RU2792294C1 - Method for manufacturing concrete products using disposable plastic moulds - Google Patents

Abstract

FIELD: building materials.

SUBSTANCE: invention can be used in the manufacture of concrete products with a relief surface finish for paving sidewalks, park paths with decorative tiles. The method includes preparing a concrete mix, laying it simultaneously with vibration into a mould that repeats the relief of the product, heat and moisture treatment. In this case, vibration is carried out with an oscillation frequency of 35-40 Hz and an oscillation amplitude of 0.2-0.5 mm. Portland cement is used for the manufacture of concrete mix. Concrete products are made by filling disposable single-place or multi-place plastic moulds made by thermoforming from polyethylene terephthalate films, 0.2-0.8 mm thick, repeating the relief-forming matrix. Prior to pouring the concrete mix, a polytesil dye is sprayed onto the inside of the mould. The finished moulds are dried for 20 minutes. At the same time, when using a multi-place plastic form, it is first filled with concrete mixture on ¾ of the height of the products, a fiberglass mesh is placed between them, which flexibly binds the products into one mat according to the mosaic principle, then the mould is completely filled. Finished products are placed on pallets and kept until hardening in disposable plastic moulds for 1-3 days.

EFFECT: acceleration of the process of manufacturing concrete products, increasing their strength and durability by using disposable plastic moulds filled with concrete mix.

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Description

The invention relates to the industry of building materials and can be used in the manufacture of concrete products and embossed surface finish for paving sidewalks, park paths with decorative tiles.

A known method for the manufacture of colored paving stones by preparing a concrete mixture of two compositions: the first is prepared from cement, a plasticizing additive and a pigment, mixed with quartz sand and water, poured into a mold at 1/6-1/3 of its height, subjected to vibration compaction and kept until setting, then the second composition of the mixture is prepared by mixing cement, plasticizing additive, quartz sand, mineral additive, coarse fractional aggregate and water, the resulting homogenized mixture is poured onto the surface of the previously laid concrete mixture to the required height of the product, while the ratio of cement and quartz sand in the first composition is 1:1.5-1:2.5, and in the second composition - 1:2.5 - 1% 3.5, respectively (see Patent RU No. 2132318, 1999). However, concrete products made by a known method are characterized by insufficient strength and durability.

The closest to the proposed solution (prototype) is a method for manufacturing concrete products, including the preparation of a concrete mixture, laying it in a form with a relief-forming matrix, vibration and heat and moisture treatment, mechanically activated cement is used to prepare the concrete mixture, and the mixture is laid simultaneously with vibrating with oscillation frequency 35-40 Hz and oscillation amplitude 0.2-0.5 mm. (see Patent RU No. 2132318, 1999). However, the known method is very laborious, and the resulting products require additional operations: cleaning from concrete, sealing joints during installation.

EFFECT: speeding up the process of manufacturing concrete products, increasing their strength and durability by using disposable plastic molds filled with concrete mix.

от высоты изделия, размещают между ними стеклосетку, гибко связывающую изделия в один мат по мозаичному принципу, затем заполняют форму полностью, готовые изделия укладывают на поддоны и выдерживают до затвердевания в одноразовых пластиковых формах в течении 1-3 суток.It is achieved by the fact that in a known method, the preparation of a concrete mixture, laying it simultaneously with vibration in a form that repeats the relief of the product, heat and moisture treatment, vibration is carried out with an oscillation frequency of 35-40 Hz and an oscillation amplitude of 0.2-0.5 mm, for preparation Portland cement is used in the concrete mix, concrete products are made by filling disposable single or multi-place plastic molds made by thermoforming from polyethylene terephthalate films with a thickness of 0.2-0.8 mm, repeating the relief-forming matrix, before pouring the concrete mixture, Polytesil dye is sprayed on the inside of the mold , ready-made forms are dried for 10-20 minutes, when using a multi-place form, it is first filled with concrete mixture for

from the height of the product, a fiberglass mesh is placed between them, flexibly connecting the products into one mat according to the mosaic principle, then the mold is completely filled, the finished products are placed on pallets and kept until hardened in disposable plastic molds for 1-3 days.

The production of finished concrete products in the form of decorative tiles using disposable plastic molds has a number of advantages: it speeds up and reduces the cost of the technological process, as it eliminates the need for special mechanisms and devices for releasing finished products from molds, finished products can be kept, stored and transported directly in plastic forms, it is not required to unmould products, disposable plastic molds allow you to create products with the same seam both on the product and between products, which makes it possible to exclude sealing of seams during installation, sticking of products in molds, chipping at the corners of products, washing with toxic acids.

Potesil is a semi-gloss, quick-drying enamel for concrete floors with a low content of organic solvents. Enamel can be applied indoors and outdoors, including at negative temperatures (up to -20 degrees), it has high adhesion to the concrete base, asphalt, cement. Enamel for concrete provides long-term, enhanced protection of concrete from the effects of precipitation, fuels and lubricants, salt, road chemicals, mechanical and shock loads (see the Internet link https://www.krasbit.ru/dlya-betonnogo-pola/kraska/politesil/ ).

Portland cement is a substance made from clinker (a product of burning limestone and clay with the addition of gypsum used to control the setting time). The composition of the material also includes special additives that give it the desired properties. It is used to create concrete, which is necessary in the construction of airfield and road surfaces, etc. Of the obvious advantages of cement, one can single out: resistance to adverse climatic conditions and chemical attack, high adhesion of the material, low cost, high strength (see Internet link http://mistroim.ru/remont/pol/advantages-and-disadvantages-of-portland-cement/ Polyethylene terephthalate (PET) is a plastic used in thermoforming to produce various types of molds (see the Internet link https://ru .wikipedia.org/wiki/Polyethylene terephthalate).

The use of PET with a thickness of 0.2-0.8 mm for the manufacture of disposable plastic molds is due to the following criteria:

- The use of PET with a thickness of less than 0.2 mm does not allow achieving the proper quality of manufactured products due to a decrease in strength.

- The use of PET with a thickness of more than 0.8 mm is impractical due to the increase in the cost of manufactured molds.

от высоты изделий, размещают между ними стеклосетку, гибко связывающую изделия в один мат, затем заполняют форму полностью, помещают на поддон и выстаивают до затвердевания в течение 1 -3 суток.The method is carried out as follows, the required number of plastic molds with a given shape and relief of the product is made. To do this, a polyethylene terephthalate (PET) film 0.2-0.8 mm thick is heated in a vacuum forming machine to a temperature of 265 ° C, repeating the relief of the matrix, a polytesil dye is sprayed on the inside of the plastic mold, which has high adhesion to concrete bases and resistance to weathering, then dry the molds for 10-20 minutes. Then, a molding concrete mix containing Portland cement as a binder is prepared in a concrete mixer. Next, the prepared mixture is placed on the required thickness of the product in a plastic disposable form. Simultaneously with laying, the concrete mixture is subjected to vibrations with a frequency of 30-40 Hz and an amplitude of 0.2-0.5 mm, and then vibrocompaction with the same vibration parameters. The molded products are subjected to heat and moisture treatment in the usual mode for this type of products. Then disposable plastic molds with products are placed on pallets and left to harden for 1-3 days. When using a multi-place plastic form, it is first filled with concrete mixture on

from the height of the products, a fiberglass mesh is placed between them, flexibly connecting the products into one mat, then the mold is completely filled, placed on a pallet and left to harden for 1-3 days.

Example 1

In a concrete mixer, a molding concrete mixture is prepared, containing Portland cement M-500 D-0 as a binder. The prepared mixture is placed in prefabricated disposable plastic molds made by thermoforming from polyethylene terephthalate (PET) films, 0.2 mm thick, in a vacuum molding machine, while the inner surface of the mold repeats the relief-forming matrix. Then, polytesil dye is sprayed onto the inside of the molds. Dry molds for 20 minutes. Next, plastic molds are filled with concrete mixture for the entire required thickness of the product. Simultaneously with laying, the concrete mixture is subjected to vibrations with a frequency of 35 Hz and an oscillation amplitude of 0.5 for 45-60 seconds, and then vibrocompaction with the same vibration parameters. Molded products are subjected to heat and moisture treatment in the usual mode for this type of products.

от высоты изделий, размещают между ними стеклосетку, гибко связывающую изделия в один мат, затем заполняют форму полностью, помещают на поддон и выстаивают изделия до затвердевания, как в одноместных пластиковых формах, так и в многоместных в течение 1 -3 суток.When using a multi-place plastic form, it is first filled with concrete mixture on

from the height of the products, a fiberglass mesh is placed between them, flexibly connecting the products into one mat, then the mold is completely filled, placed on a pallet and the products stand until hardening, both in single plastic molds and in multi-place ones for 1-3 days.

Example 2

The technology for manufacturing concrete products is according to example 1. In this case, the concrete mixture placed in the molds is subjected to vibration with a frequency of 38 Hz and an amplitude of 0.3 mm. Plastic molds are made from polyethylene terephthalate (PET) films, 0.5 mm thick.

Example 3

Technology as in example 1, but the oscillation frequency is 40 Hz, and the oscillation amplitude is 0.2 mm. Plastic molds are made from polyethylene terephthalate (PET) films, 0.8 mm thick. The experiments have shown that at an oscillation frequency of less than 0.2 mm, the concrete mixture is not sufficiently liquefied, which leads to uneven filling of plastic molds and affects the quality of the relief finish.

Increasing the frequency of oscillations over 40 Hz and the amplitude of oscillations over 0.5 mm causes a sharp deterioration in the quality of the relief finish. Exceeding or reducing the parameters of the film thickness of polyethylene terephthalate (PET), 0.2-0.8 mm thick, from which disposable plastic molds are made, leads to their deformation, which affects the quality of concrete products.

A visual assessment of the surface of the samples obtained according to examples 1-3 showed a high quality of the relief finish: the clarity of the relief pattern, the uniformity of color, the absence of concrete chips, the absence of pores and shells on the surface.

Positive effect: the proposed method makes it possible to obtain concrete products with almost any relief, while the surfaces have high performance indicators, that is, they are durable, the technological process is accelerated and cheaper due to the use of disposable plastic molds made of durable material, in which the products are not deformed and can be transported to place of installation.

Claims (1)

A method for the manufacture of concrete products using disposable plastic molds, including the preparation of a concrete mixture, laying it simultaneously with vibration in a form that repeats the relief of the product, heat and moisture treatment, vibration is carried out with an oscillation frequency of 35-40 Hz and an oscillation amplitude of 0.2-0.5 mm , characterized in that Portland cement is used for the manufacture of concrete mix, concrete products are made by filling disposable single or multi-place plastic molds made by thermoforming from polyethylene terephthalate films, 0.2-0.8 mm thick, repeating the relief-forming matrix, before pouring concrete mixture on the inner part of the mold is sprayed with polytesil dye, the finished molds are dried for 20 minutes, when using a multi-place plastic mold, it is first filled with concrete mixture on

from the height of the products, a fiberglass mesh is placed between them, which flexibly binds the products into one mat according to the mosaic principle, then the mold is completely filled, the finished products are placed on pallets and kept until hardening in disposable plastic molds for 1-3 days.