Velosit RM203 — Repair Mortar For 1 – 100 mm

VELOSIT RM 203 is designed for mineralic substrates like concrete, masonry or absorptive natural stones. Steel may be coated with a suitable bonding bridge.

Steel must be prepared to a purity of SA 2.5 acc. SIS 05 5900. 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. 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.

Mineralic substrates (concrete, masonry, cement compatible natural stones) must be prepared with sand blasting, shot blasting or ideally high pressure water blasting (> 100 bar) to remove all bond breaking substances.

On reinforced concrete remove all carbonated concrete. Test with Phenolphthalein or other suitable indicator until concrete with sufficient alkalinity for rebar protection is reached. If rebar is exposed remove concrete at least 6 mm behind rebar to fully embed the steel into VELOSIT RM 203.

Substrate must be rough, open porous and load bearing. The minimum requirement for adhesive strength is 1.5 MPa and for the compressive strength 25 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 Hychem Spetec. Before the application of VELOSIT RM 203, dampen the substrate with clean water to a saturated surface dry (SSD) condition.

Concrete repair acc. EN 1504-9 principle 3.1 or 3.2 requires a prime coat with VELOSIT CP 201 on concrete and rebar surface to ensure best adhesion strength results. The prime coat must have set before the application of VELOSIT RM 203.

VELOSIT RM 203 is a rapid setting cementitious repair mortar for various types of construction substrates. It creates a good surface for coatings and overlays.

VELOSIT RM 203 is a shrinkage compensated cementitious repair mortar with extremely fast strength development.

Processing

Mix VELOSIT RM 203 with 15 – 18 % potable water, i.e. 3.0 – 3.6 l water per 20 kg bag. Fill the 15 % mixing water (3.0 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. Add more water (max. 3 %) under stirring until the desired consistency is achieved. Only mix as much material as can be used in 10 min.

Clean mixing paddle immediately after mixing.

The product is workable for 10 min. at 23 °C.

Apply a prime coat of VELOSIT RM 203 with a wet sponge to the pre-dampened substrate. Work approximately 0.5 – 1 kg per m² into the surface pores.

If working acc. to EN 1504-9 the prime coat must be applied with VELOSIT CP 201!

Trowel application

Trowel VELOSIT RM 203 fresh in fresh into the prime coat of VELOSIT RM 203. The product can be applied up to 100 mm on vertical areas. Larger overhead areas may limit the thickness to max. 50 mm. Make sure to work in sections that can be finished within 10 min. Rebars and other penetrations must be fully embedded into the mortar.

Re-modeling of architectural features

Once VELOSIT RM 203 has started to set it can be sculpted as needed. Shave off material in thin layers to achieve desired form. If needed finish surface with a slightly wet sponge to remove surface imperfections and air voids.

VELOSIT RM 203 does not require long term curing as it reacts relatively fast with water. Only under hot weather or very dry conditions water curing for 3 – 4 hours is required.

Repair of surface defects 20 kg VELOSIT RM 203 result in approx. 12.5 litre cured mortar.

Surface Overlay:

10 kg* VELOSIT RM 203 per m² for 6 mm dry mortar thickness on smooth substrates. Depending on surface roughness application rates can be significantly higher. Only use on areas that can be covered in 10 min. For larger areas use VELOSIT RM 202 or concrete repair mortar VELOSIT RM 205.

• 10 kg VELOSIT RM 203 powder + 1.7 kg water, i.e. 11.7 kg mixed material per 6 mm and m²

VELOSIT RM 203 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.