RU2459699C1 - Method of fabricating decorative concrete articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of decorative concrete articles. Proposed method comprises preparing mix of intermediate layer of the mix of crushed glass cullet, liquid glass and water, laying concrete mix and intermediate layer mix, maturing and thermomoist processing, plasma fusion of article face surface at plasmatron power of 9 kW and plasma burner feed rate of 0.1 m/s.

EFFECT: higher quality, accelerated glasing, power savings.

3 tbl, 2 ex

Description

The invention relates to the field of manufacturing decorative concrete products and can be used in the building materials industry.

Currently, there are several methods for manufacturing decorative concrete products using screen furnaces, a gas flame, a plasma torch, and a laser beam as an energy source.

A known method of manufacturing decorative concrete products by melting the front surface with a plasma torch, followed by heat and moisture treatment and hardening for 28 days [1].

[A.C. 1705090. A method of manufacturing decorative concrete products. / Immortal B.C., Khodykin A.P., Burlakov N.M., Travkin V.M., Krokhin V.P. Declared 05/03/89. Publ. 01/15/92. Bull. No. 2. - Priority dated 05/03/89]

However, despite the good quality of the final product, the method has the following disadvantages: the duration and energy intensity of the process, a significant amount of marriage in the form of chips and delamination of the glaze layer.

The closest technical solution is a method of manufacturing decorative concrete products, which consists in preliminary preparation of the mixture of the intermediate layer, laying the concrete mixture and the mixture of the intermediate layer, exposure and heat-moisture treatment of products, plasma melting of their front surface with a plasma torch operating power of 20.34-25.30 kW .

The disadvantage of this method is the high energy intensity of the process, the low speed of the plasma torch along the front surface of the product, equal to 0.05 m / s, and the relatively low quality of the glaze layer [2]. [Gromov Yu.E., Lezhepekov VP, Severinova G.V. Industrial decoration of building facades. - M .: Stroyizdat, 1980, - p. 61-64]

The advantage of the proposed method is to improve the quality of the final product, accelerate the process of melting the front surface, reduce the energy intensity of production and, as a result, obtain high-quality competitive products.

This goal is achieved in that the intermediate layer is prepared from a mixture of glass, liquid glass and water, and plasma melting of the front surface of the products is carried out with a plasma torch operating power of 9 kW and a plasma torch passing through the front surface of 0.1 m / s.

A distinctive feature of the proposed method is the elimination of the processes of dehydration of the surface layer and the effects of thermal shock through the use of an intermediate layer based on glass breakage with liquid glass and water. This allows you to increase the speed of passage of the plasma torch on the front surface of the products and reduce energy consumption.

In the known method, the intermediate layer is prepared from lightweight concrete with aggregates of expanded clay and perlite. An intermediate layer is applied to the surface of the concrete and is subjected to plasma fusion. In the process of plasma melting, a high power of the plasma torch and a low speed of passage of the plasma torch along the surface of the products are required to obtain a uniform melt from the dehydrated products of the intermediate layer and filler. Under the action of high temperatures, dehydration processes occur in the surface fused layer of concrete products, which soften the intermediate layer. This significantly reduces the adhesion of the molten layer to the base.

It is the value of the adhesion strength of the molten layer to the base that determines the durability and quality of concrete products.

In the proposed method, in order to eliminate the effects of thermal shock and dehydration of the cement stone of the intermediate layer, the latter is made from a mixture of glass, liquid glass and water. Under the influence of high temperatures of the plasma torch, the intermediate layer melts to form a high-quality front surface and prevents concrete from dehydration and destruction, and also protects the concrete product from thermal shock.

The inventive step of the proposed method is confirmed by the fact that eliminating the effects of thermal shock and dehydration of cement stone by applying an intermediate layer of a mixture of glass breakage with liquid glass and water allows not only to obtain a high-quality product with high strength, but also to accelerate the process and reduce energy costs.

The analysis of known methods for the manufacture of decorative concrete products allows us to conclude that the claimed invention meets the criterion of "novelty."

A comparative analysis of the technological operations of the proposed and known methods is presented in table 1. As can be seen from table 1, in the known method, a rather laborious and expensive operation is the deposition of an aqueous solution of metal oxides or glaze slip on the panel surface. The most important are the operations of preparing the intermediate layer and fusing the front surface with a plasma torch. It is the technological operation of melting the front surface that is decisive in the method of manufacturing decorative concrete products.

Table 1 Comparative analysis of technological operations of the proposed and known methods [2], S. 61-62 The proposed method Known method one 2 1. Preparation of the intermediate layer of ground battle of glass, liquid glass, water 1. Preparation of a mixture of the intermediate layer of expanded clay or perlite sand, cement and water ↓ ↓ 2. Laying in the form of concrete mix and embedded parts; laying the front layer of heavy concrete with a thickness of 3 cm (filling level 2 cm from the top edge) 2. Laying in the form of concrete mix and embedded parts; laying the front layer of heavy concrete with a thickness of 3 cm (filling level 2 cm from the top edge) ↓ ↓ 3. Laying the mixture of the intermediate layer on the laid concrete mixture with a thickness of 3.0-3.5 cm in a loose state 3. Laying the mixture of the intermediate layer on the laid concrete mixture with a thickness of 3.0-3.5 cm in a loose state ↓ ↓ 4. Compaction of the mixture of the intermediate layer in the level with the edge of the form 4. Compaction of the mixture of the intermediate layer in the level with the edge of the form ↓ ↓ 5. Exposure and heat and moisture treatment of panels 5. Exposure and heat and moisture treatment of panels ↓ ↓ 6. Flashing the front surface with a plasma torch at a speed of 0.1 m / s 6. Application of an aqueous solution of metal oxides or glaze slip on the surface of the molten panel to give a given color ↓ 7. Flashing the front surface with an electric arc torch (plasma torch) * at a speed of 0.05 m / s * - authors note

The optimal experimental conditions for the melting of the front surface of concrete products are the plasmatron power of 9 kW at a plasma torch travel speed of 0.1 m / s (Table 2).

table 2 Optimal parameters of plasma fusion of the front surface of concrete products. No. p / p The power of the plasmatron, kW The consumption of plasma-forming gas, l / min The speed of the plasma torch, m / s The adhesion strength of the molten layer to the base, MPa one. 7 twenty 0,025 1.96 0,050 2.18 0,075 2.49 0,100 2.81 0.125 2.71 2. 8 twenty 0,025 2.07 0,050 2,37 0,075 2.61 0,100 2.96 0.125 2.65 3. 9* twenty* 0,025 2.68 0,050 2.84 0,075 3.02 0,100 * 3.24 * 0.125 3.06 four. 10 twenty 0,025 2.13 0,050 2,53 0,075 2.79 0,100 3.01 0.125 2.83 * - optimal mode

Comparative data of quality indicators and technological parameters of the proposed and known methods are presented in table.3.

Table 3 Quality indicators and technological parameters of the proposed and known methods. No. p / p Indicators Units measuring The proposed method The known method [2] one 2 2 four 5 one Energy consumption (plasmatron power) kw 9 20.3-25.3 113 × 180 = 20300 W = 20.3 kW 110 × 230 = 25300 W = 25.3 kW 2 The speed of the plasma torch m / s 0,100 0.05 3 The adhesion strength of the molten layer to the base MPa 3.24 - four Quality of the melted layer Flat spill Melt flows, tuberosity [2, p.62] 5 Plasma gas Argon Argon 6 The average thickness of the melted layer mm 0.3-0.5 0.3-0.8

Example. Production of decorative concrete products.

Heavy concrete was placed in a mold for the production of panels of standard sizes 2.76 × 3.18.

Pre-prepared a mixture for the intermediate layer. The ground plate glass break was mixed in a mortar mixer with liquid glass and water in the ratio: glass break: liquid glass: water = 10: 2: 3

A mixture of an intermediate layer 3.0 cm thick in a loose state was laid in a mold on the surface of heavy concrete.

The roller was sealed with a mixture of the intermediate layer in the level with the edge of the form.

The mold was kept for 2 hours and heat-wet treatment was carried out according to standard factory parameters.

The product was released from the mold and the front surface was fused with a GN-5r plasma torch of the UPU-8m electric arc plasma torch at a speed of 0.1 m / s.

Complete melting of the front surface of the panel was carried out in thirty passes of the GN-5r plasma torch. Argon served as the plasma-forming gas, the flow rate of which was 20 l / min. After plasma fusion, a high-quality glaze layer 0.3-0.5 mm thick was formed on the front surface of the panel.

After plasma fusion of the front surface of the panel, the adhesion strength of the coating to the base was determined.

An example of quality control.

To determine the adhesion strength of the melted layer, 5 samples 60 × 60 × 60 mm in size were prepared using the technology specified in the example.

Five metal rods 150 mm long and 1 cm long were glued to the fused surface of the five samples with epoxy resin. After polymerization of the epoxy resin for 24 hours, we proceeded to determine the adhesion strength of the melted layer to the base on a K-0.5 tensile testing machine. Products with metal rods were fixed in special clamps of a tensile testing machine. After uniform loading, the melted layer peeled off. The adhesion strength of the molten layer was determined as the arithmetic average of five measurements:

σ _p3 = (3.25 + 3.24 + 3.26 + 3.22 + 3.25) / 5 = 3.24 MPa.

Claims (1)

A method of manufacturing decorative concrete products, including preparing an intermediate layer mixture, laying concrete mixture and an intermediate layer mixture, compacting the intermediate layer mixture, exposure and heat-moisture treatment of products, plasma melting of their front surface, characterized in that the intermediate layer is prepared from a mixture of ground glass breakage, liquid glass and water, and plasma melting is carried out with a plasma torch operating power of 9 kW and a plasma torch passing through the front surface of 0.1 m / s.