Umafix HP

Umafix HP is a single-component, ready-to-use, grey-coloured, thixotropic, fibre-reinforced, shrinkage-compensated, high-strength, quick-setting cement mortar based on special hydraulic binders, selected aggregates and specific additives. Suitable for the passivation and restoration of concrete and reinforced concrete surfaces. Due to its special formulation, the product mixed with water has excellent workability and excellent thixotropy, which allows it to be laid even vertically in thicknesses up to 60 mm. Once applied, it sets in about 15 minutes under normal conditions (20°C). A slight expansion both in the plastic phase and in the post-hardening phase makes it possible to compensate for hydraulic shrinkage, with a considerable improvement in the final adhesion characteristics, while avoiding cracking. The hardened product is loadable after one hour and is resistant to water and frost. It is therefore suitable for both indoor and outdoor applications, and is highly waterproof. Umafix HP is a structural repair mortar of type CC and class R3 according to EN 1504-3.

Instructions for use

The substrate must be clean, sound, resistant and strongly roughened, free of oil and grease, dust, crumbly material and dirt in general, and free of paint film residues, and must be suitably cured and free of significant shrinkage. Remove any loose, crumbling and inconsistent parts with careful hammering and chiselling, down to a sound and resistant substrate. Wet to refusal and allow excess water to evaporate or remove it with a sponge, taking care to remove any surface water film.

Mixing the product
Mix Umafix HP with 19 – 20% clean water (equal to 4.75 – 5.00 litres per 25 kg bag) using a mechanical stirrer (low-speed drill with propeller) until the mix is smooth and free of lumps. The mix thus prepared has a workability time of approx. 12 minutes under normal conditions (20°C); at higher temperatures, the workability time is shortened. Prepare a quantity of mix that can be laid within its workability time. At particularly low temperatures (around +5°C), mix with warm water or keep the product in a heated room to maintain the same setting times. In case of particularly high temperatures (around 30°C), mix with cold water and keep the product in the shade.

Application
Apply the mix quickly using a trowel or paddle. As soon as the mortar starts to set, wet the surface and smooth with a float. Keep the mortar moist for the first 8 hours after application. Proceed as follows when restoring reinforced concrete:

• Expose the outcropping reinforcing bars by completely freeing them from any carbonated concrete and turning them to “white” using a hydro-sandblaster or sandblaster.
• The product has a passivating action on the reinforcement rods, but for effective anticorrosive protection apply Restauro Ferri to any reinforcement rods. After the anticorrosive protection has hardened, for better adhesion of the Umafix HP coating, apply a slurry of Umafix HP mixed with a 1:3 solution of Neoplast Latex and water (1 part by volume of Neoplast Latex and 3 parts by volume of water) to the treated reinforcement rods and surrounding concrete.
• On the fresh grout apply Umafix HP mixed only with water and possibly diluted with sand in the case of large cavities. As soon as the grout sets moisten the surface and finish with trowel.
• Keep the applied mortar moist in the first 8 hours.

Cleaning
The tools for applying the mortar may be cleaned with water before it hardens. Once hardened, the mortar must be scraped off.

Storage

Store Umafix HP in a dry, protected place. Unopened in its original bags, the product can be stored for at least 9 months.

Warnings

• Do not use Umafix HP as foundation mortar for glass cement components.
• Do not apply Umafix HP on gypsum substrates or over gypsum based mortars, renderings and fillers.
• Do not apply Umafix HP on plastic renderings, painted substrates, wood, metal or asbestos cement.
• Do not apply Umafix HP when the temperature is less than +5°C or more than +35°C.
• Do not mix the product with other binders such as cement, hydraulic lime, gypsum, etc.
• The mix cannot be diluted with water once it has started setting.
• Do not use the mixed product when it has already started to set. Therefore, always prepare quantities of mix which can be used within the pot life.
• Caution: when laying horizontally and vertically, the surface of the supporting concrete must be rough (roughness more than 5 mm deep) in order to achieve the necessary adhesion between the substrate and the Umafix HP restoration material.