Velosit SL505 — White High Strength Self Leveling Overlayment

• VELOSIT SL 505 is designed for concrete substrates. Steel may be coated with a suitable bonding bridge.
• Steel must be prepared to a purity of SA 2.5 acc. SIS 05 5900.
• Concrete must be prepared with sand blasting, shot blasting or high pressure water blasting (> 100 bar) to remove all bond breaking substances.
• Substrate must be rough, open porous and load bearing. The minimum requirement for adhesive strength is 2.0 MPa and for the compressive strength 30 MPa. Lower strength values can be accepted if lower adhesive strength is acceptable. Active water leaks must be treated and fully stopped with VELOSIT PC 222.

Leaking cracks need to be sealed with a Hychem Spetec PU

Injection material.

Steel

Apply a corrosion protection coat on rebar with VELOSIT CP 201.

Other steel areas can be primed with Hychem E100SS or E500P with a full broadcast (suitable quartz sand 0.7 mm – 1.25 mm).

Steel may expand and contract differently under temperature changes than a cementitious mortar. Thus steel application is only recommended if steel is embedded in larger concrete bodies or the temperature is not subject to major changes.

Concrete substrates with a humidity of max. 4 % and a water vapor emission rate of less than 0.6 g/m2h can be primed with VELOSIT PA 911 (Acrylic Primer).

VELOSIT PA 911 is ready to receive the leveler usually after 2 – 3 h curing. At higher moisture levels or in case the moisture levels in the substrate are expected to increase, priming must be done with Hychem GP Epoxy. VELOSIT SL 503 can be applied into the tacky primer coating within 2 – 4 hours after application. Longer wait times require a full broadcast with suitable quartz sand 0.7 mm – 1.25 mm into the primer.

VELOSIT SL 505 is a white cementitious self leveling overlayment for concrete fl oors.

It creates an abrasion resistant smooth surface. It may also be used as a high strength underlayment for coatings and fl oor coverings.

VELOSIT SL 505 is a white shrinkage compensated self leveling overlayment based on a special cement with very quick strength development.

Mix VELOSIT SL 505 with 21 – 22 % potable water, i.e. 4.2 – 4.4 l water per 20 kg bag. Fill the 21 % mixing water (4.2 l per bag) into a suitable bucket and mix the powder with a slow speed drill (300 – 600 rpm) into the water until a lump-free mix is achieved.

Use a cage type mixing paddle to reduce the air entrainment into the mix. Add max. 1 % additional water under stirring until the desired consistency is achieved. Do not over water the product!

VELOSIT SL 505 may be extended with up to 50 % clean and dried silica sand 1 – 2 mm for large application thickness.

The product is workable for 30 – 40 min. at 23 °C.

Rake application

Pour VELOSIT SL 505 onto the primed substrate and rake to the desired thickness. Make sure there are no bond breaking substances on the primer. The product can be applied up to 15 mm in one application. Make sure to work in sections that can be fi nished within 30 min. Immediately after pouring use gauge rake to achieve thickness and force entrapped air to the surface.

Alternatively a spiked roller can be used to help air to the surface at larger application thickness. Finish with a smooth rake.

Pump application

Use suitable mortar pumps such as:

• PFT GmbH: PFT G4
• HighTech GmbH: HighComb Big
• Wagner GmbH: PC 25
• Putzmeister GmbH: SP11 or MP 25
• Inotec GmbH: INOMAT-M8
• m-tec duo mix 2000

In mixing pumps feed the powder into the product hopper and adjust the water to the specifi ed rate. The water rate can be adjusted by comparing the fl ow with a hand-mixed batch with a correct water addition. Control the fl ow with a fl ow cone every 5 to 10 min. With mortar pumps add the mixed product as described under „Mixing“ into the feed hopper of the pump and pump continuously.

Rake and smooth the material as described under section “Rake application”.

Long pump interruptions may result in clogging of the pump hose.

The product may cure a lot faster if the hose is exposed to direct sunlight. Always empty and fl ush the machine after pumping or before long spray interruptions. VELOSIT SL 505 is a fast curing material and may be hard to remove if left in the machine.

Never overcoat joints or untreated cracks as this will most likely result in surface cracks!

If used as an underlayment, VELOSIT SL 505 is ready to receive a coating after 16 hours. For use as a wear surface a clear sealer, a surface hardener or VELOSIT FH 921 (silicone enhanced fl oor hardener) is recommended to improve resistance against penetrating liquids like oil, grease or cleaning agents.

VELOSIT SL 505 does not require curing. Protect the applied product for 24 hours against direct sun light, wind and temperature changes exceeding 5 °C.

Volume yield:

20 kg VELOSIT SL 505 result in approx. 11.4 Litre cured mortar.

Standard leveling:

10.5 kg* VELOSIT SL 505 per m² for 6 mm dry mortar thickness on smooth substrates. Depending on surface roughness application rates can be signifi cantly higher.

• 10.5 kg VELOSIT SL 505 powder + 2.22 kg water, i.e. 12.7 kg mixed material per 6 mm and m²

VELOSIT SL 505 can be removed in the fresh state with water.

Once it has cured acidic cleaners like muriatic acid and mechanical cleaning are required.

20 kg watertight plastic bags.

In unopened original packs for 12 months at 5 – 35 °C in a dry storage place protected against sunlight.