Concrete Corrosion Investigations
Corrosion monitoring of reinforced concrete structures can be quite challenging. It is hard to detect corrosion at the early stages; On the other hand, it is almost too late when we can see the corrosion signs on the surface. Detecting corrosion in a concrete structure requires appropriate knowledge, proper inspection tools and experience.
One of the leading causes of deterioration of a concrete structure is corrosion of the steel reinforcement. This can include concrete deficiencies in depth of cover, compaction, presence of chlorides, rusting resulting in spalling (i.e. concrete cancer) or cracking of overlying concrete.
Concrete corrosion investigations are performed when you need to know the condition of the reinforcement and its susceptibility to corrosion. Concrete assessment is a critical step in determining the condition of the concrete itself, and, the condition of the embedded rebar.
Embedded steel (rebar) in good quality concrete remains corrosion free (passive) due to the highly alkaline concrete that surrounds it. As concrete is porous, the penetration of aggressive ions, such as chlorides (from saltwater) in sufficient concentration, break down the passive conditions, and rebar corrosion occurs.
In many cases, unnecessary, and at times, costly inspections and tests are undertaken that do not provide asset owners the relevant information they require. Having the correct assessment approach and results will greatly assist asset owners and managers in making the right decisions to extend the useful life of concrete structures.
At CCE we offer the following services for concrete structures including bridges, wharves, reservoirs and buildings:
- Visual inspections and drummy (delamination) testing
- Rebar layout and depth (covermeter) testing
- Chloride and carbonation testing to confirm penetration depth and concentration
- Resistivity testing to estimate corrosion rates
- Rebar potential mapping to estimate the likelihood that corrosion is occurring
- Investigation reports and recommendations
- Concrete repair and cathodic protection specifications, including trials