Uses

• Structural concrete repair where resistance to sulphate ions is required.
• Repair of concrete exposed to sulphate-bearing soil or groundwater.
• Patch repair of concrete floor slabs.
• Filling concrete voids deeper than 5 mm.
• Horizontal repairs up to approximately 50 mm thick in a single application.
• Vertical repairs up to approximately 20 mm thick in a single application.
• Repair around properly prepared steel reinforcement.

Advantages

• Manufactured using sulphate-resistant Type V cement.
• High resistance to sulphate exposure.
• High compressive, tensile and flexural strength.
• Compensated shrinkage and good dimensional stability.
• Strong adhesion to prepared concrete substrates.
• Good workability and easy application.
• High durability.
• Reduces material drop and rebound during application.
• Single-component, ready-mixed cementitious powder.
• Requires only the addition of clean water.

Substrate Preparation

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

Remove damaged and weak concrete until sound concrete is reached, with a minimum repair depth of approximately 10 mm. Saw-cut the repair perimeter to a minimum depth of 10 mm.

Remove concrete around exposed reinforcement to provide approximately 25 mm clearance. Grit-blast corroded steel reinforcement to remove all rust and scale. Where significant loss of reinforcement cross-section has occurred, consult the project engineer regarding replacement.

Clean the prepared repair area thoroughly using a suitable brush, oil-free compressed air or another approved method. Saturate absorbent concrete with clean water and remove all standing water before priming.

Priming

• Apply one or two coats of a suitable reinforcement-corrosion inhibitor to prepared steel within 2–4 hours after grit blasting.
• Apply one coat of WHITE SAND PRIME RC to the prepared concrete substrate.
• Allow PRIME RC to become tacky before applying REP SR 150.
• Do not allow the bonding coat to dry completely before mortar placement.

Mixing

1. Place approximately 3.8 litres of clean water in a suitable mixing container for each 20 kg bag.
2. Slowly add REP SR 150 powder to the water while mixing continuously.
3. Use a grout mixer or slow-speed electric drill fitted with a high-shear mixing paddle.
4. Mix for at least three minutes until a homogeneous and uniform consistency is obtained.
5. Do not attempt partial mixing of the pack.
6. At elevated temperatures, store the bags in a cool place before use and use chilled water to keep the mixed-material temperature below 30°C.

Placement and Finishing

1. Apply REP SR 150 manually or using a suitable trowel.
2. Press the mortar firmly against the substrate and around the reinforcement.
3. Compact the material thoroughly to eliminate voids and ensure complete adhesion.
4. For thick vertical or overhead repairs, apply the mortar gradually in firmly pressed layers or patches.
5. Level the initial surface using a wooden or plastic float.
6. Complete the final finish using a steel float.
7. Do not overwork the surface.

Curing

Cure REP SR 150 using continuous clean-water curing and polyethylene sheeting. Alternatively, apply a suitable WHITE SAND-CURE curing compound to reduce surface-water evaporation.

Protect freshly applied mortar from direct sunlight, strong wind, rapid drying, rain and mechanical damage.

Cleaning

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

Storage and Shelf Life

REP SR 150 has a shelf life of 12 months when stored in its unopened and undamaged original packaging in a dry, shaded place under suitable warehouse conditions at a temperature below 35°C.

Packaging

• 20 kg 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, sulphate-resistant repairs, application, finishing and curing.