RU2268249C2 - Cellular concrete production method - Google Patents

Abstract

FIELD: building material industry, particularly to produce wall and heat-insulated materials.

SUBSTANCE: method involves preparing visco-plastic raw mixture including binging agent, inert filler and water, by mixing thereof within 7-15 min with the use of rotor apparatus; adding gas-generating additive and mixing the mixture within 1-1.5 min; hardening the mixture. Binging agent, inert filler and water are mixed inside hydropercussion rotor apparatus to obtain mass having specific surface area of 5500-6500 cm²/g. Alkaline additive is introduced along with gas-generating additive.

EFFECT: increased cellular concrete quality and reduced time of concrete production.

1 tbl

Description

The invention relates to the construction materials industry, in particular to the production of wall and thermal insulation materials.

A known method of producing non-autoclaved fly-ash aerated concrete, including the production of a viscoplastic raw material mixture consisting of a binder, ash (inert) aggregate, water and a gas or foam former (gas-forming additive), expansion or foaming of the raw material mixture, hardening by steaming. The ash (inert) aggregate is preactivated by mixing it with mixing water at a speed of 500-700 rpm for 1-5 minutes, and the raw material mixture is saturated with a gaseous medium during expansion or expansion. A hardening accelerator — calcium chloride in an amount of 2-3% by weight of cement — can be introduced into the raw material mixture (RU Patent No. 2134250 C1, C 04 B 40/00, publ. 10.08.99).

This method allows to obtain non-autoclaved fly-ash aerated concrete based on the use of dump ash of a thermal power plant without grinding it, however, this method involves steaming during hardening, i.e. requires a lot of energy. In addition, in this method, a rather lengthy process of mixing the ingredients as a result of the alternate loading of materials into the mixer, as well as a slight activation of an inert material (ash filler) as a result of a long activation time period.

The closest technical solution to the claimed one is the method of producing wall products in the form of stones or blocks from aerated concrete mixture by filling the formwork with aerated concrete mixture and processing it to obtain layers of different densities, hardening the raw material mass in natural conditions at positive temperatures and stripping the products. As a gas-concrete raw material mixture, a composition of ground siliceous component (inert aggregate), binder and water is used, which is prepared by mixing directly in the formwork with a frequency of 2000-3000 min ^-1 for 5-15 minutes, and then a gas-forming additive is added and additional mixing for 1.5-5.0 min with the formation in the peripheral zones of the product of dense shells covering the central part of the product (RU, patent No. 2045501, IPC C 04 B 40/00, publ. 10.10.95,) - prototype.

This method allows to obtain wall products with layers of different densities, however, it is completely unsuitable for obtaining equal-density products from aerated concrete.

The task of the invention is to obtain non-autoclaved aerated concrete of natural hardening based on the use of dump ash - ablation of thermal power plants or quartz sand.

The technical result that will be achieved by using this technical solution is to reduce energy costs for the production and improve the quality of aerated concrete.

The technical result is achieved due to the fact that in the method for producing cellular concrete, including the preparation of a viscoplastic raw material mixture consisting of a binder, inert aggregate and water, by mixing with a rotor for 7-15 minutes, adding a gas-forming additive, further mixing for 1-1 , 5 min and hardening, mixing of an inert aggregate and water is carried out in a rotary apparatus of hydropercussion to obtain a mass with a specific surface area of 5500-6500 cm ² / g An alkaline additive is introduced with the gas-forming additive.

The essence of the invention is to increase the activity of astringent components in the rotary apparatus due to the simultaneously occurring processes in it: grinding due to hydropercussion (dispersion) and mixing.

Dispersion of an inert aggregate (ash or sand) simultaneously with a binder and water in a rotary apparatus ensures the production of aerated concrete with high activity indicators that positively affect the quality.

The mixing time in the rotary apparatus for 7-15 minutes is necessary and sufficient to activate the astringent and active mixing (dispersion) of an inert aggregate with it. Adding the remaining ingredients to the rotary apparatus and further mixing them for 1-1.5 minutes to obtain a mass with a specific surface area of 5500-6500 cm ² / g eliminates the need for other equipment (all operations are performed in a closed cycle in the rotary apparatus). The addition of an alkaline additive at the same time as the gas-forming additive serves for gas formation. In addition, such a device allows you to enhance the positive impact of each of the ingredients on the further quality of concrete. The hardening of the raw material mass in natural conditions at positive temperatures does not require additional energy consumption for steaming and allows you to get concrete with high performance characteristics. This method of obtaining cellular concrete can reduce energy consumption, because All operations are performed in one device and for a short time.

From the analysis of scientific, technical and patent literature of the claimed combination of manufacturing methods for aerated concrete is not revealed, which allows us to conclude that the claimed technical solution meets the criteria of "novelty" and "inventive step".

The invention is as follows.

Portland cement M 400 in accordance with GOST 10178-85, inert aggregate - fly ash of the Reftinskaya state district power station in accordance with TU 21-1528-01-90 or quartz sand and water were fed into a rotary apparatus of hydropercussion in a certain ratio as binders, all these ingredients are mixed in for 7-15 minutes to obtain a mass with a specific surface area of 5500-6500 cm ² / g In the process of mixing in the apparatus, the mixture is heated to 45-50 ° C (water pre-heating is not required), at the same time, inert filler and binder are activated. When these indicators are achieved, a gas-forming additive - PAP-1 aluminum powder in accordance with GOST 5491-71 and alkaline additive - liquid glass in accordance with GOST 13078-81 are poured into the mixing tank. Mixing of the gas-forming additive in the total mass is 1-1.5 minutes. After that, the finished mixture is served in pre-prepared molds through the filling hose. After pouring the raw mix of concrete into molds, the apparatus is turned off and washed with water. The concrete mix in the molds swells and stands for 1-1.5 hours, then the molds are disassembled and the array is cut into blocks of the required size.

Properties of finished products are given in the table.

This method of preparing cellular concrete can reduce the amount of gas-forming additives, increase the number of active centers in the binder and ash aggregate, and increase the temperature of the isothermal reaction. In addition, this method does not require a large number of technological equipment (all processes occur in one - rotary apparatus hydropercussion action).

Table No. p / p Ingredients Quantity, kg / m ³ Concrete properties Energy consumption for obtaining 1 m ^{3 of} cellular concrete, kW Spill temperature, ° С The dwell time before filling the next layer, hour Activation time, min Steaming hour Density, kg / m ³ Strength, kg / cm ² one 2 3 four 5 6 one. The inventive method:
cement
400 Ash or quartz sand 250 Water 325 650 thirty 7 45 1,5 fifteen - Aluminum Paste (PAG-1) 0.3 Liquid glass 5,0

2. The inventive method: Cement 300 Quartz sand or ash one hundred Water 200 400 10 8 45 one 7 - PAG-1 0.45 Liquid glass 6.00 3. Prototype: Cement 185 Fly ash 185 500-600 / 10-5 / 33- 8-10 eighteen 6-10 20-30 - Lime 93 1100-200 35 Water 220 Aluminum powder (PAK-2) 0.72

Claims (1)

A method of obtaining aerated concrete, including the preparation of a viscoplastic raw material mixture consisting of a binder, inert aggregate and water, by stirring with a rotor for 7-15 minutes, adding a gas-forming additive and further mixing for 1-1.5 minutes and hardening, characterized in that the mixing of an astringent, inert aggregate and water is carried out in a rotary apparatus of hydropercussion to obtain a mass with a specific surface area of 5500 - 6500 cm ² / g, and an alkaline additive is introduced with a gas-forming additive.