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32857 Parchem Technical Data Compendium 2015_Crop4emag.pdf

CONTENTS CONCRETE REPAIR CORROSION CONTROL GROUTS & ANCHORS PROTECTIVE COATINGS INDUSTRIAL FLOORING SURFACE TREATMENTS JOINT SEALANTS CONCRETE JOINTING JOINT FILLERS WATERPROOFING WATERSTOPS ROOFING TIMBER FLOORING ALPHABETICAL INDEX 87 “Ring Anode” Corrosion (without Galvashield XP) Galvashield XP prevents “Ring Anode” Corrosion How does it work? When two dissimilar metals are coupled together in an electrolyte (in this case concrete), the metal with the higher potential for corrosion (zinc) will corrode in preference to the more noble metal (reinforcing steel). Galvashield XP-type anodes are embedded in concrete repairs to provide corrosion prevention or corrosion control to the reinforcing steel in the adjacent area. Product Comparison Product Name Anode Class Anode Dimension (nominal) Zinc Mass (g) Galvashield XPT Type AP 25mm x 125mm x 25mm 60 Galvashield XP Type AP 65mm (dia.) x 30mm 60 Galvashield XP2 Type AC 65mm x 80mm x 30mm 100 Galvashield XP4 Type AC 65mm x 120mm x 30mm 160 Anode Class First Letter Activation Method (A-Alkali) Second Letter Application (P-Corrosion Prevention) (C-Corrosion Control) Application Instructions Installation Concrete shall be removed from around and behind all corroding rebar in accordance with good concrete repair practice such as ACRA guideline HB84-2006. Section 6. Exposed reinforcing steel should be cleaned to remove all residual rust and concrete residue. The anode units and repair material should be installed immediately following preparation and cleaning of the steel reinforcement. The location and spacing of the units shall be as specified by the designer (refer to design criteria). The units can be placed around the perimeter of the repair or on a grid pattern to protect a second layer of steel if required. Securely fasten the anode units from the side or beneath the exposed rebar as close as practical to the surrounding concrete (preferably within 100 mm) while ensuring that enough space remains to fully encapsulate the unit in the repair. The minimum cover of the repair material over the units should be 20 mm. When required, the steel reinforcement, other than where the anodes are attached, should be primed immediately following attachment of the Galvashield XP with a 135 micron (wft) continuous coating of Nitoprime Zincrich. Over painting with the bonding agent or reinforcement primer, onto the surface of the Galvashield XP unit must be avoided. Anode-to-steel continuity and steel-to-steel continuity within the patch should be verified with an appropriate meter; discontinuous steel should be tied to continuous bars using steel tie wire and re-tested. A value between 0 and 1 ohm should be achieved. Repair Materials For optimum performance, use a repair material with resistivity less than 15,000 ohm-cm. If a higher resistivity repair material is to be used or if the resistivity of the material is unknown, pack Renderoc HB40 or HB70 between the anode unit and the substrate to provide an ionically conductive path to the substrate. Prior to placing the repair material, pre-wet the concrete substrate and the anode units to achieve a saturated surface dry condition, then complete the repair. Do not soak the anode units for greater than 20 minutes. Precautions Galvashield XP-type anode units are intended to provide localised corrosion prevention or corrosion control and do not address or repair structural or concrete damage. Where structural damage exists, consult a structural engineer. To provide protection to a broader area, install Galvashield CC anode units on a grid pattern or consult Parchem for further product recommendations. Galvashield® XP Range


32857 Parchem Technical Data Compendium 2015_Crop4emag.pdf
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