For rapid concrete repairs on exterior vertical or horizontal surfaces, Mapegrout Fast-Set Rapido provides a structural, shrink-compensated, and fibre-reinforced mortar that sets in 30 minutes. It is formulated for the fast restoration of deteriorated concrete structures, edges of beams, pillars, and balconies damaged by reinforcing rod oxidation, as well as rapid repairs to industrial concrete flooring, concrete pipes, and brick pointing.
This pre-blended hydraulic mortar is thixotropic, allowing installers to trowel applications up to 20–25 mm thick on vertical surfaces in a single layer without slumping. The shrinkage-compensated formulation prevents cracking during the rapid drying phase. Once cured, it achieves an R3 structural rating under EN 1504-3, delivering high compressive and flexural strength alongside low capillary water absorption to protect internal steel reinforcement from future corrosion.
Substrates must be mechanically prepared to a rough, sound finish with surface irregularities at least 5 mm deep to expose the aggregate. All concrete surfaces must be thoroughly wet with water, allowing excess water to evaporate so the substrate is damp but free of puddles. For optimal adhesion, brush on a bonding slurry composed of 1 part Mapegrout Fast-Set Rapido to 0.24–0.25 parts water immediately before trowelling the mortar mix.
Mix a 25 kg bag with 3.75–4 litres of clean water using an electric mixer until smooth. Apply with a float or trowel to the wet slurry. For repairs deeper than 2.5 cm, apply multiple layers at 15-minute intervals, scoring each intermediate layer with a 10 mm notched trowel. Keep restored areas damp for at least 24 hours, or protect floor repairs with polyethylene sheets or wet bags to prevent rapid evaporation.
The working time, or pot life, is approximately 10 minutes at 20 °C. It achieves initial set in under 30 minutes. Mix in small batches and place immediately to avoid premature hardening; do not re-temper with water once setting begins.
Apply Mapegrout Fast-Set Rapido up to 20-25 mm per layer on vertical or overhead substrates without slump. Its thixotropic formulation holds form. For deeper repairs, apply multiple lifts with about 15-minute intervals between layers.
Patched floors are ready for light traffic in approximately 3 hours at 20 °C. At this point, the material exceeds 10 MPa compressive strength. Avoid premature loading, especially in cooler conditions, and protect the repair during early cure.
No, Mapegrout Fast-Set Rapido is not designed for precision anchoring. For these applications, use a dedicated precision grout such as Mapefill or Mapefill R. This product is formulated for trowelled concrete repair.
It is not recommended to leave the repair uncoated as a final facade finish. Mapegrout Fast-Set Rapido may exhibit colour variation after hardening. If a protective or decorative finish is required, over-coat with the Elastocolor system after approximately 3 days at 20 °C.
| Application | Key benefit | Primary trades |
|---|---|---|
| Patching spalled concrete on beams, pillars, and balconies | Achieves >10 MPa compressive strength in 3 hours for rapid structural reinstatement. Thixotropic formulation prevents slump on vertical surfaces. | Remedial contractors, builders |
| Industrial concrete floor repairs and edge rebuilds | Enables fast return to service and heavy traffic due to high early strength. Produces a dense, wear-resistant finish when steel-floated. | Flooring contractors, builders |
| Smoothing surface defects like honeycombing, voids, and tie-holes | Provides a uniform, coat-ready substrate with strong adhesion to existing concrete, streamlining subsequent finishing. | Builders, tilers, remedial contractors |
| Sealing surface cracks in concrete and renders | Creates a durable crack fill with low capillary absorption, ensuring compatibility with protective coatings and enhanced weather resistance. | Builders, remedial contractors |
| Assembly and repair of concrete pipes | Delivers high early strength and water impermeability crucial for quick serviceability and reliable joint sealing in infrastructure. | Civil contractors, plumbers |
| Pointing between bricks prior to waterproofing systems | Improves watertightness and coating adhesion, allowing rapid turnaround before applying systems like Planiseal. | Waterproofers, tilers, builders |
Remove unsound concrete and contaminants to expose sound aggregate. Achieve a rough, open surface (≈ ≥5 mm amplitude). Clean reinforcement to bright metal where exposed, then coat with anti-corrosion protection.
Hydro-scarify, grind, or chip back to sound concrete; square patch edges to improve load transfer.
Abrasive blast rebars; apply Mapefer or Mapefer 1K as directed prior to patching.
Bring substrate to SSD, then apply a bonding slurry to high-suction areas immediately prior to placement.
Blend 1 part powder : 0.24–0.25 parts water to a brushable consistency; scrub into the surface.
Place the repair mortar while the slurry remains fresh to maximise adhesion.
Using a clean pail, add water then powder and mix mechanically to a lump-free, thixotropic mortar.
Per 25 kg bag use 3.75–4.0 L water (≈15–16%). Mix 2–3 minutes with a low-speed paddle.
Mix only what you can place within ~10 minutes at 20 °C. Do not add water once setting begins.
Trowel mortar firmly into the cavity, compacting to remove air and ensure full contact with edges and steel.
Apply up to 20–25 mm per lift on vertical/overhead surfaces without slump.
For deeper repairs, apply subsequent lifts at ~15 minutes intervals; lightly notch or key for adhesion.
On SSD substrate with fresh slurry, spread and compact the mortar; steel-float to finish and feather as required.
Patch boundaries should be cut square; avoid feathering onto weak or dusty material.
Observe minimum thickness that ensures durability; for thin film cosmetic smoothing, consider multiple light passes.
After finishing, protect from rapid evaporation with polyethylene sheets or wet coverings. Clean tools with water before the product hardens.
Maintain moisture for at least the first 24 hours on structural patches to enhance durability.
Apply Elastocolor coatings after approximately 3 days at 20 °C. Remove residues mechanically after set.
Wear chemical-resistant gloves, safety glasses, long sleeves, and pants. When mixing or pouring powder, use a P2 (or N95) dust mask or respirator to avoid inhaling cementitious dust.
Mix and apply in well-ventilated areas. Avoid creating airborne dust. Use local extraction where possible to maintain air quality.
Store unopened bags dry, out of direct sunlight, at temperatures between +5 °C and +35 °C. Keep away from moisture and incompatible chemicals. Dispose of cured material and empty containers according to local regulations.
Proper surface preparation and priming are critical for the bond strength and durability of Mapegrout Fast-Set Rapido repairs.
Surface prep: Mechanically remove all deteriorated or contaminated concrete down to a sound, rough substrate with at least 5 mm irregularities. Clean thoroughly to remove dust, laitance, oil, grease, or loose material. Saturate the surface to SSD (saturated surface-dry) condition before application.
Primer: Optional. On dry or highly absorbent substrates, a bonding slurry improves adhesion and controls suction. Mix Mapegrout Fast-Set Rapido with water at a 1:0.24-0.25 (powder:water) ratio and brush onto the SSD concrete. Apply the repair mortar wet-on-wet into the fresh slurry.
Surface prep: Abrasive blast the reinforcing steel to bright metal, removing all rust, scale, and contaminants. Ensure the repaired design provides adequate cover for the steel.
Primer: Required. Coat the prepared reinforcement with an anti-corrosion primer such as Mapefer or Mapefer 1K prior to applying the repair mortar. This inhibits further corrosion and protects the steel.
| Property | Value |
|---|---|
| Material Type | PCC (Portland Cement-based Compound) |
| Colour | Grey |
| Density | 2150 kg/m³ |
| Consistency | Powder, thixotropic when mixed |
| Compressive Strength | 3 hrs >10 MPa, 1 day >20 MPa, 7 days >28 MPa, 28 days >40 MPa |
| Flexural Strength | 3 hrs >4.0 MPa, 28 days >8.0 MPa |
| Bond Strength | >1.5 MPa |
| Modulus of Elasticity | 24 GPa |
| Pot Life | ≈ 10 minutes at 20 °C |
| Initial Set Time | < 30 minutes |
| Service Temperature | Freeze-thaw with de-icing salts >1.5 MPa |
| Mix Ratio | 100 parts product : 15–16 parts water (by weight) |
| Coverage Rate | 18 kg/m² per cm thickness |
| Application Thickness | 20–25 mm per layer |
| Maximum Gap Fill | 1 mm (for crack sealing) |
| Classification | EN 1504-3 R3 |
| Packaging | 25 kg bags |
| Storage Life | 12 months in unopened packaging at +5 °C to +35 °C |
Here are some common examples on where Mapegrout Fast-Set Rapido used by our customers.
