Corrosion Testing within Concrete Structures.
Concrete which has been damaged by water penetration can also hide other serious structural damage. Corrosion within the rebar or mesh can dramatically reduce the strength of the concrete and make it unsuitable for its intended purpose.
Previously, detection of corrosion within concrete could only be detected by drilling or coring holes into the structure. This method provides only a limited view on the extent of the corrosion within, as well as further damaging the structural integrity of the concrete.
CMD can provide a non-destructive means of gauging corrosion potential within concrete, eliminating the need for coring or drilling.
Corrosion of steel in concrete is an electrochemical process, using corrosion analysing instruments to highlight corrosion activity can identify areas of potential concern before structural failure occurs.
Corrosion Testing Demonstration: View Video
How does this system work ???
A potential field is measured on the concrete surface by the use of a reference electrode, known as a half cell, and a high-impendance voltmeter.
Exposing a piece of rebar or mesh for the high-impendance voltmeter to connect to, the surface requiring testing is then wet down to reduce the fluctuation of the measured values. The reference electrode is then placed on the surface, the measured values of the half-cell potential are then recorded at regular intervals.
The data collected is then transferred onto a windows based software programme. The programme then generates a potential map of the data collected, allowing for an efficient means of interpretation of the half-cell potentials of the investigated surface area.
What is a Half-cell ???
A half-cell is a structure that contains a conductive electrode and a surrounding conductive electrolyte.
What are its applications ???
- location of areas containing active rebar corrosion.
- Measurement of electrical resistivity of reinforced concrete structures.
