Product Data Sheet Show all documents

Sika® FerroGard®-520 Patch

Discrete anode for corrosion mitigation of incipient anode adjacent to concrete repaired areas; containing 198 g zinc

Sika® FerroGard®-520 Patch is a zinc-based discrete sacrificial anode placed inside a repaired area in a reinforced concrete structure which is corroding as a result of chloride ingress and/or carbonation. Sika® FerroGard®-520 Patch anodes are placed along the perimeter of the repair area and fixed to the reinforcement prior to the application of a concrete repair system. The reinforcement outside the repaired area is at greatest corrosion risk owing to the passive condition of the reinforcement within the repaired area. Sika® FerroGard®-520 Patch anodes corrode preferentially to the surrounding reinforcement, offering protection against incipient corrosion damage. Standard repair mortars, bonding primers and reinforcement corrosion protection coatings can be used as Sika® FerroGard®-520 Patch is placed in the parent concrete and not within the repair mortar.

  • Anodes corrode preferentially to the surrounding reinforcement, protecting it from further corrosion damage
  • Protects against incipient anode effect outside of repaired area
  • No long-term maintenance costs
  • Strengthens passive film on reinforcement
  • No rapid dissolution of activating components
  • Quick installation—no additional concrete break out
  • Bonding primers for concrete and reinforcement corrosion protection coatings can be used
  • High resistivity repair mortars can be used
  • Performance can be monitored
  • Cost-effective corrosion control solution
Product Data Sheet Show all documents

Usage

Sika® FerroGard®-520 Patch is used for:
  • Controlling the incipient anode effect by electrically balancing the anodic and cathodic areas of reinforcement
  • Targeted treatment applied to concrete repaired areas to prevent incipient corrosion damage  
  • Reinforced concrete structures such as bridges, car parks, coastal structures, industrial structures and residential high rise
  • Coastal reinforced concrete structures both in and above the tidal zone
Please note:
  • The Product may only be used by experienced professionals.
  • Design of the galvanic protection system must be undertaken by a qualified, experienced corrosion design engineer.
  • Installation must be carried out in accordance with engineer's design and specification.

Advantages

  • Anodes corrode preferentially to the surrounding reinforcement, protecting it from further corrosion damage
  • Protects against incipient anode effect outside of repaired area
  • No long-term maintenance costs
  • Strengthens passive film on reinforcement
  • No rapid dissolution of activating components
  • Quick installation—no additional concrete break out
  • Bonding primers for concrete and reinforcement corrosion protection coatings can be used
  • High resistivity repair mortars can be used
  • Performance can be monitored
  • Cost-effective corrosion control solution

Packaging

25 anodes per box, vacuum packed in 5 separate pouches

Colour

Cylindrical zinc core covered in an activated coating, separate white spacers and an integral titanium connecting wire.

Product Details

Product Information

Chemical Base

Zinc compound

Shelf Life

5 years from date of production.

Storage Conditions

Product must be stored in original, unopened and undamaged packaging in dry conditions at temperatures between +5 °C and +30 °C. Always refer to packaging. Do not allow contact with oxidizing materials. Pouches must only be opened when product is required. Any part used pouches must be re-sealed.

Length

~115 mm

Diameter

18 mm

Zinc Weight

198 g
System information

System Structure

The installation mortar is Sika® FerroGard®-500 Crete for the following anodes:

Product

Length

Zinc content

Sika® FerroGard®-510 Patch

~42 mm

~65 g

Sika® FerroGard®-515 Patch

~77 mm

~120 g

Sika® FerroGard®-520 Patch

~115 mm

~198 g
Technical Information

Current Density

>0.2–2 mA/m² in corrosive environment

This value is dependent on local conditions, including chloride concentration, concrete properties, humidity and temperature.

Application

Application Information

Ambient Air Temperature

Minimum

+5 °C

Substrate Temperature

Minimum

+5 °C

Hole Dimension

Depth

~120 mm

Diameter

~25 mm
Application steps

APPLICATION

IMPORTANT

Strictly follow installation and maintenance procedures

Strictly follow installation and maintenance procedures as defined in Method Statements, application manuals and working instructions which must always be adjusted to the actual site conditions.

Concrete repairs must be undertaken in accordance to an acknowledged national standard such as EN 1504.

Reference must be made to the Sika Method Statement: Application of Discrete Galvanic Anode using Sika® FerroGard®-500s Patch. The following is a summary.

Preconditions

The design engineer has determined the spacings of the anodes based on steel density.

Any discontinuous reinforcement has been either electrically bonded to or electrically isolated from the system negative.

  1. Within the repair area where the concrete has been removed, place the Sika® FerroGard®-520 Patch anodes along the perimeter edges of the repair.
  2. Drill the holes with a diameter and depth according to the Hole dimensions in Application information. Remove the dust.
  3. Pre-wet the drilled holes with water for a minimum of 15 minutes.
  4. Remove any excess water from the bottom of the holes.
  5. Fill the holes with Sika® FerroGard®-500 Crete embedding mortar ensuring no air is entrapped.
  6. Insert the anodes into the embedding mortar and ensure the anode bodies are completely encapsulated.  

     7. Remove excess embedding mortar from around
         the top of the anode and integrated wire.
     8. Directly connect the integrated titanium wire from
         the anode to an adjacent cleaned area of reinforce-
         ment within the repair area by winding at least
         twice around the reinforcement and fixing the tail
         with the supplied plastic cable tie.
     9. Confirm electrical continuity of the anode conduct-
         ing wire and the reinforcement
    10. Fill and finish the patch repair area using a suitable
          Sika® repair mortar within 2 hours of inserting the
          Sika® FerroGard®-520 Patch anode. The patch
          repair material cover for the Sika® FerroGard®-520
          Patch unit must have a minimum thickness of 20
          mm.
    11. Alternatively, cap the hole within 2 hours with the
          Sika® repair mortar until the final reinstatement
          is undertaken. Ensure the anode is not disturbed.

The time to achieve passivity will be dependent on site conditions. Depolarisation of treated reinforcement will be slower in moist conditions.

The installed Sika® FerroGard®-520 Patch anode can be monitored using half-cell potential surveys, current outputs and reinforcement corrosion rate measurements.

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