Corrosion Protection Solutions for New and Deteriorating Structures
Zinc Layer Anode (ZLA)
What is Zinc Layer Anode Used For?
Zinc Layer Anode is a self-contained, corrosion protection and durability enhancement system, designed to be surface mounted onto the surface of atmospherically exposed reinforced concrete structures, to provide long-term protection from corrosion.
Zinc Layer Anode provides multi-staged corrosion protection, which effectively stops and prevents concrete deterioration resulting from reinforcement corrosion.
When connected to the embedded reinforcement and in contact with the concrete surface, the zinc anode corrodes and provides galvanic cathodic protection to the embedded reinforcement.
This product provides active corrosion control by cathodic protection, meeting the requirements of BS EN 1504 Part 9 Principle 10 (cathodic protection by applying an electrochemical potential) and provides benefits in line with Principal 7 (preserving or restoring passivity) of the embedded reinforcement.
This product offers additional corrosion protection to the structure, by providing passive protection (barrier control) providing benefits in line with BS EN 1504 Part 9 Principle 8 (increasing resistivity by limiting moisture content to the surfaces) and Principal 9 (cathodic control by limiting oxygen content at the cathode by surface coatings).
Where installed with monitoring facilities, this product can be monitored and evaluated against the cathodic protection criteria listed within BS EN ISO 12696.
Zinc Layer Anode Product Description
Zinc Layer Anode consists of a high purity zinc foil, complete with an ion-conductive, auto moistening, humectant/activator/adhesive layer.
Two foil thicknesses are available, depending on exposure and design life requirements:
ZLA250 is 0.25mm thick, containing 1750g/m2 of pure zinc.
ZLA450 is 0.45mm thick, containing 3150g/m2 of pure zinc.
The zinc foil is naturally impermeable to gasses/moisture and this barrier effect may be enhanced by overcoating the installed anode with a suitable coating material to improve concrete protection by restricting access of gasses (oxygen and carbon dioxide) and chloride contaminated water.
Where Can Zinc Layer Anode Be Used?
Zinc Layer Anode is designed for protecting atmospherically exposed reinforced concrete structures, suffering from chloride or carbonation-induced reinforcement corrosion and resulting concrete deterioration.
This product provides an alternative to impressed current cathodic protection, galvanic/hybrid, galvanic discrete embedded anodes, or localized embedded galvanic anodes for patch repair enhancement. Offering an alternative to concrete overlays and drilled-in anodes, which limits the structural impact associated with increased dead load or large and frequent drilled holes.
Suitable for use locally, to provide patch repair enhancement and prevent incipient anode formation, for concrete patch repairs in chloride contaminated concrete, or when incorporating old chloride contaminated structures into a new build.
Suitable for use globally across repaired or undamaged, contaminated structures, to provide corrosion protection, durability enhancement, and deterioration prevention, when installed before the onset of corrosion-related deterioration or following structural remediation.
Suitable for use as a preventative measure for corrosion prevention, durability enhancement, or deterioration prevention, when installed in the early life of a structure, to limit contamination and prevent corrosion-related deterioration.
Suitable for use on high-risk elements like pre-stressed and post-tensioned structures, as it will not exceed the potential limits for susceptible high strength steel listed within BS EN ISO 12696, and requires no further potential limitation or control during operation.
Technical Benefits of Zinc Layer Anode
Zinc Layer Anode can be installed as a stand-alone system, connected directly to the reinforcement, or provided with embedded monitoring facilities to meet the monitoring requirements listed within BS EN ISO 12696 - Cathodic Protection of Steel in Concrete.
Offers more uniform protection across the structure, when compared with other “point-sourced” embedded galvanic, galvanic/hybrid protection systems or systems based on barrier protection alone.
The large surface area of the anode provides a low anode to cathode circuit resistance, ensuring the highest cathodic protection current flow under the natural zinc to steel, driving voltage.
The humectant/activator layer enables high dissolution and mobility of the zinc corrosion product, preventing loss of performance, typically found with embedded galvanic anode systems.
The protection provided by a Zinc Layer Anode system includes:
Stopping corrosion of the reinforcement by delivering cathodic protection.
Promotes passive film healing at corrosion sites on the embedded reinforcement by producing hydroxide.
Heals and maintains passive film stability on the reinforcement.
Reduces environment exposure and the rate of aggressive chemical or gas penetration into the concrete surfaces.
Reduces the rate of oxidation of existing corrosion products which may result in concrete spalling and cracking due to expansion of corrosion products.
Increases concrete resistivity, by isolating the concrete from free water and moisture in the surrounding environment.
Consumes water and oxygen within the concrete through electrochemical reactions.,
The system is easy to install, repair, replace, requires no additional AC or DC power for operation, does not interfere with the concrete repair activities, and is relatively maintenance-free.
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