Mapei Mapegrout T60

Mapei Mapegrout T60 is a single component, sulphate-resistant, fibre-reinforced, shrinkage compensated, thixotropic mortar for the repair of concrete and reinforced structures.

Mapegrout T60 is a pre-blended thixotropic cement based mortar composed of sulphate-resistant hydraulic binders, synthetic polyacrylonitrile fibres, organic corrosion inhibitors, select aggregates and special water-retaining admixtures developed by Mapei. Mapegrout is ideal for concrete structures subject to sulphate attack and for repairs to concrete coverings damaged by corroded reinforcing bars.

Approved for use by London Underground.

Best Uses

Use Mapegrout T60 for repairs to pre-cast concrete structures, canal linings, hydraulic works, filling of rigid joints, cracks in floors, joints between walls, etc.

Application

Preparation of the substrate
Remove deteriorated and loose concrete down to the solid, strong and roughened part of the substrate. Any previous repair work that is no longer thoroughly bonded must also be removed through suitable means (mechanical demolition, hydroscarifying, etc). Clean concrete and reinforcing rods from residues of previous scarifying works, dust, cement laitance, rust, grease, oils, paint residues and any other contaminants, through sandblasting or high pressure water jets. Once prepared, the concrete surface to be repaired must be completely visible and have an uneven texture with at least 5 mm peak roughness, with inert fraction completely exposed and free from laitance, in order to grant correct adhesion of the mortar to the substrate.

Saturate the substrate with water, then wait until the excess water has evaporated, and the surface is dry before repairing with Mapegrout T60. To facilitate the elimination of free water, use compressed air if needed.

Preparation of the mortar
Pour into the mixer the amount of water needed to obtain the consistency required for the application.

Application per 25 kg bag
Trowel approx. 4.1 - 4.3 Litres of water 
Spray approx. 4.2 - 4.4 Litres of water 

Start the mixer and slowly add Mapegrout T60 to the water in a continuous flow. If improved open-air curing of the mortar is required, add Mapecure SRA to the mix phase at a dosage of 0.25% by weight of the mortar (0.25 kg every 100 kg of Mapegrout T60). Mix for 1 to 2 minutes, then check to make sure the mix is well blended. Scrape any unmixed powder from the bottom and the sides of the mixer. Mix again for another 2 to 3 minutes. Depending on the amount needed, a mortar mixer or a drill with a mixing attachment may also be used. Mix at low speed to avoid entraining air. Remember that mixing by hand requires a larger amount of water. This adversely affects several of the mortar’s properties, including mechanical strength, shrinkage, watertightness, etc. Mapegrout T60 remains workable for approx. 1 hour at +20°C. The expansion of Mapegrout T60 is calculated to compensate for hygrometric shrinkage. For it to be effective, the expansion needs to be restrained by rebars or restraints inserted into the substrate.

If Mapegrout T60 is applied without formwork in a thickness greater than 5 cm, reinforcing rods (coated with an at least 2 cm thick layer of protective mortar) must be applied beforehand. Thinner layers can be applied also without reinforcing rods, but the substrate must be roughened enough to compensate the expansion before the application of the mortar. Expansion of the product takes place during the first few days of hardening.

Application of the mortar
Mapegrout T60 may be applied with a spatula or trowel on vertical surfaces in layers up to 10 cm thick per coat, or on ceilings in layers up to 2 cm thick per coat, without the use of reinforcing rebars. For application thickness between 10 and 50 mm repair can be carried out in one single coat. In case of repair thickness over 30 mm, the use of reinforcing rebars is required. For application thickness between 50 and 100 mm repairs must be carried out in more coats (also consecutive), with application of reinforcing rebars and at least 2 cm covering. Apply approximately ¾ of the total thickness in one coat until the rebar is completely covered, using a suitable tool to create a surface roughness between 5 and 10 mm (10 mm notched trowel). The second coat may be applied after 24 hours. Before application, scarify the first coat with high pressure water jets until a clean and laitance-free substrate with at least 5 mm roughness is obtained.

Mapegrout T60 may also be applied using a suitable double-mixing piston or worm-screw type rendering machine. The product is not compatible with application through continuous mixing type rendering machine. For repairing concrete faces (e.g. balconies, columns, beams, etc.) we recommend treating the rebars with Mapefer or Mapefer 1K Zero after sanding them.