Uses

• Repair of broken structural concrete elements.
• Honeycomb repairs and general concrete repairs.
• Vertical concrete repairs up to 75 mm thick in a single layer.
• Overhead concrete repairs up to 40 mm thick in a single layer.
• Horizontal and patch repairs up to 100 mm thick in a single layer.
• High-build structural repairs on horizontal, vertical and overhead surfaces.
• Concrete repairs requiring high mechanical strength and low permeability.

Advantages

• High-strength structural concrete repair mortar.
• Polymer-modified and fiber-reinforced formulation.
• Enhanced with microsilica.
• Thixotropic properties allow high build-up on vertical and overhead surfaces.
• Non-shrink properties provide dimensional stability.
• Excellent mechanical properties.
• Excellent adhesion to properly prepared concrete.
• Easy to mix, apply and finish.
• Extremely low permeability.
• Helps protect reinforcement against corrosion.
• Resistant to the ingress of contaminants.
• Compatible with the host concrete.
• Single-component product requiring only clean water.

Substrate Preparation

The substrate must be sound, clean and free from dust, oil, grease, laitance, weak concrete and any contaminants that may reduce adhesion.

Cut back all damaged and weak concrete until sound concrete is reached, with a minimum repair depth of approximately 10 mm. Saw-cut the perimeter of the repair area to a minimum depth of 10 mm and avoid feather edges.

Remove concrete from around exposed steel reinforcement to provide approximately 25 mm clearance. Grit-blast corroded reinforcement to remove rust, scale, oil and grease.

If the reinforcement has suffered significant loss of cross-section, consult the structural engineer regarding replacement or strengthening.

Thoroughly clean the prepared area using a brush, oil-free compressed air or another suitable method. Any shuttering must be watertight, rigid and adequately supported.

Priming

1. Apply one or two coats of a suitable corrosion-inhibiting primer to cleaned reinforcement within 2-4 hours of grit blasting.
2. Thoroughly pre-soak the concrete repair area using clean water.
3. Remove all standing and excess water.
4. Apply one coat of WHITE SAND PRIME RC acrylic primer and bonding agent.
5. Allow PRIME RC to become tacky before applying REP FR 400.

Mixing

1. Use approximately 3.8-4 litres of clean water for each 20 kg bag.
2. Place the measured water in a clean mixing container.
3. Slowly add REP FR 400 powder while mixing continuously.
4. Use a grout mixer or slow-speed electric drill fitted with a high-shear mixing paddle.
5. Mix for at least three minutes until the mortar becomes homogeneous and uniform.
6. Do not divide the packs or attempt partial mixing.
7. During hot weather, store the bags in a cool environment and use chilled mixing water.
8. Keep the mixed-material temperature below 30°C.

Placement and Finishing

1. Apply REP FR 400 using a suitable trowel or by hand while wearing protective gloves.
2. Press the mortar firmly against the prepared substrate and reinforcement.
3. Compact the mortar thoroughly to eliminate trapped air and voids.
4. For thick vertical and overhead repairs, apply the mortar gradually in firmly pressed patches or layers.
5. Ensure complete bonding between the substrate and subsequent layers.
6. Initially level the surface using a wooden or plastic float.
7. Complete the final finishing using a steel float.

Curing

Cure REP FR 400 in the same manner as concrete by continuous water curing and covering the repair with polyethylene sheets.

Alternatively, apply a suitable WHITE SAND-CURE curing compound to reduce water evaporation from exposed surfaces.

Cleaning

Clean tools and equipment immediately after use and before the initial cure using clean water. Hardened material must be removed mechanically.

Storage and Shelf Life

REP FR 400 has a shelf life of 12 months when stored in unopened and undamaged original packaging in a dry, shaded place under suitable warehouse conditions at a temperature below 35°C.

Packaging

• 20 kg paper bags.

Health and Safety

• Wear suitable protective gloves and safety goggles during mixing and application.
• Avoid unnecessary contact with the skin and eyes.
• In case of skin contact, wash immediately with soap and clean water.
• In case of eye contact, rinse immediately with plenty of clean, cold water.
• Seek medical advice if irritation continues.
• The product is non-flammable and is not classified as hazardous under current legislation.
• Do not dispose of the material in water or soil. Follow applicable local regulations.

Quality and Technical Support

WHITE SAND products are developed and manufactured under a quality-oriented product-development process and an independently certified quality management system.

WHITE SAND provides technical assistance regarding concrete assessment, reinforcement preparation, repair design, priming, placement and curing.