CN108274589B

CN108274589B - Method for making decorative concrete products

Info

Publication number: CN108274589B
Application number: CN201711479021.6A
Authority: CN
Inventors: 张运华; 张志鹏; 闵捷; 袁颂东; 刘芷怡
Original assignee: Hubei University of Technology
Current assignee: Hubei University of Technology
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2020-08-07
Anticipated expiration: 2037-12-29
Also published as: CN108274589A

Abstract

The invention discloses a method for manufacturing a decorative concrete product, which solves the problems of complex process and poor pattern forming fineness of the existing concrete surface pattern modification method. The technical scheme comprises the following steps of preparing concrete decorative paper: coating a film on one surface of the paper, and partially coating a film on the other surface according to a design pattern to obtain concrete decorative paper; the paper is absorbent paper, and the membrane is a hydrophobic membrane; paving the concrete decorative paper at the bottom of the mould, and enabling one surface of the film with the pattern to face upwards; pouring concrete in the mould; maintaining, hardening and then removing the mold; finally uncovering the concrete decorative paper; and washing the surface of the concrete product with the torn concrete decorative paper by using water to obtain a pattern on the surface of the concrete product. The invention has simple process, low production cost, easy operation and high pattern forming precision.

Description

Method for making decorative concrete products

Technical Field

The invention relates to the technical field of concrete decoration, in particular to a manufacturing method of a decorative concrete product.

Background

In most cases, concrete has been developed with the advantages of high strength, low cost and durability in the last two centuries. It seems that the concrete itself has no decorative effect, and the building is complete by covering it with materials such as tiles, plaster and the like. If the concrete has the decoration, the cost of construction and decoration on the surface of the building can be saved, and the concrete has original taste and flavor and natural aesthetic feeling.

Under these circumstances, some people have begun to use fair-faced concrete. The fair-faced concrete is formed by directly exposing concrete as a decorative surface. It does not need any external decoration, and the concrete itself is the decoration. This can be said to be a major leap. However, the bare concrete has high requirements for construction, particularly maintenance, for example, the cement must be baked in the same furnace in the same project to keep the color of the cement consistent. The sand and stone fields need to be protected independently, so that the stable quality of the sand and stone fields is ensured. The curing process of the clear concrete is also strict, otherwise, the surface of the concrete is easy to cause color difference. Therefore, in general, the existing construction background in China is difficult to popularize the bare concrete in a large range. Other decorative concretes have also begun to be used. However, the shape and style of the existing cement decoration panel are changed mainly by the shape change of the concrete mould. The mould comprises a steel mould, a wood mould, a plastic mould and the like, and has various patterns. The method is characterized in that moulds with different patterns are required to obtain concrete with different patterns. Obviously, the process has high cost, difficult mass production, long period and great waste. This is also why it has not been popularized domestically.

Under these circumstances, it has been reported that a concrete surface is finished by using a transfer technique. The transfer printing technology is realized by printing the retarder on a PVA base film. However, including the examples cited in the document, the retarder is usually a water agent, and after such a liquid retarder is printed on the base film by screen printing, the pattern formed by the liquid retarder on the concrete is changed in the concrete pouring and vibrating processes, and the retarder is extremely easy to diffuse, migrate and change shape, so that the amount of the local retarder is insufficient, the retarding effect cannot be achieved, the pattern cannot be obtained, or the retarder migrates or changes shape, so that the final pattern is directly deformed, and the fineness of the pattern is influenced.

Disclosure of Invention

The invention aims to solve the technical problems and provides a manufacturing method of a decorative concrete product, which has the advantages of extremely simple process, easy operation and high pattern forming precision.

The technical scheme comprises the following steps:

a. preparing concrete decorative paper: coating a film on one surface of the paper, and partially coating a film on the other surface according to a design pattern to obtain concrete decorative paper; the paper is absorbent paper, and the membrane is a hydrophobic membrane;

b. paving concrete decorative paper: paving the concrete decorative paper at the bottom of the mould, and enabling one surface of the film with the pattern to face upwards;

c. pouring concrete: pouring concrete in the mould;

d. maintaining and removing the mold: curing, hardening and then removing the mold to obtain a concrete product;

e. uncovering the concrete decorative paper: tearing off the concrete decorative paper from the surface of the concrete product;

f. water washing: and washing the surface of the concrete product with the torn concrete decorative paper by using water to expose part of the aggregate, thereby obtaining a pattern on the surface of the concrete product.

The Cobb value of the paper is 15-400 g/m²。

The Cobb value of the paper is optimally 30-300 g/m²。

The thickness of the paper is 0.02-0.5 mm.

The thickness of the film is 0.005 mm-0.030 mm.

Aiming at the problems in the background art, the inventor creatively changes the thinking mode and ingeniously utilizes the combination of paper and a film to solve the technical problems, the mechanism is that one surface of the paper is completely coated with the film, the other surface of the paper is coated with the film according to the design pattern, one surface of the film with the pattern faces upwards, after concrete is poured, the concrete is in a state that part of the concrete is in contact with the film and part of the concrete is in direct contact with the paper, and because the paper has water absorbability, the water in a cement layer in contact with the paper can be absorbed, so that the water-cement ratio of a water layer in the area is reduced and the water-cement; and the concrete cement layer of other areas contacted with the film can be normally coagulated, the concrete layer is washed by water after demoulding, the cement layer of the uncoagulated part is washed down to expose the aggregate, and the aggregate is not exposed in other areas, so that visual contrast is generated to form a pattern. In the method, the conventional thinking of using retarder and coating printing technology is completely abandoned, and the water absorption principle of paper is ingeniously utilized, so that the operation difficulty and the production cost are greatly reduced, and the problems of diffusion, migration, shape change and the like existing in the coating of the liquid retarder are solved.

Further, it is preferable that the paper has a water absorption Cobb value of 15 to 400g/m²More preferably 30 to 300g/m²Too high can lead to paper to absorb water too much, and the concrete pattern part is too deep influences pleasing to the eye and meticulous degree, and too low can lead to paper to absorb water too little, and the pattern part is difficult to form contrast with non-pattern part, influences the meticulous degree of pattern, can't form the pattern even. The thickness of the paper is preferably 0.02mm to 0.5mm, too high may result in too strong water absorption of the paper, ultimately affecting the fineness of the concrete pattern, and too low may result in too weak water absorption of the paper, ultimately rendering the concrete unpatterned. The membrane is a hydrophobic membrane, such as a BOPP (biaxially oriented polypropylene film) or BOPP/PE (polyethylene)) Or BOPP/CPP (cast polypropylene);

has the advantages that:

the method has the advantages of simple process and ingenious conception, absorbs the moisture of the concrete layer by utilizing the water absorption performance of the paper to prevent the cement layer from being condensed, thereby being capable of conveniently washing with water to form patterns after the concrete product is stripped, having low operation difficulty, short production period and low production cost, being capable of forming the patterns with clear and accurate lines and uniform corrosion depth on the concrete and having wide market prospect.

Detailed Description

The process example comprises the following steps:

c. pouring concrete: pouring concrete in the mould;

The concrete in the above-mentioned process steps uses ordinary portland cement whose strength grade is not less than 42.5 grade.

To quantify the final pattern effect, the rate of change of the final concrete surface pattern from the original pattern will be tested. The concrete is characterized in that dry flour particles are filled in the pattern area, flour in the non-pattern area is removed, and the pattern area is white and the non-pattern area is gray of concrete. At the moment, the concrete is photographed, the graph is processed by computer software and is compared with the original graph, and the graph change rate is obtained.

The process steps of examples 1-9 are as above, wherein the water absorption, paper thickness and film thickness and the effect of the product forming pattern are evaluated as shown in Table 1:

TABLE 1 characteristics of concrete decorative paper and Pattern Effect of decorative concrete

Comparative example:

printing a liquid retarder on the coated surface of the single-surface coated art paper according to the pattern, enabling the coated surface to face upwards, preparing the decorative concrete by the steps, and finally obtaining the concrete with the defects that the pattern deformation cannot be distinguished, the diffusion condition is serious, the depths are inconsistent, the average value of the pattern change rate measured by the same test method is 89%, and the index does not meet the design requirement.

And (4) evaluating the results: through the processes, the finally obtained concrete pattern in the embodiment is clear and fine, has no diffusion condition and more consistent depth, and the indexes meet the design requirements. The liquid retarder in the comparative example can not form a film, so that the construction process difficulty is increased, and the problems of diffusion, migration, change of pattern area and uneven depth are difficult to avoid. Comparing the pattern change rates of the examples 1 to 9 and the comparative examples, the pattern change rate of the examples was reduced by 80% compared to the comparative examples, i.e., the degree of fineness was greatly improved.

Claims

1. The manufacturing method of the decorative concrete product is characterized by comprising the following steps:

c. pouring concrete: pouring concrete in the mould;

2. A method of making a decorated concrete article according to claim 1 wherein the paper has a thickness of from 0.02mm to 0.5 mm.

3. The method of claim 1, wherein the film has a thickness of 0.005mm to 0.030 mm.