbonation process and reinstating steel passivity, ER helps to prevent corrosion before it starts, and extends asset life without permanent installation.
Extract chlorides
Pulling salt contaminants out of the concrete cover to stop corrosion at the source.
Electrochemical Chloride Extraction (ECE) removes harmful chlorides from within the concrete cover, targeting the root cause of reinforcement corrosion. This system helps to reverse the effects of salt exposure, reducing long-term maintenance needs while preserving the structure’s integrity.
Both treatments are temporary, non-invasive, and don’t require ongoing maintenance once complete. In many cases, a few months of treatment can deliver up to 25+ years of protection against corrosion.
How does electrochemical repair and protection work?
Steel needs high alkalinity to stay stable inside concrete. But over time, exposure to air and water (carbonation) or salt (chlorides) breaks that protection down.
Electrochemical systems:
- Use a controlled electrical current to drive ions through the concrete
- Either pushes chloride ions out, or pushes alkaline ions back in
- Restores the natural balance that protects the steel
- Avoids the need for traditional concrete breakout or rebuild
Less disruption. Greater durability. Better sustainability.
MCM GreenTech Shield offers a modern alternative to traditional concrete repair or cathodic protection systems, without the demolition, downtime, or ongoing maintenance. There’s no need for concrete breakout, chases, or core holes, and no requirement for permanent power or monitoring systems. The system can be applied precisely where it’s needed, keeping upfront costs down and avoiding unnecessary disruption to surrounding areas. It’s reusable, completely chemical-free, and leaves nothing embedded in the structure once the treatment is complete.
Fully compliant with NACE/AMPP SP0107-2021, it meets international standards for electrochemical treatment, and cuts concrete-related CO₂ emissions by up to 99% compared to rebuild options – offering a cleaner, more sustainable fix that’s easier on your asset and the environment.
This approach is ideal for concrete structures showing early signs of corrosion, especially in environments exposed to chlorides (like marine or roadside locations) or where carbonation has reduced the natural alkalinity of the concrete. It’s particularly valuable when a traditional repair would involve major demolition, or when you want to extend the life of an ageing structure without the cost and carbon footprint of rebuild.
Not sure if it’s the right fit?
We’ll help you figure it out.
At Contech, we believe practical innovation and engineering excellence go hand-in-hand. Our team of structural engineers will work with you to assess whether a MCM GreenTech Shield solution is the right fit for your concrete remediation needs, and help you plan a smarter, cleaner solution.
Let’s protect what you’ve built.
CONTECH HAS BRANCHES IN AUCKLAND, WELLINGTON AND CHRISTCHURCH.
If you would like some advice on a project or need a quote tell us a little about the project and the relevant expert will get back to you soon.