Mapei Mapegrout Fast-Set Rapid Concrete Repair Mortar – 25kg

Mapei Mapegrout Fast-Set Concrete Repair Mortar

Rapid-Setting R3 Mortar for Structural Concrete Repairs

Mapei Mapegrout Fast-Set is a rapid-setting, shrinkage-compensated repair mortar for restoring damaged horizontal and vertical concrete surfaces. The fibre-reinforced formulation provides excellent workability, allowing it to be applied to vertical repairs without slumping.

Once mixed with water, the mortar sets in approximately 30 minutes and repaired areas can be placed back into use after approximately 2–3 hours. Its high strength, adhesion, water resistance and wear resistance make it suitable for structural concrete repairs, industrial floors, balconies, beams, pillars and concrete pipes.

Key Features & Benefits

• Rapid-setting and hardening concrete repair mortar
• Fibre-reinforced and shrinkage compensated
• Class R3 structural repair mortar to EN 1504-3
• Suitable for horizontal and vertical repairs
• Excellent thixotropic consistency prevents slumping
• Sets in less than 30 minutes at 20°C
• Repaired areas can be ready for use after approximately 2–3 hours
• Suitable for light foot traffic after approximately three hours
• High compressive and flexural strength
• Excellent adhesion to properly prepared existing concrete
• Excellent resistance to water penetration
• Good resistance to wear
• Suitable for layers between 5mm and 20–25mm thick
• Deeper repairs can be completed in multiple layers
• Suitable for internal and external concrete repairs

Typical Applications

• Repairing damaged or deteriorated concrete
• Restoring concrete beams, pillars and balconies
• Repairing concrete damaged by corroding reinforcement
• Fast repairs to industrial concrete flooring
• Sealing surface cracks in concrete and cement renders
• Filling aggregate bridging and surface defects
• Filling shrinkage joints and formwork spacer holes
• Covering exposed reinforcing rods following preparation
• Assembling concrete pipes
• Repairing damaged concrete pipe edges
• Pointing brickwork before waterproofing with Planiseal 88

Surface Preparation

Remove all loose, damaged, contaminated or poorly bonded concrete until a rough, sound and resistant substrate is exposed. Existing coatings and previous repairs that are not firmly bonded must also be removed.

Clean the concrete and reinforcement thoroughly to remove dust, laitance, rust, grease, oil, paint and other contaminants. The prepared concrete should have a rough surface with irregularities at least 5mm deep and exposed aggregate to support effective adhesion.

Protect exposed reinforcing steel with Mapefer or Mapefer 1K where required. Saturate the prepared concrete with clean water, then allow excess water to evaporate before applying the mortar. The receiving surface should be damp without standing water.

For improved adhesion, apply a bonding slurry made from one part Mapegrout Fast-Set mixed with approximately 0.24–0.25 parts water. Apply the repair mortar while the bonding slurry remains fresh.

Mixing

1. Place 3.75–4 litres of clean water into a suitable mixing container.
2. Gradually add one 25kg bag of Mapegrout Fast-Set while mixing.
3. Mix using an electric paddle mixer until a smooth, lump-free mortar is produced.
4. Prepare only as much material as can be applied within approximately 10 minutes.

Do not add extra water after the mortar has started to set. Do not add cement, lime, gypsum or other admixtures.

Application

1. Apply the mixed mortar to the freshly prepared or slurry-coated substrate using a float, trowel or gauging trowel.
2. Apply at a thickness between 5mm and 20–25mm per layer.
3. For deeper repairs, apply additional layers at intervals of approximately 15 minutes.
4. Work each intermediate layer with a 10mm notched trowel to improve adhesion between coats.
5. Finish the final surface using a suitable plastering trowel.
6. Keep repaired concrete patches damp for at least 24 hours.

Protect repaired floors against rapid moisture evaporation using polyethylene sheets or damp coverings. The repaired surface can normally accept light traffic after approximately three hours at 20°C.

Coverage

Approximate consumption is 18kg per m² for every 10mm of applied thickness. Actual consumption will depend on the depth, profile and condition of the repair.

Technical Information

Property	Specification
Product type	Fibre-reinforced, shrinkage-compensated cementitious repair mortar
Classification	EN 1504-3 Class R3 structural repair mortar
Consistency	Thixotropic powder mortar
Colour	Grey
Maximum aggregate size	1mm
Mixing water	3.75–4 litres per 25kg bag
Pot life	Approximately 10 minutes at 20°C
Setting time	Less than 30 minutes
Application thickness	5–25mm per layer
Waiting time between layers	Approximately 15 minutes
Ready for use	Approximately 2–3 hours
Application temperature	5°C to 35°C
Consumption	Approximately 18kg per m² per 10mm thickness
Density of mixed mortar	Approximately 2,150kg/m³
Compressive strength after 3 hours	More than 10MPa
Compressive strength after 28 days	More than 40MPa
Bond strength	More than 1.5MPa
Reaction to fire	Euroclass A1
Pack size	25kg
Shelf life	Up to 12 months when unopened and stored correctly

Important Application Information

• Do not apply to dry, dirty or contaminated surfaces
• Do not apply below 5°C
• Do not use damaged or previously opened bags
• Do not use for application with plaster-spraying equipment
• Do not use for precision anchoring applications
• Use cold mixing water during warm weather
• Use lukewarm mixing water in low temperatures
• Protect fresh repairs against rapid moisture loss
• Do not leave as a decorative facade finish, as the colour may change after hardening

Storage and Safety

Store unopened bags in a dry, covered location at temperatures between 5°C and 35°C. Protect the product from direct sunlight and moisture before use.

Mapegrout Fast-Set is intended for professional use. Wear suitable gloves, protective clothing and eye protection during mixing and application. Always consult the current technical data sheet and safety data sheet before use.