There are, of course, many reinforced concrete structures worldwide, such as bridges and wharves, which are exposed to aggressive chloride environments – and that display evidence of steel corrosion far too soon in their service life. As you are no doubt aware, it’s a very short step between steel corrosion of a concrete structure, and advance deterioration of the concrete.
HOW ARE CATHODIC ANODES RELEVANT?
Sacrificial cathodic anodes have been more commonly associated with protection of metal structures and ships. The use of sacrificial anodes for corrosion prevention in reinforced concrete structures has increased in recent years due to several factors, including the ease of installation, and low maintenance requirements.
CAN HYDROGEL TREATMENTS BE USED ALONG WITH CATHODIC ANODES?
If you’re not familiar with the use of concrete hydrogel treatments for concrete remediation and protection, be free to read more here and here before proceeding!
Hydrogel treatments are frequently called on for remediation of early deterioration of concrete, and as such may be specified for bridges or marine structures where cathodic protection is in active use. The question then arises, will the hydrogel have any negative impact on the ongoing effectiveness of the anodes?
The question has been studied by at least two independent consultants and is backed up in practice by a number of cases in the field. The following are extracts from recent responses to the question under consideration:
“The Aquron will do its job by reducing moisture and salt migration in the concrete. I believe the residual chlorides that are localized to the [anode] would migrate to the [anode] for corrosion as opposed to the steel, effectively acting as another mechanism for corrosion control and enhanced durability.” – Jon Belkowitz, PhD., Director, Intelligent Concrete [Anode brand redacted]
“In effect the hydrogel has waterproofed the concrete, re-positioned the chlorides, and is preventing further chlorides and moisture entering. Meanwhile, any anode system is still operating as intended. It may mean the anodes are not being sacrificed as fast as if the hydrogel was not present. This is also positive for the longer-term durability of the galvanic anode system.” – Murray Gilbertson, BCE, MBA, Director, G-Group Consulting
Long story short, hydrogel treatment will not interfere with the operation of the anodes. However due to immobilising the reactivity of the elements within the concrete, the hydrogel reduces the rate at which the anodes are being sacrificed. This is definitely a win-win situation, and if you’re an engineer looking for belt-and-braces protection you might want to give this more detailed consideration.
Our technical support team is happy to discuss your specific infrastructure with you – get in touch!
Note – Markham does not offer cathodic protection as part of its Adding Life to Concrete range. This article is solely about compatibility between cathodic anodes and Aquron hydrogel treatments.
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