RU2378108C2 - Method for production of concrete items and device for realisation of this method - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention is related to the field of construction materials production. Method for production of concrete items includes laying of concrete mass into vibromould, also with arranged armature, vibration compaction of concrete mass, process of produced item hardening. At the same time in process of concrete mass vibration compaction, vibration parametre signals of sensors installed on vibromould in areas of vibration exciters fixation are recorded onto information mediums, produced item is tested. Test results are used to correct vibration parametres of compaction, and the next items are produced, also with recording of all vibration parametres, to the moment of reference item production. Further vibration parametres of reference item compaction are used to make series of concrete items. Device for production of concrete items comprises vibromould with fixed sensor of vibration parametres and vibration exciter joined to control device, comparison device and negative feedback, which connects sensor of vibration parametres with comparison device.

EFFECT: improved quality of produced items.

3 cl, 1 dwg

Description

The invention relates to the production of concrete and reinforced concrete products, in particular to a method for manufacturing concrete products for the construction of buildings and structures, and will allow to create concrete and reinforced concrete structures with high performance.

Known methods for the production of concrete and reinforced concrete products for construction, including laying concrete mass in a mold, including with installed reinforcement, vibration compaction of the concrete mass, the hardening process of the manufactured product (K.V. Chaus and others. "Production technology of building materials, products and structures ", Moscow: Stroyizdat, 1998, pp. 213-215). Manufactured products are periodically tested for strength, crack resistance and stiffness. If the tests showed low strength properties of the concrete product, then the process parameters are adjusted.

However, during sampling, it is not known how many manufactured products, prior to and after testing, do not have the corresponding strength characteristics. A disadvantage of the known methods of manufacturing concrete products is also the instability of their strength characteristics, which is mainly associated with the uncontrollability and, consequently, the lack of predictability of the vibration parameters during the process of vibration compaction of the concrete mixture. While other parameters of the technological process of manufacturing concrete products - time, temperature, composition of the concrete mix and the degree of its elaboration - are controlled by instruments, visually or automatically maintained.

The problem solved by the invention is to improve the quality and repeatability of the characteristics of concrete products.

The technical result is the manufacture of concrete products with pre-guaranteed strength characteristics.

Vibrational effects on vibroforms have a wide and poorly defined energy spectrum, consisting of a number of components:

- the main frequency of the vibrator with a virtually unchanging disturbing force (vibration force) in the steady state;

- a set of even and odd harmonics with varying amplitudes arising in the limiter of the amplitude of oscillations of each vibrator;

- interference amplitude-frequency beats that occur when several vibrators work on a common load;

- a component associated with the nonlinearity of the suspension system of the vibration form - means of depreciation and damping;

- vibrations arising in the tooth magnetic system of the vibrator motor (magnetic noise);

- spectra of oscillations arising in transient start-up modes and, in particular, upon completion of the vibration process.

In the energy spectrum of vibrations of vibroforms, some of them contribute to the formation of the structure of concrete, another part impedes this process. When the vibrations that form (create) the structure of the concrete structure prevail, the quality of the concrete product improves, and when reproducing such an energy "spectrum, the repeatability of the product characteristics also improves.

The technical result of the application of the invention is the manufacture of concrete products with guaranteed strength characteristics.

The specified technical result is achieved by the fact that in the manufacture of concrete products in the process of vibration compaction with the help of vibro drives, the mass of concrete in the vibration form records the signals of the vibration parameters from the sensors installed at the characteristic points of the vibration form on an analog or digital information carrier, namely: signals of vibration displacement, vibration velocity and vibration acceleration of the vibration form .

Initially, the recording of vibro-parameter signals is made in the manufacture of a concrete product, which then passes strength tests. If the test results are positive, then the recorded signals of the vibration parameters in accordance with the technological sequence diagram are used in the manufacture of subsequent concrete products as reference for controlling the vibration drives with the correction of the current vibration parameters of the technological process according to the criterion of their smallest difference from the reference ones (control with negative feedback by vibration parameters). This provides both the necessary quality of the products according to the strength criterion, and their repeatability (reproducibility) up to the parameters of the technological process, including vibration parameters.

Before the next strength tests, the signals of the vibration parameters are recorded on a parallel information carrier, and if the strength characteristics of the tested product turn out to be better than the previous ones, the newly recorded signals are used as reference signals for controlling the vibration drives with correction of the current vibration parameters of the technological process according to the criterion of their smallest difference from the reference ones.

The proposed method of manufacturing concrete products allows to improve their quality to make changes to the recorded signals of the vibration parameters according to the results of studies, including modeling, and based on experience. When carrying out these works, a digital form of representing the signals of the vibration parameters, as well as a computer, is used to model and control both the vibration drives and the technological process as a whole.

As a result of this procedure, the quality of concrete products is gradually improving, and the repeatability (reproducibility) of the strength characteristics of the products supports this finishing iterative process.

The method can be used for vibration processing not only concrete, but also other materials.

The described method is implemented in the proposed device.

As a prototype of the claimed device, a vibratory plate with a variable amplitude of oscillations according to the patent of the Russian Federation No. 2233738 was adopted, which contains a working body - a vibrating table installed by means of elastic gaskets on the base, an unbalanced vibration exciter with two coaxial shafts driven from two asynchronous motors and a system mounted on the bottom of the vibrating table automatic control of these engines, which includes a vibration frequency adjuster, an oscillation amplitude adjuster of the working body, the first and second control Orae system controlling the angle of rotation of the shaft of the first motor with detector angle of rotation, first and second regulators rotation angle of the shaft of the second engine control system equipped with a steering angle sensor, the summation block. Moreover, the automatic control system of the vibration exciter additionally contains a regulator of the amplitude of the oscillations of the working body, a vibration sensor connected to the working body, a second summing unit, the output of the setpoint of the amplitude of the vibrations of the working body connected to a direct input of the second summing unit, the output of which is connected to the input of the oscillation amplitude regulator, the output which is connected to the second input of the first summing unit, and the output of the vibration sensor is connected to the inverse input of the second summing unit.

The disadvantage of the prototype is the presence of one unbalanced vibration exciter, which will not allow even in a controlled mode to eliminate uncontrolled swaying of the vibration platform with the vibration form and, moreover, to ensure its controlled swinging.

The technical result of the claimed device is to obtain concrete products with pre-guaranteed strength characteristics by accurately reproducing the stored vibrations of previous products for the manufacture of the following products with improved strength characteristics.

Common with the prototype signs: the presence of a vibration form with a vibration sensor attached to it and a vibration exciter associated with a control device, a comparison device and negative feedback connecting the vibration parameter sensor to the comparison device.

Distinctive features: the presence of at least two exciters made in the form of short-stroke linear synchronous electric motors with excitation from permanent magnets. Each of the vibration exciters is connected to its control device, which, in turn, is connected to a comparison device. Two storage devices for vibration parameters, taken as a standard, are connected to the inputs of the comparison device. Storage devices are connected to computers.

A device for manufacturing concrete products contains a vibration form for loading concrete, which is elastically mounted on the base and allows you to adjust the vibration parameters (vibration displacement, vibration velocity, vibration acceleration) of the vibration form, at least two vibration exciters located at characteristic points of the vibration form. The vibration exciters are made in the form of short-stroke linear synchronous electric motors with excitation from permanent magnets, and each of the vibration exciters is connected to its control device, which, in turn, is connected to a comparison device. Storage devices for vibration parameters taken as a standard and sensors of current values of vibration parameters installed at characteristic points of the vibration form are connected to the inputs of the comparison devices.

Vibration exciters, control devices, comparison devices, storage devices and sensors of the current values of vibration parameters are interconnected, forming three-loop systems of subordinate regulation of vibration drives: feedback on vibration acceleration acts in the internal circuits, vibration velocity acts in the middle, and vibration displacement in the middle. The adjustment of such automatic control systems is carried out by known methods, for example: Basharin A.V., Novikov V.A., Sokolovsky G.G. Electric Drive Management: A Textbook for High Schools. - L.: Power Publishing House. Leningra. Otdel, 1982.- 392 p., ill., chap. 1-3. Standard settings and their application.

In addition to storage devices for vibration parameters, taken as a reference and controlling the movement of the vibration drives, the device for the manufacture of concrete products contains identical storage devices for the current values of vibration parameters received from the corresponding sensors, used to update the reference values of the vibration parameters found in the main storage devices, according to results of strength tests of concrete products, or according to the results of research and modeling. The storage devices are connected to a computer, into which data of the current process parameters can also be entered. The computer is used for modeling and control.

Due to the wide amplitude-frequency spectrum of vibrations of the vibroforms, the known controlled unbalanced vibrators cannot be used as vibration exciters as part of the vibration drives when implementing the proposed method. The most suitable for these purposes are short-stroke linear synchronous electric motors with excitation from permanent magnets, having sufficient speed and linear amplitude characteristic.

The drawing shows a diagram of a device for the manufacture of concrete products according to the above method.

The device comprises a vibration form 1, elastically mounted on the base 2, equipped with shock absorbers. Concrete mixture is placed in vibroform 1. Between the vibroform 1 and the base 2 there are linear electric motors of the vibration exciters 3, each of which is connected to its control device 4 connected to the comparison device 5.

On the vibration form 1 near the vibration exciters 3 installed sensors 6 vibration parameters. Comparison devices 5 have two inputs. One of the inputs is connected to the sensors 6 of the vibration parameters, and the other inputs through the switches 7 are connected to the identical storage devices 8 or 9: when the switches 7 of the comparison device 5 are in the upper position, they are connected to the storage devices 8, and when the switches 7 of the switches 7 are in the lower position, they are connected to the storage devices 9 .

The sensors 6 of the vibration parameters through the switches 10 are also connected to the storage devices 8 or 9: at the upper position of the switches 7, the sensors 6 of the vibration parameters 10 are connected to the storage devices 9, at the lower position of the switches 7, the sensors 6 of the vibration parameters 10 are connected to the storage devices 8.

With storage devices 8 and 9, a computer 11 is connected.

The device operates as follows. At the initial stage of starting the process of vibro-compaction of concrete according to the proposed method, the signals of vibro-parameters from sensors installed on some other installation of a similar purpose are recorded in memory devices 8, on which concrete products intended for production on the proposed device (installation) are made of acceptable quality according to traditional vibration technology . Alternatively, the signals of the vibration parameters for recording in the storage device 8 can also be generated by modeling using a computer 11 based on existing knowledge and experience.

Then, the concrete mixture is placed in the vibroform 1. Under the influence of vibration exciters 3, the movement of the vibration form 1 reproduces the signals of the vibration parameters recorded in the storage devices 8, taken as a reference. In this case, the switches 7 and 10 are in the upper position. The accuracy of the reproduction is determined by the parameters of the three-loop system of subordinate regulation of the vibration drive with negative feedback on the vibration parameters (vibration displacement, vibration speeds, vibration acceleration), the signals of which are taken from the sensors 6.

In accordance with the principle of operation of systems with negative feedback, the signals of the vibration parameters recorded in the storage devices 8 and taken as the reference ones, and the signals of the sensors 6 of the current values of the vibration parameters are input into the comparison devices 5, where the mismatch signals are generated. The control device 4 converts the mismatch signals and amplifies the power to control the movement of the vibration exciters 3. With a typical setup of the automatic control system of the vibration drive in the frequency band of the playback, the movement of the vibration form 1 with the specified system parameters repeats the movement recorded in the form of vibration parameters of the vibration form of an installation of a similar purpose, on which Concrete products of acceptable quality.

Due to the identity of the movements of the vibroforms, provided that other parameters of the technological process are equal, the acceptable quality of the concrete product manufactured in the vibroform 1 is repeated. For verification, a test of the manufactured product is carried out and, with positive results, a series of concrete products is produced until the next test prescribed by the process. During this period of time, vibration parameters 1 of the vibration form 1 are recorded in the storage devices 9 from the sensors 6, studies are carried out, and, based on the results, they make changes to the recorded vibration parameters to improve the quality of concrete products. After the release of the planned series of concrete products, the switches 7 and 10 are moved to a different position and the concrete product is manufactured, taking the signals of the vibration parameters of the storage devices 9 as a standard. Next, the product is tested and, if its quality is improved, the next series of concrete products are released when the position of the switches 7 and 10.

The finishing process can be repeated many times until concrete products of the required quality are obtained. The reference vibroparameters of the brought concrete products can also be stored in the memory of the computer 11 and stored in the corresponding storage devices if necessary to produce a demanded series.

Claims (3)

1. A method of manufacturing concrete products, including laying the concrete mass in a vibration form, including with installed reinforcement, vibration compaction of the concrete mass, the hardening process of the manufactured product, characterized in that in the process of vibration compaction of the concrete mass, the signals of vibration parameters of sensors mounted on the vibration form are recorded on information carriers in the places of attachment of the vibration exciters, the manufactured product is tested, the vibration parameters of the seal are adjusted according to the test results, and the following product is manufactured I am also writing down all of vibration, until the production of standard products, and further vibration parameters of the reference product seal is used to make a series of concrete products. 2. A device for the manufacture of concrete products containing a vibration form with a vibration sensor attached to it and a vibration exciter associated with a control device, a comparison device and negative feedback connecting the vibration parameter sensor with a comparison device, characterized in that the vibration exciter is made in the form of at least , two short-stroke synchronous linear electric motors with excitation from permanent magnets, each of which is connected with its control device, a device eniya and storage devices, and memory devices associated with computers. 3. A device for the manufacture of concrete products according to claim 2, characterized in that the storage devices can be alternately connected by means of switches with their vibration sensor and its comparison device.

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