UA124294C2 - METHOD OF OBTAINING UNCONSTRUCTED CONCRETE - Google Patents

Abstract

The invention relates to the construction industry, in particular to methods for producing aerated concrete intended for the manufacture of building structures having high strength characteristics and low thermal conductivity. The method of obtaining cellular concrete includes mixing the components of the hardening mixture, introducing a foaming solution into the hardening mixture, saturating the hardening mixture with air, forming a porous product. The foaming solution is pre-aerated by compressed air, the outlet of which is formed by a Laval nozzle, after which the air-saturated foaming agent is foamed by dividing into separate streams with a chaotic direction of motion vectors, for which the flow is moved through a porous medium particles in the limited space of the foam generator, after which the foamed foamer under pressure is fed perpendicular to the pressure flow of the curing solution, create a zone of turbulence and mix the foamed foamer with the curing solution, after which the formed flow is fed under pressure into the flow of the curing mixture in turbulent motion, for which the flow of the curing mixture is subjected to interaction with swirlers in the form of plates, the planes of which are directed at different angles relative to the flow of the curing mixture, to uniform distribution of gaseous and solid phases in the curing mixture, then the resulting product is unloaded from a pneumatic mixer. The invention provides a cellular concrete of high strength characteristics.

Description

directed at different angles relative to the flow of the hardening mixture, until the gaseous and solid phases are evenly distributed in the hardening mixture, after which the resulting product is discharged from the pneumostatic mixer.

The invention ensures the production of aerated concrete with high strength characteristics.

The invention belongs to the construction industry, in particular, it relates to methods of obtaining aerated concrete intended for the manufacture of building structures with high strength characteristics and low thermal conductivity.

The invention can be used for the development of device structures that ensure the implementation of the method of obtaining aerated concrete, to solve the problems of implementing energy-saving technologies in the construction of buildings and structures in industrial and civil construction, and to manufacture ready-to-use aerated concrete of high strength.

The invention is intended for the implementation of the technological process of manufacturing aerated concrete, in which the preparatory and main operations, as well as the process of obtaining the finished product, can be implemented in a device whose operational parameters provide the necessary physical and mechanical parameters of the product.

The invention is intended for the production and delivery of aerated concrete, completely ready for laying in forms or formwork space, to the required distance and height.

The invention is intended for the formation of foam concrete roofs by the method of continuous casting 3 with a high level of productivity, given strength and thermal characteristics depending on the type of binder in combination with reinforcing elements or without them.

The device can be used to prepare the mixture for the production of foam concrete in conditions of shortage of energy carriers and the need to perform a significant volume of concrete works.

There is a well-known method of preparing foam concrete, which consists in the fact that water, binder and foaming agent are simultaneously mixed in a given ratio. Compressed air is fed into the resulting mixture. The ratio of solid and liquid phases, as well as the geometric parameters of the pores formed in the concrete, are regulated by the time of mixing and the volume of air supplied to the mixer

Russian Patent No. 2148494 for the invention.

The disadvantage of the known method is that it involves only the simultaneous mixing of all components in the receiving hopper of the mixer with the subsequent supply of compressed air.

Mixing of components and air supply is carried out until the formation of a limited volume of the receiving hopper of the product with the specified parameters of porosity.

In the known method, the finished product is obtained only cyclically and in a limited amount

With the geometric parameters of the receiving hopper. The method is characterized by low productivity and can be implemented in mobile devices for performing minor repair work related to concreting objects, for example, restoration of a damaged roof.

A significant drawback of the method is that mixing the mixture and saturating it with air is carried out due to mechanical mixing of the abrasive medium, which leads to intensive wear of the mixer's structural elements, significantly reducing its operational resource.

In addition, the process of mixing the hardening mixture with the help of rotating blades makes special demands on the drive due to the high density of the product. If the power of the drive and, accordingly, the speed of rotation of the blades is not enough, the porization process takes place inactively, which negatively affects the spatial distribution of gaseous and solid phases and, as a result, the strength characteristics of porous concrete.

A known method for obtaining foam concrete is that water containing foaming additives is mixed with a dry hardening mixture. After moistening, the resulting mixture is stirred at high speed with the help of blades until the formation of air bubbles, which arise due to cavitation discharge, which ensures the supply of the necessary amount of atmospheric air into the mixture.

In the cavitation zone, the air breaks into small bubbles that are surrounded by a water film. The large air bubbles obtained at the stage of homogenization are crushed into smaller bubbles (Russian Patent

Mo. 2081099 on the invention.

The disadvantage of the known method is that its implementation is connected with the possibility of preparing only aerated concrete of low density. When increasing the density of concrete, it is difficult to create such a speed of rotation of the mixer rotor at which cavitation discharge will appear. To implement the method, a complex kinematic scheme of the mechanism is required, which determines the probability of failure under significant technological loads.

The high energy intensity of the method increases the cost of ready-made aerated concrete.

There is a known method of preparing aerated concrete by forming a cement-water suspension, which is dosed and mixed with an aqueous solution of the foaming agent. |Russian patent No. 2350461 on the invention.

The disadvantage of the known method is its complex constructive implementation, because the active mixing of the components of the mixture is carried out due to centrifugal acceleration.

The method cannot be implemented if there is a need to quickly change the mode of mixing the components of the mixture to obtain the regulated quality of porous concrete.

The method is implemented in relation to small-sized and low-performance devices.

The task of the invention is to improve the method of preparing aerated concrete due to the fact that: - before preparing aerated concrete, the ready solution of the foaming agent is pre-saturated with air, for this purpose it is aerated due to the dynamic effect of a stream of compressed air moving at a high speed; - a nozzle is used to form a dynamic flow with high kinetic energy

Laval, with the help of which the maximum possible air saturation of the foaming agent is ensured; - the flow of the foaming agent for the implementation of the foam creation process is divided into separate flows with chaotic direction of motion vectors, which spontaneously cross each other and form new flows; - the creation of the foam of the foaming agent is ensured due to the activation of mineral or organic surface-active substances contained in the air-saturated liquid created by the turbulent flows; - the formation of turbulent flows is ensured by the movement of a foaming agent saturated with compressed air through a porous medium, which can be made, for example, of metal shavings or any bulk filler; - the degree of turbulence of the foaming agent flow is set by changing the granulometric parameters of the particles that make up the porous medium; - saturation of the hardening solution with a foamed foaming agent is carried out by supplying it under pressure, perpendicular to the axis of the pressure flow of the hardening mixture; - uniform distribution of the foaming agent and, accordingly, air bubbles in the mass of the hardening mixture is ensured by means of a pneumostatic mixer; - mixing of the medium in the pneumostatic mixer is carried out at the expense of

From the transformation of the translational movement of the flow of the hardening mixture into a turbulent one; - for intensive mixing, the flow of the hardening mixture is subjected to interaction with swirlers in the form of plates - blades, the planes of which are directed at different angles relative to the axis of the hardening flow of the mixture.

The task is solved due to the fact that the method of obtaining porous concrete includes mixing the components of the hardening mixture, introducing a foaming agent solution into the hardening mixture, saturating the hardening mixture with air to form a porous hardening product.

The foaming agent solution is pre-aerated by compressed air. The output air flow is formed using a Laval nozzle. The air-saturated foaming agent is foamed.

For this, the general flow of the foaming agent is divided into separate flows with a chaotic direction of motion vectors. This is done by moving the foaming agent through the porous medium formed by unbound particles through the limited space of the foam generator.

The foamed foaming agent under pressure is supplied perpendicular to the axis of the pressure flow of the hardening solution, creating a turbulence zone. At the same time, the foaming foaming agent is mixed with the hardening solution. The formed flow is fed under pressure into the limited working space of the pneumostatic mixer.

In a pneumostatic mixer, the translational movement of the solidifying mixture flow is transformed into a turbulent one. For this, the flow of the hardening mixture is subjected to interaction with swirlers in the form of blade plates. The planes of the swirler blade plates are directed at different angles relative to the flow of the hardening mixture. The interaction of the flow with the swirler plates is carried out until the gaseous and solid phases are evenly distributed in the hardening mixture.

The formed hardening mixture is discharged from the pneumostatic mixer.

The technical result of the use of the invention is that: - the method allows to form stable high-quality foam upon activation of any type of foaming agent; - the method is not energy-intensive, and for its implementation, mobile power generators are sufficient; - a high degree of air saturation of the foaming agent is provided due to the use of a Laval nozzle;

- stable foam is formed due to the use of a porous medium through which the foaming agent is moved; - high-quality mixing of the hardening mixture with uniform distribution of gaseous and solid phases is ensured; - the formed solidifying mixture maintains a uniform distribution of solid and liquid phases during transportation through the pressure pipeline for a considerable distance, as well as during subsequent pouring into molds.

The method is implemented as follows:

The method ensures the production of porous concrete with high strength characteristics and thermal insulation.

Aerated concrete requires several components: a hardening mixture with a given water-cement ratio, a foaming agent solution, air to form a porous product - concrete bodies with bubbles of given geometric parameters.

To obtain aerated concrete, the original organic or mineral foaming agent is mixed with water to a given concentration.

After moistening the hardening mixture to the specified water-cement ratio, it is saturated with air to form foam. Studies have shown that the maximum possible pricing is achieved when the solution interacts with a high-pressure air flow, which can be achieved using a Laval nozzle. The use of the Laval nozzle ensures maximum air saturation of the foam generator, reduction of energy consumption for subsequent foaming, and also allows minimizing the size of the foam generator, which is used to form the foam.

After the foaming agent is saturated with air, it is foamed. Effective foaming can be achieved by moving the foaming agent through a layer of porous material. Porous material, for which metal shavings, fractions or any unbound particles can be used, ensures the formation of separate flows with a chaotic direction of movement vectors.

The formed streams of the foaming agent collide, resulting in the release of air and the formation of a body of foam. It was established that the parameters of the foam bubbles depend on the parameters of the particles from which the porous medium is formed, as well as the parameters of the channels,

From formed porous medium.

Studies have shown that the most effective way of connecting the hardening mixture with the foamed foaming agent is to supply the latter perpendicular to the flow of the hardening mixture. This ensures partial ejection of the flow and uniform distribution of gaseous and solid phases due to the formation of a turbulence zone.

The resulting mixture is not a finished product and requires additional efforts for the specified and uniform distribution of air bubbles from the hardening mixture. The strength parameters of aerated concrete and its heat-insulating properties depend on this.

The final formation of the body of aerated concrete is carried out in a pneumostatic mixer. In it, the formed flow is fed under pressure and the translational movement of the solidifying mixture flow is again transformed into a turbulent flow.

The mixture has a high viscosity, so the maximum degree of turbulence is ensured due to the fact that the flow interacts with swirlers in the form of blade plates. Blade plates are arranged so that their planes are directed at an angle relative to the flow axis, due to this, multidirectional flows are formed, which, colliding, form a stable turbulence zone, the length of which is limited by the length of the pneumostatic mixer body.

In the pneumostatic mixer, the final formation of the air-entrained concrete mass takes place, in which the air bubbles have given geometric parameters and are distributed as evenly as possible throughout the volume of the hardening mixture.

The process of preparing aerated concrete proceeds continuously, therefore, at the exit from the pneumostatic mixer, the resulting product can be used for feeding into molds for the manufacture of building structures or for continuous feeding during the formation of ceilings of a given thickness on houses or structures.

Studies have shown that various mobile and stationary devices can be manufactured for the implementation of the method, for obtaining porous concrete.

The method can be implemented at industrial enterprises that produce ready-made building structures, as well as directly at the place of repair and construction works.

The method makes it possible to obtain aerated concrete of high quality and low cost, which is competitive on the market of construction products or services. (510)

Claims (1)

FORMULA OF THE INVENTION The method of obtaining aerated concrete, which includes mixing the components of the hardening mixture, introducing a foaming agent solution into the hardening mixture, saturating the hardening mixture with air, forming a porous hardening product, which is distinguished by the fact that the foaming agent solution is pre-aerated by compressed air, the output flow of which is formed using a Laval nozzle, after which the air-saturated foaming agent is foamed by dividing it into separate streams with the chaotic direction of the movement vectors, for which the flow is moved through a porous medium formed from unconnected particles in the limited space of the foam generator, after which the foamed foaming agent is fed under pressure perpendicular to the pressure flow of the hardening solution, a turbulence zone is created and the foamed foaming agent is mixed with the hardening solution , after which the formed flow is fed under pressure into the limited working space of the pneumostatic mixer, in which the translational movement of the flow of the hardening mixture is transformed into turbulent motion, for this the flow of the hardening mixture is subjected to interaction with swirlers in the form of a astin, the planes of which are directed at different angles relative to the flow of the hardening mixture, to the uniform distribution of gaseous and solid phases in the hardening mixture, after which the resulting product is unloaded from the pneumostatic mixer.