Mapei Mapemortar HB R3 Zero

Mapei Mapemortar HB R3 Zero is a medium strength high build repair mortar meets EN 1504-3 R3 classification.

Best Uses

Mapei Mapemortar HB R3 Zero is ideal for repairing damaged concrete surfaces in overhead, vertical and horizontal situations, where a medium strength high build mortar is required.

Some application examples include:

• Repair of damaged concrete surfaces, corners of beams, columns and other concrete members damaged by corroded steel
• Repairs to bridges, culverts and diaphragms etc
• Repairs to concrete walls and tunnel linings
• Repairs to concrete segments
• Repairs to balconies and soffits

Mapemortar HB R3 is a premixed powder mortar composed of cement, graded aggregates and special additives. When mixed with water Mapemortar HB R3 forms an easy to apply high build mortar that can be applied without slumping even in substantial thicknesses on vertical surfaces without the aid of formwork.

When fully cured Mapemortar HB R3:

• Has moderate flexural and compressive strength
• Has a modulus of elasticity, thermal expansion coefficient and permeability coefficient similar to medium strength concrete
• Has excellent adhesion to existing concrete surfaces providing they have been pre-soaked and still damp with clean water
• Reinforcing bars should be treated with Mapei Mapefer or Mapei Mapefer 1K.

Application

Preparation of the substrate
Remove degraded and damaged concrete until the substrate is solid, resistant and rough. Any previous repair work that is no longer thoroughly bonded should be removed. Gritblast the concrete and reinforcing bars to ensure any corrosion is removed as well as any dirt, concrete laitance, grease, oils or coatings. Saturate the substrate with clean water. Before repairing with Mapemortar HB R3, wait until the excess water has evaporated. To facilitate this the use of compressed air may be required. A slurry made from Mapemortar HB R3 could be used if it is not possible to pre- soak the substrate.

Preparing the mortar
Measure the amount of clean water needed into the mixer to obtain the required consistency for the application.
APPLICATION LITRES OF WATER PER 25 KG BAG - Trowel application 3.4 litres, Hand application 3.6 litres

Start the mixer and slowly add the Mapemortar HB R3 to the water in a continuous way. Mix for 1 - 2 minutes, then make sure that the mix is well blended. Scrape any unblended powder from the bottom and sides of the mixing drum, and then mix for a further 3 minutes. Either a forced action mixer or a suitable drill and paddle may be used according to the amount of mortar required. Mixing must be carried out at low speeds to avoid air being entrapped in 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 mix is achieved. It is important, to keep in mind if mixing by hand more water will be required. This will affect the mortars characteristics including its mechanical strength, shrinkage and impermeability. Mapemortar HB R3 remains workable for approximately 40 mins at +20°C.

The expansion of Mapemortar HB R3 is calculated to compensate for plastic shrinkage. For it to be effective the substrate needs to be adequately reinforced with rebars or forms. The expansion phase ends during the first days of curing.

Application procedure
The Mapemortar HB R3 can be applied by trowel or by gloved hand on vertical surfaces or overhead situations with or without formwork to a depth of 70mm per layer. Reinforcing bars should be treated with Mapefer or Mapefer 1K before applying the Mapemortar HB R3. Where required apply a second layer of Mapemortar HB R3 before the previous layer has cured.

The complete system calls for smoothing with Planitop 200, Monofinish or Mapelastic and then protecting with Elastocolor Paint.