Preparation method and application of high-homogeneous cement mortar material

Abstract

The present invention relates to the technical field of cement-based materials, and in particular to a preparation method and application of a highly homogeneous cement mortar material. The method comprises the following steps: (1) mixing nano hydrotalcite powder with anhydrous ethanol containing EGTA after calcination, and separating the solid product as modified nano hydrotalcite powder; (2) adding fly ash microbeads to anhydrous ethanol containing a silane coupling agent, stirring and dispersing, adding the modified nano hydrotalcite powder, and heating and heat preservation under stirring conditions; the separated solid product is dried to obtain modified fly ash microbeads; (3) uniformly mixing silicate cement, modified fly ash microbeads, surface-treated slag fine aggregate, surfactant, water reducer, and water to obtain the highly homogeneous cement mortar material. The above method not only effectively improves the compatibility between fly ash microbeads and cement mortar to obtain highly homogeneous cement mortar, but also overcomes the adverse effects on the mechanical properties of the mortar.

Description

Technical Field

[0001] The present invention relates to the technical field of cement-based mortar materials, and in particular to a preparation method and application of a highly homogeneous cement mortar material. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Cement mortar is a building material mainly formed by mixing raw materials such as cement, fine aggregate, and water. It is widely used in construction projects, such as the repair and maintenance of damaged roads, the repair of cracks in concrete structures, wall insulation, and waterproofing projects. Fly ash microbeads are a kind of gray-white hollow glass formed by the high-temperature suspension combustion of powdered coal particles. They are very light and have low thermal conductivity. Therefore, adding fly ash microbeads to cement mortar can not only reduce the density of the mortar, but also improve the thermal insulation performance. However, since the density of fly ash microbeads is significantly lower than that of cement mortar, the compatibility between fly ash microbeads and mortar is poor. During the mixing process, the problem of fly ash microbeads floating and segregating is easy to occur, resulting in the inability of fly ash microbeads to be evenly distributed in cement mortar, affecting the homogeneity of cement mortar, causing the decline of mechanical properties of cement mortar, and also causing the fly ash microbeads to fail to play their due role and reduce their utilization value.

[0004] At present, although the problem of fly ash micro-beads floating can be suppressed by reducing the amount of water in cement mortar, it will lead to insufficient fluidity of cement mortar, reduce workability and affect the full hydration reaction of cement mortar, thus causing a decrease in mechanical strength. In addition, the uneven distribution of fly ash micro-beads leads to an increase in the difference in mechanical strength of cement mortar, which in turn makes it easier for cement mortar to crack due to uneven volume shrinkage during dehydration and hardening, resulting in a decrease in waterproof, anti-permeability, mechanical strength and other properties, resulting in a decrease in the protective effectiveness of cement mortar materials. Summary of the invention

[0005] In view of the shortcomings of the prior art, the first object of the present invention is to provide a method for preparing a highly homogeneous cement mortar material, which not only effectively improves the compatibility between fly ash microbeads and cement mortar to obtain highly homogeneous cement mortar, but also overcomes the adverse effects on the mechanical properties of the mortar.

[0006] The second object of the present invention is to provide an application of the above-mentioned high-homogeneity cement mortar material.

[0007] To achieve the above objectives, the present invention discloses the following technical solutions.

[0008] A method for preparing a highly homogeneous cement mortar material comprises the following steps:

[0009] (1) reversibly calcining nano-hydrotalcite powder, cooling the mixture, mixing the obtained calcined nano-hydrotalcite powder with anhydrous ethanol containing ethylene glycol bis-α-aminoethyl ether tetraacetic acid (EGTA), and allowing the mixture to stand to separate a solid product, thereby obtaining a modified nano-hydrotalcite powder;

[0010] (2) adding fly ash microbeads to anhydrous ethanol containing a silane coupling agent and stirring to disperse, then adding the modified nano-hydrotalcite powder obtained in step (1), and heating and heat preservation under stirring conditions, separating the solid product after completion, and drying to obtain modified fly ash microbeads;

[0011] (3) adding slag fine aggregate and silane coupling agent to acrylic acid solution, stirring, standing and filtering, and obtaining a solid product as surface-treated slag fine aggregate;

[0012] (4) According to their weight parts, 43-60 parts by weight of silicate cement, 20-40 parts by weight of the modified fly ash microspheres obtained in step (2), 100-150 parts by weight of surface-treated slag fine aggregate, 1-2 parts by weight of a surfactant, 0.07-0.12 parts by weight of a water reducing agent and 22-28 parts by weight of water are mixed and stirred uniformly to obtain the highly homogeneous cement mortar material.

[0013] Furthermore, in step (1), the nano-LDHs powder is at least one of aluminum-magnesium hydrotalcite powder, magnesium-zinc-aluminum hydrotalcite powder, zinc-aluminum hydrotalcite powder and calcium-aluminum hydrotalcite powder.

[0014] Furthermore, in step (1), the calcination temperature is 320-400° C., and the calcination time is 2-3 h.

[0015] Furthermore, in step (1), the mass volume ratio of the calcined nano-hydrotalcite powder to the anhydrous ethanol containing ethylene glycol bis-α-aminoethyl ether tetraacetic acid is 1 g: (10-30) mL.

[0016] Furthermore, the ethylene glycol bis-α-aminoethyl ether tetraacetic acid in the anhydrous ethanol containing ethylene glycol bis-α-aminoethyl ether tetraacetic acid is in a saturated state.

[0017] Furthermore, in step (1), the standing time is 36 to 48 hours, so that the EGTA can be intercalated between the layers of the hydrotalcite.

[0018] Furthermore, in step (2), the mass ratio of the fly ash microbeads to the anhydrous ethanol containing the silane coupling agent is 1 g: (10-40) mL.

[0019] Furthermore, the mass fraction of the silane coupling agent in the anhydrous ethanol containing the silane coupling agent is 0.5% to 2%.

[0020] Furthermore, in step (2), the silane coupling agent is at least one of vinyl triethoxysilane (A151), vinyl trimethoxysilane (A171), vinyl tri(β-methoxyethoxy) silane (A172), γ-aminopropyl triethoxysilane (KH550), γ-glycidyloxypropyl trimethoxysilane (KH560), γ-methacryloxypropyl trimethoxysilane (KH570) and N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane (KH792).

[0021] Furthermore, in step (2), the mass ratio of the modified nano-hydrotalcite powder to the fly ash microbeads is (1-3):(8-12).

[0022] Furthermore, in step (2), the heating and insulation temperature is 50-70° C. and the time is 1-2 h.

[0023] Furthermore, in step (2), the modified fly ash microbeads are obtained after drying at 60-75° C. to constant weight.

[0024] Furthermore, in step (3), the mass volume ratio of the slag fine aggregate to the acrylic acid solution is 1 g: (20-40) mL.

[0025] Furthermore, in step (3), the mass fraction of the silane coupling agent in the acrylic acid solution is 1% to 2%.

[0026] Furthermore, in step (3), the mass fraction of the acrylic acid solution is 10-25%.

[0027] Furthermore, in step (3), the standing time is 30 to 60 minutes to graft acrylic acid monomers onto the surface of the slag fine aggregate particles.

[0028] Furthermore, in step (3), the silane coupling agent is at least one of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-aminopropyl triethoxysilane, γ-glycidyloxypropyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane and N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane.

[0029] Furthermore, in step (4), the surfactant is at least one of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate.

[0030] Furthermore, in step (4), the water reducer is a polycarboxylate water reducer, a wood sulfonate water reducer, a naphthalene water reducer or a polycyclic aromatic salt water reducer.

[0031] Furthermore, in step (4), the raw materials also include an initiator.

[0032] Furthermore, the initiator is 0.1-0.3% of the mass of the surface-treated slag fine aggregate.

[0033] Furthermore, the initiator includes any one of potassium persulfate, ammonium persulfate and the like.

[0034] Furthermore, additives such as defoamers and retarders may be added to the raw materials in step (4) as required.

[0035] Application of the high-homogeneity cement mortar material prepared by the above method, wherein the high-homogeneity cement mortar material is used in the field of construction.

[0036] Beneficial effects: (1) To prevent the fly ash microbeads from being difficult to evenly distribute in the cement mortar, thereby affecting the performance of the cement mortar. The present invention firstly performs a reversible calcination treatment on the hydrotalcite to remove the water molecules between the hydrotalcite layers while maintaining the layered structure of the hydrotalcite. After the hydrotalcite treated as above is mixed with anhydrous ethanol containing EGTA, the EGTA molecules can be intercalated into the interlayer structure of the hydrotalcite for modification. Since the interlayer water molecules of the hydrotalcite are removed, it is easy to intercalate more EGTA molecules. After the obtained modified hydrotalcite is mixed with fly ash microbeads and a silane coupling agent in anhydrous ethanol, the modified hydrotalcite nanoparticles are grafted onto the fly ash microbeads by the coupling agent through the organic matter EGTA intercalated therein to form modified fly ash microbeads. After entering the cement mortar, the memory effect of the hydrotalcite nanoparticles on the fly ash microbeads enables it to absorb the moisture in the cement mortar for structural recovery, effectively improving the affinity of the fly ash microbeads and the cement mortar, making the fly ash microbeads more evenly distributed in the cement mortar, overcoming the adverse effects on the mechanical properties of the mortar. At the same time, the EGTA intercalated between the hydrotalcite layers can also effectively capture the calcium ions generated by cement hydration, thereby reducing the calcium ion concentration in the system and promoting the hydration reaction. The hydrotalcite nanoparticles as nucleation inducers also help to promote the hydration reaction, thereby improving the mechanical strength of the cement mortar. In addition, the good lubricity of the hydrotalcite also helps to improve the working performance of the cement mortar, so that the cement mortar prepared by the present invention can be better suitable for crack repair engineering.

[0037] (2) The present invention also performs surface treatment on slag fine aggregate, further improving the crack resistance of the cement mortar of the present invention. This is because the acrylic acid monomer grafted on the surface of the slag fine aggregate particles undergoes a polymerization reaction under the action of the initiator and the hydration heat of cement to form polyacrylic acid, and its good bonding performance can effectively increase the bonding between the fine aggregate and the mortar matrix and the toughness of the mortar material, and alleviate the problem that the hydration products formed by cement during the dehydration and hardening process are more likely to shrink in volume, while the rigid fine aggregate is not prone to shrink in volume, which in turn causes cracks to easily form between the fine aggregate and the mortar matrix, thereby improving the crack resistance of the cement mortar material of the present invention, reducing the occurrence of microcracks, and improving the mechanical strength and waterproof and anti-seepage performance. At the same time, the formation of the polyacrylic acid also helps to increase the consistency of the cement slurry, further preventing the phenomenon of the fly ash microbeads floating up. In addition, the formation of the polyacrylic acid also helps to improve the waterproof and anti-seepage performance of the cement mortar material of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein:

[0039] Figure 1 This is a microscopic image of the highly homogeneous cement mortar material prepared in Example 1 under a microscope;

[0040] Figure 2 This is a sample picture of the cement-based mortar material prepared in Comparative Example 1;

[0041] Figure 3 This is a microscopic image of the cement-based mortar material prepared in Comparative Example 1 under a microscope;

[0042] Figure 4 This is a microscopic image of the cement-based mortar material prepared in Comparative Example 1 under a microscope. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0044] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. The reagents or raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in a conventional manner in the art or in accordance with the product instructions. The preparation method of the high-homogeneity cement mortar material of the present invention is now further described in conjunction with the accompanying drawings and specific embodiments of the specification.

[0045] Example 1

[0046] A method for preparing a highly homogeneous cement mortar material comprises the following steps:

[0047] (1) Nano-hydrotalcite powder (Mg6Al2(CO3)(OH) 16 ·4H2O) was heated to 320℃ and kept warm for 3 h. After completion, it was cooled to room temperature. The calcined nano-hydrotalcite powder was mixed with saturated anhydrous ethanol solution of EGTA at a solid-liquid ratio of 1 g:10 mL and stirred evenly. Then it was allowed to stand for 36 h. After completion, the solid product was separated by centrifugation to obtain the modified nano-hydrotalcite powder, which was dried and set aside.

[0048] (2) fly ash microspheres and anhydrous ethanol solution with a mass fraction of 0.5% of a silane coupling agent (A151) are mixed at a solid-liquid ratio of 1 g:40 mL, and then ultrasonically dispersed. The modified nano-hydrotalcite powder obtained in step (1) is added at a mass ratio of 1:8 to the fly ash microspheres. The mixture is heated to 50°C and kept warm for 2 h. During the process, stirring is continued at a rate of 60 r / min. After completion, the solid product is separated by filtration, and the solid product is stirred and dried at 60°C to a constant weight to obtain modified fly ash microspheres for later use.

[0049] (3) Add slag fine aggregate with a particle size of 0.2-0.5 mm and silane coupling agent (KH550) to a 25% by mass acrylic acid solution, and the ratio of the slag fine aggregate to the acrylic acid solution is 1 g:40 mL. The mass fraction of the silane coupling agent in the acrylic acid solution is 2%. Stir evenly and let stand for 30 min. Then filter and separate the solid product. After drying, the surface-treated slag fine aggregate is obtained.

[0050] (4) 42.5 ordinary Portland cement, the modified fly ash microspheres of step (2), the surface-treated slag fine aggregate of step (3), ammonium persulfate, sodium dodecylbenzene sulfonate, polycarboxylic acid water reducer and clean water are mixed in a mass ratio of 43:20:100:0.1:1:0.07:22, and stirred for 2 minutes to obtain a highly homogeneous cement mortar material.

[0051] According to the "Test Method for Degree of Separation of Cement Mortar" (T0588-2020), the degree of separability of the highly homogeneous cement mortar material prepared in Example 1 was tested to measure the homogeneity of the highly homogeneous cement mortar material.

[0052] According to the "Test Method for Strength of Cement Mortar (ISO Method)" (GB / T 17671-2021), the 28 d compressive strength of the high-homogeneous cement mortar material prepared in Example 1 was tested.

[0053] The water seepage height of the high homogeneous cement mortar material prepared in Example 1 was tested according to the Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete (GBT50082-2009). The test results are shown in Table 1.

[0054] Table 1 Highly homogeneous cement mortar materials prepared in Example 1

[0055] Statistical table of stratification, compressive strength and water seepage height

[0056]

[0057] Figure 1 From the microscopic image of the highly homogeneous cement mortar material prepared in this embodiment under a microscope, it can be seen that it also has good homogeneity.

[0058] Example 2

[0059] A method for preparing a highly homogeneous cement mortar material comprises the following steps:

[0060] (1) Heat nano-hydrotalcite powder (Ca4Al2O6(NO3)2·10H2O) to 400℃ and keep it for 2.5 h. After completion, cool it to room temperature. Mix the calcined nano-hydrotalcite powder with saturated anhydrous ethanol solution of EGTA at a solid-liquid ratio of 1 g:30 mL and stir evenly. Then let it stand for 48 h. After completion, centrifuge to separate the solid product to obtain the modified nano-hydrotalcite powder, dry it and set it aside.

[0061] (2) Mix the fly ash microspheres with anhydrous ethanol solution containing 2% of a silane coupling agent (KH560) at a solid-liquid ratio of 1 g:10 mL, and then perform ultrasonic dispersion treatment. Then add the modified nano-hydrotalcite powder obtained in step (1) at a mass ratio of 3:12 to the fly ash microspheres. Then heat to 70°C and keep warm for 1 h. Stir continuously at a rate of 60 r / min during the process. After completion, filter and separate the solid product. Stir and dry it at 75°C to constant weight to obtain the modified fly ash microspheres for later use.

[0062] (3) Add slag fine aggregate with a particle size of 0.2-0.5 mm and silane coupling agent (KH570) to a 10% by mass acrylic acid solution, and the ratio of the slag fine aggregate to the acrylic acid solution is 1 g: 20 mL. The mass fraction of the silane coupling agent in the acrylic acid solution is 1%. Stir evenly and let stand for 60 min. Then filter and separate the solid product. After drying, the surface-treated slag fine aggregate is obtained.

[0063] (4) 42.5 ordinary Portland cement, the modified fly ash microspheres of step (2), the surface-treated slag fine aggregate of step (3), potassium persulfate, sodium dodecyl sulfate, sodium wood sulfonate water reducer and clean water are mixed in a mass ratio of 60:40:150:0.45:2:0.12:28, and stirred for 3 minutes to obtain a highly homogeneous cement mortar material.

[0064] The degree of stratification, 28d compressive strength, and water seepage height of the high-homogeneous cement mortar material prepared in Example 2 were tested (the method was the same as that in Example 1). The test results are shown in Table 2.

[0065] Table 2 Highly homogeneous cement mortar materials prepared in Example 2

[0066] Statistical table of stratification, compressive strength and water seepage height

[0067]

[0068] Comparative Example 1

[0069] A method for preparing a cement-based mortar material comprises the following steps:

[0070] (1) Nano-hydrotalcite powder (Mg6Al2(CO3)(OH) 16 ·4(H2O)) was heated to 380℃ and kept for 2 h. After completion, it was cooled to room temperature. The calcined nano-hydrotalcite powder was mixed with saturated anhydrous ethanol solution of EGTA at a solid-liquid ratio of 1 g: 25 mL and stirred evenly. Then it was allowed to stand for 40 h. After completion, the solid product was separated by centrifugation to obtain the modified nano-hydrotalcite powder, which was dried and set aside.

[0071] (2) Fly ash microspheres and anhydrous ethanol solution with a mass fraction of 1.5% of a silane coupling agent (KH550) are mixed at a solid-liquid ratio of 1 g:30 mL, and then ultrasonically dispersed. The modified nano-hydrotalcite powder obtained in step (1) is added at a mass ratio of 2:9 to the fly ash microspheres. The mixture is heated to 65°C and kept warm for 2 h. During the process, stirring is continued at a rate of 60 r / min. After completion, the solid product is separated by filtration, and the solid product is stirred and dried at 70°C to constant weight to obtain modified fly ash microspheres for later use.

[0072] (3) 42.5 ordinary Portland cement, the modified fly ash microspheres prepared in step (2), slag fine aggregate with a particle size of 0.2-0.5 mm, sodium dodecyl sulfate, polycarboxylate water reducer and clean water were mixed in a mass ratio of 49:30:120:1.3:0.1:25 and stirred for 2 min to obtain a cement-based mortar material such as: Figure 2 shown.

[0073] The delamination degree, 28-day compressive strength and water seepage height of the cement-based mortar material prepared in Comparative Example 1 were tested. The test results are shown in Table 3.

[0074] Table 3 Cement-based mortar materials prepared in Comparative Example 1

[0075] Statistical table of stratification, compressive strength and water seepage height

[0076]

[0077] Figure 3 From the microscopic image of the cement-based mortar material prepared in Comparative Example 1 under a microscope, it can be seen that it has good homogeneity.

[0078] Comparative Example 2

[0079] A method for preparing a cement-based mortar material comprises the following steps:

[0080] Mix 42.5 ordinary Portland cement, fly ash beads, slag fine aggregate with a particle size of 0.2-0.5 mm, sodium dodecyl sulfate, polycarboxylic acid water reducer and clean water in a mass ratio of 49:30:120:1.3:0.1:25 and stir for 2 min to obtain a cement-based mortar material.

[0081] The delamination degree, 28d compressive strength and water seepage height of the cement-based mortar material prepared in Comparative Example 1 were tested (the method was the same as that in Example 1). The test results are shown in Table 4.

[0082] Table 4 Cement-based mortar materials prepared in Comparative Example 2

[0083] Statistical table of stratification, compressive strength and water seepage height

[0084]

[0085] Figure 4 This is a microscopic image of the cement-based mortar material prepared in Comparative Example 2 under a microscope, from which it can be seen that the cement-based mortar material has poor homogeneity.

[0086] Comparative Example 3

[0087] A method for preparing a cement-based mortar material comprises the following steps:

[0088] (1) Nano-hydrotalcite powder (Mg6Al2(CO3)(OH) 16 ·4(H2O)) and saturated anhydrous ethanol solution of EGTA were mixed at a solid-liquid ratio of 1g:25mL and stirred evenly, and then allowed to stand for 40 hours. After completion, the solid product was separated by centrifugation to obtain modified nano-hydrotalcite powder, which was dried and set aside;

[0089] (2) Fly ash microspheres and anhydrous ethanol solution with a mass fraction of 1.5% of a silane coupling agent (KH550) are mixed at a solid-liquid ratio of 1 g:30 mL, and then ultrasonically dispersed. The modified nano-hydrotalcite powder obtained in step (1) is added at a mass ratio of 2:9 to the fly ash microspheres. The mixture is heated to 65°C and kept warm for 2 h. During the process, stirring is continued at a rate of 60 r / min. After completion, the solid product is separated by filtration, and the solid product is stirred and dried at 70°C to constant weight to obtain modified fly ash microspheres for later use.

[0090] (3) 42.5 ordinary Portland cement, the modified fly ash microspheres prepared in step (2), slag fine aggregate with a particle size of 0.2-0.5 mm, sodium dodecyl sulfate, polycarboxylic acid water reducer and clean water were mixed in a mass ratio of 49:30:120:1.3:0.1:25, and stirred for 2 min to obtain a cement-based mortar material.

[0091] The delamination degree, 28d compressive strength and water seepage height of the cement-based mortar material prepared in Comparative Example 3 were tested (the method was the same as that in the above-mentioned Example 1). The test results are shown in Table 5.

[0092] Table 5 Cement-based mortar materials prepared in Comparative Example 3

[0093] Statistical table of stratification, compressive strength and water seepage height

[0094]

[0095] Comparative Example 4

[0096] A method for preparing a cement-based mortar material comprises the following steps:

[0097] (1) Nano-hydrotalcite powder (Mg6Al2(CO3)(OH) 16 4 (H2O)) was heated to 380℃ and kept for 2 h, and then cooled to room temperature to obtain modified nano-hydrotalcite powder, which was dried and used for later use;

[0098] (2) Fly ash microspheres and anhydrous ethanol solution with a mass fraction of 1.5% of a silane coupling agent (KH550) are mixed at a solid-liquid ratio of 1 g:30 mL, and then ultrasonically dispersed. The modified nano-hydrotalcite powder obtained in step (1) is added at a mass ratio of 2:9 to the fly ash microspheres. The mixture is heated to 65°C and kept warm for 2 h. During the process, stirring is continued at a rate of 60 r / min. After completion, the solid product is separated by filtration, and the solid product is stirred and dried at 70°C to constant weight to obtain modified fly ash microspheres for later use.

[0099] (3) 42.5 ordinary Portland cement, the modified fly ash microspheres obtained in step (2), slag fine aggregate with a particle size of 0.2-0.5 mm, sodium dodecyl sulfate, polycarboxylic acid water reducer and clean water are mixed in a mass ratio of 49:30:120:1.3:0.1:25, and stirred for 2 min to obtain a cement-based mortar material.

[0100] The delamination degree, 28d compressive strength and water seepage height of the cement-based mortar material prepared in Comparative Example 4 were tested (the method was the same as that in Example 1), and the test results are shown in Table 6.

[0101] Table 6 Cement-based mortar materials prepared in Comparative Example 4

[0102] Statistical table of stratification, compressive strength and water seepage height

[0103]

[0104] Comparative Example 5

[0105] A method for preparing a cement-based mortar material comprises the following steps:

[0106] (1) Fly ash microspheres and anhydrous ethanol solution with a mass fraction of 2% of a silane coupling agent (KH560) were mixed at a solid-liquid ratio of 1 g:10 mL, and then subjected to ultrasonic dispersion treatment. Nano-hydrotalcite powder (Ca4Al2O6(NO3)2·10H2O) was added at a mass ratio of 3:12 to the fly ash microspheres. The mixture was heated to 70°C and kept warm for 1 h. During the process, stirring was continued at a rate of 60 r / min. After completion, the solid product was separated by filtration, and the solid product was stirred and dried at 75°C to constant weight to obtain modified fly ash microspheres for later use.

[0107] (2) Add slag fine aggregate with a particle size of 0.2-0.5 mm and silane coupling agent (KH570) to a 10% by mass acrylic acid solution, and the ratio of slag fine aggregate to acrylic acid solution is 1 g: 20 mL. The mass fraction of the silane coupling agent in the acrylic acid solution is 1%. Stir evenly and let stand for 60 min. Then filter and separate the solid product. After drying, the surface-treated slag fine aggregate is obtained.

[0108] (3) 60 parts by weight of 42.5 ordinary Portland cement, 40 parts by weight of modified fly ash microspheres prepared in step (1), 150 parts by weight of surface-treated slag fine aggregate prepared in step (2), 0.45 parts by weight of potassium persulfate, 2 parts by weight of sodium dodecyl sulfate, 0.12 parts by weight of sodium lignosulfonate water reducer and 28 parts by weight of clean water were mixed in a mass ratio of 60:40:150:0.45:2:0.12:28, and stirred for 3 minutes to obtain a cement-based mortar material.

[0109] The delamination degree, 28d compressive strength and water seepage height of the cement-based mortar material prepared in Comparative Example 5 were tested (the method was the same as that in Example 1). The test results are shown in Table 7.

[0110] Table 7 Cement-based mortar materials prepared in Comparative Example 5

[0111] Statistical table of stratification, compressive strength and water seepage height

[0112]

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still repair the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any repair, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a highly homogeneous cement mortar material, characterized in that: The preparation method comprises the following steps: (1) mixing the calcined nano-hydrotalcite powder with anhydrous ethanol containing EGTA, allowing the mixture to stand, and separating a solid product to obtain a modified nano-hydrotalcite powder; (2) adding fly ash microbeads to anhydrous ethanol containing a silane coupling agent and stirring, adding the modified nano-hydrotalcite powder obtained in step (1), heating, separating, and drying the solid product to obtain modified fly ash microbeads; (3) adding slag fine aggregate and silane coupling agent to acrylic acid solution, stirring, standing and filtering, and obtaining a solid product as surface-treated slag fine aggregate; (4) Mix 43-60 parts of raw material silicate cement, 20-40 parts of the modified fly ash microspheres, 100-150 parts of surface-treated slag fine aggregate, 1-2 parts of surfactant, 0.07-0.12 parts of water reducer and 22-28 parts of water according to their weight proportions, wherein the raw material also includes an initiator, and the amount of the initiator is 0.1%-0.3% of the weight of the surface-treated slag fine aggregate, and stir to obtain the highly homogeneous cement mortar material.

2. The preparation method according to claim 1, characterized in that In step (1), the calcination temperature is 320-400°C and the calcination time is 2-3 h; The nano hydrotalcite powder is at least one of aluminum-magnesium hydrotalcite powder, magnesium-zinc-aluminum hydrotalcite powder, zinc-aluminum hydrotalcite powder and calcium-aluminum hydrotalcite powder.

3. The preparation method according to claim 1, characterized in that: In step (1), the EGTA in the anhydrous ethanol containing EGTA is saturated; The mass volume ratio of the calcined nano-hydrotalcite powder to the anhydrous ethanol containing EGTA is 1 g: (10-30) mL; The standing time is 36 to 48 hours.

4. The preparation method according to claim 1, characterized in that In step (2), the mass volume ratio of the fly ash microbeads to the anhydrous ethanol containing the silane coupling agent is 1 g: (10-40) mL; The mass fraction of the silane coupling agent in the anhydrous ethanol containing the silane coupling agent is 0.5% to 2%; The silane coupling agent is at least one of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-aminopropyl triethoxysilane, γ-glycidyloxypropyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane and N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane; The mass ratio of the modified nano-hydrotalcite powder to the fly ash microbeads is (1-3): (8-12).

5. The method for preparing a highly homogeneous cement mortar material according to claim 1, characterized in that: In step (2), the heating temperature is 50-70°C and the heating time is 1-2 h; The drying temperature is 60-75°C.

6. The preparation method according to claim 1, characterized in that: In step (3), the mass volume ratio of the slag fine aggregate and the acrylic acid solution is 1 g: (20-40) mL; The mass fraction of the silane coupling agent in the acrylic acid solution is 1% to 2%; The mass fraction of the acrylic acid solution is 10% to 25%; The standing time is 30 to 60 min; The silane coupling agent is at least one of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-aminopropyl triethoxysilane, γ-glycidyloxypropyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane and N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane.

7. The preparation method according to claim 1, characterized in that: In step (4), the surfactant is at least one of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate; The water reducer is a polycarboxylate water reducer, a wood sulfonate water reducer, a naphthalene water reducer or a polycyclic aromatic salt water reducer.

8. The preparation method according to claim 1, characterized in that: The initiator is potassium persulfate or ammonium persulfate.

9. Application of the high homogeneous cement mortar material prepared by the method according to any one of claims 1 to 8, characterized in that: The high-homogeneity cement mortar material is used in the field of construction.

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