Electrochemical Treatment of Concrete Corrosion

What causes corrosion in concrete?

One of the primary mechanisms for concrete degradation is corrosion.  Severe corrosion occurs when concrete is exposed to aggressive salts such as de-icing chemicals that are used to keep the streets and bridges safe for the traveling public.  Corrosion on buildings can also be caused by carbonation, a natural aging process where the alkalinity of the concrete is lost.

When rust forms on steel rebar inside concrete, it expands, causing cracking from the inside out. This leads to high maintenance costs and can also pose a significant threat to structural integrity.  Corrosion is an electrochemical process and thus it can be also mitigated with electrochemical techniques.

What is an electrochemical treatment for concrete corrosion?

Electrochemical treatments for concrete corrosion consist of a short term application of electrical current to the reinforcing steel that passivates corrosion.  Electrochemical chloride extraction (ECE) reduces the chloride levels around the steel.  Realkalization reverses the effects of carbonation by creating an alkaline buffer around the steel.

What is the benefit of ECE or Realkalization?

Concrete preservation is vastly better than demolition and rebuilding. As infrastructure quality comes under greater scrutiny, decisions about cost and safety are increasingly important. Electrochemical treatments provide long-term corrosion control by treating the problem at its source thus economically increasing safety and extending the life of the structure.