RU2245865C2 - Cellular concrete mixture and method for production the same - Google Patents

Abstract

FIELD: building material technology, in particular heat-retention concretes.

SUBSTANCE: cellular concrete mixture contains (mass %) Portland cement 15-30; lime 15-20; aluminum powder 0.03-0.10; silica component (e.g. ground quartz sand) 30-42; alkali inverted slurry, obtained from technological waste from green body cutting, 15-20, gypsum 1.5; and balance: water. Claimed mixture is obtained by preparation and mixing in blender of Portland cement, lime, aluminum powder, ground quartz sand, alkali inverted slurry. In this method slurry is outwashed with water into vessel wherein constant mixing and dispersion are carried out, charged in blender, dosed and mixed with other components in following sequence: ground quartz sand, said alkali inverted slurry, Portland cement, lime, additionally gypsum, aluminum powder. Optionally part of alkali inverted slurry is fed from vessel into slime bath for further agitation and homogenizing.

EFFECT: cellular concrete with improved physical and technical characteristics; stimulation of production process; decreased cost of product.

2 cl, 1 tbl, 1 ex, 1 dwg

Description

The invention relates to the production technology of building materials and can be used for the manufacture of heat-insulating and structural-heat-insulating cellular concrete autoclaved for various purposes.

Known raw mix for the manufacture of cellular concrete and the method of its preparation according to the patent of the Russian Federation No. 2058968. The composition of the mixture includes Portland cement, fly ash, urea, calcium hypochloride, a surfactant. The method of preparation consists in the sequence of mixing the components, namely, first water and fly ash are mixed, then Portland cement and calcium hypochloride are added, and after mixing, the remaining components are added.

The disadvantage of the raw mix and method is that the concrete is quite heavy with a specific gravity of more than 1000 kg / m ³ .

Also known are the raw mix and the method of its preparation according to A. St. USSR No. 1402591, according to this method, finely ground steamed waste of aerated concrete raw is added to the raw material mixture. The duration of the concrete production process is extremely long: the expansion time is 33 ... 39 hours, the exposure time to cut "pink salmon" is about 3 hours and the exposure time to autoclave processing is about 5 hours, as a result, the process takes 41 ... 47 hours. Fine grinding steamed waste aerated concrete requires large energy costs and a long time.

Also known is the composition and method of preparing aerated concrete mix according to A. St. USSR No. 1402591.

The composition of this raw mix: Portland cement, fine sand, lime - 3.5%, aluminum powder, steamed aerated concrete waste, water - the rest. In this way, all components are mixed at the same time.

The closest analogue to the claimed mixture is a cellular concrete mixture, including, kg per 1 m ^{3 of the} mixture: Portland cement 150, lime 100, siliceous component - acid fly ash 380, aluminum powder PAP-1 0.4, waste from the production of aerated concrete mixture - aerated concrete - raw with a moisture content of 10-20% in an amount of 20-60% per 100% (CaO + MgO) active, water 315 (patent SU No. 1539190, С 04 В 38/02, 01/30/1990, description).

The closest analogue to the claimed method is a method for preparing a cellular concrete mixture, including the preparation and mixing of components, including waste from the production of aerated concrete in a mixer, in the following sequence, water, a siliceous component, an astringent, including lime with the specified waste, aluminum powder, moreover, the specified waste with a moisture content of 10-20% is introduced as a moisture-containing component when grinding lime (patent SU No. 1539190, С 04 В 38/02, 01/30/1990, description).

The objective of the invention is to increase the physico-technical properties of cellular concrete, the intensification of the process of their production, reducing the cost of production.

This problem is solved in that the cellular concrete mixture, including Portland cement, lime, aluminum powder, a siliceous component, waste from the production of aerated concrete and raw water, contains silica sand as a siliceous component, waste from the production of aerated concrete - alkaline reverse sludge prepared from technological waste cutting raw mass and slicing "peppers", and additionally - gypsum, with the following ratio of components, wt.%:

portland cement 15-30

lime 15-20

aluminum powder 0.03-0.10

ground quartz sand 30-42

specified alkaline back cuttings 15-20

gypsum 1.5-2.0

water rest

This problem is also solved by the fact that in the method of preparing aerated concrete mixture, including preparing and mixing Portland cement, lime, aluminum powder, a siliceous component, a waste from the production of aerated concrete, a alkaline reverse sludge prepared from aerated concrete is used from technological wastes of cutting a raw mass array and slicing a “hump”, which are washed off with water into a container, where they constantly mix and disperse, then the specified slurry m is fed to a mixer, where metered and mixed together with other components in the sequence as silica component - ground quartz sand, said alkaline return sludge, Portland cement, lime, gypsum additionally, aluminum powder. Moreover, it is possible that part of the specified alkaline reverse sludge from the tank is fed into the sludge pool for further mixing and averaging.

The invention is illustrated in the drawing and table 1. The drawing shows the installation diagram for implementing the method.

Table 1 shows the composition and physico-mechanical properties of the proposed mixture.

The installation comprises a mixer 1, to which the supply lines of components 2 ... 7 are connected with the executive bodies 8 ... 13, designed to control the flow of each component of the mixture. From the mixer 1, the mixture supply line 14 departs. On the conveyor 15, the raw material array 16 is cut to size, and the waste is discharged into a mixer vessel 17 containing a mixing unit 18. A pipe 19 with a pump 20 departs from the vessel 17 to supply the resulting mixture to the sludge pool 21, in which the mixing device 22 is also installed. The pipe 23 and the pump 24 are designed to return the waste sludge to the mixer 1. The pipe 23 is equipped with a weighing loop 25, designed to continuously weigh the solution of the return sludge and holding its density at the level of 1.45 kg / dm ³ .

Examples of the composition are given in table 1.

An example implementation of the method.

Technological waste resulting from cutting a raw mass and cutting the "hump" is washed off with water in a tank 17, where it is machined, mixed with water, dispersed. As a result of waste processing, an alkaline reverse sludge is obtained, giving an alkaline reaction of the liquid phase (pH more than 10) due to the hydration of unreacted grains of cement and lime contained in the waste. The high alkalinity and dispersion of the particles of the reverse sludge contribute, as you know, to an accelerated and more complete reaction in the hardening concrete mixture, a faster set of plastic and final strength, a reduction in the maturing time of concrete, the duration of the expansion process, and the cost of preparing the mixture is reduced by 30 .. .35%. The alkaline reverse sludge prepared in this way is pumped by pump 20 to the sludge pool 21, where it is additionally constantly mixed and averaged, and then fed to mixer 1, where it is dosed and mixed with other components. The pipeline 23 contains a weighing "loop" 25, which automatically maintains a given density of the sludge of 1.45 kg / DM ³ .

The application of the invention allowed to obtain a number of crucial advantages, namely:

1. To reduce by several times the timing of the preparation of the mixture for aerated concrete.

2. To reduce the cost of production by 30 ... 35%.

3. To increase the strength properties of the finished product with its low density, good thermal insulation properties.

4. Automate the process of manufacturing cellular concrete, make it waste-free.

5. Ensure the continuity of the production cycle.

6. Improve working conditions and safety.

Significant intensification of the product manufacturing cycle is ensured at almost all technological limits (the time of expansion, exposure, autoclaving decreased).

In addition, there was a decrease in adhesion between the layers of finished products prepared by the proposed method.

Table 1 Composition The content of dry components, mass. % Waste production of cellular concrete, wt.% Process Limit Characteristics Physical and mechanical properties Portland cement Lime Ground quartz sand Gypsum Aluminum powder Steamed aerated concrete waste Alkaline back cuttings Expansion time, hour Holding time before cutting / steaming Duration of parking, hour Density, kg / m ³ Strength, kgf / cm ² Mark of frost resistance, F 1 fifteen twenty 42 2.0 0.10 twenty 23 3.3 / 4.4 12 670 55.0 35 2 23.0 16,2 37 1.9 0,036 - 16,2 25 3.5 / 4.5 thirteen 714 60.0 35 3 thirty fifteen thirty 1,5 0,03 - fifteen 24 3.6 / 4.6 14 724 65.0 35

Claims (3)

1. Aerated concrete mixture, including Portland cement, lime, aluminum powder, a siliceous component, waste from the production of aerated concrete and water, characterized in that it contains ground silica sand, waste from the production of aerated concrete - alkaline reverse sludge, prepared from technological waste by cutting a raw mass array and slicing a “hump”, and additionally gypsum in the following ratio of components, wt. %: Portland cement 15-30 Lime 15-20 Aluminum powder 0.03-0.10 Ground Quartz Sand 30-42 Specified alkaline back cuttings 15-20 Gypsum 1.5-2.0 Water Else 2. A method of preparing a cellular concrete mixture, including preparing and mixing Portland cement, lime, aluminum powder, a siliceous component, raw cellular concrete production wastes in a mixer, characterized in that alkaline reverse sludge prepared from technological waste cutting mass of raw and slicing "peppers", which are washed with water in a tank, where they carry out constant mixing and dispersion, then the specified slurry is fed into the mix l where metered and mixed together with other components in the sequence as silica component - ground quartz sand, said alkaline return sludge, Portland cement, lime, gypsum additionally, aluminum powder. 3. The method according to p. 2, characterized in that part of the specified alkaline reverse sludge from the tank is fed into the sludge pool for further mixing and averaging.