Composition for preparing UHPC decorative board, UHPC decorative board, preparation method and application thereof

Abstract

The present invention relates to the technical field of building materials, and discloses a composition for preparing a geopolymer-based UHPC decorative board, a geopolymer UHPC decorative board, a preparation method thereof and an application thereof. The composition contains the following components stored independently or in a mixture of two or more: a gelling material, an alkali activator, an organic polymer emulsion and quartz sand. The geopolymer-based UHPC decorative board provided by the present invention has higher flexural and folding resistance, a lower compressive-to-flexural ratio, and at the same time has low brittleness, which can reduce breakage; in particular, the geopolymer-based UHPC decorative board provided by the present invention has high whiteness and stable color, and can better meet its application in building materials.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and particularly relates to a composition for preparing a geopolymer-based UHPC decorative board, a geopolymer UHPC decorative board, and a preparation method and application thereof. Background Art

[0002] Ultra-high performance concrete (UHPC) is regarded as the most potential cement-based material in the 21st century. It has excellent mechanical properties and durability, and is an environmentally friendly material. At present, various enterprises and institutions of higher learning are actively promoting the application and development of UHPC in the construction field. Compared with structural members, the stress requirements and specification limitations considered for UHPC in decorative members are relatively small, and the value brought by the excellent performance of UHPC is being exerted.

[0003] Among them, the decorative board made of UHPC can replace traditional stone materials and artificial boards, and has many advantages that traditional decorative boards do not have, such as low self-weight, strong plasticity, good durability, high impact resistance, excellent cost performance, etc., becoming a powerful product for the replacement of wall, floor, and tabletop decorative boards.

[0004] However, there are still many deficiencies in the current UHPC-made decorative boards. For example, the time required for production and demoulding is slightly longer, resulting in low turnover of molds and production efficiency; at the same time, the bending and flexural strengths of the board matrix itself are not high, and the brittleness is large, resulting in easy edge chipping and fracture of the board during production, transportation, and installation, increasing the loss of the board and reducing the finished product rate.

[0005] Coarse fibers (generally with a diameter greater than 0.1 mm) are usually added to UHPC structural members to improve the bending and flexural strengths and compensate for brittleness (fine fibers are mainly used to prevent crack formation). However, in UHPC decorative boards, the added coarse fibers will be exposed after surface processing, affecting the decorative effect, and steel fibers will also pose a potential safety hazard to human beings. These reasons make it difficult to apply this method well.

[0006] In the prior art, UHPC decorative boards mainly use portland cement as a gelling material, add early strength materials to achieve higher early strength, and use coarse fibers as a toughening and strengthening means.

[0007] CN109704679A discloses a self-leveling and self-compacting ultra-high performance concrete decorative board with early strength under natural curing, adding a strength-promoting and shrinkage-reducing agent accounting for 5%-30% of the mass of the binder to achieve early strength; adding a mixture of 1%-2% by volume of alkali-resistant glass fiber and copper-plated steel fiber to improve the anti-fracture ability of the board.

[0008] However, this method uses portland cement as the main binder. The early-strength materials added are not easy to control, the flexural strength of the system is not high, and the shrinkage deformation is large. The UHPC decorative board prepared is prone to warping and deformation. The strength development speed is average, which affects the demolding production efficiency of the UHPC decorative board. Moreover, the cement industry with high pollution and energy consumption is facing transformation and upgrading, and more environmentally friendly binders will be vigorously developed. Summary of the Invention

[0009] The object of the present invention is to overcome the defects of the UHPC decorative board in the prior art, such as large brittleness, poor flexural and flexural resistance performance, and large shrinkage deformation.

[0010] During the research process, the inventors found that adding a specific type of organic polymer to geopolymers can enable the organic polymer gel film to intertwine with the reaction products of geopolymers, increasing the interfacial adhesion and filling pores. At the same time, orthosilicate aluminates molecules will be formed during the polycondensation reaction of geopolymers. The organic polymer provided by the present invention can carry out a polycondensation reaction with it to form a stable organic-inorganic flexible structure, thereby significantly improving the brittleness and impact resistance of the product. Based on this, the inventors of the present invention completed this solution.

[0011] To achieve the above object, the first aspect of the present invention provides a composition for preparing a geopolymer-based UHPC decorative board, which contains the following components stored independently or mixed with two or more of them:

[0012] Binder, alkali activator, organic polymer emulsion, and quartz sand;

[0013] Based on the total mass of the composition, the content of the binder is 40-60 wt%, the content of the alkali activator based on dry basis is 3-6 wt%, the content of the organic polymer emulsion based on dry basis is 0.05-1 wt%, and the content of the quartz sand is 35-56 wt%;

[0014] Based on the total mass of the binder, the binder contains 10-30 wt% of white cement, 45-65 wt% of coarse particle metakaolin, and 10-35 wt% of fine particle metakaolin;

[0015] The average particle size of the coarse particle metakaolin is 20 μm-45 μm, and the average particle size of the fine particle metakaolin is 0.5 μm-3 μm;

[0016] The organic polymer emulsion is selected from at least one of sodium polyacrylate, polyacrylate, and anionic polyacrylamide.

[0017] The second aspect of the present invention provides a method for preparing a geopolymer-based UHPC decorative board, which includes:

[0018] (1) Contact and mix a retarder, a water reducer, an antifoaming agent, a concrete shrinkage reducing agent, crack-resistant fibers, inorganic pigments, water and the components in the composition described in the first aspect to obtain a mixed material;

[0019] (2) Pour the mixed material in a mold to obtain a poured material, and perform a shaping process on the poured material to obtain a precursor of the decorative board;

[0020] (3) Cure and perform a surface treatment on the precursor of the decorative board in sequence.

[0021] The third aspect of the present invention provides a geopolymer-based UHPC decorative board prepared by the method described in the second aspect.

[0022] The fourth aspect of the present invention provides the application of the geopolymer-based UHPC decorative board described in the third aspect in building materials.

[0023] Compared with the existing UHPC decorative board technology, the present invention has the following beneficial effects:

[0024] The geopolymer-based UHPC decorative board provided by the present invention has higher flexural and flexural strength, lower compressive-flexural ratio, and at the same time has low brittleness, which can reduce breakage; in particular, the geopolymer-based UHPC decorative board provided by the present invention has high whiteness and stable color, and can better meet its application in building materials. Description of the Drawings

[0025] Figure 1 is a surface appearance diagram of the geopolymer-based UHPC decorative board prepared in Example 1 provided by the present invention;

[0026] Figure 2 is a surface appearance diagram of the geopolymer-based UHPC decorative board prepared in Example 2 provided by the present invention;

[0027] Figure 3 is a surface appearance diagram of the geopolymer-based UHPC decorative board prepared in Example 3 provided by the present invention. Detailed Embodiments

[0028] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0029] It should be noted that in various aspects of the present invention, for the same components in each aspect, the present invention only describes them once in one aspect without repeating the description. Those skilled in the art should not understand this as a limitation of the present invention.

[0030] As described above, the first aspect of the present invention provides a composition for preparing a geopolymer-based UHPC decorative board, characterized in that the composition contains the following components stored independently or in a mixture of two or more:

[0031] Cementitious material, alkali activator, organic polymer emulsion and quartz sand;

[0032] Based on the total mass of the composition, the content of the cementitious material is 40-60 wt%, the content of the alkali activator based on dry basis is 3-6 wt%, the content of the organic polymer emulsion based on dry basis is 0.05-1 wt%, and the content of the quartz sand is 35-56 wt%;

[0033] Based on the total mass of the cementitious material, the cementitious material contains 10-30 wt% of white cement, 45-65 wt% of coarse particle metakaolin and 10-35 wt% of fine particle metakaolin;

[0034] The average particle size of the coarse particle metakaolin is 20 μm - 45 μm, and the average particle size of the fine particle metakaolin is 0.5 μm - 3 μm;

[0035] The organic polymer emulsion is selected from at least one of sodium polyacrylate, polyacrylate, and anionic polyacrylamide.

[0036] Preferably, the organic polymer emulsion is a low molecular weight and easily dispersible organic polymer emulsion with a number average molecular weight of 500-5000.

[0037] The inventors of the present invention also found that after compounding white cement and two types of metakaolin with specific particle sizes in a specific ratio and then subjecting them to alkali activation, and using a specific type of organic polymer emulsion in combination, the components in the obtained composition system can further fill and overlap each other in structure to achieve close packing, thereby obtaining a UHPC decorative board with excellent compressive and flexural strengths.

[0038] Preferably, based on the total mass of the cementitious material, the cementitious material contains 15-25 wt% of the white cement, 50-65 wt% of the coarse particle metakaolin and 15-25 wt% of the fine particle metakaolin. The inventors found that by adopting the specific implementation mode in this preferred case, the prepared UHPC decorative board has higher strength and stronger practicability.

[0039] In the present invention, the white cement is preferably P.W52.5 portland white cement and / or P.W42.5 portland white cement. The inventors have found that under this preferred specific embodiment, the UHPC decorative board prepared has higher strength.

[0040] Preferably, based on the total mass of the composition, the content of the cementitious material is 40 - 55 wt%, the content of the alkali activator based on dry basis is 3 - 5 wt%, the content of the organic polymer emulsion based on dry basis is 0.1 - 1 wt%, and the content of the quartz sand is 39 - 56 wt%.

[0041] Preferably, the modulus of the alkali activator is 0.5 - 2. The inventors have found that under this preferred embodiment, the UHPC decorative board prepared has relatively high early strength.

[0042] In the present invention, the modulus of the alkali activator refers to the ratio of the amount of substance of silicon dioxide to the total amount of substance of sodium oxide and potassium oxide, that is, the calculation formula of the modulus is: M(SiO2) / n(Na2O + K2O), formula (1); in formula (1), M and n are the amounts of substance.

[0043] More preferably, the alkali activator is selected from at least one of the mixed solutions of sodium hydroxide and sodium silicate, sodium hydroxide and potassium silicate, potassium hydroxide and sodium silicate, and potassium hydroxide and potassium silicate.

[0044] Preferably, the quartz sand is a combination of coarse quartz sand, medium quartz sand, and fine quartz sand with a mass ratio of 1:1 - 3:0.2 - 0.5.

[0045] More preferably, the average particle size of the coarse quartz sand is 0.4 mm - 0.85 mm, the average particle size of the medium quartz sand is 0.2 mm - 4 mm, and the average particle size of the fine quartz sand is 0.1 mm - 0.2 mm.

[0046] As mentioned above, the second aspect of the present invention provides a method for preparing a geopolymer - based UHPC decorative board, and the method includes:

[0047] (1) Contact - mixing the retarder, water - reducing agent, defoamer, concrete shrinkage - reducing agent, anti - cracking fiber, inorganic pigment, water, and each component in the composition provided in the first aspect to obtain a mixed material;

[0048] (2) Pouring the mixed material in a mold to obtain a poured material, and shaping the poured material to obtain a decorative board precursor;

[0049] (3) Curing and surface - treating the decorative board precursor in sequence.

[0050] Preferably, in step (1), the mass ratio of the composition, the retarder, the water reducer, the defoamer, the concrete shrinkage reducing agent, the anti-cracking fiber, and the inorganic pigment is 1: 0.0005 - 0.003: 0.002 - 0.008: 0.0005 - 0.002: 0.001 - 0.005: 0.0005 - 0.002: 0.0005 - 0.03.

[0051] In the present invention, the retarder can provide an operation time for production. Preferably, the retarder is a composite retarder of phosphate and barium salt.

[0052] Preferably, the water reducer is selected from at least one of polycarboxylate superplasticizers.

[0053] Preferably, the defoamer is selected from at least one of silicone-based compounds.

[0054] Preferably, the concrete shrinkage reducing agent is at least one of organic alcohols.

[0055] Preferably, the inorganic pigment is at least one of iron-based pigments.

[0056] Preferably, the anti-cracking fiber is selected from at least one of PVA type or PP type. Among them, the average diameter of the anti-cracking fiber is not more than 20 μm. The inventor found that in this preferred embodiment, the decorative effect of the product can be enhanced.

[0057] Preferably, in step (1), the mass ratio of the water to the binder is 0.18 - 0.25: 1.

[0058] Preferably, in step (1), the step of contacting and mixing includes: first mixing the binder, the quartz sand, the retarder, the water reducer, the defoamer, the concrete shrinkage reducing agent, the anti-cracking fiber, and the inorganic pigment to obtain a first mixed material, and second mixing the first mixed material, the alkali activator, the water, and the organic polymer emulsion to obtain a mixed material.

[0059] More preferably, in step (1), the method further includes: diluting the alkali activator with the water before the second mixing to obtain an alkali activator dilution with a concentration of 15 - 40 wt%.

[0060] Preferably, in step (1), the conditions for the first mixing include: a stirring speed of 60 - 150 rpm, a temperature of 10 - 35 °C, and a time of 1 - 3 min.

[0061] Preferably, in step (1), the conditions for the second mixing include: a stirring speed of 60 - 150 rpm, a temperature of 10 - 35 °C, and a time of 4 - 8 min.

[0062] Preferably, in step (2), the steps of the pouring treatment include: using a pumping and distributing head with a diameter not exceeding 15 cm to pour the mixed material in a reciprocating and translational manner in the mold to obtain the poured material with an average thickness of 2 - 5 cm.

[0063] To better achieve defoaming and material leveling and reduce hole defects, preferably, in step (2), the forming treatment is carried out under vibration conditions, and the conditions for the forming treatment at least include: a vibration time of 30 - 120 s, a vibration frequency of 40 - 60 Hz, and a vibration amplitude of 0.5 - 1.5 mm.

[0064] Further preferably, the conditions for the forming treatment further include: tightly pressing the mold against the vibration table surface.

[0065] Preferably, in step (3), the conditions for the curing at least include: a temperature of 10 - 35 °C, a relative humidity of 40 - 80%, and a time of 1 - 3 d.

[0066] The present invention has no special requirements for the specific operation method of the surface treatment, and the methods known to those skilled in the art can be adopted. The inventor will not elaborate one by one here, and those skilled in the art should not consider it as a limitation to the present invention.

[0067] To better remove the rough layer and alkali marks on the surface of the decorative board precursor, according to a preferred specific embodiment of the present invention, in step (3), the steps of the surface treatment include: sandblasting or polishing the surface of the cured decorative board precursor to remove the 1 - 3 mm thick rough layer and alkali marks on the surface of the cured decorative precursor, and coating a protective agent.

[0068] In the present invention, the protective agent is preferably at least one of the protective agent with the brand A16 purchased from Yantai Aoya Stone Application Technology Co., Ltd., the protective agent with the brand BC007 purchased from Suzhou Baichi Nano Technology Co., Ltd., and the protective agent with the brand CN02S purchased from Shuke Nano Hydrophobic Technology (Jiaxing) Co., Ltd.

[0069] The method of the present invention may further include various conventional post - treatment methods in the art. For example, the polished or shot - peened material can be surface - cleaned and dried to obtain the UHPC decorative board. The present invention will not elaborate here, and those skilled in the art should not consider it as a limitation to the present invention.

[0070] As described above, the third aspect of the present invention provides a geopolymer-based UHPC decorative board prepared by the method described in the foregoing second aspect.

[0071] As described above, the fourth aspect of the present invention provides the application of the geopolymer-based UHPC decorative board described in the foregoing third aspect in building materials.

[0072] The present invention will be described in detail below by way of examples.

[0073] In the following examples, unless otherwise specified, the experimental instruments and raw materials involved are all commercially available products.

[0074] Raw materials

[0075] White cement: White cement I, P.W52.5 portland white cement, purchased from Anqing Albo Portland Cement Co., Ltd.;

[0076] White cement: White cement II, P.W42.5 portland white cement, purchased from Anqing Albo Portland Cement Co., Ltd.;

[0077] Coarse-grained metakaolin: Coarse-grained metakaolin I, with an average particle size of 20 μm, purchased from Jiaozuo Yukun Mining Co., Ltd.;

[0078] Coarse-grained metakaolin: Coarse-grained metakaolin II, with an average particle size of 45 μm, purchased from Jiaozuo Yukun Mining Co., Ltd.;

[0079] Fine-grained metakaolin: Fine-grained metakaolin I, with an average particle size of 3 μm, purchased from Inner Mongolia Chaopai Metakaolin Co., Ltd.;

[0080] Fine-grained metakaolin: Fine-grained metakaolin II, with an average particle size of 0.5 μm, purchased from Inner Mongolia Chaopai Metakaolin Co., Ltd.;

[0081] Alkali activator: Alkali activator I, a mixed solution of sodium hydroxide and sodium silicate, with a modulus of 1.2, purchased from Guangdong Kening Technology Co., Ltd.;

[0082] Alkali activator: Alkali activator II, a mixed solution of sodium hydroxide and sodium silicate, with a modulus of 0.8, purchased from Guangdong Kening Technology Co., Ltd.;

[0083] Alkali activator: Alkali activator III, a mixed solution of sodium hydroxide and sodium silicate, with a modulus of 1, purchased from Guangdong Kening Technology Co., Ltd.;

[0084] Organic polymer emulsion: Organic polymer emulsion I, a mixture of sodium polyacrylate and anionic polyacrylamide in a mass ratio of 3:7;

[0085] Organic polymer emulsion: Organic polymer emulsion II, a mixture of sodium polyacrylate, polyacrylate, and anionic polyacrylamide in a mass ratio of 1:1:1;

[0086] Organic polymer emulsion: Organic polymer emulsion III, a mixture of polyacrylate and anionic polyacrylamide in a mass ratio of 1:1;

[0087] Organic polymer emulsion: Organic polymer emulsion Ⅳ, vinyl acetate-ethylene copolymer emulsion;

[0088] In the following examples, the grade of sodium polyacrylate used is Derin42N, purchased from Delin New Material Technology Co., Ltd.; the grade of anionic polyacrylamide used is PAM1800, purchased from Henan Boyuan New Material Co., Ltd.; the grade of polyacrylate used is R 478, purchased from Syntagma; the grade of vinyl acetate-ethylene copolymer emulsion used is CP 149, purchased from Nanjing Danpei Chemical Co., Ltd.

[0089] Quartz sand: Quartz sand I, containing 20 wt% of coarse quartz sand (particle size range of 0.4 mm - 0.85 mm), 65 wt% of medium quartz sand (particle size range of 0.2 - 0.4 mm), and 15 wt% of fine quartz sand (particle size range of 0.1 - 0.2 mm);

[0090] Quartz sand: Quartz sand II, containing 25 wt% of coarse quartz sand (particle size range of 0.4 mm - 0.85 mm), 60 wt% of medium quartz sand (particle size range of 0.2 - 0.4 mm), and 15 wt% of fine quartz sand (particle size range of 0.1 - 0.2 mm);

[0091] Retarding agent: A composite of phosphate and barium salt, obtained by premixing sodium hexametaphosphate at 30 wt% and barium chloride at 70 wt%; the CAS number of sodium hexametaphosphate is 10124-56-8, in powder form, purchased from Shandong Guohua Chemical Co., Ltd.; the CAS number of barium chloride is 10361-37-2, in powder form, purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0092] Water reducing agent: Polycarboxylate superplasticizer, grade 2651F, purchased from BASF Germany;

[0093] Defoamer: Organosilicon type, grade P841, purchased from Münzing Chemie GmbH;

[0094] Concrete shrinkage reducing agent: Organic alcohol type, grade PSR105, purchased from Evonik Industries AG;

[0095] Anti-cracking fiber: Anti-cracking fiber I, PVA anti-cracking fiber, with a diameter of 20 μm, purchased from Changzhou Tianyi Engineering Fiber Co., Ltd.;

[0096] Anti-cracking fiber: Anti-cracking fiber II, PVA anti-cracking fiber, with a diameter of 10 μm, purchased from Changzhou Tianyi Engineering Fiber Co., Ltd.;

[0097] Anti-cracking fiber: Anti-cracking fiber III, PP anti-cracking fiber, with a diameter of 10 μm, purchased from Hunan Zhengmude New Materials Co., Ltd.;

[0098] Inorganic pigment: Inorganic pigment I, yellow iron-based pigment, with the brand number S313, purchased from Shanghai Yipin Co., Ltd.;

[0099] Inorganic pigment: Inorganic pigment II, black iron-based pigment, with the brand number 4330, purchased from Shanghai Yipin Co., Ltd.;

[0100] Inorganic pigment: Inorganic pigment III, red iron-based pigment, with the brand number 4130, purchased from Shanghai Yipin Co., Ltd.;

[0101] Conventional cementitious system: containing 85 wt% of P.W52.5 portland white cement and 15 wt% of bk97 white silica fume. P.W52.5 portland white cement was purchased from Anqing Albo Portland Cement Co., Ltd., and bk97 white silica fume was purchased from Bokken Silicon Materials Co., Ltd.

[0102] Protective agent: with the brand number A16, purchased from Yantai Aoya Stone Application Technology Co., Ltd.;

[0103] In the following examples, without special instructions, every 1 wt% represents 1 kg.

[0104] In the following examples, the performance test methods involved are as follows:

[0105] The compressive strength was tested according to the current standard (method) of GB / T 31387;

[0106] The flexural strength was tested according to the current standard (method) of GB / T 31387;

[0107] The 28d shrinkage deformation rate was tested according to the current standard (method) of T / CECS 10107;

[0108] The 28d impact resistance was tested according to the current standard (method) of GB / T 15231;

[0109] The 28d flexural toughness was tested according to the current standard (method) of JSCE-SF4;

[0110] The flexural fracture ultimate displacement was tested according to the current standard (method) of JSCE-SF4.

[0111] In the following examples, the amounts of the gelling material, alkali activator, organic polymer emulsion, and quartz sand are based on the total mass of the composition for preparing the geopolymer-based UHPC decorative board, while the amounts of the retarder, water reducer, defoamer, concrete shrinkage reducer, anti-cracking fiber, inorganic pigment, and water are relative to 100 wt% of the composition for preparing the geopolymer-based UHPC decorative board.

[0112] Example 1

[0113] This example is used to illustrate that the composition of the geopolymer-based UHPC decorative board according to the present invention is prepared into the geopolymer-based UHPC decorative board according to the formula and process parameters in Table 1 and the method described as follows.

[0114] The method for preparing the geopolymer-based UHPC decorative board includes the following steps:

[0115] (1) Dilute a part of the water with the alkali activator to obtain an alkali activator dilution solution with a concentration of 30 wt%, for later use;

[0116] Mix and stir the retarder, water reducer, defoamer, concrete shrinkage reducer, anti-cracking fiber, inorganic pigment, gelling material, and quartz sand (stirring speed is 60 rpm, temperature is 20 °C) for 3 min, then add the remaining part of the water, the previously prepared alkali activator dilution solution, and the organic polymer emulsion and continue to stir (stirring speed is 120 rpm, temperature is 20 °C) for 6 min to obtain a mixed material;

[0117] (2) Pour the mixed material into a mold with a size of 800 mm × 1200 m in a reciprocating translation manner through a pumping distribution head to obtain a poured material, and place the poured material on a vibrating table for forming treatment to obtain a decorative board precursor;

[0118] (3) After the decorative board precursor is statically coagulated, cover it with a film, keep it warm and humid in a curing room for 1 day, then demold and remove the rough layer and alkali marks on the surface of the cured decorative precursor, and then perform surface cleaning, drying, and coating with a protective agent.

[0119] Without special instructions, the remaining examples are carried out using the same process as Example 1, except that the formula and process parameters for preparing the geopolymer-based UHPC decorative board are different, as shown in Table 1 for details; the comparative examples are carried out using the same process as Example 1, except that the formula used is different, as shown in Table 2 for details.

[0120] Table 1

[0121]

[0122]

[0123] Table 2

[0124]

[0125]

[0126] Test example

[0127] The performance of the geopolymer-based UHPC decorative boards obtained in each example and comparative example was measured by the aforementioned test method, and the specific results are shown in Table 3.

[0128] Table 3

[0129]

[0130] Table 3 (continued table)

[0131]

[0132] It can be seen from the results in Table 3 that the geopolymer-based UHPC decorative board prepared by using the composition provided by the present invention has relatively high early strength, and demoulding can be carried out in 1 day, which improves the factory production efficiency and increases the number of times of mold turnover; the shrinkage rate is lower and the product size is more stable; at the same time, the geopolymer-based UHPC decorative board provided by the present invention has low brittleness and improved toughness, and the edge chipping and fracture of the board during production, transportation and installation are reduced, the yield is increased, and the economic benefit is improved.

[0133] The present invention exemplarily provides the surface appearance diagrams of the geopolymer-based UHPC decorative board prepared in Example 1 provided by the present invention, the surface appearance diagram of the geopolymer-based UHPC decorative board prepared in Example 2, and the surface appearance diagram of the geopolymer-based UHPC decorative board prepared in Example 3, as shown in Figures 1 - 3 .

[0134] From Figures 1 - 3 it can be seen that the geopolymer-based UHPC decorative board prepared with yellow iron-based pigment in Example 1 has a yellow appearance, a flat surface, no damage, holes or crack defects after heavy-duty polishing, and high gloss; the geopolymer-based UHPC decorative board prepared with black iron-based pigment in Example 2 has a black appearance, a flat surface, no damage, holes or crack defects after impact shot peening, and obvious particle sense. The geopolymer-based UHPC decorative board prepared with red iron-based pigment in Example 3 has a red appearance, a flat surface, no damage, holes or crack defects after heavy-duty polishing, and high gloss.

[0135] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including the combination of each technical feature in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A composition for preparing a geopolymer-based UHPC decorative board, characterized in that, The composition contains the following components stored independently or mixed in combination of two or more: Cementitious material, alkali activator, organic polymer emulsion and quartz sand; Based on the total mass of the composition, the content of the cementitious material is 40 - 60 wt%, the content of the alkali activator based on dry basis is 3 - 6 wt%, the content of the organic polymer emulsion based on dry basis is 0.05 - 1 wt%, and the content of the quartz sand is 35 - 56 wt%; Based on the total mass of the cementitious material, the cementitious material contains 10 - 30 wt% of white cement, 45 - 65 wt% of coarse metakaolin and 10 - 35 wt% of fine metakaolin; The average particle size of the coarse metakaolin is 20 μm - 45 μm, and the average particle size of the fine metakaolin is 0.5 μm - 3 μm; The organic polymer emulsion is a low - molecular - weight easily - dispersible organic polymer emulsion with a number - average molecular weight of 500 - 5000; The organic polymer emulsion is selected from at least one of sodium polyacrylate, polyacrylate, and anionic polyacrylamide.

2. The composition according to claim 1, wherein, Based on the total mass of the cementitious material, the cementitious material contains 15 - 25 wt% of the white cement, 50 - 65 wt% of the coarse metakaolin and 15 - 25 wt% of the fine metakaolin.

3. The composition according to claim 1, wherein, Based on the total mass of the composition, the content of the cementitious material is 40 - 55 wt%, the content of the alkali activator based on dry basis is 3 - 5 wt%, the content of the organic polymer emulsion based on dry basis is 0.1 - 1 wt%, and the content of the quartz sand is 39 - 56 wt%.

4. The composition according to any one of claims 1-3, wherein, The modulus of the alkali activator is 0.5 - 2; and / or The alkali activator is selected from at least one of the mixed solutions of sodium hydroxide and sodium silicate, sodium hydroxide and potassium silicate, potassium hydroxide and sodium silicate, and potassium hydroxide and potassium silicate.

5. The composition according to any one of claims 1-3, wherein, The quartz sand is a combination of coarse quartz sand, medium quartz sand and fine quartz sand with a mass ratio of 1:1 - 3:0.2 - 0.5; and / or The average particle size of the coarse quartz sand is 0.4 mm - 0.85 mm, the average particle size of the medium quartz sand is 0.2 mm - 0.4 mm, and the average particle size of the fine quartz sand is 0.1 mm - 0.2 mm.

6. A method for preparing a geopolymer-based UHPC decorative board, characterized in that, The method includes: (1) Contact - mixing a retarder, a water - reducing agent, an antifoaming agent, a concrete shrinkage - reducing agent, anti - cracking fibers, inorganic pigments, water and the components in the composition according to any one of claims 1 - 5 to obtain a mixed material; (2) Pouring the mixed material in a mold to obtain a poured material, and shaping the poured material to obtain a precursor of the decorative board; (3) Curing and surface - treating the precursor of the decorative board in sequence.

7. The method according to claim 6, wherein, In step (1), the mass ratio of the amounts used of the composition, the retarder, the water reducer, the defoamer, the concrete shrinkage reducing agent, the anti-cracking fiber, and the inorganic pigment is 1: 0.0005 - 0.003: 0.002 - 0.008: 0.0005 - 0.002: 0.001 - 0.005: 0.0005 - 0.002: 0.0005 - 0.03; and / or In step (1), the mass ratio of the amount of water to the amount of the binder is 0.18 - 0.25:

1.

8. The method according to claim 6, wherein, In step (2), the shaping treatment is carried out under vibration conditions, and the conditions of the shaping treatment at least include: the vibration time is 30 - 120 s, the vibration frequency is 40 - 60 Hz, and the vibration amplitude is 0.5 - 1.5 mm.

9. The method according to any one of claims 6-8, wherein, In step (3), the curing conditions at least include: the temperature is 10 - 35 °C, the relative humidity is 40 - 80%, and the time is 1 - 3 d.

10. A geopolymer-based UHPC decorative board prepared by the method according to any one of claims 6-9.

11. Application of the geopolymer-based UHPC decorative board according to claim 10 in building materials.

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