SU1747272A1 - Method of product molding from dry-concrete mixes - Google Patents

Abstract

Use: in the building materials industry in the production of drainage products from rigid expanded clay concrete mixes of complex configuration with a height of up to 500 mm. SUMMARY OF THE INVENTION: A method for forming articles from rigid concrete mixtures comprises laying the concrete mixture into a mold in 2 steps with vibrating after laying the next portion of the mixture at an industrial frequency and amplitude of 0.8-1.5 mm for 3-5 seconds, compaction with static and inertial loads from below with a value of 0.4–0.8 MPa and static loading from above with a value of 0.08–0.30 MPa for 35–45 s and a clearance from the action of static loading from above with a value of 0.06–0.08 MPa and vibration applied to the side walls of the form, with an amplitude of oscillation s 0.2- 0.4 mm. The resulting products are thin-walled structures of complex configuration with a height of 490-500 mm, filtering capacity of 270-310 m / day, cement consumption per 1 m3 of the mixture is 310 kg. 2 tab. M yo

Description

The invention relates to the building materials industry and can be used in the manufacture of drainage products from hard expanded clay concrete mixes of complex configuration with a height of up to 500 mm.

There is a known method for forming filter elements from coarse-grained concrete mixtures by compaction by vibrating with a load.

Its disadvantages are the complexity of the process, which requires additional equipment that ensures the supply of compressed air of the required temperature, an increased consumption of cement, is impossible. ability to get products from hard

mixtures, and in addition, this method requires a high production culture, and with the slightest deviation from the technology, the percentage of defective products increases dramatically.

The closest to the invention is a method of molding articles from rigid concrete mixtures, including laying the concrete mixture with a vibration effect at an oscillation frequency of 25-75 Hz, compaction within 1-5 s with a load with inertial and static loads of 0.015-0.03 MPa with the subsequent removal of the inertial load and compaction under pressure with a static load of 0.005–0.01 MPa for 2–25 s.

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The known method allows to obtain dense blocks that cannot be used as drainage products. In addition, this method is characterized by a high cement consumption and is unacceptable for molding articles from hard ceramic concrete mixtures, since the structure of the ceramic granite concrete mixture differs sharply from sand concrete, which leads to internal stresses preventing the removal of products.

The aim of the invention is to reduce the consumption of cement and increase the filtration coefficient in the manufacture of drainage products from porous kerame concrete mix.

The goal is achieved by the fact that in the method of forming articles from rigid concrete mixtures, including laying the concrete mixture into a mold, compacting it first by vibrating with an industrial frequency and vibration amplitude of 0.8-1.5 mm for 3-5 seconds, then with the simultaneous application of static and inertial loads from the bottom and subsequent demoulding, the mixture is laid in two stages with vibration, compaction is carried out with a load value from below 0.4-0.8 MPa and additional loading of the mixture from the top with a pressure of 0.08-0, 3 Mpa for 35-45 s. and the formwork is carried out by applying a static load on top of 0.06-0.08 MPa and vibration applied to the side walls of the mold with an oscillation amplitude of 0.2-0.4 mm.

The method for forming articles from rigid concrete mixtures is carried out as follows.

In the form installed on the vibroplatform and representing a pallet with a matrix rigidly fixed on it, the rigid (180 s) claydite-concrete mixture is filled up completely to the full height of the form and include a short-term vibration of 3-5 with an amplitude of 0.8-1.5 mm and a frequency 50 Hz. Then the second portion of the claydite-concrete mixture is laid (up to the upper edge of the form) and the vibration is again switched on for 3-5 seconds with an amplitude of 0.8-1.5 mm. The mixture thus laid is exposed from below by a stamp consisting of a drive-driven hydraulic system (static load) and a gravity load (inertial load), creating a specific pressure of 0.4-0.8 MPa. Simultaneously

from the top, using a hydraulic punch, the mixture is subjected to a static load, the specific pressure of which is 0.08-0.30 MPa. The amplitude of the load oscillations is constant and equal to 0.8-1.5 mm. Their exposure time is 35-45 seconds. After the completion of compaction, the vibration is turned off and the demolding is carried out, for which the molded product is subjected to a static load from the top using a hydraulic punch, a specific pressure created by a value of 0.06-0.08 MPa and vibration applied to the side walls of the mold, with an amplitude of 0 , 20, 4 mm. The effect of static load and vibration during the demoulding continues until the initial separation of the product from the matrix. Heat treatment duration 5 hours.

According to the technology described above, products were made of expanded clay concrete mixture with a stiffness of 180 with the following composition (1 m3 of mixture), kg:

Portland cement M400310,0

Expanded clay M550720,5

Water160.0

Table 1 shows the technological parameters of the molding process. The physicomechanical characteristics obtained as a result of product testing are presented in Table 2

Claims (1)

The invention The method of forming products from hard concrete mixes, which includes laying the concrete mix into a mold, compacting it first by vibrating with an industrial frequency and an amplitude of 0.8-1.5 mm for 3-5 seconds, then applying a static and inertial load from below and then discharging, that, in order to reduce cement consumption and increase the filtration rate when the manufacture of drainage products from large-poredite concrete mixture, laying the mixture is performed in two stages with vibrating, compaction is carried out at a load value from below 0.4-0.8 MPa and additional loading of the mixture from the top with a pressure of 0.08-0.3 MPa for 35-45 s, and the stripping is performed by applying a static load on top of 0.06-0.08 MPa and vibration applied to side walls of the form with an amplitude of 0.2-0.4 mm. table 2