RU2259971C1 - Method of concrete mix preparation - Google Patents

Abstract

FIELD: building materials, particularly used for producing concrete structures and articles.

SUBSTANCE: method involves metering quartz sand, binging material components and additive, namely hardening intensifier; mixing above materials and forming articles. Ash-and-slag-and-alkaline binding agent is used as the binding material. Ash-and-slag-and-alkaline binding agent includes liquid glass and ash-and-slag mixture. Liquid glass is produced from large-tonnage crystalline silicon production waste obtained at aluminum smelter, namely of microsilica, and including highly-dispersed carbon mixtures, namely graphite and carborundum with silica modulus n=1 and 1.37-1.45 g/cm³ density, in amount of up to 6-7% by weight. Ash-and-slag mixture is obtained by brown coal burning and is grinded so that not more that 2% of material is retained on sieve with 0.08 mm openings. Ash-and-slag mixture contains 35% of slag component and 65% of ash component. The hardening intensifying additive is Portland cement. Concrete mix components are taken in the following amounts (% by weight): liquid glass - 13.5-28.2, ash-and-slag mixture - 24.3-50.1, quartz sand - 31.4-54.5, Portland cement - 0.7-1.8. The mix may be hardened under temperature of up to -18°C.

EFFECT: increased frost-resistance and extended range of concrete mix hardening temperatures.

1 ex, 2 tbl

Description

The invention relates to the construction materials industry and can be used in the manufacture of structures and concrete products.

A hydraulically hardening composition is known that hardens at low temperatures and contains 50-80 parts of BTsM, 13-35 parts of fly ash, 0-10 parts of metakaolin, 0-6 parts of slag, 0-4 parts of timing control additives setting the binder and 1-5 hours of potassium carbonate [US Patent No. 4842649, 1989].

The disadvantage of this composition is its multicomponent.

The closest analogue to the described invention is a method of preparing a concrete mixture, including dosing of quartz sand, binder components containing carbon-containing liquid glass, made from large-tonnage waste from the production of crystalline silicon of the Bratsk aluminum plant - silica fume and containing up to 6-7 wt.% Of highly dispersed carbon impurities - since the graphite and silicon carbide SiC with the silicate modulus n = 1-3 and the density ρ = 1,20-1,43 g / cm ³ and ground to a residue on sieve №008 2-3,2% ash and slag moldboard cm B-7 CHP Bratsk Irkutsk region, mixing of the components and molding [RF patent №2138455, 1999 g].

The disadvantages of the described method of preparing a concrete mixture are the inability to harden at a negative temperature and relatively low frost resistance (200 cycles).

The problem solved by the invention is to improve the quality of concrete.

EFFECT: increased frost resistance of concrete, expansion of the range of hardening temperature (up to -18 ° С).

The specified technical result in the implementation of the invention is achieved by the fact that the preparation of concrete mixture includes dosing of quartz sand, binder components and additives, a hardening intensifier, mixing and molding of products, ashes and binders, ash-and-alkali binders (ZHSHV), consisting of carbon-containing liquid glass made of carbon, are used large-tonnage waste from the production of crystalline silicon of the Bratsk aluminum plant - silica fume and containing up to 6-7 wt.% highly dispersed carbon hydrocarbon impurities of graphite C and carborundum SiC with silicate module n = 1 and density ρ = 1.37-1.45 g / cm ³ and ground to a residue on sieve No. 00 of up to 2% of the waste ash and slag mixture obtained from burning brown Kansk-Achinsky coal at CHPP-6 in Bratsk, Irkutsk region and for 35% consisting of slag and 65% of the ash component, and as an additive. - Portland cement brand 400 in the following ratio of components, wt.%:

Carbon Liquid Glass silica fume 13.5-28.2 Ash and slag mixture 24.3-50.1 Quartz sand 31.4-54.5 Portland cement 0.7-1.8

The chemical composition of fly ash is presented in table 1

Table 1
The average chemical composition of the ash and slag mixture of TPP-6 (Bratsk) Content, wt.% SiO ₂ Fe ₂ About ₃ Al ₂ About ₃ CaO MgO SO ₃ R ₂ O 57.3 13.5 12.0 13.7 2.2 0.7 0.5

Example. Concrete mixture was prepared as follows. In a laboratory ball mill, 37.2% of the ash and slag dump mixture, consisting of 35% of the slag and 65% of the ash component, was ground to a residue of sieve No. 008 to 2%. The ground ash and slag mixture was mixed with 33.5% quartz sand and 1.1% Portland cement of grade 400. After this, the resulting mixture was closed with 28.2% carbon-containing liquid silica glass with silicate module n = 1 and density ρ = 1.41 g / cm ³ . Mixing of the concrete mixture was carried out in a forced-action concrete mixer for 2-3 minutes. The samples were formed on a laboratory vibratory platform. Samples in the molds solidified at a temperature of T = 16-20 ° C in air-dry conditions for 24 hours, after which they were redressed and placed in a freezer at a temperature of -18 ° C for further testing. The test results are shown in table.2.

table 2
Properties of concrete based on ZHShchV, hardening at a negative temperature Hardening temperature Compressive strength, MPa aged Frost resistance cycles -18 ° C 1 day 3 days 7 days 14 days 28 days 250 7.3 11.8 12.7 18.0 26.2

An analysis of the data shows that the proposed concrete mixture is able to gain strength not only during steaming (as in the prototype), but also at low temperatures (-18 ° C). The frost resistance of concrete obtained from the proposed concrete mixture also differs more favorably from the frost resistance of known concrete (250 instead of 200 cycles). In addition, the possibilities of using the proposed concrete mixture are much wider: factory conditions, construction site conditions. Moreover, in the latter case, construction is possible not only in the summer - frost-free period, but in the spring and autumn at T up to -18 ° С.

Claims (1)

A method of preparing a concrete mixture, including dosing of quartz sand, binder components and additives - hardening intensifier, mixing and forming products, characterized in that the ash and slag binder is used as the binder, consisting of carbon-containing liquid glass made from large-tonnage waste of the production of crystalline silicon of Bratsk aluminum aluminum plant - silica fume and containing up to 6-7 wt.% highly dispersed carbon impurities of graphite C and carborundum SiC, with silicate m module n = 1 and density ρ = 1.37-1.45 g / cm ³ , and ground to a residue on sieve No. 008 up to 2% of the waste ash and slag mixture obtained from burning brown Kansk-Achinsk coal at TPP-6. Bratsk, Irkutsk region, and 35% consisting of slag and 65% of the ash component, and Portland cement grade 400 as an additive in the following ratio of components, wt.%: Carbon Liquid Glass silica fume 13.5-28.2 Ash and slag mixture 24.3-50.1 Quartz sand 31.4-54.5 Portland cement 0.7-1.8