RU2351575C2 - Composition for manufacture of heat insulation structural foam concrete of non-autoclave hardening - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is related to production of construction materials and may be used for manufacture of wall blocks used in inside rooms. Composition for manufacture of heat insulation structural foam concrete of non-autoclave hardening contains the following components, wt %: Portland cement 36 - 40, filler - non-ground powdered product of concrete structures crushing, where coarse filler is dense limestone, fraction of up to 2.5 mm or mentioned product, which is additionally crushed to specific surface of 3000 cm²/g 36 - 40, foam maker "ПБ"-2000 0.75 - 1, water - the rest.

EFFECT: increased strength properties of items.

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Description

The invention relates to the production of building materials and can be used for the manufacture of elements such as wall blocks used in the interior.

Known inventions that are analogues in technical essence to the claimed invention: RU 2233817 C1, 08/10/2004; RU 2262497 C2, 10.20.2005; RU 2156226 C1, 09/20/2000; RU 2003114445 A, 11.27.2004; RU 2292322 C1, 01/27/2007; DE 3444686 A1, 06/12/1986.

The closest in combination of features to the present invention is a composition for the manufacture of non-autoclaved foam concrete according to the patent of the Russian Federation No. 2233817, 08/10/2004, 4 pages, including, wt.%: Portland cement 41-62, siliceous aggregate - sand 13-36, foaming agent - PB-2000 foam concentrate aqueous solution 0.09-0.3, hardening regulator 0.82-1.86, water - the rest.

The solution of the technical problem according to the invention is aimed at improving the strength properties of products.

This is achieved according to the invention in that the composition for the manufacture of building materials contains a chemically active aggregate.

According to the invention, products obtained from the proposed foam concrete composition have a density of 600 kg / m ³ , 700 kg / m ³ , 800 kg / m ³ , compressive strength of 2.5-5 MPa in accordance with tables 1 and 2.

The proposed composition in strength is 1.5 times higher than this indicator, achieved using ordinary quartz sand, with the same ratio of binder and aggregate.

The composition for the manufacture of heat-insulating and structural non-autoclaved foam concrete includes the following materials: Portland cement, grade M500, aggregate is a non-ground dusty product of crushing concrete structures, where dense limestone, fractions up to 2.5 mm or specified product, additionally ground to specific surface area 3000 cm ² / g, synthetic blowing agent grade PB-2000, water, in the following ratio of components, wt.%: Portland cement 36-40, the specified aggregate 36-4 0, foaming agent PB-2000 0.75-1, the rest is water.

The choice of Portland cement of the M500 brand is due to its large-tonnage production, the choice of the dust-like product of crushing concrete structures as a filler is due to its large accumulation in the territories adjacent to populated cities, the choice of the PB-2000 foaming agent is due to its large-tonnage production.

The manufacture of products from the proposed composition is carried out on any standard equipment for foam concrete, while the pulverized crushing product is loaded into a hopper designed for aggregate. After preparation, the foam concrete is fed into metal molds and then hardens to a set of strength necessary for the stripping of the products molded from the foam concrete mass. At an air temperature of + 25 ° C, the set of strength required to demount the products molded from the foam concrete mass is 24 hours. For products subjected to heat treatment at a temperature of + 40 ° C, the duration of preliminary exposure is reduced to 12 hours.

When demolishing obsolete and unsuitable for operation buildings, concrete structures are transported by road to mobile crushing and screening plants for crushing them. In foam concrete, a crushing product of concrete structures with a grain size from 0 to 2.5 mm is used, in which the content of dust particles from 0 to 0.08 mm in size is 40% of the total mass. The resulting final product according to the inventive foam concrete composition is environmentally friendly.

The combination of a binder with a pulverized product of crushing concrete structures and water provides foam concrete products with a sufficiently high compressive strength, simple manufacturing technology and environmental friendliness. Additional grinding in a ball mill of a pulverized product crushing concrete structures to Ssp. = 3000 cm ² / g increases the chemical activity of this material in accordance with tables 1 and 2.

Concrete scrap crushing products were obtained from concrete products in which Portland cement was used as a binder, which explains the content of unhydrated Portland cement minerals that were discovered during crushing during the breakdown of hydration products. The content of Portland cement minerals ready for hydration is up to 5% of the total mass of the pulverized product of crushing of concrete structures.

Crushing products were obtained from concrete products, in which dense limestone was previously used as a large aggregate, which explains the high content of calcium carbonates in the material in an amount up to 30% of the total mass of dust-like crushing product of concrete structures.

The production of foam concrete using dusty concrete crushing products together with Portland cement leads to the appearance of neoplasms with a fine crystalline structure, such as: hydrosilicates, hydroaluminosilicates, calcium hydroaluminoferrites, as a result of cement hardening. The formation of calcium hydrocarbon aluminates CaAl ₂ (CO ₃ ) ₂ (OH) ₄ · 6H ₂ O is observed, which leads to an increase in the strength characteristics of foam concrete.

The invention can be applied in the production technology of building materials as the basis for wall thermal insulation and structural building materials.

Table 1.
Physico-mechanical properties of non-autoclaved foam concrete based on non-milled dusty products of crushing of concrete structures The average density, kg / m ³ Compressive strength, MPa 600 1.8-2.2 700 2.7-3.1 800 3.6-4.1 Table 2.
Physico-mechanical properties of non-autoclaved foam concrete based on dusty products of crushing concrete structures after additional grinding them in a ball mill The average density, kg / m ³ Compressive strength, MPa 600 2.5-2.8 700 3.4-3.9 800 4,5-5

Examples of the invention. For the preparation of foam concrete with an average density of 800 kg / m ³

Raw materials Content% Portland cement 40 Dusty product of crushing of concrete structures fraction 2.5 mm 40 Water 19.25 Frother PB-2000 0.75

For the preparation of foam concrete with an average density of 700 kg / m ³

Raw materials Content% Portland cement 37 Dusty product of crushing of concrete structures, ground to a specific surface of 3000 cm ² / g 37 Water 25.25 Frother PB-2000 0.75

For the preparation of foam concrete with an average density of 600 kg / m ³

Raw materials Content% Portland cement 36 Dusty product of crushing of concrete structures, ground to a specific surface of 3000 cm ² / g 36 Water 27 Frother PB-2000 one

Claims (1)

Composition for the manufacture of heat-insulating structural foam of non-autoclaved hardening, containing Portland cement, aggregate, PB-2000 foaming agent and water, characterized in that it contains a non-ground pulverized pulverized product of crushing concrete structures, where dense limestone of fraction up to 2 is used as a large aggregate, 5 mm or the specified product, additionally ground to a specific surface of 3000 cm ² / g, with the following ratio of components, wt.%:
Portland cement 36-40 specified placeholder 36-40 PB-2000 foaming agent 0.75-1 water rest