SK32004A3 - Method of manufacturing concrete and reinforced concrete products - Google Patents

Abstract

A method for manufacturing concrete and ferroconcrete goods involves mixing components on concrete mix, embedding mix into the shape, vibrocompaction of concrete mix, keeping the shaped article in the mold with subsequent form removal thereof. The concrete mix vibrocompaction is continued after initiation of delamination thereof and finished at the stage of a clear delamination of the mix in light fraction which base is cement and liquid filling agent, and hard fraction with base formed of coarse and fine filling agents with cement and liquid filling agent. The light fraction is removed and reused. Articles of high strength and density are obtained at lowering cement consumption and increasing the content of cheaper components of concrete mix.

Description

Technical field

The invention relates to the field of construction and can be used in the manufacture of concrete and reinforced concrete products, in particular various constructions and blocks, parts for common and special applications, panels, pillars, partitions, cladding boards, as well as subsequently sanded and polished boards, paving elements and the like.

BACKGROUND OF THE INVENTION

There is known a method for manufacturing structures from a concrete mixture (Russian Federation Patent, RU 2010019 of 30.03.1994, MPT 5: C04B 28/00, 40/00), which describes the preparation of a concrete mixture by mixing cement, sand, water and coarse filler, placing in the mold or formwork, compacting the mixture by vibration, curing and detaching the product.

The closest solution to the application for a summary of features is the method of obtaining concrete products from a concrete mixture (Russian Federation Patent, RU 2103234 of 27.01.1998, MPT 6: C04B 28/00, B28B 1/08, 11/00, 5 / 00, 15/00), which comprises mixing the components of the concrete mixture, placing the mixture in molds, compacting it by vibration, curing the molded products in molds and then disengaging them, wherein the vibration compaction is carried out until cement milk is formed on the surface of the mixture.

The disadvantages of these methods in their implementation are the high production price of the products thus obtained, which is related to the rather high costs of the most expensive concrete-forming component - cement, as well as limited coefficients of physico-mechanical properties of concrete products.

The technical problem to be solved by the invention is to obtain concrete and reinforced concrete products with improved properties, which would allow to extend the range of use of such products, increase their shelf life, while substantially reducing the cost of the structures obtained by said process.

SUMMARY OF THE INVENTION

The object is solved by the fact that, in said method, which comprises mixing the components of the concrete mixture, putting the mixture into a mold or molding it, compacting by vibration, curing the formed product in a mold with subsequent disintegration, according to the invention it stratifies and terminates at the exact stratification stage of the mixture into two layers - a light and heavy fraction, after which the light fraction is collected and used for the second time to prepare the concrete mixture.

In contrast to the closest analogous solution in which concrete stratification is not allowed and the vibration compaction is carried out until a light fraction is formed on the surface of the mixture, the so-called cement milk, which indicates the start of stratification of the mixture. mass on two layers. This means that the vibration compaction is carried out only after the necessary degree of stratification of the concrete mixture has been reached, for example complete (maximum). The degree of stratification is derived from the characteristics to be achieved by the product obtained.

The stratification during vibration of the mixture occurs due to the different weights of the concrete forming components. The top light fraction, or the top layer basically consists of a cement and a liquid filler (water, alkali), i. j. gel-like cementitious material, and the lower heavier fraction or backsheet contains, in addition to cement, heavier components such as gravel, fine gravel (coarse filler) and sand (fine filler).

Said method makes it possible to remove the maximum amount of excess cement (gel-like cement mass) and use it for the second time to produce a concrete mixture, while obtaining a denser material of the backing layer, i. j. of the product itself.

Thus, the technical result is to save costly materials, namely cement - the most expensive concrete component, thanks to its second use, and also to improve the physico-mechanical properties of concrete and reinforced concrete products such as strength, wear resistance, fire resistance and frost resistance, water impermeability. and the like, resulting from a more dense material.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 is a flow chart of the production of concrete and reinforced concrete products.

DETAILED DESCRIPTION OF THE INVENTION

According to the method, the components of the concrete mixture, such as cement, gravel, sand, water, flowing agent, cohesion inhibitor, superplasticizer, are added from the respective containers (containing 1, 2, 3, 4, 5, 6) (Fig. 1) to the mixer. 7 for forced concrete where they are mechanically mixed.

- cement content,

- gravel content,

- sand content,

- water content,

- content of the fluid

- the content of the cohesion inhibitor.

Thereafter, the concrete mix from the concrete mixer 7 is placed in a mold 9 for producing concrete or reinforced concrete products, which is deposited on a vibrating table 8, where the mixture is compacted and the product is formed. In this case, the mixture is vibrated until it is completely stratified or the stratification is completed to a light and heavy fraction, i.e. the vibration time of the concrete mixture is chosen longer than the vibration time that is applied in known concrete product manufacturing processes where stratification is not allowed. In this way, a mixture with two layers is obtained: a top layer 11 (light fraction) and a bottom layer 10 (heavy fraction). The top layer consists basically of cement and water, and the base of the lower, denser layer consists of heavier components - sand, and sand. Next, the topsheet 11, i. j. the liquid mixture is removed (for example, by a sliding frame, suction, pouring and others) and returned to the concrete mixer 7 for the second use and recovery of the concrete mixture. The concrete products advance to the steaming chamber 12, after which the final production is decoupling.

Cements of all kinds can be used to form the concrete mixture: Portland cement, slag-portland cement, aluminous cement, gypsum-aluminum cement, magnesium cement, alkaline slag cement and others. The gravel is in fractions of 5-10 mm, 10-20 mm, 20-40 mm and 40-70 mm, using sand with a modulus of strength up to 2.7.

During laboratory investigations, the percentage composition of the concrete-forming components in the upper and lower layers of the mixture was experimentally determined:

- top layer - 40-60% gel-like cement mass (cement + liquid);

- bottom layer - 100% gravel, 100% sand and 40-60% gel-like cement mass (cement + liquid).

This implies that cement savings are approximately 40-60%.

The comparative table shows the quantitative composition and the physical-mechanical properties of the concrete products obtained by conventional technology (without stratification of the mixture) and the products obtained by the method described.

Tab. 1

mark material process Composition and properties cement (Kg) gravel (Kg) sand (Kg) Water (I) plasticizers. bark. (Kg) Y density (kg / m ³ ) R strength (kg / cm ² ) M 400 concrete Concrete without creaming 430 1150 620 145 2.5 2310 410 12-15 Concrete s stratified 215 1438 775 72 1.25 2430 455

It is clear from the table that using this method of producing concrete products, which envisages stratification of the mixture, the costs of cement are drastically reduced and the content of cheaper components - cement and sand - is increased.

In this way, the method makes it possible to achieve substantial savings in cement while improving the strength and other properties of concrete products.

For carrying out the method, the necessary conventional equipment is used, i. j. this method does not require special mechanisms and equipment and can be carried out in any designated enterprise.

Claims (2)

Method for producing concrete and reinforced concrete products, which comprises mixing the components of a concrete mixture, at least cement, liquid, coarse and fine filler, placing the mixture in a mold, compacting the concrete mixture by vibration, curing the formed product in mold with subsequent disintegration, that vibration compaction of the concrete mixture extends beyond the start of its stratification and ends at the exact stratification stage of the mixture into a light fraction based on cement and liquid filler and a heavy fraction based on a coarse and fine filler with cement and liquid filler, the light fraction is removed. Method according to claim 1, characterized in that the collected light fraction is used for the second time to prepare the concrete mixture.