Cathodic protection reduces the corrosion rate by cathodic polarization of the reinforcing steel in concrete. The rationale behind cathodic protection is to prevent the reinforcing steel from giving up electrons so that corrosion can be mitigated. This is achieved by supplying the electrons from another source.
Sacrificial Systems
Sacrificial anodes, also called a galvanic anodes, corrode preferentially producing electrons. Typical anodes are zinc, aluminum, magnesium and their alloys, which are more active than iron to protect reinforcing steel. Unlike impressed current systems, sacrificial systems do not require a power supply or monitoring.
LifeJacket® Cathodic Protection System
The LifeJacket® galvanic protection system provides a simple and cost-effective solution for steel and steel reinforced concrete damage due to rebar corrosion on bridges and other saltwater structures.
Impressed Current Systems
In impressed current cathodic protection systems, a small direct current is passed from a permanent anode to the reinforcing steel. An external power supply is connected between the anode and the steel with the appropriate polarity and voltage to prevent the reinforcing steel from giving up electrons. These systems repel chloride ions away from the reinforcing steel towards the installed anode. These systems provide flexibility since the current or output can be easily adjusted.