LAKHTA joint waterproofing — non-shrink compound for joints and cracks

LAKHTA joint mix is a non-shrink cement compound with reinforcing fibres used to fill chased-out grooves in formed butt joints, joints, cracks and junctions of cast-in-place and precast reinforced concrete. The hardened mortar has grade W16, compressive strength of 40 MPa, bond to concrete of 2.0 MPa and frost resistance F300, and it works on both the positive and the negative pressure side. The compound is not intended for expansion joints. The manufacturer’s instructions permit its use in drinking water tanks, and an expert opinion has been issued for the material.

Specifications

Manufacturer	Rastro (LAKHTA, SLAVYANKA, Izhora) — ZAO “Rastro”, Bolshaya Izhora
Type	coating waterproofing
Use	joints and junctions, foundations and basements, tanks and pools, drinking water
Base	non-shrink one-component cement compound (dry mix): Portland cement, quartz filler, reinforcing fibres, active chemical additives
Colour	grey dry mix
Packaging	paper bags with PE liner, 10 and 25 kg
Application method	chase out butt joints, joints, cracks and junctions to a depth of 30 mm and a width of 20 mm, clean, wash out or blow out; dampen without free water or prime with LAKHTA latex primer (drying 1 h at +20 °C); for heavily water-bearing joints, first place 20 mm of LAKHTA water plug, then 30 mm of the joint compound (total depth at least 50 mm); mix the powder with water at +20±2 °C as per the label, stir with a drill for 2 min; fill the chase by hand with a spatula or trowel, tamping it in, minimum filling depth 30 mm; moist curing 3 days
Application temperature	not lower than +5 °C and not higher than +35 °C (air and structure, over a 24-hour period)
Curing	pot life 40 min from mixing; moist curing 3 days; painting and finishing not earlier than after 3 days
Key properties	water-tightness grade W16; compressive strength 40 MPa; flexural strength 9.0 MPa; frost resistance F300, contact zone Fkz50; bond strength to concrete 2.0 MPa; average density 2,250 kg/m³; capillary water absorption 0.2 kg/m²·h^0.5, over 48 h 4.0 %; workability Pk2; water retention 99.0 %; resistance to aggressive media (3<pH<13): magnesium 10,000 mg/l and ammonium 2,000 mg/l (highly aggressive), acidic pH3 and carbonic 80 mg/l (moderately aggressive), sulphate 1,000 mg/l (slightly aggressive); mineral oil, kerosene, AI-95 petrol 100 % — resistant; service under constant exposure to temperatures up to +250 °C; UV resistance; suitability for drinking water tanks — permitted; hazard class 3
Layer thickness	joint filling depth at least 30 mm
Consumption	1.06 kg/linear m for a 30×20 mm chase; 2.12 kg/linear m for a 30×40 mm chase
Shelf life	12 months from the date of packing; in dry rooms in the manufacturer's packaging; at temperatures above +30 °C protect from direct sunlight
Standards	TU 5745-007-11149403-2001; GOST 31357-2007

Data from the manufacturer’s technical data sheet. The coating system, number of coats and quantity are selected for your project on request.