PL240773B1 - Circulating plate for the vibration-pressed concrete elements - Google Patents

Description

Description of the invention

The subject of the invention is a circulation plate for vibro-pressed concrete elements, in particular for paving stones.

Nowadays, small-sized concrete elements, which include paving stones, are mainly produced by the method of concrete vibropress, which consists in compacting the mixture to the appropriate consistency on special production boards (circulation plates) for vibropress. This guarantees the highest quality products, valued especially for their durability.

Concrete prefabricated elements of road surfaces consist of two layers - textural (top) and construction (bottom). Concrete for the production of paving stones does not have any reinforcement, and its main raw materials are: Portland cements of high strength classes, fine aggregates with a grain size of 0/2 mm, fractionated gravel-pebble and broken aggregates or their mixtures with a grain size of 2/8 mm and 8/16 mm and water. In order to improve its physical properties, the following are also added: mineral additives, chemical additives, pigments.

The production process of precast concrete pavements begins in the factory, where the selected ingredients are successively dosed into the mixing machine according to appropriate recipes, separately for the texture layer and the construction layer. Ready concrete mixes are dropped into baskets, charging concrete blocks. Then they go to drawers, from which the mold is precisely filled on the circulation plate. First, the bottom layer (most of the product) is covered, which is responsible for all the more important technical parameters, then the top layer (a few millimeters), mainly responsible for the final appearance and color of the cube.

After backfilling, the punch is nailed - the pressing process and the main vibration - the vibration process. The entire cycle of vibropressing takes approx. 15 seconds. Fresh prefabricated elements (on circulation plates) are transported by a conveyor straight to the ripening room, where the conditions for the concrete are appropriate. After a stay in the ripening room, the paving stones go to the stretcher. From there, the circulation plates for block making machines are moved by a conveyor to the stacker. Stacking consists in stacking the finished cubes on transport pallets, most often using a specialized forklift. The already empty circulation plates go to cleaning and impregnation, from where they go back to the vibropress, where the whole cycle repeats itself. The paving stones go to the warehouse, where they can wait for the final recipient.

The automation of the production process, its repeatability and the possibility of easy product quality control puts the concrete vibropressing method at the forefront when it comes to the production of paving stones and other concrete elements. Compliance with the standards of the product and the technological process guarantees obtaining high-quality cubes at relatively low costs. This can be achieved by using the appropriate design of the circulation plates, which during their operation are exposed to the effects of, among others: vibrations, pressures, processes, abrasive wear, temperature, moisture, and chemical factors. The final form of prefabricated concrete elements produced on them depends on their condition. They are the lower supporting surface for the mold. Therefore, one should strive to ensure high strength and reliability of the circulation plates, because it is thanks to them that paving stones in the process of laying road pavements allow to obtain even and smooth surfaces.

The circulation plates currently used in the technology of vibro-pressing of paving stones are most often made of: twisted metal rods, mainly pine boards, waterproof plywood, plywood covered with a phenolic film, plywood with a polypropylene top layer or made entirely of plastic. Wooden circulating boards withstand vibrations caused by pressing well, but due to humidity and temperature in the ripening room, they are often damaged due to swelling (the corrugated surface of the top makes the bottom of the cube not flat, which hinders the process of laying it). Circulating fluids made of impregnated plywood wear out as a result of wiping its surface, as a result of the technological process of the cube production. The boards made entirely of plastic are resistant to moisture and temperature, on the other hand, they are expensive and not very resistant to impact cracking caused by the block vibropressing process.

The essence of the invention is a circulation plate for vibro-pressed concrete elements, in particular for the production of paving stones, in which the core is a flexible sheet of waterproof plywood made of hardwood.

A layer of plastic reinforced with a mat or cut glass fiber is pressed onto the upper and lower surface of the plywood core.

PL 240 773 BI

The circulation plate has symmetrical, cuboidal cutouts on its short sides. The binders are phenolic resins.

The new design of the circulation plate is cheaper than the plates made entirely of plastic and does not have the disadvantages of wooden and plywood tops, and is easily regenerated.

The structure of the new circulation plate is characterized by:

• flexible, susceptible to vibrations core of the pallet, thickness adjusted to the technological line of the block press;

• resistance to moisture, temperature, concrete chemicals and abrasive wear of the top layer of the panel;

• regenerability;

• ease of use.

The subject of the invention in the form of the structure of the circulating plate is shown in the drawing.

Sample palette:

Production pallet, option I - shown in the drawing, which includes 1 - a core made of waterproof plywood; 2 - plastic layers in the form of claddings, hot laminated; 3 - rectangular cutouts on the sides to facilitate the stacking process.

The structure of the circulation plate for the production of paving stones is based on a flexible core 1 made of hardwood plywood (waterproof). A layer of plastic reinforced with a mat or chopped glass fiber 2 is pressed onto the upper and lower surface of the plywood core 1. As a result, a composite material is obtained, whose core 1 transmits vibrations well, is dimensionally stable, and the external claddings protect the internal structure of the circulating plate against moisture, temperature, cement chemistry, and at the same time show high resistance to abrasive wear. The side surfaces of the circulation plate have cuboidal millings 3 in order to facilitate the stacking process. The remaining, unprotected, open surfaces of the core 1 were protected against harmful factors by spraying with several layers of a protective agent in the form of acrylic paint.

Claims (4)

A circulating plate for vibro-pressed concrete elements, especially for the production of paving stones, characterized in that the core (1) is a flexible sheet of hardwood plywood. 2. The circulation plate according to claim 1 1. The method according to claim 1, characterized in that a layer of plastic reinforced with a mat or chopped glass fiber (2) is pressed onto the upper and lower surfaces of the plywood core (1). 3. The circulation plate according to claim 1 A machine according to claim 2, characterized in that it has symmetrical rectangular cutouts 3 on its short sides. 4. The circulation plate according to claim 1 The process of claim 3, wherein the binder is phenolic resins.