Mapei Planitop HPC

Mapei Planitop HPC is a two component, ultra-high performance, shrinkage-compensated, free-flowing, high ductility fibre-reinforced cementitious mortar with stiff steel fibres. Class R4.

Best Uses

Mapei Planitop HPC is a two-component fluid mortar suitable for casting into formwork without risk of segregation. When applied in layers up to 40 mm thick, it can be cast without using reinforcing bars. For thicker applications, it is possible to design a suitable reinforcement mesh. Planitop HPC is a ready-mixed free-flowing mortar made of two components: component A (powder) and component B (Fibre HPC). Planitop HPC component A (powder) is made of high-strength cement, selected aggregates and special additives.

To allow the product’s expansive properties to develop fully and correctly, Planitop HPC must be cured in a damp environment. To allow expansion in the open air, Planitop HPC can also be admixed with 0.25% of Mapecure SRA, a special admixture that reduces plastic and hydraulic shrinkage. Mapecure SRA carries out an extremely important role and guarantees better curing of the mortar. When mixed with Planitop HPC, it can be considered a technologically advanced system, as it is able to reduce the rapid evaporation of water and promote the development of hydration reactions. Mapecure SRA acts basically as an internal curing agent and, thanks to its interaction with some of the main components in the cement, reduces final shrinkage by 20% to 50% compared with the same product without the admixture, which means there is also a lower risk of cracking. The use of Mapecure SRA could slightly reduce mechanical performance characteristics by 5-6%.

The product may also be used without adding Mapecure SRA when climatic conditions allow a favourable curing cycle to be carried out.

Once hardened, Planitop HPC has the following characteristics:

• Very high flexural and compressive strength
• High ductility
• High resistance to cyclical loads
• Impermeability to water
• Excellent adhesion to both old concrete (if soaked with water before application) and rebars, especially if treated beforehand with Mapefer or Mapefer 1K Zero
• High resistance to wear due to abrasion or impact

Mapei Planitop HPC is ideal for the reparation and strengthening of reinforced concrete structures that require the use of a free-flowing, ultra high performance, and high ductility mortar without using reinforcing bars in order to limit the thickness applied.

Some application examples include:

• Seismic retrofitting of elements subject to high stresses and where high ductility is required
• Structural strengthening of reinforced concrete pillars and beams by column and beam jacketing
• Repairs to the lower sections of pre-tensioned beams in viaducts
• Rebuilding and levelling off the upper parts of piers caps and bearings on motorway viaducts
• Reparation of floor slabs after removal of damaged areas by scarifying

Application

Preparation of the substrate
Remove all damaged and detached areas of concrete to form a sound, rough (roughness of at least 5 mm) and strong substrate. Any areas previously restored which are not perfectly attached must also be removed. Remove all dust, rust, cement laitance, grease, oil and old paint from the concrete and reinforcing bars by sandblasting. Saturate the substrate with water. Before casting, wait until the excess water has evaporated. If necessary, this operation may be speeded up by using compressed air.

Preparation of the mortar
Pour Planitop HPC component A (powder) in the mixer and add 3.0 litres of water per bag of product. The mixing time depends on the efficiency of the mixer. For example, with a forced-action mixer, mixing requires approximately 4 minutes. When the product is well blended and lump-free, add the relevant quantity of component B (Fibre HPC) and mix for 2 more minutes. If a traditional cement mixer is used, mix component A (powder) with the relevant quantity of water for 8 minutes. After the addition of component B (Fibre HPC), mix for 4 - 5 more minutes. At the end of the mixing process, the mix must be smooth (the fibres must be completely dispersed), fluid, and
lump-free. Small variations in the quantity of mixing water (2.9-3.1 l) are allowed depending on the mixing equipment and the climate conditions. It is recommended to apply the product within 30 minutes of mixing.

Application of the mortar
Pour Planitop HPC into the formwork in a continuous flow from one side only, making sure all the air is expelled. The formwork must not absorb any of the water from Planitop HPC. It is recommended to treat the formwork beforehand with a form release agent (such as Mapeform DMA 1000). Make sure that all the members to be strengthened are completely filled. To help the mortar flow into the more difficult areas, use wooden rods, round iron bars, or vibrate lightly.

FINISHING AND PROTECTIVE COATING
In the case of application in exteriors, protect Planitop HPC with the finishing cycles composed of Mapei Primer EP Rustop and Mapecoat PU33, or Mapelastic Zero and Elastocolor Pittura. The protective finish can be applied directly on Planitop HPC or on the overlaying skim coat, if any. Refer to the relevant Technical Data Sheet for details on how to apply the aforementioned products.