COMPOSITION FOR PROTECTION OF CONCRETE SURFACES AND METHOD FOR PROTECTION OF CONCRETE SURFACES Russian patent published in 2009 - IPC C04B28/04 C04B111/27 

FIELD: construction.

SUBSTANCE: invention is related to compositions of concrete mixes used for protection of concrete surfaces of monolithic precast concrete and reinforced concrete structures of buildings and facilities, and also to methods for application of protective layer on protected surfaces. Composition for protection of concrete surfaces contains the following components, wt %: Portland cement 36.0-38.0; sand 39.0-46.5; sodium nitrate 0.9-1.7; sodium carbonate 2.0-3.0; sodium sulfate 2.5-3.0; calcium chloride 0.05-0.15; calcium carbide 0.75-1.15; calcium hydroxide 0.8-1.0; brine leaching solution - bischofite of sulfate type with density of 1.24-1.35 t/m³, 2.0-3.0; water the rest. Method for protection of concrete surfaces with application of above specified composition includes preliminary treatment of protected surface to depth of open porous system of concrete by means of arrangement of systematically located indents on it to create cellular surface with area that exceeds area of protected surface, water impregnation of cellular surface for 36-48 hours, besides specified area of cellular surface is installed depending on temperature of concrete impregnated with water prior to application of protective composition on it based on the following expression: S=[1.4-k(t-5)]·ω, where S is area of cellular concrete surface, m²; k=0.01°C^-1 - size coefficient; t - concrete temperature, °C; ω-area of protected surface, m².

EFFECT: faster development of strength and increased water permeability at low temperatures (5-10°C) at early hardening times.

3 cl, 7 tbl