CONCRETE MIXTURE, ADDITIVE FOR CONCRETE MIXTURE AND CEMENT MODIFIED WITH SAME ADDITIVE (VARIANTS) Russian patent published in 2005 - IPC

FIELD: concrete composition, cement modified with additive and additive for concrete mixture.

SUBSTANCE: claimed additive contains silica component (e.g., tripoli or sodium methasilicate); superplasticizer; Lignopane with molecular weight of 10-50 kDa; air-entraining agent (e.g., neutralized air-entraining resin or wood saponificated resin) and additionally carboxymethyl cellulose. Additive is obtained by mixing of dry components in ratio (mass %): tripoli or sodium methasilicate (calculated as Si₂O) 20-25; neutralized air-entraining resin or wood saponificated resin 0.005-0.01; superplasticizer 0-20; Lignopane 10-11; carboxymethyl cellulose 1-8. Said additive content is 0.3-2.5 calculated as cement mass. Concrete mixture may comprise (kg/m³) cement 250-600; filler 1590-2030; water 105-190; coarse filler (chip and/or gravel of grade 5-20 mm or 5-40 mm) and/or fine filler (sand of fineness not more than 5 mm). As fine filler at least one component selected from group containing quartz sand, sand from igneous formation, sand from metamorphic formation, haydite sand, and sand from blast-furnace dross is used. As coarse filler at least one component selected from group containing chip from igneous formation, chip from metamorphic formation, chip from sediment, chip from blast-furnace dross, etc. is used. According to one embodiment modified cement is obtained by dry agitation with 0.3-2.5 mass % of above mentioned additives. According to other embodiment modified cement is obtained by simultaneous milling of Portland cement clinker, gypsum and additive of said composition in amount of 0.3-1.0 %. Composition of present invention is useful in building industry for production of monolith and precast concrete and reinforced concrete construction, etc.

EFFECT: concrete mixture of increased water impermeability, freeze resistance, and strength.

11 cl, 3 tbl