1. Surface Preparation
Cut back all damaged and weak concrete until a sound surface is reached. Also, cut back to the application's minimum depth.
Grit blast corroded steel reinforcements to remove all traces of rust.
Compensate steel loss with up to 25% of the original section.
Replace the steel reinforcement for section losses exceeding 25%.
Remove all concrete forms around at least 25 mm of the exposed steel reinforcements.
Saw cut the perimeters of the repair area to a minimum depth of 10 mm.
Clean the prepared area thoroughly using a brush and/or compressed air.
Use a water-tight form-work to avoid material loss.
Soak the areas to be repaired with Vetorep CR521 with clean water for several hours before applying the Vetorep system.
Remove all excess water.
2. Priming
For the steel reinforcement to accept Vetorep CR521, it must be primed (with one or two coats of Saveto corrosion inhibitor for steel reinforcement Vetoprime CP436) and grit blasted within 2 to 4 hours.
Normally, a primer is not required for the concrete substrate, provided the substrate is soaked thoroughly in clean water and it is damp when applying the product.
For concrete highly contaminated with soluble salts, it is recommended to use Vetobond EB430 (an epoxy bonding agent) to prevent migration of salts (such as chloride ions and sulfate) to the repair patch. Vetobond EB430 also provides an enhanced bond for Vetorep CR520 to host concrete.
3. Mixing
Mix properly using a mechanical power mixer or drill fitted with a suitable paddle.
Add 3 - 3.5 liters of clean water per 25 kg bag (or 6 - 7 liters per 50 kg bag) to a clean container.
Then add the powder slowly to the water while continuously mixing (with a low-speed mixer/drill, 400 - 600 rpm).
Mix for 3 minutes until a uniform consistency is achieved.
4. Placing and Finishing
Pour Vetorep CR521 in a single continuous operation within 25 minutes of mixing.
Pour the mixed material slowly to prevent air entrapment.
The Vetorep CR521 repaired area should not exceed 2.5 m² in a single application.
5. Curing
Vetorep CR521 is a cementitious-based material and can be cured like concrete by continuous watering and covering with polyethylene sheets.
Alternatively, you can use Vetobond AB432 for curing.
6. Cleaning
Clean all tools with freshwater immediately after application.
Clean hardened materials mechanically.
Remember that stated consumption data are for general guidance, and actual consumption depends on the nature of the substrate, method of application, and wastage. Always refer to the latest updated TDSs, as technical data sheets are continuously updated as per R&D improvements and new 3rd party testing. Saveto endeavors to ensure the accuracy of advice but cannot accept liability arising from the use of products because it has no direct control over application.
