LAKHTA R-245 — structural polyurethane resin for crack injection
Rigid low-viscosity polyurethane resin for bonding cracks and joints and restoring the load-bearing capacity of concrete; 80 MPa compressive.

LAKHTA elastic “Standard” consists of two components — a dry mix with polymer additives and a liquid elastifier, supplied as a 32 kg kit. The coating is designed for structures where cracks, settlement, vibration and deformation are possible: precast reinforced concrete, aerated and foam concrete, brick and metal, outside and inside, including ceilings. It elongates by 30 % before break, stays flexible at −10 °C, bonds to concrete and metal with a strength of 1.0 MPa and bridges cracks up to 1 mm, and with fabric reinforcement cracks up to 2 mm. The compound is compatible with tile adhesive.
| Manufacturer | Rastro (LAKHTA, SLAVYANKA, Izhora) — ZAO “Rastro”, Bolshaya Izhora |
|---|---|
| Type | coating waterproofing |
| Use | foundations and basements, interiors, tanks and pools |
| Base | two-component polymer-cement compound: component No. 1 — dry mix (Portland cement, quartz filler, polymer additives), component No. 2 — elastifier (milky-white liquid) |
| Colour | mix grey with a violet tint; coating grey |
| Packaging | 32 kg kit: dry mix 24 kg (paper bag with PE liner) + elastifier 8 kg (plastic bucket) |
| Application method | substrate at least 14 days old, sound and even; reinforce cracks wider than 1 mm with polypropylene mesh or tape, chase out cracks wider than 2 mm and construction joints and caulk them with LAKHTA joint waterproofing; fillets 30×30 mm; dampen without free water or prime with LAKHTA latex primer; add the dry mix to the elastifier (1 kg : 0.33 kg), stir with a drill for 3 min; do not add water, cement or sand; apply with a spatula or stiff brush in two crosswise coats, no more than 1.5 mm per pass; protect from sun, rain and frost |
| Application temperature | +5…+35 °C (air and substrate); material and elastifier at 20±5 °C before mixing |
| Curing | pot life 40 min; next coat after 4 h at +20 °C (4…6 h at +15…+20 °C, 6…8 h at +10…+15 °C, 8…10 h at +5…+10 °C); film polymerisation from 4 h to 3 days; final properties after 28 days; finishing not earlier than after 3 days |
| Key properties | 2 mm membrane: tensile strength 0.8 MPa; elongation at break 30 %; flexibility on a Ø10 mm bar without cracks at −10 °C; heat resistance 150 °C for 5 h; increase in water-tightness on W2 concrete specimens under positive pressure 10 atm; bond strength to concrete 1.0 MPa, to metal 1.0 MPa; crack bridging up to 1 mm without reinforcement, up to 2 mm with polypropylene fabric reinforcement; aggressive media pH 4…12 (ammonium, magnesium up to 10,000 g/m3, 10 % caustic soda, sea salt 3 %, MgCl2 10 %, NaOH 3 % — resistant); resistant to groundwater and wastewater; permitted under constant presence of water; service up to +150 °C; hazard class 4 |
| Layer thickness | optimum 2 mm (two coats, no more than 1.5 mm per pass) |
| Consumption | 3.2 kg/m² per 2 mm of thickness (for concrete of category A3 according to GOST 13015-2012) |
| Shelf life | 12 months from the date of packing; store and transport at temperatures not lower than +5 °C; do not freeze |
| Standards | TU 20.30.22-017-11149403-2019 (identical to TU 5775-017-11149403-2010) |
Data from the manufacturer’s technical data sheet. The coating system, number of coats and quantity are selected for your project on request.
Rigid low-viscosity polyurethane resin for bonding cracks and joints and restoring the load-bearing capacity of concrete; 80 MPa compressive.
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