Concrete spalling repairs. Where no water is present.

Concrete Spalling Repairs - where no water is present
To be read in conjunction with Product Data Sheets

GENERAL:
This method statement details the products and procedures to carry out concrete spalling repairs where concrete reinforcement has been subjected to corrosion.

SPALLING REPAIR SCHEMATIC:
Spalling Repair - Where water is not present

PRODUCTS:
Xypex Concentrate
Xypex Megamix II

PREPARATION:
Concrete substrate should be clean and sound. All loose material and surface laitance must be removed, preferably by grit or water blasting. All corroded steel must be exposed, therefore the concrete must be scabbled to a depth so as to achieve a sound substrate. Continue chipping out the concrete to a minimum of 25mm beyond the corroded reinforcement to totally expose the corroded steel bar.

Remove all scale and rust and have the superintendent inspect the reinforcement to determine if replacement of the corroded bar is required. If replacement of the steel bar is required, then this shall be carried out in accordance with the specification.

APPLICATION:
1.    After all preparation has been completed and where necessary, the corroded reinforcement bar replaced, saturate the concrete with clean water so as to achieve a saturated surface damp condition.

2.    Mix Xypex Concentrate, five (5) parts powder to two (2) parts clean water, into a slurry and apply by brush to the prepared reinforcement steel. This will reinstate the passive alkaline barrier around the reinforcement steel. Refer to Product Data Sheet for mixing rates and procedures.

3.    Mix Xypex Megamix II, concrete repair mortar with clean water. Apply a scrub coat of this mixed material to the prepared, saturated concrete surface. This scrub coat aids bonding. While the scrub coat is still green, apply Xypex Megamix II by trowel. Refer to Product Data Sheet for mixing rates and procedures.

4.    Xypex Megamix II should be applied in layers not greater than 50mm in thickness. Allow each layer to reach initial set before applying subsequent layers, the surface should be “scratched” to allow for increased bond of subsequent layers.

5.    Return the concrete surface to contour as per the requirement of the specification.

6.    Where the enhanced waterproofing and concrete protection is required, Xypex Concentrate coating should be applied over Megamix II after the curing period. Refer to Product Data Sheet


CURING:
The repaired areas should be protected from rapid drying out by using moist curing methods for three days, or by using a curing compound.

Although every care is taken by Xypex to ensure that the material contained in this publication is accurate, Xypex does not guarantee the suitability, completeness or accuracy of any of the material in this publication, Consequently, Xypex can accept no responsibility for unsuitable, incomplete or inaccurate material which may be contained here. The user shall determine the suitability of the product for its intended use.

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