Method of manufacturing decorative facing material

Abstract

FIELD: construction; production of building materials.SUBSTANCE: invention can be used for the production of facing tiles, wall stones, paving slabs and other small-piece products with a decorative surface. The method involves mixing cement, water and shells as a decorative filler, moulding and curing the products, and exposing the decorative surface. In this case, grey, white or coloured cements are used as cement, and crushed rapana shells of various fractions are used as decorative filler. The ratio of the amount of cement and shell fractions when mixing them is 1:3 by weight, the amount of water introduced into the raw mixture is 9-10 wt.%. In this case, the moulding of the products is carried out by pressing at a specific pressure of 15-20 MPa, and the hardening of the moulded products is carried out by steaming them at a temperature of 90 °C, and the exposure of the front decorative surface of the hardened products is carried out by grinding to a depth of 2-3 mm in the presence of an aqueous solution of a hydrophobic additive.EFFECT: it is possible to produce products of high strength and frost resistance with a decorative front surface and improved consumer properties.3 cl, 3 dwg, 8 ex

Description

[0001] The invention relates to the field of construction and production of building materials and can be used for the production of facing tiles, wall stones, paving slabs and other small-piece products with a decorative surface.

[0002] A known method for producing decorative facing material is described in the method for producing decorative concrete products (RU Patent No. 2330000, 2006). The method involves preparing and dosing a binder, water, fine and coarse aggregate, bonding the coarse aggregate grains to form a design outline, preparing a concrete mix, placing it in a product mold in which the bonded coarse aggregate has been previously placed, curing the concrete mix, and mechanically processing it. The coarse aggregate grains are bonded by placing them in a bottomless mold in a simmered container filled with sand to form a design outline, removing the bottomless mold, filling the coarse aggregate grains with cement mortar or cement paste, and allowing them to harden. During mechanical processing, the said products are sawn along the bonded coarse aggregate.

[0003] A disadvantage of this method, chosen as an alternative, is the high labor intensity of manufacturing decorative products due to the large number of manufacturing steps, which reduces production productivity and increases the cost of the products. Furthermore, when producing decorative facing materials using this method, the quality of the textured surface of some of the facing materials is unsatisfactory due to damage to the grains of coarse aggregate during sawing, which reduces the consumer properties of concrete products.

[0004] The closest to the proposed invention in technical features and the achieved result is a method for producing a decorative facing material (Patent of the Russian Federation, No. 2058893, 1996), imitating natural stone, including mixing cement, glue, pigment, water and decorative filler, molding products by pouring the resulting mixture into molds, hardening and exposing the textured surface, characterized in that when mixing, cement, water, glue and pigment are first mixed in a ratio of cement and water of 1: (0.3-0.4), then the resulting suspension is mixed with a decorative filler, and the exposure of the textured surface is carried out by milling, while shells are used as a decorative filler in the following ratio of components, wt.%:

[0005] Cement 30-60

[0006] Water 9-24

[0007] Glue 0.5-2.5

[0008] Pigment 0.5-2.5

[0009] Sinks 15-60.

[0010] The main disadvantages of the described method, chosen as a prototype, include the multi-component nature of the raw material mixture and the use of a slurry as a binder containing a large amount of water. This prevents the production of products with a compressive strength exceeding 21 MPa and frost resistance no higher than F35, making it unsuitable for use as a decorative material for cladding and paving slabs. The use of silicate adhesive in the mixture leads to the formation of efflorescence on the surface of decorative products during use. Furthermore, this method is incapable of recycling large shells, such as those of the rapana mollusc, which are 7–12 cm in size, making their disposal an environmental issue.

[0011] The objective of the invention is to develop a method for producing a decorative material with increased strength and frost resistance based on cements and crushed shells of rapana sea mollusks to obtain products with a high-quality decorative surface, as well as to solve the environmental problem of recycling rapana shell waste.

[0012] The stated problem is solved in that in the method for producing decorative facing material, which includes mixing cement, water and decorative filler - shells, molding and curing of products, exposing the decorative surface, gray, white or colored cements are used as cement, crushed rapana shells of various fractions are used as decorative filler, the ratio of the amount of cement and shell fractions when mixing them is 1:3 (by weight), the amount of water introduced into the raw mixture is 9-10% (by weight), the products are molded by pressing at a specific pressure of 15-20 MPa, curing of the molded products is carried out by steaming them at a temperature of 90 ° C, exposure of the front decorative surface of the cured products is carried out by grinding to a depth of 2-3 mm in the presence of an aqueous solution of a hydrophobic additive.To obtain a decorative surface for facing materials containing large inclusions of rapana shell particles, whole rapana shells are crushed to a particle size no larger than 10 mm. Particles smaller than 1 mm are screened out, and a 1-10 mm fraction is used. To obtain a decorative surface for facing materials containing small inclusions of particles no larger than 5 mm, particles smaller than 1 mm are screened out, and a 1-5 mm fraction is used. The resulting products are highly durable and frost-resistant, with a beautiful decorative surface and enhanced consumer properties.

[0013] The method for producing decorative facing material is illustrated by drawings. Fig. 1 shows the decorative surface of products using gray cement and decorative filler made from crushed rapana shells of 1–10 mm fraction. Fig. 2 shows the decorative surface of products using white cement and decorative filler made from crushed rapana shells of 1–5 mm fraction. Fig. 3 shows the decorative surface of products using green cement and decorative filler made from crushed rapana shells of 1–5 mm fraction.

[0014] Technical solution features common with the prototype:

[0015] - mixing cement, water and decorative filler;

[0016] - molding and curing of products;

[0017] - exposure of the decorative surface.

[0018] Distinctive features of the technical solution:

[0019] - use of colored cements;

[0020] - use as a decorative filler for rapana shells;

[0021] - crushing rapana shells into fractions of different sizes;

[0022] - molding of products by pressing;

[0023] - grinding of products to a depth of 2–3 mm in an aqueous solution of a hydrophobic additive.

[0024] The inventive step is determined by the totality of the features of the invention.

[0025] The method is implemented as follows.

[0026] Take gray, white, or colored cement and mix them separately in a paddle mixer with decorative filler—rapana shells crushed in a jaw crusher to a size of 1–10 mm or 1–5 mm—and water. The required rapana shell size fractions are obtained by screening, separating particles larger than 10 mm and smaller than 1 mm for the 1–10 mm fraction, and separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm fraction. The ratio of each cement to each shell size during mixing is 1:3 (by weight). The amount of water added to the mixture is 9–10% (by weight). From the raw mix obtained in the mixer with a moisture content of 9–10%, products are pressed in a hydraulic press at a specific pressing pressure of 15–20 MPa and sent for curing to a steam chamber, where they are steamed at 90 °C for 10 hours.After steaming, the hardened products are ground on a grinding machine to a depth of 2–3 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0027] As a result of implementing the proposed method for producing decorative material, products are obtained using rapana shells with a decorative surface shown in Fig. 1, Fig. 2 and Fig. 3 with a compressive strength of 42.0–46.0 MPa and a frost resistance grade of at least F150.

[0028] The increased strength and high frost resistance of decorative facing products made from rapana shell waste, manufactured using the proposed method, are due to the production of a compacted material with a dense structure using crushed fractions of an optimal size, ensuring their highly durable contact with the cement stone during the hardening process. Furthermore, exposing the decorative surface by grinding in the presence of an aqueous solution of a hydrophobic additive, in addition to intensifying the grinding process, imparts water-repellent properties to the face layer of the products, which further enhances the frost resistance of the products and prevents the formation of efflorescence on the decorative surface.

[0029] Examples:

[0030] 1. Take gray cement and mix it separately in a paddle mixer with decorative filler—rapana shells of 1–10 mm size, crushed in a jaw crusher—and water. The required fraction of rapana shells is obtained by screening them, separating particles larger than 10 mm and smaller for the 1–10 mm fraction. The ratio of gray cement to 1–10 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 9% (by weight). From the raw mix obtained in the mixer, with a moisture content of 9%, cylindrical samples 7 cm in diameter and height are pressed in a hydraulic press at a specific pressing pressure of 15 MPa and sent to a steam curing chamber, where they are steamed at 90 °C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 2 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0031] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 1, with a compressive strength of 43.2 MPa and a frost resistance grade of at least F150.

[0032] 2. Take gray cement and mix it in a paddle mixer with decorative filler—rapana shells crushed in a jaw crusher to a size of 1–10 mm—and water. The required size fraction of the rapana shells is obtained by screening them, separating particles larger than 10 mm and smaller than 1 mm for the 1–10 mm size fraction. The ratio of gray cement to 1–10 mm shells during mixing is 1:3 (by weight). The amount of water added to the mixture is 9.5% (by weight). From the raw mix obtained in the mixer with a moisture content of 9.5%, products are pressed in a hydraulic press in the form of cylindrical samples with a diameter and height of 7 cm at a specific pressing pressure of 17.5 MPa and sent for curing in a steam chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 2.5 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0033] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 1, with a compressive strength of 45.4 MPa and a frost resistance grade of at least F150.

[0034] 3. Take gray cement and mix it in a paddle mixer with decorative filler—rapana shells of 1–10 mm size, crushed in a jaw crusher—and water. The required fraction of rapana shells is obtained by screening them, separating particles larger than 10 mm and smaller than 1 mm for the 1–10 mm fraction. The ratio of gray cement to 1–10 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 10% (by weight). From the raw mix obtained in the mixer, with a moisture content of 9–10%, products are pressed in the form of cylindrical samples with a diameter and height of 7 cm in a hydraulic press at a specific pressing pressure of 20 MPa and sent to a steam curing chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 3 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0035] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 1, with a compressive strength of 46 MPa and a frost resistance grade of at least F150.

[0036] 4. Take white cement and mix it in a paddle mixer with decorative filler—rapana shells crushed in a jaw crusher to a size of 1–5 mm—and water. The required fraction of rapana shells is obtained by screening them, separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm fraction. The ratio of white cement to 1–5 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 9% (by weight). From the raw mix obtained in the mixer, with a moisture content of 9%, cylindrical samples 7 cm in diameter and height are pressed in a hydraulic press at a specific pressing pressure of 15 MPa and sent to a steam curing chamber, where they are steamed at 90 °C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 2 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0037] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 2, with a compressive strength of 42.1 MPa and a frost resistance grade of at least F150.

[0038] 5. Take white cement and mix it in a paddle mixer with decorative filler—rapana shells of 1–5 mm size, crushed in a jaw crusher—and water. The required fraction of rapana shells is obtained by screening them, separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm fraction. The ratio of white cement to 1–5 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 9.5% (by weight). From the raw mix obtained in the mixer, with a moisture content of 9.5%, products are pressed into cylindrical samples in a hydraulic press at a specific pressing pressure of 17.5 MPa and sent to a steam curing chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 2.5 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0039] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 2, with a compressive strength of 43.3 MPa and a frost resistance grade of at least F150.

[0040] 6. Take white cement and mix it in a paddle mixer with decorative filler—rapana shells crushed in a jaw crusher to a size of 1–5 mm—and water. The required size fraction of rapana shells is obtained by screening them, separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm size fraction. The ratio of white cement to 1–5 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 10% (by weight). From the raw mix obtained in the mixer, with a moisture content of 10%, cylindrical samples 7 cm in diameter and height are pressed in a hydraulic press at a specific pressing pressure of 20 MPa and sent to a steam curing chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 3 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0041] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 2, with a compressive strength of 44.3 MPa and a frost resistance grade of at least F150.

[0042] 7. Green cement is mixed in a paddle mixer with decorative filler—rapana shells crushed in a jaw crusher to a size of 1–5 mm—and water. The required fraction of rapana shells is obtained by screening them, separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm fraction. The ratio of green cement to 1–5 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 9% (by weight). From the raw mix obtained in the mixer, with a moisture content of 9%, cylindrical samples 7 cm in diameter and height are pressed in a hydraulic press at a specific pressing pressure of 15 MPa and sent to a steam curing chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 2 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0043] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 3, with a compressive strength of 42.0 MPa and a frost resistance grade of at least F150.

[0044] 8. Green cement is mixed in a paddle mixer with decorative filler—rapana shells of 1–5 mm size, crushed in a jaw crusher—and water. The required fraction of rapana shells is obtained by screening them, separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm fraction. The ratio of green cement to 1–5 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 9.5% (by weight). From the raw mix obtained in the mixer, with a moisture content of 9.5%, products are pressed in the form of cylindrical samples with a diameter and height of 7 cm in a hydraulic press at a specific pressing pressure of 17.5 MPa and sent to a steam curing chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 2.5 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0045] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 3, with a compressive strength of 43.5 MPa and a frost resistance grade of at least F150.

[0046] 9. Green cement is mixed in a paddle mixer with decorative filler—rapana shells crushed in a jaw crusher to a size of 1–5 mm—and water. The required size fraction of rapana shells is obtained by screening them, separating particles larger than 5 mm and smaller than 1 mm for the 1–5 mm size fraction. The ratio of green cement to 1–5 mm shells during mixing is 1:3 (by weight). The amount of water introduced into the mixture is 10% (by weight). The raw mix obtained in the mixer, with a moisture content of 10%, is pressed into cylindrical specimens 7 cm in diameter and height in a hydraulic press at a specific pressing pressure of 20 MPa and sent to a steam curing chamber, where they are steamed at 90°C for 10 hours.After steaming, the front surface of the hardened products is ground on a grinding machine to a depth of 3 mm in the presence of an aqueous solution of a hydrophobic additive, for example, a 10% aqueous solution of organosilicon liquid GKZh-11K, until the decorative surface is exposed.

[0047] The resulting products made from decorative material using rapana shells have a high-quality decorative surface, shown in Fig. 3, with a compressive strength of 44.8 MPa and a frost resistance grade of at least F150.

[0048] This technical solution ensures the production of building materials with a high-quality and beautiful decorative surface, increased strength, and a high frost resistance rating.

[0049] The use of grey, white and coloured cements in combination with decorative filler made from crushed rapana shells allows for an expanded colour range of products with a decorative front surface and increases their consumer appeal.

[0050] The use of crushed rapana shells of 1-10 mm fraction in concrete mix allows for the creation of a decorative surface of products with large shell inclusions (see Fig. 1). Increasing the particle size of crushed granules above 10 mm leads to their destruction during pressing and reduces the strength of products by 15-20%. The use of rapana shells of 1-5 mm fraction in concrete mix allows for the creation of a decorative surface of products with small inclusions (see Fig. 2 and Fig. 3). The need to screen out crushed shell particles smaller than 1 mm from the fractions used is due to the decrease in the strength of the material in their presence of up to 25%.

[0051] The optimal ratio of cement to shells is 1:3 (by weight). Increasing the shell content above 3 parts results in a decrease in product strength; for example, with a ratio of 1:4 (by weight), product strength decreases by 9–10 MPa. Increasing the cement content above the optimal amount does not significantly increase product strength, reduces the decorative appeal of their surface, and increases the cost.

[0052] The optimal amount of water added to the raw mix is ​​9–10% (by weight), which corresponds to normal molding moisture during molding. Reducing the water content to less than 9% and increasing it to more than 10% will impair the molding process.

[0053] Pressing products at a specific pressure of 15–20 MPa is optimal, since pressing pressure of less than 15 MPa reduces the strength of the products, and pressing products at a pressure of more than 20 MPa does not cause a significant increase in their strength, but at the same time increases the wear of the molds and the energy consumption of pressing.

[0054] Curing products by steam curing at 90°C for 10 hours is the standard used in the production of concrete products.

[0055] Exposing the surface of cured products by grinding to a depth of 2–3 mm is optimal. Reducing the grinding depth to less than 2 mm results in insufficient exposure of the material's voids and a reduction in the product's decorative appeal, while increasing the grinding depth beyond 3 mm increases the energy consumption of this process.

[0056] Sanding products in the presence of an aqueous solution of a hydrophobic additive increases the intensity of exposure of their decorative surface, hydrophobicizes the surface layer of the product, further enhances their frost resistance, and prevents the formation of efflorescence on the decorative surface during use. The examples used an aqueous solution of a hydrophobic organosilicon liquid with a 10% concentration. This concentration of this additive is optimal for complete hydrophobicization, in accordance with the manufacturer's recommendations.

[0057] Thus, the use of the proposed method for producing decorative facing material makes it possible to obtain products with a high-quality decorative surface and high consumer properties, possessing high strength and frost resistance using rapana shell waste as a decorative filler, and also to solve the environmental problem of recycling this waste.

Claims

1. A method for producing a decorative facing material, which includes mixing cement, water in an amount of 9-10 wt.% and a decorative filler - shells, molding and hardening of the products, exposing the decorative surface, characterized in that gray, white or colored cements are used as cement, crushed rapana shells of various fractions are used as a decorative filler, the ratio of the amount of cement and shell fractions when mixing them is 1:3 by weight, molding of the products is carried out by pressing at a specific pressure of 15-20 MPa, exposure of the front decorative surface of the hardened products is carried out by grinding to a depth of 2-3 mm in the presence of an aqueous solution of a hydrophobic additive.

2. The method according to paragraph 1, characterized in that the rapana shells are crushed to a particle size not exceeding 10 mm, particles smaller than 1 mm are screened out, and a fraction of 1-10 mm is used.

3. The method according to paragraph 1, characterized in that the rapana shells are crushed to a particle size not exceeding 5 mm, particles smaller than 1 mm are screened out, and a fraction of 1-5 mm is used.

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