FINE-GRAINED CONCRETE AND METHOD OF THE CONCRETE MIXTURE PREPARATION FOR ITS PRODUCTION Russian patent published in 2018 - IPC C04B28/04 C04B14/06 C04B14/26 C04B24/26 C04B103/32 C04B103/46 C04B111/20 

FIELD: construction.

SUBSTANCE: invention relates to the construction materials manufacturing, in particular to the fine-grained concrete and to the concrete mixture for its production preparation method, and can be used for manufacturing of the concrete products and structures, both monolithic and prefabricated, used in the building materials industry and construction, where the technology requires increased mixture fluidity at the application stage, and high strength of the fine-grained concrete. Produced from a concrete mixture including the Portland cement, quartz sand, filler, based on the “Melflux” polycarboxylate ether powdered hyper-plasticizer, water-retaining additive, water, the fine-grained concrete, as the Portland cement contains the Portland cement without additive with the cement paste normal density index of not more than 26 %, as the filler, micro-calcite with the calcium carbonate content of not less than 97 % with the fraction particles of not more than 120 mcm of not less than 98 % is used, including fractions of less than 20 microns – no more than 7 %, as the water-retaining additive, the condensed unconsolidated micro-silica is used with the amorphous silica content of at least 85 % and specific surface of 12–25 m²/g or metakaolin with the amorphous alumina content of at least 40 %, amorphous silica of not less than 50 %, aluminosilicate structure amorphisation of at least 90 % and specific surface of 1.2–2.5 m²/g in following ratio of components, mass%: Portland cement without additives with the cement paste normal density indicator of not more than 26 % – 15.8–23.6, quartz sand is 35.6–61.4, micro-calcite with the calcium carbonate content of not less than 97 % with the fraction particles of not more than 120 mcm of not less than 98 %, including fractions of less than 20 microns of no more than 7 % – 1.8–27.4, based on the “Melflux” polycarboxylate ether powdered hyperplasticizer – 0.14–0.30, condensed unconsolidated micro-silica with the amorphous silica content of at least 85 % and specific surface of 12–25 m²/g or metakaolin with the amorphous alumina content of at least 40 %, amorphous silica of not less than 50 %, aluminosilicate structure amorphisation of at least 90 % and specific surface of 1.2–2.5 m²/g – 0.81–4.20, water – the balance. In the concrete mixture for the fine-grained concrete production preparation method, consisting in the concrete mixture components successive mixing until the required fluidity and mobility is obtained, initially, the Portland cement and powdered hyperplasticizer are mixed in the mixer for 1–2 minutes, then the micro-calcite and water-retaining additive are filled in and mixed for 1–2 minutes, after which quartz sand is introduced and the dry mixture is stirred until uniformity for 1–2 minutes, then the first portion of water is introduced in an amount of 60–70 % and stirred for 1–2 minutes, at the final stage, adding the remaining portion of water in an amount of 30–40 % and mixing until the required mobility and uniformity concrete mixture is obtained.

EFFECT: invention is developed in subclaims.

9 cl, 3 tbl