1. What is Corrosion Control?
Corrosion control is preventing or slowing corrosion. CSI control corrosion by applying sacrificial anodes to steel reinforcement to prevent/slow rust. A rusting rebar has a higher volume than its non-oxidised counterpart and, when encased in concrete, causes it to crack. Sacrificial anodes slow this process by reducing the iron to ensure rust does not develop. The anodes are inserted and grouted into predrilled holes, and wired to the reinforcement.
2. When would you use Corrosion Control?
You may use this service whenever you have metal particularly susceptible to corrosion, e.g. rebar in a marine environment (chloride ions in salt exacerbate corrosion)
3. What are the Benefits of Corrosion Control?
- Prevents or slows rebar corrosion
- Cheap to maintain once installed
- Long service life
While CSI curb the corrosion process by installing zinc anodes, another method, Impressed Current Cathodic protection (ICCP) is used to prevent corrosion occurring in the first place. ICCP forces a direct current from an external power supply to flow from an anode through the concrete to the reinforcing steel. A current of sufficient magnitude and direction is necessary to overcome the natural flow of electrons resulting from the corrosion process.
The direct current is supplied from an external source, most often an AC/DC (transformer) rectifier.
Standard – ASTM Standard STP 1137: Corrosion Forms and Control For Infrastructure