Selecting the appropriate level of corrosion protection is based on many factors such as the level of chloride contamination and carbonation, amount of concrete damage, location of corrosion activity (localized or widespread), the cost and design life of the corrosion protection system, and the expected service life of the structure.

Corrosion Prevention

Corrosion prevention is used to prevent corrosion activity from initiating in contaminated concrete. In concrete repair projects, the removal and replacement of damaged concrete if completed in accordance with industry guidelines (ICRI Guideline No. 03730) will addresses the areas with the highest levels of corrosion. However, new corrosion sites are likely to form in the surrounding contaminated concrete which was passive before the repairs. To mitigate new corrosion activity from occurring around concrete repairs or at other interfaces between new and old concrete such as bridge widening, joint repairs and slab replacements, a simple localized corrosion prevention strategy utilizing with Vector Galvashield® XP or Vector Galvashield® XP+ embedded galvanic anodes, can extend the life of concrete repairs.

Corrosion Control

Corrosion control systems are utilized where corrosion has initiated but corrosion has not yet progressed to the point of causing concrete damage. The use of corrosion control systems will either stop on-going corrosion activity or provide a significant reduction in the corrosion rate and an increased service life of the rehabilitated structure. In many cases, this level of protection can be provided with low incremental cost as the protection can be targeted at specific areas of contamination or corrosion activity. Vector Galvashield® XP+ anodes can be used in corrosion control or corrosion prevention applications. Vector Galvashield® CC anodes are used to provide targeted galvanic corrosion control to columns, beams, decks, post-tensioned anchorages and other structures where on-going corrosion activity threats the service life of the structure.

Corrosion Passivation

Corrosion Passivation is provided by electrochemical treatments which are aimed at directly addressing the cause of the corrosion activity. Norcure® Chloride Extraction is used to address chloride contaminated structures such as bridges and parking garages. Norcure® Re-alkalization is commonly used on carbonated building facades. These systems are installed onto the structure, operated for a short duration, then dismantled and removed leaving the structure in a passive condition. Electrochemical treatments provide many of the long-term corrosion mitigation benefits of cathodic protection systems but without the need for maintenance and monitoring.

For more information regarding corrosion management, please contact Vector Corrosion Technologies.

Cathodic Protection

Cathodic protection provides the highest level of protection and is intended to stop on-going corrosion activity. Cathodic protection should be selected when the highest level of protection is necessary and the cost economically justified. Cathodic protection systems are grouped into two general categories: impressed current (ICCP) and galvanic.

Impressed current systems such as those that use Vector® Ebonex® discrete anodes and Vector® Vectrode™ catalyzed titanium anodes utilize an outside power source. For long-term performance, these systems should be monitored and maintained. Ebonex anodes are ideal to protect heavily reinforced concrete, thick structural sections such as columns or beams, or steel framed masonry buildings while Vectrode anodes are placed into slots cut into the concrete surface or underneath a concrete overlay.

Galvanic systems are self-powered and require less monitoring and maintenance. Vector® Galvanode™ Jackets are used to protect marine pilings and other structures. Vector® Galvashield® MA is a surface mounted galvanic cathodic protection system that utilizes zinc mesh technology. With Vector® Galvanode™ ASZ+, zinc is metalized directly onto the concrete surface and treated with a chemical humectant/activator for increased performance. Galvanic anodes can also be used in concrete overlays, concrete jacketing and other concrete repair applications to provide long lasting galvanic protection.

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