Mapegrout T40 is a premixed powdered mortar composed of cement, graded aggregates and special additives.

Quick Links - Click To Jump To Section:

   
• Features & Benefits
• Technical Characteristics
• Recommendations
• How to Use
• Precautions To Be Taken During And After Application
• Cleaning
• Consumption
• Technical Data

Features & Benefits

When fully cured, Mapegrout T40:

• Has moderate flexural and compressive strength
• Has a modulus of elasticity, thermal expansion coefficient and permeability coefficient similar to that of medium quality concrete
• Is waterproof
• Has excellent adhesion to existing concrete surfaces provided they are saturated with water and reinforcing bars are first treated with Mapefer or Mapefer 1K

Technical Characteristics

When mixed with water Mapegrout T40 forms an easy to apply thixotropic mortar that can be applied without slumping even in substantial thicknesses on vertical surfaces without formwork.

If Mapegrout T40 is prepared by only adding water, it must be cured under damp conditions in order to guarantee that the product’s expansive properties develop completely and correctly. However, it is not very easy to guarantee that these conditions are created on site.

Therefore, to guarantee that the expansive properties of Mapegrout T40 take place when drying in the open air, 0.25% of Mapecure SRA, a special additive which has the property of reducing both plastic and hydraulic shrinkage, may be used to great advantage by adding it to the mix.

Mapecure SRA has a very important role to play, in guaranteeing better curing of mortar. Also, when mixed with Mapegrout T40, it may be considered a technologically advanced system, in that the additive has the capacity of slowing down evaporation of the water and of promoting the development of hydration reactions.

Mapecure SRA behaves like an internal curing agent and, thanks to its interaction with some of the main components which make up the cement, it helps to reduce shrinkage by between 20% and 50% compared with the standard values of the product without the additive. This will obviously lead to a reduced risk of cracking.

Mapegrout T40 meets the requirements defined by EN 1504-9 (“Products and systems for the protection and repair of concrete structures - Definitions, requirements, quality control and evaluation of conformity - General principles for the use of products and systems”) and the minimum requirements claimed by EN 1504-3 (“Structural and non structural repair”) for structural mortars of class R3.

Recommendations

• Do not use Mapegrout T40 to repair structures subject to high compressive loads, high impact or abrasion: use Mapegrout Thixotropic or Mapegrout T60 instead
• Do not use Mapegrout T40 when the material has to be pumped over long distances or in the case of large pumping heads
• Do not use Mapegrout T40 on smooth concrete surfaces. Roughen the surface thoroughly and add reinforcing if necessary
• Do not use Mapegrout T40 for anchoring (use Mapefill)
• Do not pour Mapegrout T40 for pumping into formwork (use Mapegrout Hi-Flow)
• Do not add cement or admixtures to Mapegrout T40
• Do not add water once the mix has begun to set
• Do not use Mapegrout T40 at temperatures lower than 5°C
• Do not use Mapegrout T40 if the bag has been damaged or already opened

How to Use

Substrate preparation

• Remove degraded and loose concrete until the substrate is solid, resistant and rough. Any previous repair work that is no longer thoroughly bonded must also be removed
• Sandblast the concrete and the reinforcing bars until they are free of dirt, rust, cement laitance, grease, oil, varnish or old paint
• Saturate the substrate with water. Before repairing with Mapegrout T40, wait until the excess water has evaporated. To facilitate the elimination of free water, use compressed air if needed

Preparing the mortar

• Pour into the mixer the amount of water needed to obtain the consistency required for the application

Application per 25KG:

• Trowel: from 3.8L to 4.0L
• Spray: from 3.9L to 4.1L

• Start the mixer and slowly add the Mapegrout T40 to the water in a continuous flow
• If improved open-air curing of the mortar is required, add Mapecure SRA at the end of the mixing phase at a dosage of 0.25% in weight of the mortar (0.25 kg every 100 kg of Mapegrout T40)
• Mix for 1 to 2 minutes, then make sure the mix is well blended. Scrape any unblended powder from the bottom and the sides of the mixer. Mix again for another 2 to 3 minutes
• Either a cement mixer or a drill equipped with a mixing attachment may be used, according to the amount of material to be prepared. Mixing must be carried out at low speeds, to avoid air being entrained into the mix
• Avoid mixing manually unless absolutely necessary. If so, mix small amounts at a time for at least 5 to 6 minutes until a completely homogeneous paste is obtained

Keep in mind that mixing by hand requires a larger amount of water. This adversely affects several of the mortar’s characteristics, including mechanical strength, shrinkage, impermeability, etc.

Mapegrout T40 remains workable for approximately 1 hour at 20°C.

The expansion of Mapegrout T40 is calculated to compensate for plastic shrinkage. For it to be effective, the substrate needs to be adequately reinforced with rebars or forms.

Applying Mapegrout T40 without formwork in thicknesses of more than 2 cm should be done only after reinforcing and roughening the surface of the concrete, taking care to cover the reinforcement with a layer at least 20 mm thick.

Lower thicknesses can be applied without reinforcing as long as the substrate has been substantially roughened to counter the expansion.

The expansion phase ends during the first days of curing.

Application procedure

The mortar can be applied with a trowel or gauging trowel without formwork even on vertical surfaces or ceilings in maximum thicknesses of 30 to 35 mm per layer.

Mapegrout T40 can also be spray applied, using Turbosol or Putzmeister type equipment, excluding continuous mixing machines.

Reinforcing bars must be previously treated with Mapefer 1K before applying the Mapegrout T40.

Where necessary, apply a second layer of Mapegrout T40 before the previous layer has finished setting (within 4 hours at 23°C).

After completing repair work, the surfaces may be skimmed with Monofinish, Mapefinish, or with an elastic skimming product such as Mapelastic or Mapelastic Guard.

Coloured Elastocolor Paint may then be applied to create a protective finish.

Precautions To Be Taken During And After Application

• Only use bags of Mapegrout T40 which have been stored on their original pallets
• In warm weather store the material in a cool place. Use cold water to prepare the mix
• In cold weather, store the product in a place which is protected from frost at a temperature of 20°C, and use tepid water to blend the mortar

After applying Mapegrout T40, it is recommended that it is cured carefully, especially in hot or windy weather, to avoid the water evaporating too quickly and causing the formation of surface cracks due to plastic shrinkage. Spray water on the surface 8-12 hours after applying the mortar, and repeat the operation (every 3-4 hours) for at least the first 48 hours. As an alternative, after tamping the mortar, spread on a layer of either Mapecure E anti-evaporation treatment in watery emulsion with a low-pressure pump, Mapecure S solvent-based curing film for mortar and concrete or Elastocolor Primer solvent-based, high-penetration primer for absorbent substrates and curing agent for repair mortar.

Mapecure E and Mapecure S, as with all the best quality products in the same category which are currently available on the market, impede bonding of successive dressing layers. Therefore, if a smoothing layer or paint is to be applied later, they must be completely removed by sandblasting. If Elastocolor Primer is used as an anti-evaporation treatment, on the other hand, a final protective layer of Elastocolor Paint or Elastocolor Rasante may be applied directly on the treated surface without having to remove it.

Cleaning

Mortar that has not yet hardened can be removed from tools with water.

After setting, cleaning is very difficult and can only be done mechanically.

Consumption

Approx. 18.5 kg/m² per cm of thickness.

Technical Data