RU2281267C1 - Raw mixture and method for producing vibro-swollen gas-ash concrete - Google Patents

Abstract

FIELD: building industry and materials.

SUBSTANCE: invention relates to manufacturing cellular concretes of non-autoclave hardening. The raw mixture for producing vibro-swollen gas-ash concrete comprises the following components, wt.-%: Portland cement, 9.7-23.3; fly ash from heat and electric power plant-7 of town Bratsk obtained in combustion of brown coals Kansk-Achinsk fuel-energy complex, 43.2-54.8; building gypsum, 1.9-2; detergent agent "Taiga" of indicated composition, 0.2-0.21; aluminum powder, 0.06-0.07, and water, the balance. Method for making vibro-swollen gas-ash concrete articles of reduced density from the abovementioned raw mixture involves preparing the indicated mixture, its placing into a shape that is installed on a vibrating platform showing the following parameters of vibration: preliminary holding is 0.5-1 h; amplitude vibration is 0.2-0.3 mm; vibration frequency is 50-100 Hz. Then mixture is swollen for 5-7 min when the shape is placed on the vibrating platform and articles are held in shapes for 2-3 h at temperature below 20°C followed by cutting of the "hump" and shape is placed into chamber for thermal-moisture treatment that is carried out in regimen (3+5+2) at isothermal holding temperature 95°C. Invention can be used in making building articles and constructions. Invention provides reducing an average density, heat conductivity, water absorption and capillary inflow, enhancing the compression strength value after steaming and the gas concrete quality coefficient.

EFFECT: improved producing method, enhanced quality and properties of concrete and articles.

2 cl, 2 tbl, 1 ex

Description

The invention relates to the production of non-autoclaved cellular concrete and can be used for the manufacture of building products and structures.

Known raw mix, including, wt.%: Cement - 54.91; ash - 3.87; aluminum powder - 0.07 and water 41.15.

The disadvantage of this mixture is its high water absorption and capillary suction.

An object of the invention is to reduce the average density, thermal conductivity, water absorption and capillary suction, increase the compressive strength after steaming and the quality factor of aerated concrete.

The technical result is achieved by the fact that the raw material mixture for the preparation of vibration-expanded gas-ash concrete, including Portland cement, fly ash, gypsum, water, detergent MC Taiga, aluminum powder and water, contains ashes fly ash, fly ash TPP-7 g Bratsk obtained by burning brown coal of KATEK, in the following ratio of components, wt.%:

specified fly ash 43.2-54.8 Portland cement 9.7-23.3 gypsum plaster 1.89-2 indicated by MS "Taiga" 0.16-0.28 aluminum powder 0.06-0.07 water rest

Fly ash from burning brown coal of the Kansk-Achinsk basin (Irsha-Borodinskoye, Nazarovskoye, Berezovskoye deposits) are high-calcium and contain, in wt.%: SiO _i - 21 ... 55; Al ₂ O ₃ - 4 ... 11; Fe ₂ O ₃ 6 ... 16; CaO - 20 ... 46; MgO - 3 ... 6; K ₂ O - 0.2 ... 0.6; SO ₃ - 0.9 ... 9; CaO _St. - 3 ... 13; combustible impurities - not more than 2 ... 2.5.

Closest to the proposed method according to the technical essence and the achieved effect, the method [1], including the preparation of the mixture, molding and heat and moisture treatment.

The disadvantage of this method is the high water content of the mixture, large air shrinkage, high thermal conductivity and low quality factor.

The above technical result is achieved by the fact that in the method of manufacturing vibration-diluted gas-concrete products of reduced density from a raw material mixture, including preparing the mixture, molding and heat and moisture treatment, the mixture is prepared, laid in a mold, this mold is mounted on a vibration platform with the following vibration parameters:

preliminary exposure - 0.5-1 h,

vibration amplitude - 0.2-0.3 mm,

vibration frequency - 50-100 Hz.

The swelling of the mixture occurs within 5-7 minutes, while the form is on the vibrating platform. The products are kept in the molds for 2-3 hours at a temperature not lower than 20 ° С, then a “hump” is cut, the mold is placed in the heat-moisture treatment chamber, heat-moisture treatment is carried out according to the (3 + 5 + 2) mode at an isothermal exposure temperature of 95 ° С .

Example

The process of preparing the concrete mixture includes the following operations. Dry components are metered, thoroughly mixed and an aqueous solution (t = 40 ... 50 ° C) of Taiga detergent is introduced. The mixture is stirred for 3 ... 4 minutes. The finished suspension of aluminum powder is introduced into the mixture and mixed for no more than 1 minute. After pouring the mixture into a well-lubricated and hermetically assembled form, the mixture is subjected to preliminary exposure, during which the aluminum powder interacts with calcium oxide located in Portland cement and fly ash. Then this form is installed on a vibration platform with the following vibration parameters:

preliminary exposure - 0.5-1 h,

vibration amplitude - 0.2-0.3 mm,

vibration frequency - 50-100 Hz.

The swelling of the mixture occurs within 5-7 minutes, while the form is on the vibrating platform. The products are kept in the molds for 2-3 hours at a temperature not lower than 20 ° С, then a “hump” is cut, the mold is placed in the heat-moisture treatment chamber, heat-moisture treatment is carried out according to the (3 + 5 + 2) mode at an isothermal exposure temperature of 95 ° С .

Physico-mechanical properties of products obtained on the basis of the proposed vibro-expanded mixtures and prototype are presented in table 1.

As can be seen from table 1, the proposed compositions in comparison with the prototype can increase the quality factor of products by 57-98%, reduce their thermal conductivity by 20-40%, increase their compressive strength by 8-23% after steaming, in addition, ash -unos as a finely dispersed component, does not need additional grinding, which simplifies the manufacturing technology of products, eliminating the need for autoclaving, therefore, the cost is reduced.

Table 2 shows the compositions of the three proposed mixtures and prototype.

table 2 Components Amount, wt.% Prototype one 2 3 Quartz sand 52.93 Pyroplast 7 Aluminum powder 0.06 0,065 0,07 0,07 Portland cement 16.5 23.3 9.7 40 Fly ash 49 43,2 54.8 Gypsum plaster 1.9 2 1.89 Detergent "Taiga" 0.21 0.28 0.24 Water Rest

The source of information

1. Glukhovsky V.D. et al. Fundamentals of technology for finishing, heat and waterproofing materials. - Kiev, 1986, p. 159.

Claims (2)

1. The raw material mixture for the preparation of vibration-expanded gas-ash concrete, characterized in that it contains fly ash from TPP-7 in Bratsk, obtained by burning brown coals of KATEK, Portland cement, gypsum, gypsum, detergent MS Taiga with contents up to 98, 6 wt.% Tall fatty acids saponified and up to 0.5 wt.% Sodium salt of carboxymethyl cellulose or methyl cellulose, aluminum powder in the following ratio, wt.%: Indicated ash 43.2-54.8 Portland cement 9.7-23.3 Gypsum plaster 1.89-2 The specified MS "Taiga" 0.16-0.28 Aluminum powder 0.06-0.07 Water Rest 2. A method of manufacturing a low-density vibration-swelled gas-concrete products from a raw material mixture according to claim 1, characterized in that the mixture is prepared, placed in a mold, this mold is mounted on a vibration plate with the following vibration parameters: preliminary exposure time 0.5-1 h, amplitude vibrations of 0.2-0.3 mm, vibration frequency of 50-100 Hz, carry out the expansion of the mixture for 5-7 minutes, while the mold is on the vibrating plate, the products are kept in molds for 2-3 hours at a temperature of at least 20 ° C , then cut off the "hump", forms they are placed in a chamber of heat-moisture treatment, heat-moisture treatment is carried out according to the regime (3 + 5 + 2) at an isothermal exposure temperature of 95 ° C.