Mapegrout Thixotropic is a ready-mixed powdered mortar composed of high-strength cements, selected aggregates, special additives and synthetic fibres.

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

Features & Benefits

Once hardened, Mapegrout Thixotropic has the following properties:

• Very high flexural and compressive strength
• Modulus of elasticity, coefficient of thermal expansion and permeability to water vapour similar to those of high quality concrete
• Waterproof
• High adhesion to old concrete, provided it has been soaked with water beforehand, and also to reinforcing rods, especially if they have been treated with Mapefer or Mapefer 1K
• High resistance to abrasion

Technical Characteristics

When mixed with water, Mapegrout Thixotropic becomes an easily workable mortar with high thixotropic properties that can be applied on vertical surfaces without sagging even in great thicknesses and with no need for formwork.

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

However, to guarantee that the expansive properties of Mapegrout Thixotropic are carried out 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 when added to the mix.

Mapecure SRA has a very important role to play, in guaranteeing better curing of mortar. Also, when mixed with Mapegrout Thixotropic, 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 Thixotropic 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 R4.

Recommendations

• Do not use Mapegrout Thixotropic on smooth concrete surfaces: roughen them well, and if necessary add reinforcing rods
• Do not use Mapegrout Thixotropic for anchors (use Mapefill)
• Do not use Mapegrout Thixotropic to repair structures by pouring into formwork (use Mapegrout Hi-Flow)
• Do not add cement, aggregates or additives to Mapegrout Thixotropic
• Do not add water after the mix has started to set
• Do not apply Mapegrout Thixotropic at temperatures below 5°C
• Do not use Mapegrout Thixotropic if the packing has been damaged or if it has been opened beforehand

Application Procedure

Preparing the substrate

• Remove deteriorated and loose concrete until the substrate is solid, strong and rough. Any previous restoration work which is not soundly bonded should also be removed
• Clean the concrete and reinforcing rods until free of dust, rust, cement laitance, grease, oils and previously applied paints by sand-blasting
• Soak the substrate with water

Before repairing with Mapegrout Thixotropic allow the excess water to evaporate. If necessary, use compressed air to facilitate the removal of water.

Preparing the mortar

• Pour into the mixer the amount of water corresponding to the consistency required for the application (15.5-16.5% of the powder)
• Start the concrete mixer and slowly and continuously pour Mapegrout Thixotropic into the water
• If improved open-air curing of the mortar is required, add Mapecure SRA to the final mix at a dosage of 0.25% by weight of the mortar (0.25 kg every 100 kg of Mapegrout Thixotropic)
• Mix for 1-2 minutes, checking the homogeneity of the mix while scraping any unmixed powder off the sides of the mixer; remix for another 2-3 minutes
• Depending on the quantity being prepared, a mortar mixer or a drilling machine with a stirrer attachment can be used
The mixing must be carried out at low speed to avoid entraining an excess of air into the mix.
• Only in exceptional circumstances should the mortar be mixed by hand. In this case prepare small quantities and mix for at least 5-6 minutes until the slurry is completely smooth and even

It should be remembered that manual preparation requires greater quantities of water which are detrimental to some characteristics of Mapegrout Thixotropic, such as mechanical strength, shrinkage, waterproofing, etc.

Mapegrout Thixotropic has a pot life of about 1 hour at 20°C.

The expansion of Mapegrout Thixotropic has been calculated to compensate for hygrometric shrinkage.

In order to be effective, the expansion must be countered with suitable reinforcement or formwork around the structure.

Without formwork, Mapegrout Thixotropic can only be applied in thicknesses greater than 3 cm if the surface has been roughened and reinforcing rods have been placed, taking care to apply at least 2 cm of cover to the reinforcement.

Smaller thicknesses can be applied without reinforcing rods as long as the substrate is sufficiently rough to be able to counter the expansion. This expansion phase is completed during the first days of curing.

Laying the mortar

The mix can be applied with a flat or gauging trowel with no need for formwork even on vertical surfaces or ceilings; the maximum thickness allowed is 50 mm per coat.

Mapegrout Thixotropic can also be sprayed with a suitable piston or worm screw type rendering machine (Turbosol - Putzmeister), excluding continuous mixing machines.

Apply Mapegrout Thixotropic after treating the reinforcing rods with Mapefer or with Mapefer 1K. When a further coat of Mapegrout Thixotropic is necessary, it must be applied before the previous one has completely set (not more than 4 hours at 23°C).

The repair process is complete when a smoothing coat of Mapefinish and a coat of Elastocolor Paint have been applied.

Precautions To Be Taken During And After Application

• Only use bags of Mapegrout Thixotropic which have been stored on their original pallets
• In hot weather, store the product in a cool place and use only cold water to blend the mortar
• 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 laying Mapegrout Thixotropic, we recommend that it is cured carefully, especially in hot or windy weather, to avoid the water evaporating off too quickly and causing the formation of surface cracks due to plastic shrinkage. Spray water on the surface after 8-12 hours of laying 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 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

Before hardening, the mortar can be cleaned from tools with water.

After setting, cleaning is very difficult and the mortar can only be removed mechanically.

Consumption

19 kg/m² per cm of thickness.

Technical Data