SU1520054A1 - Concrete mix - Google Patents

Abstract

The invention relates to the field of building materials, namely, compositions of acid-resistant aerated concrete mixtures, and can be used in the manufacture of self-supporting and fencing products and structures of industrial and civil buildings, including exploited environments. The invention makes it possible to increase the strength and the coefficient of the constructive quality of concrete. The concrete mixture includes, in wt.%: Tridymite-cristabalite in the form of 25 ... 55, ground silica component 23 ... 44, aluminum powder 0.04 ... 0.07, alkaline earth metal oxide 0.5 ... 1 2, water the rest. The strength of concrete is 10.9-36 MPa, the coefficient of structural quality of 170-250. 1 tab.

Description

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The invention relates to building materials, namely, compositions of acid-resistant aerated concrete mixes, and can be used in the manufacture of self-supporting and fencing products and structures of industrial and civil buildings, including those used in aggressive environments.

The aim of the invention is to increase the strength and the coefficient of structural quality of concrete.

The addition of additives to the hardening and structuring enhancers is due to the fact that the silica compound has an insufficient pH for the gassing reaction and also because it does not harden under natural conditions.

Alkaline earth metal oxide combines the functions of these two additives. At the first stage, it performs the role of an intensifier of structure formation, i.e. increases the pH of the medium, which contributes to the passage of the gas formation reaction and the release of hydrogen. Further, as a result of this reaction, an alkaline earth metal hydroaluminate (e.g., 3CaOC1-2.0xX X) is formed, which has astringent properties and acts as a hardening intensifier. The unexpected effect is that, as a result of the gassing reaction, the free aluminum binds to the named compound, which does not interfere with the structure formation of silica in the autoclaving process. Thus, the proposed mixture does not contain any additives for silica, which improves the mechanical strength of the substance, as well as

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on noBbtiue.HHH coe (} fn 1; the design quality of an acid-resistant aerated concrete on silica in a tent.

Example. In the specified ratios, the dry components are metered: TK in the living, silica component in the form of ground quartz sand and alkaline earth oxide. The dry ingredients are thoroughly mixed in a paddle paddle. Separately, an aluminum-water suspension is prepared, which is fed together with water heated to 55t5 ° C into a concrete mixer and the mixture is stirred again. The mixture is then placed into molds with a fin size of 100 mm and vibrated during the process of gas generation. After that, after 30 - 60 minutes, the cap is cut off. Next, the concrete mixture in the forms is placed in an autoclave, where they are heat treated in a saturated steam environment at 87 ° C and pressure, 2 MPa according to the mode 3 1 6 - 4 hours. The obtained samples are drawn, measured, weighed and tested for strength. under compression.

The compositions of the concrete mixture and the test results are given; In the table,

Concrete obtained from the proposed mixture has a strength of 1.5 - 2 times higher than known concrete, equivalent to the average density, which decreases its coefficient of structural quality.

In addition, when using the proposed concrete mix, energy consumption associated with the preparation and preparation for use (grinding) of active alkali-containing silica, scarcity and high cost of raw materials (ground glass and aluminous cement) are excluded. The known composition contains many components, which complicates technology.

Formula and 3 obrat shadows

The concrete mixture comprising the tumbling, ground silica component, aluminum powder, structure formation enhancer, and water, characterized in that, in order to increase the strength and coefficient of structural quality, it contains as a tritic tridimocristobalite in the tidal fraction O , -, 25 mm, and as an intensifier of structure formation - an alkaline earth metal oxide in the following ratio of components, wt.%: Tridymite-cristobalite stinging, Ground silica component Oxy-aluminum powder alkaline earth metal / Water

25-55

23-44 0.04-0.07

0.5-1.2 Else

Claims (1)

Claim A concrete mixture comprising a binder, ground silica component, aluminum powder, an intensifier of structure formation and water, characterized in that, in order to increase strength and coefficient of structural quality, it contains 0.1-1.25 mm fractions of a tridymite-cristobalite binder fraction , and as an intensifier of structure formation - alkaline earth metal oxide in the following ratio of components, wt. £: Tridimito-cristobalite binder 25-55 Ground silica th component 23-44 Aluminum powder 0.04-0.07 Alkaline oxide grinding metal 0.5-1.2 Water Rest Concrete characteristics Indicators, May for composition 2_J 2 > 1 famous The content of components, wt. X: TC binder 25 37 55 ground silica component (silica sand) 44 37 23 alkaline earth metal oxide 1.2 0.9 . 0.5 aluminum powder 0.04 0,055 0,07 water 29.76 25,045 21.43 The average density in the dry state, kg / m ³ 1200 1000 800 700 Strength, MPa 36.0 20,0 10,9 ‘ 5.7 Quality factor 250 200 170 61-82