Slow-setting imaging concrete capable of preventing aggregate sedimentation and preparation method of slow-setting imaging concrete

Abstract

The invention discloses delayed coagulation imaging concrete capable of preventing aggregate sedimentation and a preparation method of the delayed coagulation imaging concrete. According to the delayed coagulation imaging concrete provided by the invention, a formula is adjusted, multi-size carborundum is adopted as aggregate, and a proper water-binder ratio is adjusted, so that the aggregate can be effectively prevented from settling in a concrete hardening process, noise points exposed on a concrete imaging surface are reduced, and the texture of a concrete finished product is improved; in addition, the thickening agent in the concrete formula can avoid aggregate sedimentation, the early strength agent can promote cement thickening, and the aggregate can be effectively prevented from being settled to a concrete pattern surface under the combined action of the thickening agent and the early strength agent. Finally, under the synergistic effect of multiple components, the delayed coagulation imaging concrete provided by the invention can well prevent sedimentation of aggregate, aggregate noise points are not easy to expose on a concrete imaging surface, and the quality of a concrete finished product is improved.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to a slow-setting image-forming concrete capable of preventing aggregate settlement and a preparation method thereof. Background Art

[0002] Slow-setting imaging concrete is a concrete imaging technology that uses retarders to delay the hydration process of concrete to obtain customized patterns. It can be used to decorate concrete surfaces. Its production method is: use spray slow-setting ink to print the pattern on a specially treated printing medium (base film), called a slow-setting film; then place the slow-setting film on a flat and smooth workbench with the slow-setting surface (pattern surface) facing up; then install the frame according to actual requirements and pour concrete; when the concrete reaches the final setting state, remove the slow-setting film and rinse the concrete surface with a high-pressure water gun, then the glue at the original slow-setting ink position will be washed away, exposing the aggregate; the color difference between the different colors of the aggregate and the glue can form a pattern.

[0003] In the related art, the existing slow-setting imaged concrete production method is usually to transport the slow-setting ink with a pattern to the surface in contact with the concrete through printing or output technology, and then wash it to form a pattern. For example, Chinese patent CN202210993872.7 discloses a UHPC formula image concrete and its production method (including slow-setting film and UHPC concrete formula), and the image concrete is produced by making a slow-setting film, laying a slow-setting film, pouring concrete and demolding and flushing. Chinese patent CN201510354203.5 discloses a concrete washing slow-setting finishing art transfer film, including a base film and a slow-setting coating, wherein the retarder coating is attached to the surface of the base film, and the surface area of ​​the retarder coating is smaller than the base film; the retarder is coated on the pattern area on the base film in a membrane structure; the concrete washing slow-setting finishing art transfer film is at the bottom of the mold, and after pouring concrete and demolding the concrete components, it is then washed and eroded to produce the design pattern, and the exposed aggregate pattern finish is formed on the concrete surface. The decorative surface with contrast and convex and concave changes with the plain concrete base surface is formed. However, the above-mentioned retarder film production methods all use screen printing to transfer the retarder ink coating to the base film, and the retarder film product is obtained after the retarder ink coating is dried. This method has a long cycle, which reduces the efficiency of retarder film preparation; and the retarder layer is easily damaged during storage and transportation. In addition, most of the existing retarder components are water-soluble, and the patterns produced by the retarder are easily distorted during the concrete pouring process, reducing the beauty of the concrete product. In addition, most of the UHPC concrete formulas currently used are prone to aggregate settlement during the concrete pouring process, and the final concrete imaging surface is prone to reveal aggregate noise.

[0004] Therefore, providing a slow-setting imaging concrete that is not prone to aggregate settlement, can keep the slow-setting layer from being damaged, avoids pattern distortion on the slow-setting film, and improves the clarity of the pattern of the concrete finished product has important practical significance and production value. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a slow-setting imaging concrete with anti-aggregate settlement and a preparation method thereof, aiming to solve the problems that the current slow-setting imaging concrete is prone to aggregate settlement, the slow-setting layer is prone to damage, and the pattern of the slow-setting ink is prone to distortion during the concrete pouring process.

[0006] In a first aspect of the present invention, a slow-setting imaging concrete is provided, wherein the raw materials of the slow-setting imaging concrete include cementitious materials, aggregates, admixtures and water, and the water-cement ratio is 0.22-0.30; in terms of weight, the cementitious materials include 30-45 parts of white cement and 10-20 parts of metakaolin; the aggregates include 15-30 parts of corundum with a size of 0.6-0.7 mm, 25-40 parts of corundum with a size of 0.3-0.4 mm, and 5-15 parts of corundum with a size of 0.1-0.2 mm; the admixtures include thickeners, early strength agents, silicon-based defoamers, and water reducers.

[0007] The slow-setting imaging concrete according to the embodiment of the present invention has at least the following beneficial effects: the present invention adjusts the concrete formula, uses multi-sized corundum as aggregate, and adjusts the appropriate water-cement ratio, which can effectively prevent the aggregate from settling during the concrete hardening process, reduce the noise exposed on the concrete imaging surface, and improve the texture of the finished concrete product; the present invention also reasonably adjusts the ratio of coarse sand, medium sand, and fine sand of different sizes in the aggregate, and the synergistic effect between the components improves its packing density and effectively prevents the sedimentation of the aggregate; in addition, the thickener in the concrete formula can avoid the sedimentation of the aggregate, and the early strength agent can promote the thickening of cement. Under the joint action of the thickener and the early strength agent, the aggregate can also be effectively prevented from settling to the concrete pattern surface. Finally, under the synergistic effect of multiple components, the slow-setting imaging concrete provided by the present invention can well prevent the sedimentation of the aggregate, and the concrete imaging surface is not easy to expose the aggregate noise, which improves the quality of the finished concrete product.

[0008] In some embodiments of the present invention, the admixture includes, by weight, 0.05 to 0.1 parts of a thickener, 0.05 to 0.1 parts of an early strength agent, 0.05 to 0.1 parts of a silicon-based defoamer, and 0.05 to 0.1 parts of a water reducer.

[0009] In some embodiments of the present invention, the thickener includes hydroxypropyl methylcellulose, polycarboxylate, expanded clay, polyacrylamide, but is not limited thereto. Preferably, the thickener is hydroxypropyl methylcellulose.

[0010] In some embodiments of the present invention, the early strength agent includes nanocrystalline nucleating agent, calcium chloride, sodium chloride, water glass, sodium aluminate, sodium carbonate, calcium carbonate, sodium fluoride, triethanolamine, but is not limited thereto. Preferably, the early strength agent is a nanocrystalline nucleating agent.

[0011] The thickener in the concrete formula of the present invention can prevent aggregate settlement, and the early strength agent can promote cement thickening. Under the joint action of the thickener and the early strength agent, the aggregate can also be effectively prevented from settling to the concrete pattern surface.

[0012] In some embodiments of the present invention, the gelling material further comprises calcium powder for improving whiteness. The amount of calcium powder used is relatively small, and the specific weight can be adjusted adaptively.

[0013] In some embodiments of the present invention, the slow-setting imaging concrete further comprises a slow-setting film located on the surface of the concrete; the slow-setting film comprises a base film and a slow-setting ink cured on the surface of the base film, and the slow-setting ink is close to the surface of the concrete.

[0014] In some embodiments of the present invention, the retarding ink comprises a compound retarder and a solvent-based ink; the composition of the compound retarder comprises, by weight: 20 to 30 parts of triethyl citrate, 15 to 40 parts of tributyl citrate, and 35 to 50 parts of trioctyl phosphate; the composition of the solvent-based ink comprises, by weight: 40 to 60 parts of epoxy acrylate resin, 5 to 15 parts of 4-methylbenzophenone, 20 to 30 parts of alkoxy acrylate, and 15 to 25 parts of pigment.

[0015] The retarding ink provided by the present invention comprises a compound retarder and a solvent-based ink in its formula. The compound retarder is an ester-based compound retarder (including triethyl citrate, tributyl citrate and trioctyl phosphate). Since it contains multiple ester groups and has a large steric hindrance, the hydrolysis rate is relatively slow, so that a long-term slow release can be achieved. At the same time, the citric acid released by hydrolysis also has a certain retarding effect. The synergistic effect of the two can achieve an excellent retarding effect. When the compound retarder is added to the retarding ink and acts on the concrete surface, its retarding effect is relatively mild and will not react violently. The retarded area will not spread, and the hydration process of the concrete in the non-retarded area will not be affected. When preparing the finished concrete product, the diffusion of the solidified retarding ink can be prevented, and the pattern formed by the retarding ink can be avoided from being distorted, thereby improving the clarity of the pattern of the finished concrete product. In addition, the retarding ink uses solvent-based ink instead of water-soluble ink, so the pattern produced is not easily distorted during the pouring of concrete; and the retarding film can be prepared by transfer printing using a solvent-based inkjet printer, which reduces the preparation time of the retarding film and improves the preparation efficiency of the retarding film. Moreover, the above-mentioned compound retarder has good compatibility with the solvent-based ink, and the retarding film produced by their combined action can be placed for a long time (more than 3 months) after curing, which is more convenient for long-term storage and transportation, and has very important economic benefits and production value.

[0016] In some embodiments of the present invention, the mass ratio of the compound retarder to the solvent-based ink is (1.5-2.5):(7.5-8.5).

[0017] In some embodiments of the present invention, the pigment is an organic pigment.

[0018] In some embodiments of the present invention, the base film comprises PP synthetic paper, glass paper, PVC film or polyester film, preferably PP synthetic paper or glass paper.

[0019] At present, the base film used to prepare the slow-setting film is mostly pulp, which is easy to be damaged and susceptible to moisture. After being damp, the retarder will become ineffective and the slow-setting film cannot be used normally; and the surface of the pulp is relatively rough, which can easily reduce the texture of the pattern surface of the finished concrete product and affect the appearance. Based on this, the slow-setting film of the present invention changes the type of base film and adopts PP synthetic paper, glass paper and other paper with high tensile strength and smooth surface as the base film, which solves the problem of pulp being susceptible to moisture and facilitates the long-term storage and transportation of the slow-setting film; at the same time, PP synthetic paper, glass paper and the like have a smooth surface, which can also improve the smoothness of the surface of the finished concrete product, thereby improving the texture of the finished concrete product.

[0020] In some embodiments of the present invention, the slow-setting ink is cured on the surface of the base film by UV light curing. The present invention adopts a UV light curing slow-setting ink process, which can prevent the slow-setting ink from diffusing after curing when preparing the finished concrete product, avoid the distortion of the pattern on the slow-setting film, and thus improve the clarity of the pattern of the finished concrete product; and the slow-setting film after curing is more convenient for long-term storage and transportation.

[0021] In some embodiments of the present invention, the UV light is mainly ultraviolet light, the light source is an LED lamp, and the wavelength range is 320-400nm.

[0022] The role of conventional UV light curing is to isolate the concrete surface from the external environment, thereby improving the durability of the concrete; however, the slow-setting ink of the present invention, after UV light curing, can reduce the slow-setting rate of the slow-setting component in the slow-setting ink, so that the reaction rate of the slow-setting component with the concrete can be controlled, and then in the subsequent high-pressure water flushing process, the lines of the slow-setting area are made smoother, thereby improving the clarity of the slow-setting imaging concrete product.

[0023] The retarding film provided by the present invention adopts solvent-based ink, not water-soluble, so it can be prepared by transfer printing with a solvent-based inkjet printer, which reduces the preparation time of the retarding film, improves the preparation efficiency of the retarding film, and can keep the retarding ink from being easily damaged during storage and transportation, and the pattern on the retarding film is not easily distorted during the pouring of concrete. In addition, the retarding film adopts an ester-based composite retarder (including triethyl citrate, tributyl citrate and trioctyl phosphate), which contains multiple ester groups and has a large steric hindrance, and the hydrolysis rate is relatively slow, so that a long-term slow release can be achieved. At the same time, the citric acid released by hydrolysis also has a certain retarding effect, and the synergistic effect of the two can achieve an excellent retarding effect; when the above-mentioned ester-based composite retarder is added to the retarding ink and acts on the concrete surface, its retarding effect is relatively mild, and there will be no violent reaction, and the retarding area will not spread, so it will not affect the hydration process of the concrete in the non-retarding area. The retarding film of the present invention adopts the process of curable retarding ink, which can prevent the diffusion of the retarding ink after curing when preparing the finished concrete product, avoid the distortion of the pattern on the retarding film, and thus improve the clarity of the pattern of the finished concrete product. In addition, the compound retarder in the retarding film has good compatibility with the solvent-based ink, and the retarding film can be placed for a long time (more than 3 months) after curing treatment, which is more convenient for long-term storage and transportation. At the same time, the retarding film of the present invention adopts PP synthetic paper, glass paper and other paper with high tensile strength and smooth surface as the base film, which solves the problem that the pulp is easily affected by moisture, and is convenient for long-term storage and transportation of the retarding film; PP synthetic paper, glass paper and the like have a smooth surface, which can also improve the smoothness of the surface of the finished concrete product, thereby improving the texture of the finished concrete product.

[0024] The second aspect of the present invention provides a method for preparing the above-mentioned slow-setting imaging concrete, comprising the steps of:

[0025] S100, preparing a slow-setting film in advance, and laying the slow-setting film with the pattern surface facing upward inside the mold and fixing it;

[0026] S200, by weight, 30-45 parts of white cement, 10-20 parts of metakaolin, 15-30 parts of corundum with a size of 0.6-0.7 mm, 25-40 parts of corundum with a size of 0.3-0.4 mm, and 5-15 parts of corundum with a size of 0.1-0.2 mm are put into a mixer for pre-mixing, and then water and a water-reducing agent are added at a water-binder ratio of 0.22-0.30. After the second mixing, a thickener, an early strength agent, and a silicon-based defoaming agent are added. After the third mixing, the obtained concrete is poured into a mold;

[0027] S300, after a predetermined standard curing period, the mold is removed, the slow-setting film on the concrete surface is removed, and high-pressure water flushing is performed to obtain the slow-setting imaging concrete.

[0028] The method for preparing slow-setting imaging concrete according to the embodiment of the present invention has at least the following beneficial effects: the preparation process is faster, and after the concrete is mixed and poured, there is no need to use a vibrating table, which reduces the preparation process and makes the concrete preparation more convenient. The high-pressure flushing time is also shorter, and the early strength is higher. The addition of nanocrystalline nucleating agent will increase the early strength of concrete, shorten the curing time, and help improve production efficiency.

[0029] In some embodiments of the present invention, the thickener is 0.05 to 0.1 parts by weight.

[0030] In some embodiments of the present invention, the thickener includes hydroxypropyl methylcellulose, polycarboxylate, expanded clay, polyacrylamide, but is not limited thereto. Preferably, the thickener is hydroxypropyl methylcellulose.

[0031] In some embodiments of the present invention, the early strength agent is 0.05 to 0.1 parts by weight.

[0032] In some embodiments of the present invention, the early strength agent includes nanocrystalline nucleating agent, calcium chloride, sodium chloride, water glass, sodium aluminate, sodium carbonate, calcium carbonate, sodium fluoride, triethanolamine, but is not limited thereto. Preferably, the early strength agent is a nanocrystalline nucleating agent.

[0033] In some embodiments of the present invention, the silicon-based defoaming agent is 0.05 to 0.1 parts by weight.

[0034] In some embodiments of the present invention, the water reducing agent is 0.05 to 0.1 parts by weight.

[0035] In some embodiments of the present invention, in step S100, the pattern surface of the retarding ink is facing upward, the retarding film is spread flat inside the mold, the air between the retarding film and the mold is exhausted, and the retarding film is fixed to the mold.

[0036] In some embodiments of the present invention, in step S200, the pre-stirring is low-speed dry powder stirring, with a rotation speed of 80 to 120 r / min, preferably about 100 r / min; the secondary stirring is medium-speed stirring, with a rotation speed of 130 to 200 r / min, preferably about 166 r / min; the tertiary stirring is rapid stirring, with a rotation speed of 280 to 500 r / min, preferably about 360 r / min.

[0037] In some embodiments of the present invention, in step S300, the curing is performed in a standard curing room for 6 to 10 hours, preferably about 8 hours.

[0038] In some embodiments of the present invention, the method for preparing the retarding film comprises the steps of:

[0039] S10, mixing triethyl citrate, tributyl citrate and trioctyl phosphate in parts by weight, stirring and mixing to obtain a composite retarder;

[0040] S20, mixing epoxy acrylate resin, 4-methylbenzophenone, alkoxy acrylate, and pigment in parts by weight, and stirring to obtain a solvent-based ink;

[0041] S30, mixing the compound retarder and the solvent-based ink, and stirring and mixing to obtain a retarding ink;

[0042] S40, processing the pattern to be presented and mirror-flipping it to obtain a pattern to be printed;

[0043] S50, using a solvent-based inkjet printer to output the slow-setting ink onto the base film in the style of the pattern to be printed, and using UV light to cure the slow-setting ink on the surface of the base film to obtain the slow-setting film.

[0044] The current method for making a retarding film is to transfer the retarder coating onto the base film by screen printing, and the finished retarding film is obtained after the retarder coating is dried. The production cycle of this retarding film is too long, which reduces the efficiency of retarding film preparation; and the retarding coating is easily damaged during storage and transportation. Based on this, the preparation method of the retarding film proposed in the present invention adopts a more efficient retarding film preparation process, and uses a solvent-based inkjet printer to transfer and prepare the retarding film, which reduces the preparation time of the retarding film, improves the preparation efficiency of the retarding film, and can keep the retarding ink from being easily damaged during storage and transportation.

[0045] In some embodiments of the present invention, in step S50, while the slow-setting ink is output onto the base film in the style of the pattern to be printed, the slow-setting ink on the surface of the base film is cured by UV light. The present invention uses a UV light curing process to cure the slow-setting ink pattern, which can prevent the slow-setting ink from diffusing after curing when preparing the finished concrete product, avoid distortion of the pattern on the slow-setting film, and thus improve the clarity of the pattern of the finished concrete product; and the slow-setting film after curing is more convenient for long-term storage and transportation.

[0046] In some embodiments of the present invention, the light source of the UV light (ultraviolet light) is an LED lamp with a wavelength range of 320 to 400 nm.

[0047] In some embodiments of the present invention, the base film comprises PP synthetic paper, glass paper, PVC film or polyester film, preferably PP synthetic paper or glass paper.

[0048] In some embodiments of the present invention, in step S10, 20 to 30 parts of triethyl citrate, 15 to 40 parts of tributyl citrate, and 35 to 50 parts of trioctyl phosphate are mixed by weight, and stirred to obtain a composite retarder. Preferably, the mixture is stirred and mixed by a magnetic stirrer. Preferably, the rotor speed of the magnetic stirrer is 300 to 700 r / min, more preferably 450 to 500 r / min; the stirring time is 5 to 15 min, more preferably about 10 min.

[0049] In some embodiments of the present invention, in step S20, 40 to 60 parts of epoxy acrylate resin, 5 to 15 parts of 4-methylbenzophenone, 20 to 30 parts of alkoxy acrylate, and 15 to 25 parts of pigment are mixed by weight, and stirred to obtain a solvent-based ink. Preferably, the mixture is stirred and mixed by a magnetic stirrer. Preferably, the rotor speed of the magnetic stirrer is 600 to 1000 r / min, more preferably 700 to 800 r / min; the stirring time is 10 to 20 min, more preferably about 15 min.

[0050] In some embodiments of the present invention, in step S30, the compound retarder and the solvent-based ink are mixed in a mass ratio of compound retarder: solvent-based ink = (1.5-2.5): (7.5-8.5), and stirred and mixed to obtain a retarded ink. Preferably, the mixing is stirred and mixed by a magnetic stirrer. Preferably, the rotor speed of the magnetic stirrer is 400-800 r / min, more preferably 500-600 r / min; the stirring time is 5-15 min, more preferably about 10 min.

[0051] In some embodiments of the present invention, in step S40, the pattern to be presented is processed by image processing software, and the pixels are adjusted and the image is flipped to obtain the pattern to be printed. The image processing software can be commonly used software and is not limited here.

[0052] In some embodiments of the present invention, in step S50, a base film (e.g., PP synthetic paper) is spread flat on the operating table of a solvent inkjet printer, and the retarding ink is injected into the ink cartridge of the solvent inkjet printer. The solvent inkjet printer is used to output the retarding ink to the base film in the style of a pattern to be printed, with a printing thickness of 1 layer. While the pattern is being printed, UV light (ultraviolet light) is used to perform a unidirectional printing operation to solidify the retarding ink on the surface of the base film, thereby obtaining the retarding film.

[0053] In some embodiments of the present invention, the slow-setting ink can be printed onto the base film once or multiple times, that is, the printing thickness can be ≥ 1 layer, which can be adjusted according to the pattern and is not limited here. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0055] Figure 1 This is a picture of the finished product of the slow-setting imaging concrete prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0056] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0057] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0058] If no specific techniques or conditions are specified in the following examples, the methods or conditions described in the literature in the art or the product instructions are used. All reagents or instruments without manufacturer specified are conventional products that can be purchased commercially.

[0059] Example 1

[0060] The concrete formula is: 1275g white cement, 225g metakaolin, 450g corundum with a size of 0.6-0.7mm, 900g corundum with a size of 0.3-0.4mm, 150g corundum with a size of 0.1-0.2mm, and a water-cement ratio of 0.28; 4.5g hydroxypropyl methylcellulose with a viscosity of 100000mPa·s, 15g nanocrystalline nucleating agent, 15g silicon-based defoaming agent, and 24g water reducing agent.

[0061] The retarding ink consists of 20 wt. % of a compound retarder and 80 wt. % of a solvent-based ink.

[0062] The composition of the compound retarder is: 50g of triethyl citrate, 50g of tributyl citrate, and 100g of trioctyl phosphate; the composition of the solvent-based ink is: 400g of epoxy acrylate resin, 50g of 4-methylbenzophenone, 200g of alkoxy acrylate, and 150g of organic pigment.

[0063] The specific steps of the preparation process of slow-setting imaging concrete are as follows:

[0064] 1) Preparation of compound retarder: 50 g of triethyl citrate, 50 g of tributyl citrate and 100 g of trioctyl phosphate were placed in a glass beaker, stirred with a magnetic stirrer, the rotor speed was set to 500 r / min, and stirred for 10 min;

[0065] 2) Prepare solvent-based ink: put 400g of epoxy acrylate resin, 50g of 4-methylbenzophenone, 200g of alkoxy acrylate and 150g of organic pigment in a glass beaker, stir with a magnetic stirrer, set the rotor speed to 800r / min, and stir for 15min;

[0066] 3) Preparation of retarding ink: 200 g of ester-based composite retarder and 800 g of solvent-based ink were placed in a glass beaker, stirred with a magnetic stirrer, the rotor speed was set to 600 r / min, and stirred for 10 min;

[0067] 4) Pattern processing: Use image processing software to process the desired pattern, adjust the pixels and flip the image to obtain the pattern style to be printed;

[0068] 5) Pattern printing and back-end processing: lay the base film (PP synthetic paper) flat on the operating table of the solvent-based inkjet printer, inject the slow-setting ink into the ink cartridge of the solvent-based inkjet printer, and use the solvent-based inkjet printer to output the slow-setting ink to the base film according to the pattern to be printed, with a printing thickness of 1 layer; while printing the pattern, use UV light for unidirectional printing to solidify the slow-setting ink on the surface of the base film to obtain a slow-setting film, which takes about 5 minutes;

[0069] 6) Mould processing: Place the slow-setting film with the slow-setting ink pattern facing upwards, lay the slow-setting film flat inside the mould, exhaust the air between the slow-setting film and the mould, and fix the slow-setting film to the mould;

[0070] 7) Concrete pouring: put 1275g white cement, 225g metakaolin, 450g corundum with a size of 0.6-0.7mm, 900g corundum with a size of 0.3-0.4mm, and 150g corundum with a size of 0.1-0.2mm into a mixer and pre-mix the dry powder at a low speed (100r / min) for 3min; add 840g water and 24g water reducer and stir at a medium speed (166r / min) for 1min; finally, add 4.5g hydroxypropyl methylcellulose, 15g nanocrystalline nucleating agent and 15g silicon-based defoaming agent and stir quickly (360r / min) for 2min; slowly pour the stirred concrete into the mold;

[0071] 8) Curing and flushing: After 8 hours of curing in a standard curing room, the formwork is removed, the retarding film on the concrete surface is torn off, and the concrete surface is flushed with high-pressure water to obtain retarding imaging concrete that prevents aggregate settlement.

[0072] The picture of the finished product of the slow-setting imaging concrete prepared in Example 1 is as follows Figure 1 As shown, in the image shown in the figure, the lines of the retarding area are smooth, the retarding ink has not spread, the pattern on the retarding film has no distortion, and the finished concrete pattern has high clarity and good quality.

[0073] Example 2

[0074] The difference between Example 2 and Example 1 is that the concrete formula is different.

[0075] The concrete formula of Example 2 is: 1300g white cement, 200g metakaolin, 300g corundum with a size of 0.6-0.7mm, 1000g corundum with a size of 0.3-0.4mm, 200g corundum with a size of 0.1-0.2mm, and a water-cement ratio of 0.285; 4.5g hydroxypropyl methylcellulose with a viscosity of 100000mPa·s, 15g nanocrystalline nucleating agent, 15g silicon-based defoaming agent, and 24g water reducer.

[0076] Example 3

[0077] The difference between Example 3 and Example 1 is that the concrete formula is different.

[0078] The concrete formula of Example 3 is: 1400g white cement, 100g metakaolin, 200g corundum with a size of 0.6-0.7mm, 1100g corundum with a size of 0.3-0.4mm, 200g corundum with a size of 0.1-0.2mm, and a water-cement ratio of 0.29; 4.5g hydroxypropyl methylcellulose with a viscosity of 100000mPa·s, 15g nanocrystalline nucleating agent, 15g silicon-based defoaming agent, and 24g water reducer.

[0079] Comparative Example 1

[0080] The UHPC concrete formula is: 1.75kg white cement, 0.25kg metakaolin, 2kg continuous graded black sand, 400g water, and 64g composite admixture; wherein the composite admixture is 50wt.% of early-strength polycarboxylate water-reducing agent, 19wt.% of silicon-based defoaming agent, and 31wt.% of nano early-strength agent.

[0081] The retarding ink ratio is: 22wt% water-based pigment, 78wt% retarder; the composition of the retarder is as follows: 11g sodium gluconate, 14g sodium citrate, 2g sodium metaphosphate, and 75g distilled water.

[0082] The concrete preparation process steps are as follows:

[0083] 1) Digital image processing: Use image processing software to process the digital image to be presented, adjust the pixels and flip the image to obtain the pattern style;

[0084] 2) Making a slow-setting film: Outputting the slow-setting ink onto the base film (PP synthetic paper) according to the pattern to obtain a slow-setting film;

[0085] 3) Dry the slow-setting film: Place the slow-setting film in a ventilated and dry environment for 8 hours to dry the surface;

[0086] 4) Laying the retarding film: Lay the retarding film on the bottom of the mold for pouring concrete, with the side with the pattern facing up;

[0087] 5) Pouring concrete: Mix concrete according to the above formula, and pour the concrete evenly and slowly into the mold (mixing conditions: stir slowly for 2 minutes with a mortar mixer, then stir quickly for 5 minutes);

[0088] 6) Formwork removal and curing: After 16 hours of curing, the formwork is removed, the retarding film is torn off along one side, and the concrete film surface is flushed with high-pressure water. After subsequent curing, the UHPC formula retarded imaging concrete is obtained.

[0089] Comparative Example 2

[0090] The concrete formula is 1275g PⅡ42.5 cement, 225g silica fume, 1500g continuous graded black sand, 330g water, and 15g defoaming agent.

[0091] The retarding ink is composed of 20wt.% of retarder and 80wt.% of solvent-based ink. The retarder ratio is 4g of white sugar, 2g of citric acid, 13g of sodium gluconate, 10g of tartaric acid, 1g of borax, 12g of maltodextrin, 1g of methylcellulose, and 60g of water; the solvent-based ink is composed of 400g of epoxy acrylate resin, 50g of 4-methylbenzophenone, 200g of alkoxy acrylate, and 150g of organic pigment.

[0092] The concrete preparation process steps are as follows:

[0093] 1) Digital image processing: Use image processing software to process the digital image to be presented, adjust the pixels and flip the image to obtain the pattern style;

[0094] 2) Making a slow-setting film: Outputting the slow-setting ink onto the base film (cellophane) according to the pattern to obtain a slow-setting film;

[0095] 3) Dry the slow-setting film: Place the slow-setting film in a ventilated and dry environment for 16 hours to dry the surface;

[0096] 4) Laying the retarding film: Lay the retarding film on the bottom of the mold for pouring concrete, with the side with the pattern facing up;

[0097] 5) Pouring concrete: Mix concrete according to the above formula, and pour the concrete evenly and slowly into the mold (mixing conditions: stir slowly for 2 minutes with a mortar mixer, then stir quickly for 5 minutes);

[0098] 6) Formwork removal and curing: After 18 hours of curing, the formwork is removed, the retarding film is torn off along one side, and the concrete film surface is flushed with high-pressure water. After subsequent curing, the retarded concrete is obtained.

[0099] Comparative Example 3

[0100] The difference between Comparative Example 3 and Example 1 is that the concrete formula is different.

[0101] The concrete formula of Comparative Example 3 is: 1300g white cement, 200g metakaolin, 1500g corundum with a size of 0.6-0.7mm, 0g corundum with a size of 0.3-0.4mm, 0g corundum with a size of 0.1-0.2mm, and a total water ratio of 0.275; 4.5g hydroxypropyl methylcellulose with a viscosity of 100000mPa·s, 15g nanocrystalline nucleating agent, 15g silicon-based defoaming agent, and 24g water reducing agent.

[0102] Comparative Example 4

[0103] The difference between Comparative Example 4 and Example 1 is that the concrete formula is different.

[0104] The concrete formula of Comparative Example 4 is: 1300g white cement, 200g metakaolin, 0g corundum with a size of 0.6-0.7mm, 0g corundum with a size of 0.3-0.4mm, 1500g corundum with a size of 0.1-0.2mm, and a total water ratio of 0.290; 4.5g hydroxypropyl methylcellulose with a viscosity of 100000mPa·s, 15g nanocrystalline nucleating agent, 15g silicon-based defoaming agent, and 24g water reducer.

[0105] Comparative Example 5

[0106] The difference between Comparative Example 5 and Example 1 is that the concrete formula is different.

[0107] The concrete formula of Comparative Example 5 is: 1300g white cement, 200g metakaolin, 0g corundum with a size of 0.6-0.7mm, 1500g corundum with a size of 0.3-0.4mm, 0g corundum with a size of 0.1-0.2mm, and a total water ratio of 0.295; 4.5g hydroxypropyl methylcellulose with a viscosity of 100000mPa·s, 15g nanocrystalline nucleating agent, 15g silicon-based defoaming agent, and 24g water reducer.

[0108] Test Case

[0109] The slow-setting inks, slow-setting films and slow-setting imaging concrete prepared in Examples 1-3 and Comparative Examples 1-5 were tested, including the following test items:

[0110] 1. Test the diffusion of retarding ink: Use a solvent-based inkjet printer to print a circle with a diameter of 10 mm on the retarding film. After pouring concrete and curing for 8 hours, remove the film and flush with water to obtain a retarding imaging concrete product. Use a vernier caliper to measure the diameter and depth of the circle on the surface of the finished product to reflect the diffusion of the retarding ink;

[0111] 2. Test the moisture resistance of the slow-setting film: Use a solvent-based inkjet printer to apply the slow-setting ink to the slow-setting film to prepare an A4-sized slow-setting film. Place the prepared slow-setting film in a curing room with a humidity of 95±5% and a temperature of 20±2°C. At the same time, put a blank slow-setting film base film as a reference sample. The standing time is 24 hours. The moisture resistance of the slow-setting film is tested according to the water absorption rate (the mass of the reference sample base film before standing, the mass of the reference sample base film after standing, and the mass of the test sample slow-setting film before standing, m x And the mass M of the retarding film of the test sample after standing x , then the water absorption rate of the slow setting film = [(M x -M0)-(m x -m0)]÷m0×100%);

[0112] 3. Test the aggregate packing density.

[0113] The performance test results are shown in Tables 1, 2 and 3 below:

[0114] Table 1:

[0115]

[0116] Table 2:

[0117]

[0118] Table 3:

[0119]

[0120] In summary, the present invention adjusts the concrete formula, uses multi-sized corundum as aggregate, and adjusts the appropriate water-binder ratio, which can effectively prevent the aggregate from settling during the concrete hardening process, reduce the noise points exposed on the concrete imaging surface, and improve the texture of the finished concrete product; the present invention also reasonably adjusts the ratio of coarse sand, medium sand, and fine sand of different sizes in the aggregate, and the synergistic effect between the components increases its packing density and effectively prevents the sedimentation of the aggregate. Finally, under the synergistic effect of multiple components, the slow-setting imaging concrete provided by the present invention can well prevent the sedimentation of aggregates, and the concrete imaging surface is not easy to expose the aggregate noise points, which improves the quality of the finished concrete product.

[0121] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A slow-setting concrete, characterized in that: The raw materials of the slow-setting imaging concrete include cementitious materials, aggregates, admixtures and water, and the water-cement ratio is 0.22-0.30; In terms of weight, the cementitious material includes 30 to 45 parts of white cement and 10 to 20 parts of metakaolin, and the aggregate includes 15 to 30 parts of corundum with a size of 0.6 to 0.7 mm, 25 to 40 parts of corundum with a size of 0.3 to 0.4 mm, and 5 to 15 parts of corundum with a size of 0.1 to 0.2 mm; The additives include thickener, early strength agent, silicon-based defoamer and water reducer.

2. The slow-setting imaging concrete according to claim 1, characterized in that: In parts by weight, the admixture includes 0.05 to 0.1 parts of thickener, 0.05 to 0.1 parts of early strength agent, 0.05 to 0.1 parts of silicon-based defoamer, and 0.05 to 0.1 parts of water reducer.

3. The slow-setting imaging concrete according to claim 1, characterized in that: The slow-setting imaging concrete also includes a slow-setting film located on the surface of the concrete; the slow-setting film includes a base film and a slow-setting ink cured on the surface of the base film, and the slow-setting ink is close to the surface of the concrete.

4. The slow-setting imaging concrete according to claim 3, characterized in that: The retarding ink comprises a compound retarder and a solvent-based ink; The composition of the composite retarder includes, by weight: 20 to 30 parts of triethyl citrate, 15 to 40 parts of tributyl citrate, and 35 to 50 parts of trioctyl phosphate; The solvent-based ink comprises, by weight, 40 to 60 parts of epoxy acrylate resin, 5 to 15 parts of 4-methylbenzophenone, 20 to 30 parts of alkoxy acrylate, and 15 to 25 parts of pigment.

5. The slow-setting imaging concrete according to claim 4, characterized in that: The mass ratio of the compound retarder to the solvent-based ink is (1.5-2.5):(7.5-8.5).

6. The slow-setting image-forming concrete according to claim 3, characterized in that: The base film includes PP synthetic paper, glassine paper, PVC film or polyester film.

7. The slow-setting image-forming concrete according to claim 3, characterized in that: Using UV light curing to cure the slow-setting ink on the surface of the base film; Preferably, the light source of the UV light is an LED lamp with a wavelength range of 320 to 400 nm.

8. A method for preparing the slow-setting image-forming concrete according to any one of claims 1 to 7, characterized in that: Includes steps: A slow-setting film is prepared in advance, and the slow-setting film is laid flat inside the mold with the pattern side facing upward and fixed; According to weight, 30-45 parts of white cement, 10-20 parts of metakaolin, 15-30 parts of corundum with a size of 0.6-0.7 mm, 25-40 parts of corundum with a size of 0.3-0.4 mm, and 5-15 parts of corundum with a size of 0.1-0.2 mm are put into a mixer for pre-mixing, and then water and a water-reducing agent are added at a water-binder ratio of 0.22-0.

30. After the second mixing, a thickener, an early strength agent, and a silicon-based defoaming agent are added. After the third mixing, the obtained concrete is poured into a mold; After a predetermined standard curing time, the mold is removed, the slow-setting film on the concrete surface is removed, and high-pressure water flushing is performed to obtain the slow-setting imaging concrete.

9. The method for preparing slow-setting image-forming concrete according to claim 8, characterized in that: The method for preparing the retarding film comprises the following steps: Mix triethyl citrate, tributyl citrate and trioctyl phosphate according to weight proportions, and stir to obtain a composite retarder; Mix epoxy acrylate resin, 4-methylbenzophenone, alkoxy acrylate and pigment according to weight proportions, and stir to obtain solvent-based ink; The compound retarder and the solvent-based ink are mixed and stirred to obtain a retarding ink; After processing the pattern to be presented and mirror-flipping it, a pattern to be printed is obtained; The retarding ink is outputted onto the base film according to the pattern to be printed by using a solvent-based inkjet printer, and the retarding ink on the surface of the base film is cured by using UV light to obtain the retarding film.

10. The method for preparing slow-setting image-forming concrete according to claim 9, characterized in that: Mix 20-30 parts of triethyl citrate, 15-40 parts of tributyl citrate and 35-50 parts of trioctyl phosphate by weight, and stir to obtain a composite retarder; And / or, 40 to 60 parts of epoxy acrylate resin, 5 to 15 parts of 4-methylbenzophenone, 20 to 30 parts of alkoxy acrylate, and 15 to 25 parts of pigment are mixed by weight, and stirred to obtain a solvent-based ink; And / or, the compound retarder and the solvent-based ink are mixed in a mass ratio of compound retarder: solvent-based ink = (1.5-2.5): (7.5-8.5), and the mixture is stirred and mixed to obtain the retarded ink.

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