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Mapegrout T40: A Product Overview
Mapegrout T40 is a pre-mixed, medium-strength concrete repair mortar designed for predictable, professional results. As a Class R3 structural mortar compliant with EN 1504-3, it provides a high-performance solution for repairing degraded concrete on vertical and horizontal surfaces. Its thixotropic, fibre-reinforced formula can be applied by trowel or spray up to 35 mm thick without slumping, making it the smart choice for overhead and vertical work like balconies, pillars, and tunnels. This shrinkage-compensated mortar ensures excellent adhesion and a waterproof, durable finish, removing the risk of costly callbacks and delivering a job done right.
> 40 MPa
Compressive Strength (28 Days). Exceeds medium-quality concrete, ensuring your repair is tough, durable, and built to last.
Core Features & Specifications
- Thixotropic Consistency — Apply up to 35 mm vertically or overhead without slump or the need for formwork, dramatically speeding up repairs on balconies and ceilings.
- Fibre-Reinforced — Provides enhanced tensile strength and crack resistance, ensuring the repair withstands movement and environmental stress for long-term durability.
- Shrinkage Compensated — Expansive properties counteract shrinkage during curing, ensuring a monolithic bond and preventing cracks at the joint for a seamless, permanent repair.
- Medium Strength (40 MPa) — Achieves a final compressive strength greater than 40 MPa, with characteristics similar to medium-quality concrete for a compatible and robust structural fix.
- Excellent Adhesion — Bonds tenaciously to properly prepared concrete (saturated) and steel (treated with Mapefer), achieving over 2 MPa bond strength.
The Mapegrout T40 Advantage
- No Slump, No Formwork: The thixotropic mix stays exactly where you put it. This saves enormous time and labour costs on vertical and overhead jobs, protecting your profit margin.
- Certified Performance: With EN 1504-3 (R3) and AS/NZS 4020:2005 (Potable Water) compliance, you have verified proof that your repair meets strict structural and safety standards.
- Job-Site Versatility: Apply by trowel for detailed patching or spray-apply for large-scale vertical surfaces. One bag gives you the flexibility to tackle the whole job.
- Durable & Waterproof: Cures to a waterproof finish with low permeability, protecting the structure and rebar from future water ingress and degradation. This is the fix that prevents future callbacks.
Mapei tips for using Mapegrout T40
Scenario: Applying to a smooth or unprepared surface
Potential Outcome: Poor adhesion or complete delamination. The mortar's expansive properties can push it off a smooth surface.
Mapei Best Practice: Always remove loose concrete and roughen the substrate thoroughly. For thicknesses over 2 cm, ensure the surface is reinforced. A solid, rough substrate is critical for predictable performance.
Scenario: Rusted rebar is not treated
Potential Outcome: Rust continues to grow under the new repair, cracking the mortar from within and causing the spalling to return. This is a guaranteed callback.
Mapei Best Practice: Sandblast all rebar until free of rust. Apply Mapefer or Mapefer 1K to the steel before applying Mapegrout T40. This passivates the steel and ensures a permanent, integrated repair.
Applications in Practice: Trade Scenarios
For Remedial Contractors: Balcony & Façade Repair
The Professional's Challenge
Repairing spalling concrete on a balcony edge or beam. The repair is vertical and overhead, needs to be structural, and must be done efficiently without complex formwork.
The Mapei Solution
Mapegrout T40 is purpose-built for this. Its thixotropic nature means you can trowel-apply up to 35 mm directly overhead with no slump. After prepping the substrate and treating the rebar with Mapefer, apply the mortar to rebuild the original profile. You get 40 MPa strength in a product that's easy to work, letting you complete the repair first-time-right. Success means a fast, compliant repair and a happy client.
Best Practice Note
Ensure the concrete substrate is saturated with water, but with no standing water (Saturated Surface Dry - SSD). This prevents the concrete from "sucking" the moisture from the mortar too quickly and ensures maximum bond strength.
For Specifiers & Engineers: Structural Reinstatement
The Professional's Challenge
Specifying a compliant, reliable mortar for repairing concrete structures like tunnels, canals, or pillars that meets EN 1504 standards and is suitable for contact with potable water.
The Mapei Solution
Mapegrout T40 removes the guesswork. It is a certified EN 1504-3 Class R3 structural mortar and also meets AS/NZS 4020:2005 for potable water use. Its physical properties (elastic modulus, thermal expansion) are designed to be similar to medium-quality concrete, ensuring compatibility and monolithic performance. Success means your specification is backed by certified data, mitigating risk for the asset owner.
Best Practice Note
For optimal curing and shrinkage reduction in open-air environments, specify the addition of 0.25% Mapecure SRA to the mix. This additive acts as an internal curing agent, reducing the risk of cracking.
Frequently Asked Questions
What is the maximum thickness I can apply Mapegrout T40 on a wall?
You can apply Mapegrout T40 in a single layer up to 30-35 mm thick, even on vertical or overhead surfaces, without using formwork. Its thixotropic, no-slump formula is designed for this, allowing you to build back concrete profiles quickly. For thicknesses over 2 cm, ensure the surface is properly roughened and reinforced.
Do I need to treat rusty rebar before using Mapegrout T40?
Yes, this is a critical step for a permanent repair. All rust, dirt, and loose concrete must be removed, typically by sandblasting. Before applying the mortar, you must treat the exposed, clean reinforcing bars with Mapefer or Mapefer 1K anti-corrosion cementitious mortar to protect them.
Is Mapegrout T40 considered a structural repair mortar?
Yes, Mapegrout T40 is a certified Class R3 structural mortar according to standard EN 1504-3. This means it meets specific minimum requirements for compressive strength (≥ 25 MPa) and bond strength (≥ 1.5 MPa), though Mapegrout T40 significantly exceeds these with >40 MPa compressive and >2.0 MPa bond strength.
How do I cure Mapegrout T40 to prevent cracking?
Proper curing is essential, especially in hot or windy weather. You must prevent rapid water evaporation by spraying the surface with water for at least 48 hours, or by applying a curing compound like Mapecure E or Elastocolor Primer. Alternatively, adding Mapecure SRA to the mix acts as an internal curing agent and reduces shrinkage by 20-50%.
Applications & Benefits
| Application / Use Case | Key Benefit | Primary Trades |
|---|---|---|
| Repair of spalling concrete on balconies, beams, and pillars | Thixotropic, no-slump formula allows for vertical and overhead application without formwork, saving time and labour. | Remedial Contractors, Builders |
| Reinstatement of rebar concrete cover | Fibre-reinforced and shrinkage-compensated for a durable, crack-resistant repair that protects steel. | Remedial Contractors, Civil Contractors |
| Repairs in tunnels, canals, and hydraulic projects | Certified to AS/NZS 4020:2005 for use with potable water and provides a waterproof, low-permeability finish. | Civil Contractors, Asset Maintenance |
| Patching surface irregularities (exposed aggregate, formwork holes) | Achieves excellent bond strength (>2 MPa) and a finish compatible with medium-quality concrete. | Builders, Concrete Placers |
Applying Mapegrout T40: Enhanced Protocols & Best Practices
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Step 1: Mortar Preparation
Prepare the mix using a low-speed mechanical mixer. Do not mix by hand.
Mixing Water per 25 kg Bag
Trowel Application: Use 3.8 to 4.0 litres of clean water. Spray Application: Use 3.9 to 4.1 litres of clean water.
Mixing Procedure
Add the required water to the mixer first. Slowly add the 25 kg bag of Mapegrout T40 while mixing. Mix for 1-2 minutes, scrape down the sides and bottom of the mixer, and then mix for another 2-3 minutes until a completely homogenous, thixotropic paste is formed.
Timing: The mortar remains workable for approximately 1 hour at +20°C.Pro Tip: For improved open-air curing and reduced shrinkage, add 0.25% Mapecure SRA additive at the end of the mixing phase. -
Step 2: Mortar Application
Apply the mortar to the prepared, Saturated Surface Dry (SSD) substrate.
Trowel Application
Apply with a trowel or gauging trowel. The thixotropic mix allows application on vertical surfaces or ceilings in thicknesses up to 30-35 mm per layer without formwork.
Spray Application
Spray apply using suitable equipment (e.g., Turbosol, Putzmeister). This is ideal for large vertical surface repairs.
Pro Tip: Ensure reinforcing bars have been pre-treated with Mapefer or Mapefer 1K. If a second layer is needed, apply it before the first layer has finished setting (within approx. 4 hours at +23°C). -
Step 3: Curing and Finishing
Proper curing is critical to prevent surface cracks from rapid water evaporation, especially in hot or windy conditions.
Water Curing
Spray water on the surface 8-12 hours after application. Repeat this process every 3-4 hours for at least the first 48 hours.
Curing Compound
Alternatively, apply a curing compound like Mapecure E, Mapecure S, or Elastocolor Primer with a low-pressure pump after tamping the mortar.
Pro Tip: If a smoothing layer or paint is to be applied, Mapecure E/S must be removed by sandblasting. If Elastocolor Primer is used, Elastocolor Paint can be applied directly. Surfaces can also be skimmed with Monofinish, Mapefinish, or Planitop 200.
Limitations & Safety
Product Limitations
Do not use for high-impact or high-abrasion applications. Use Mapegrout Thixotropic or Mapegrout T60 instead.
Do not use for anchoring purposes. Use Mapefill or Mapefill R instead.
Do not use for pumping into formwork. Use Mapegrout Hi-Flow instead.
Do not apply on smooth concrete surfaces; the substrate MUST be roughened.
Do not apply at temperatures below +5°C or above +35°C.
Do not add cement, admixtures, or water once the mix has begun to set.
This is a product for professional use only.
Safety & Handling Requirements
Personal Protective Equipment
Wear protective gloves (Nitrile rubber suggested), comprehensive skin clothing, and close-fitting safety goggles. Do not wear contact lenses.
Ventilation & Handling
Use only outdoors or in a well-ventilated area. Avoid breathing dust. This product contains cement and crystalline silica, which can cause serious irritation.
Emergency First Aid
Eyes:
IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. Seek immediate medical attention.
Skin:
IF ON SKIN: Wash with plenty of water. If skin irritation or rash occurs: Get medical advice/attention. Take off contaminated clothing and wash it before reuse.
Inhaled:
IF INHALED: Remove person to fresh air and keep comfortable for breathing. Call a POISON CENTER (13 11 26) if you feel unwell.
Swallowed:
Do NOT induce vomiting. Get medical attention immediately, showing the SDS or label.
Seek medical attention immediately in all cases of serious exposure. Contact Australian Poisons Information Centre (13 11 26).
Mapegrout T40 Substrate Preparation
Degraded Concrete Substrates
Surface Preparation
Remove all degraded, loose, or unbonded concrete until the substrate is solid, resistant, and rough. Sandblast the surface to remove all dirt, laitance, grease, oil, or old paint. Saturate the substrate with water. Before application, wait for excess water to evaporate (Saturated Surface Dry - SSD). Use compressed air to remove free water if needed.
Exposed Reinforcing Bars (Rebar)
Corrosion Treatment
Sandblast the reinforcing bars to completely remove all rust. Any steel must be free of all contaminants. Before applying Mapegrout T40, the clean rebar MUST be treated with Mapefer or Mapefer 1K anti-corrosion mortar, applied according to its technical data sheet.
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