Strictly follow installation procedures as defined in method statements, application manuals and working instructions which must always be adjusted to the actual site conditions.
Reference must be made to the Sika Method Statement: Application of Discrete Galvanic Anode using Sika® FerroGard®-600`s Anodes for further details.
Surface Preparation - Concrete
All loose and spalled concrete must be removed in accordance with national standards and guidelines such as EN 1504-10 or ICRI Guideline No. 310.1 R-2008 making sure that enough space is available to fully encapsulate the anode with a bridging mortar.
Surface Preparation – Steel reinforcement
The surface of the steel must be prepared in accordance with national standards and guidelines such as EN 1504-10 or ICRI Guideline No. 310.1 R-2008.
Extra preparation of the steel must be carried out in the area of the anode tie wire connections to provide a bright steel finish to ensure a good electrical connection.
Steel continuity
The steel reinforcement within the repair area must be tested for continuity. DC resistance between bars must be ≤1 Ω.If discontinuous steel is present, re-establish continuity with steel tie wires.
Anode positioning
In most applications, Sika® FerroGard®-650 anodes must be positioned along the perimeter edges of the repair and on the side or beneath the exposed reinforcement while ensuring the required level of repair mortar / concrete cover. Anodes must be positioned so the entire anode and steel reinforcement are totally covered by the repair mortar once the repair is complete.
Anode preparation
Pre-soaking the anodes in clean water for several minutes prior to installation is recommended to minimise the dehydration of the repair mortar.
Anode attachment
Securely fasten the two pairs of pre-twisted galvanised wires around the steel reinforcement in a double wrap pattern using a suitable wire twisting tool to eliminate free movement, and to ensure a good electrical connection.
Anode electrical verification
Verify electrical connection to the steel reinforcement. DC resistance must be ≤1 Ω.
Anode embedment and encapsulation
The Sika® FerroGard®-650 anodes must be embedded onto the substrate and then encapsulated with the suitable Sika® low resistivity mortar (Contact local Sika representative for recommendation) ensuring complete encapsulation of the anode and wire connections. Corrosion protection has been shown to be most enhanced when using mortars with a resistivity of < 20 000 Ω·cm, however mortars with a resistivity up to < 50 000 Ω·cm may be used.
Concrete repair
Once the bridging mortar has stiffened sufficiently to prevent movement of the anode, the suitable Sika® low resistivity concrete repair mortar and associated system parts, such as reinforcement protection coating and bonding bridge, are then applied within the repair area. If the required grade of repair mortar has a higher resistivity, encase the anode and bridge the gap between the anode and the existing concrete with a low resistivity bridging mortar.
System monitoring
If required, the anode installation can be monitored using half-cell potential surveys, current outputs and reinforcement corrosion rate measurements.
Corrosion prevention in new construction
Sika® FerroGard®-650 anodes are attached to the reinforcement by the integral tie wires at regular spacing’s (refer to the Method Statement). They must be properly fixed to the bar with additional plastic tie wires to prevent the anodes being displaced during concrete casting.
