Guniting material and preparation method thereof

Abstract

The invention belongs to the technical field of guniting materials, and particularly relates to a guniting material and a preparation method thereof.The guniting material is prepared from, by weight, 45-65 parts of cement, 30-50 parts of aggregate, 11-15 parts of fiber composition, 6-8 parts of polymer emulsion and 8-12 parts of additive. The guniting material prepared by the preparation method disclosed by the invention is low in rebound rate, relatively high in compressive strength and breaking strength, and good in impermeability.

Description

Technical Field

[0001] The present invention belongs to the technical field of shotcrete materials, and particularly relates to a shotcrete material and a preparation method thereof. Background Art

[0002] In projects such as rapid slope repair, surrounding rock support, roadway repair and reinforcement, leak stoppage, and road emergency repair, in order to construct efficiently, shotcrete materials are often required. Shotcrete materials usually consist of components such as cement, aggregate, water, admixtures, and fibers. However, with the improvement of the standards for construction projects, the adhesion between traditional shotcrete materials and the base material is poor, and they are prone to falling off, which reduces the stability and durability of buildings and requires multiple re-application, making it difficult to meet the requirements of efficient and high-quality construction. To solve this problem, people in this field have developed various shotcrete materials or shotcrete admixtures with different components.

[0003] Patent CN102826774A discloses a nano-level modified admixture for shotcrete. Its mass composition is: 60 - 95 parts of nano-SiO₂; 5 - 40 parts of ultra-fine mineral admixture; 0 - 10 parts of surfactant. Among them, the nano-SiO₂ is a high-activity nano-particle material with a SiO₂ content of ≥95%. This invention improves the workability and durability of concrete by adding a large amount of nano-silica, but the dosage of this admixture in concrete is relatively large, and the cost of nano-silica is relatively high, which limits its popularization and application.

[0004] Patent CN105110718B discloses a dry-mixed shotcrete material for underground bolt-net support with high fly ash and gangue content. It consists of the following raw materials: 800 - 1800 parts of fly ash, 800 - 1800 parts of gangue, 50 - 200 parts of cement, 50 - 150 parts of slag powder, 5 - 10 parts of silicon dioxide, 30 - 100 parts of microsilica, 5 - 10 parts of naphthalene-based water reducer; 0.1 - 0.3 parts of polypropylene fiber, which saves resources and reduces environmental pollution; at the same time, it reduces production costs. In addition, it reduces the number of underground operators and mixing equipment, reduces labor intensity, and improves the safety factor; the rebound rate is low, and the storage time is long, but the permeability of this invention is insufficient, the filling effect is poor, and the compressive strength of the material is relatively poor.

[0005] Therefore, there is an urgent need in the market for a shotcrete material with wide applicability and high compressive strength. Summary of the Invention

[0006] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a shotcrete material and a preparation method thereof. The shotcrete material prepared by the present invention has high compressive strength and flexural strength, good impermeability, low resilience, and wide applicability.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] In the first aspect of the present invention, a shotcreting material is provided, which comprises the following raw materials in parts by weight: 45-65 parts of cement, 30-50 parts of aggregate, 11-15 parts of fiber composition, 6-8 parts of polymer emulsion, and 8-12 parts of admixture.

[0009] In some embodiments, the fiber composition is modified carbon fiber and polypropylene fiber, and the mass ratio thereof is (1.2-1.6):1.

[0010] In some embodiments, the preparation method of the modified carbon fiber comprises the following steps:

[0011] A1. Immerse the carbon fiber in nitric acid for 3-5 h to obtain pretreated carbon fiber;

[0012] A2. Add the pretreated carbon fiber obtained in step A1, silane coupling agent, N-phenethyl methacrylamide and sodium ethoxide into absolute ethanol, stir at 50-60 °C for 3-4 h, wash and dry to obtain modified carbon fiber.

[0013] Preferably, the silane coupling agent is aminoethyl aminopropyl trimethoxysilane.

[0014] Adding fibers to the shotcreting material can significantly improve its mechanical properties, durability and construction performance, improve the performance of the shotcreting material, and also reduce the long-term maintenance cost. The present invention selects polypropylene fiber to be added to the shotcreting material, which can effectively inhibit plastic shrinkage cracks and dry shrinkage cracks and is applicable to early crack prevention. However, the modulus of polypropylene fiber is low, resulting in a decrease in the flexural strength of the shotcreting material. The applicant adds carbon fiber to improve the flexural performance of the shotcreting material. However, it is difficult to disperse the carbon fiber directly. The applicant modifies the carbon fiber to improve the dispersibility of the carbon fiber in the shotcreting material, so that the flexural strength of the shotcreting material is improved. The possible reason is that the pretreated carbon fiber has higher activity and is more likely to react with the silane coupling agent. Then, the silane coupling agent reacts with N-phenethyl methacrylamide, increasing a certain amount of amide groups, which can coordinate with the metal in the cement to make it disperse evenly, and also increase the compactness of the shotcreting material. At the same time, it can make up for the problem of the decrease in the compressive strength of the shotcreting material caused by the excessive presence of rigid groups such as benzene rings.

[0015] In some embodiments, the mass ratio of the pretreated carbon fiber to N-phenethyl methacrylamide in step A2 is 1:(0.4-0.8).

[0016] The present invention limits the ratio of the pretreated carbon fiber to N-phenethyl methacrylamide to increase the dispersibility of the carbon fiber while avoiding the decrease in the compressive strength of the shotcreting material, and also avoiding the problem of the increase in the resilience of the shotcreting material caused by the decrease in the interfacial bonding force with the polymer emulsion.

[0017] In some embodiments, the method for preparing the polymer emulsion comprises the following steps:

[0018] B1. Add 3-pentenoic acid, trifluoropentanol, and concentrated sulfuric acid to dichloromethane, react at 70 - 80 °C for 5 - 6 h, wash and dry to obtain a compound;

[0019] B2. Add the compound obtained in step B1, styrene, and an emulsifier to water, stir for 30 - 40 min, then add an initiator and react at 70 - 80 °C for 1 - 2 h to obtain a polymer emulsion.

[0020] Adding the polymer emulsion to the shotcrete material can effectively improve the construction convenience. In the present invention, adding the polymer emulsion to the shotcrete material not only increases the construction convenience, but also increases the flexural strength of the shotcrete material, reduces the resilience of the shotcrete material, reduces the slump loss, and saves costs. The possible reason is that after the compound with a large number of fluorine atoms polymerizes with styrene, the surface energy of the polymer chain segment is reduced. On the one hand, it is easier to mix evenly with other substances and increase the compressive strength. On the other hand, it can better fill the microcracks and capillary pores of the cement matrix and improve the impermeability. In addition, the addition of the benzene ring and alkane chain segments in the polymer emulsion enhances the interaction with carbon fibers, further enhancing the flexural strength of the shotcrete material and reducing the resilience at the same time.

[0021] In some embodiments, the mass ratio of the 3-pentenoic acid to the trifluoropentanol in step B1 is 1:(1.4 - 1.7).

[0022] In some embodiments, the mass ratio of the compound to the styrene in step B2 is (0.1 - 0.4):1.

[0023] The present invention adds fluorine atoms to the polymer emulsion by limiting the ratio of 3-pentenoic acid to trifluoropentanol, and at the same time limits the mass ratio of the compound to styrene to enhance the impermeability of the shotcrete material while avoiding the problem of reduced resilience caused by excessive fluorine atoms.

[0024] In some embodiments, the aggregate is ordinary quartz sand with a particle size of 10 - 40 mesh.

[0025] Preferably, the aggregate is a composition of ordinary quartz sand with an average particle size of 15 mesh and 35 mesh, and the mass ratio of the two is (2 - 3):1.

[0026] Further preferably, the aggregate is a composition of ordinary quartz sand with an average particle size of 15 mesh and 35 mesh, and the mass ratio of the two is 2.5:1.

[0027] In some embodiments, the admixture, by weight parts, comprises the following raw materials: 0.8 - 1 part of guar gum, 25 - 30 parts of copolymer, 2 - 5 parts of modifier, 0.2 - 0.4 part of initiator, and 90 - 100 parts of solvent.

[0028] In some embodiments, the preparation method of the copolymer comprises the following steps:

[0029] (1) Add pentaerythritol triacrylate, pyromellitic acid, and hydroquinone into dichloromethane, heat up to 70 - 80 °C, add concentrated sulfuric acid, and then continue to react for 7 - 8 h. Wash and dry to obtain a compound.

[0030] (2) Add the compound obtained in step (1), pentaerythritol, allyl glycidyl ether, and a catalyst into a reaction vessel, heat up to 160 - 200 °C, and stir at -0.1 Kpa to 1 Kpa for 3 - 4 h to obtain a copolymer.

[0031] In some embodiments, the mass ratio of pentaerythritol triacrylate to pyromellitic acid is 1:(0.9 - 1.3).

[0032] In some embodiments, the mass ratio of the compound to pentaerythritol in step (2) is 1:(0.7 - 1).

[0033] In some embodiments, the mass ratio of the compound to allyl glycidyl ether in step (2) is 1:(0.05 - 0.15).

[0034] In some embodiments, the preparation method of the modifier includes the following steps: Add resveratrol oxide, sodium gluconate, isocyanate, trans - 1,2,3 - propenetricarboxylic acid, and dibutyltin dilaurate into acetone, react at 70 - 80 °C for 1 - 2 h, and dry to obtain the modifier.

[0035] Preferably, the isocyanate is isophorone diisocyanate.

[0036] In some embodiments, the mass ratio of resveratrol oxide to isocyanate is (0.1 - 0.3):1.

[0037] In some embodiments, the mass ratio of sodium gluconate to isocyanate is (0.7 - 1.2):1.

[0038] In some embodiments, the mass ratio of trans - 1,2,3 - propenetricarboxylic acid to isocyanate is (1 - 1.5):1.

[0039] In some embodiments, the initiator is 2,2'-azobis(2 - methylpropionamidine) dihydrochloride.

[0040] In some embodiments, the preparation method of the admixture comprises the following steps:

[0041] S1. Prepare the solution: Add guar gum into half of the weight portion of the solvent, heat it to 40 - 60°C and stir for 60 - 90 min to obtain a guar gum solution;

[0042] Add the modifier and copolymer into the remaining solvent and stir for 30 - 50 min to obtain a mixture;

[0043] S2. Add the mixture obtained in step S1 into the guar gum solution, then add the initiator, react at 65 - 75°C for 3 - 4 h, dry and pulverize to obtain the admixture for shotcrete materials.

[0044] The second aspect of the present invention provides a preparation method of a shotcrete material, which comprises the following steps: Stir cement, aggregate, fiber composition, polymer emulsion and admixture at 30 - 45°C for 1 - 2 h to obtain the product.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1. The present invention prepares a shotcrete material by using cement, aggregate, fiber composition, polymer emulsion and admixture, which has high compressive strength, flexural strength and impermeability, and can reduce the resilience of the shotcrete material at the same time.

[0047] 2. The present invention reacts the pretreated carbon fiber with a silane coupling agent, and then modifies the carbon fiber by reacting the silane coupling agent with N - phenylethyl methacrylamide to improve the dispersion of the carbon fiber in the shotcrete material, solves the problem of the flexural strength of the shotcrete material, and makes up for the defect that the excessive presence of rigid groups such as benzene rings leads to the reduction of the compressive strength of the shotcrete material.

[0048] 3. By adding polymer emulsion to the shotcrete material, the present invention not only increases the construction convenience, but also makes it easier to mix with other substances evenly, solves the problems of low compressive strength and large resilience after adding conventional polymer emulsion, and can better fill the voids of the cement matrix and improve the impermeability at the same time. Specific embodiments

[0049] The following will illustrate the present invention in combination with specific embodiments. It should be noted that the following examples and comparative examples are only used to illustrate the present invention, rather than to limit the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the main idea or scope of the present invention.

[0050] For the convenience of those skilled in the art to implement the present invention, some raw materials and manufacturers of the examples and comparative examples are described as follows:

[0051] The compounds and related reagents used in the following examples and comparative examples are all commercially available. Among them, the polypropylene fiber with a diameter of 20 μm is purchased from Tai'an Hongfang New Materials Co., Ltd.; the carbon fiber with a diameter of 7 μm is purchased from Yancheng Xiangsheng Carbon Fiber Technology Co., Ltd.; the cement is ordinary type 425 cement; the commercially available admixture is GH-201 type shotcrete admixture for tunnel construction, purchased from Guangxi Nanning Gaohong Herun Building Materials Technology Co., Ltd.

[0052] Preparation Example 1

[0053] The preparation method of the copolymer comprises the following steps:

[0054] (1) Add 10 g of pentaerythritol triacrylate, 11 g of pyromellitic acid, and 0.01 g of hydroquinone to 200 ml of dichloromethane. Heat to 75 °C and add 5 ml of 95 wt% concentrated sulfuric acid. Then continue the reaction for 7.5 h, wash, and dry to obtain the compound.

[0055] (2) Add 10 g of the compound obtained in step (1), 9 g of pentaerythritol, 1 g of allyl glycidyl ether, and 0.1 g of tetrabutyl titanate to the reaction vessel. Heat to 180 °C and stir at -0.1 Kpa for 3.5 h to obtain the copolymer.

[0056] Preparation Example 2

[0057] The preparation method of the modifier includes the following steps: Add 2 g of resveratrol oxide, 10 g of sodium gluconate, 10 g of isophorone diisocyanate, 13 g of trans-1,2,3-propenetricarboxylic acid, and 0.2 g of dibutyltin dilaurate to 100 ml of acetone. React at 75 °C for 1.5 h and dry to obtain the modifier.

[0058] Preparation Example 3

[0059] By weight, the admixture contains the following raw materials: 0.9 part of guar gum, 28 parts of copolymer, 4 parts of modifier, 0.3 part of 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 95 parts of water.

[0060] The preparation method of the admixture comprises the following steps:

[0061] S1. Prepare the solution: Add guar gum to half of the weight parts of water, heat to 50 °C, and stir for 75 min to obtain the guar gum solution.

[0062] Add the modifier and copolymer to the remaining water and stir for 40 min to obtain the mixture.

[0063] S2. Add the mixture obtained in step S1 to the guar gum solution, then add 2,2'-azobis(2-methylpropionamidine) dihydrochloride, react at 70 °C for 3.5 h, dry, and pulverize to obtain the shotcrete material admixture.

[0064] Preparation Example 4

[0065] A method for preparing modified carbon fiber-1, comprising the following steps:

[0066] A1. Add 10 g of carbon fiber to 200 ml of 75 wt% nitric acid solution and soak for 4 h to obtain pretreated carbon fiber;

[0067] A2. Add 5 g of the pretreated carbon fiber obtained in step A1, 3 g of aminoethylaminopropyltrimethoxysilane, 3 g of N-phenylethylmethacrylamide, and 0.1 g of sodium ethoxide to 100 ml of absolute ethanol, stir at 55 °C for 3.5 h, wash and dry to obtain modified carbon fiber-1.

[0068] Preparation Example 5

[0069] A method for preparing modified carbon fiber-2, the specific implementation method is the same as that of Preparation Example 4, the difference is that the addition amount of N-phenylethylmethacrylamide is 5 g.

[0070] Preparation Example 6

[0071] A method for preparing polymer emulsion-1, comprising the following steps:

[0072] B1. Add 10 g of 3-pentenoic acid, 15 g of trifluoropentanol, and 5 ml of 80 wt% concentrated sulfuric acid to 100 ml of dichloromethane, react at 75 °C for 5.5 h, wash and dry to obtain a compound;

[0073] B2. Add 2 g of the compound obtained in step B1, 10 g of styrene, and 0.5 g of sodium dodecylsulfonate to 200 ml of water, stir for 35 min, and then add 0.1 g of azobisisobutyronitrile and react at 75 °C for 1.5 h to obtain polymer emulsion-1.

[0074] Preparation Example 7

[0075] A method for preparing polymer emulsion-2, the specific implementation method is the same as that of Preparation Example 6, the difference is that the addition amount of trifluoropentanol is 12 g.

[0076] Preparation Example 8

[0077] A method for preparing polymer emulsion-3, the specific implementation method is the same as that of Preparation Example 6, the difference is that the addition amount of the compound in step B2 is 5 g.

[0078] Preparation Example 9

[0079] A method for preparing polymer emulsion-4, comprising the following steps:

[0080] Add 2 g of 3-pentenoic acid, 10 g of styrene, and 0.5 g of sodium dodecyl sulfonate to 200 ml of water, stir for 35 min, then add 0.1 g of azobisisobutyronitrile and react at 75 °C for 1.5 h to obtain polymer emulsion 4.

[0081] Example 1

[0082] A shotcrete material, by weight, comprises the following raw materials: 55 parts of cement, 40 parts of aggregate, 14 parts of fiber composition, 7 parts of polymer emulsion-1, and 10 parts of admixture;

[0083] Wherein the fiber composition includes modified carbon fiber-1 and polypropylene fiber, and the mass ratio of the two is 1.4:1; the aggregate is a composition of ordinary quartz sand with an average particle size of 15 mesh and 35 mesh, and the mass ratio of the two is 2.5:1.

[0084] The preparation method of the shotcrete material in this example comprises the following steps: Stir cement, aggregate, fiber composition, polymer emulsion-1, and admixture at 40 °C for 1.5 h to obtain.

[0085] Example 2

[0086] A shotcrete material, by weight, comprises the following raw materials: 45 parts of cement, 30 parts of aggregate, 11 parts of fiber composition, 6 parts of polymer emulsion-1, and 8 parts of admixture;

[0087] Wherein the fiber composition includes modified carbon fiber-1 and polypropylene fiber, and the mass ratio of the two is 1.2:1; the aggregate is a composition of ordinary quartz sand with an average particle size of 15 mesh and 35 mesh, and the mass ratio of the two is 2.5:1.

[0088] The preparation method of the shotcrete material in this example comprises the following steps: Stir cement, aggregate, fiber composition, polymer emulsion-1, and admixture at 30 °C for 2 h to obtain.

[0089] Example 3

[0090] A shotcrete material, by weight, comprises the following raw materials: 65 parts of cement, 50 parts of aggregate, 15 parts of fiber composition, 8 parts of polymer emulsion-1, and 12 parts of admixture;

[0091] Wherein the fiber composition includes modified carbon fiber-1 and polypropylene fiber, and the mass ratio of the two is 1.6:1; the aggregate is a composition of ordinary quartz sand with an average particle size of 15 mesh and 35 mesh, and the mass ratio of the two is 2.5:1.

[0092] The preparation method of the shotcrete material in this example comprises the following steps: Stir cement, aggregate, fiber composition, polymer emulsion-1, and admixture at 45 °C for 1 h to obtain.

[0093] Example 4

[0094] A shotcrete material and its preparation method. The specific implementation method is the same as that of Example 1, except that modified carbon fiber - 1 is replaced with modified carbon fiber - 2 in equal amounts.

[0095] Example 5

[0096] A shotcrete material and its preparation method. The specific implementation method is the same as that of Example 1, except that polymer emulsion - 1 is replaced with polymer emulsion - 2 in equal amounts.

[0097] Example 6

[0098] A shotcrete material and its preparation method. The specific implementation method is the same as that of Example 1, except that polymer emulsion - 1 is replaced with polymer emulsion - 3 in equal amounts.

[0099] Example 7

[0100] A shotcrete material and its preparation method. The specific implementation method is the same as that of Example 1, except that polymer emulsion - 1 is replaced with polymer emulsion - 4 in equal amounts.

[0101] Example 8

[0102] A shotcrete material and its preparation method. The specific implementation method is the same as that of Example 1, except that the admixture is replaced with a commercially available admixture in equal amounts.

[0103] Comparative Example 1

[0104] A shotcrete material and its preparation method. The specific implementation method is the same as that of Example 1, except that modified carbon fiber - 1 is replaced with carbon fiber in equal amounts.

[0105] Performance Test

[0106] 1. Compressive strength, flexural strength and impermeability

[0107] The shotcrete materials obtained from each example and comparative example are then added to a cube mold with a side length of 100 mm and vibrated densely using an electric vibrating table. After 24 hours, the mold is removed, and the specimens are cured for 28 days under the conditions of a temperature of 25°C and a relative humidity of 95% to obtain test specimens;

[0108] Refer to GB / T 50081 - 2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete" to test the compressive strength and flexural strength;

[0109] Refer to the step - by - step pressure method in "GB / T 50082 2009 Standard for Test Methods of Long - Term Performance and Durability of Ordinary Concrete" to test the impermeability grade.

[0110] 2. Rebound rate

[0111] Refer to JGJ / T 372-2016 "Technical Specification for Application of Shotcrete" to test the rebound rate.

[0112] The test results are shown in Table 1.

[0113] Table 1

[0114] Group Compressive strength / MPa Flexural strength / MPa Impermeability grade Rebound rate % Example 1 55.8 16.1 >P12 5.6 Example 2 53.2 15.4 >P12 5.8 Example 3 54.4 15.8 >P12 5.9 Example 4 51.1 13.2 >P12 6.8 Example 5 52.4 15.6 P11 5.8 Example 6 47.8 11.5 >P12 7.9 Example 7 44.5 10.9 P10 6.3 Example 8 41.6 10.3 P11 7.6 Comparative example 1 42.1 9.5 P11 9.3

[0115] It can be seen from the comparison of the experimental data of Examples 1-3 in Table 1 that the shotcrete material obtained by the present invention has good compressive strength, flexural performance and impermeability, and a low rebound rate; comparing Example 4 with Example 1, it can be seen that the change in the ratio of pretreated carbon fiber to N-phenethyl methacrylamide may lead to too many rigid structures and poor binding ability with the polymer emulsion, resulting in a decrease in the compressive strength and flexural strength of the shotcrete material and an increase in the resilience; comparing Example 5 with Example 1, it can be seen that the change in the ratio of 3-pentenoic acid to trifluoropentanol may lead to a decrease in the purity of the prepared compound and a decrease in the uniformity of mixing with other substances, resulting in a decrease in the impermeability of the shotcrete material; comparing Example 6 with Example 1, it can be seen that the change in the ratio of the compound to styrene may result in an excess of fluorine atoms, a change in the viscosity of the shotcrete material, and an impact on the hydration reaction of cement, an increase in resilience, and a decrease in compressive strength and flexural strength; comparing Example 7 with Example 1, it can be seen that without adding trifluoropentanol, the surface energy of the polymer emulsion may be relatively large, resulting in a decrease in the compressive strength, flexural strength and impermeability of the shotcrete material and an increase in resilience; comparing Example 8 with Example 1, it can be seen that the performance of the shotcrete material using ordinary commercially available admixtures has decreased; comparing Comparative Example 1 with Example 1, it can be seen that without modifying the carbon fiber, the compatibility of the carbon fiber in the shotcrete material is poor and the binding force is weak, resulting in a decrease in the performance of the shotcrete material.

[0116] The above is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to make equivalent embodiments with equivalent changes, but as long as it does not depart from the technical content of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A shotcrete material, characterized in that, It contains the following raw materials by weight parts: 45-65 parts of cement, 30-50 parts of aggregate, 11-15 parts of fiber composition, 6-8 parts of polymer emulsion, and 8-12 parts of admixture.

2. The shotcreting material according to claim 1, wherein The fiber composition is modified carbon fiber and polypropylene fiber, and the mass ratio of the two is (1.2-1.6):

1.

3. The shotcrete material according to claim 2, wherein The preparation method of the modified carbon fiber comprises the following steps: A1. Immerse carbon fiber in nitric acid for 3-5 h to obtain pretreated carbon fiber; A2. Add the pretreated carbon fiber, silane coupling agent, N-phenethyl methacrylamide and sodium ethoxide obtained in step A1 into absolute ethanol, stir at 50-60 °C for 3-4 h, wash and dry to obtain modified carbon fiber.

4. The shotcrete material according to claim 3, characterized in that, In step A2, the mass ratio of the pretreated carbon fiber to N-phenethyl methacrylamide is 1:(0.4-0.8).

5. The shotcrete material according to claim 1, characterized in that, The preparation method of the polymer emulsion includes the following steps: B1. Add 3-pentenoic acid, trifluoropentanol and concentrated sulfuric acid into dichloromethane, react at 70-80 °C for 5-6 h, wash and dry to obtain a compound; B2. Add the compound, styrene and emulsifier obtained in step B1 into water, stir for 30-40 min, then add initiator and react at 70-80 °C for 1-2 h to obtain a polymer emulsion.

6. The shotcrete material according to claim 5, wherein, In step B1, the mass ratio of 3-pentenoic acid to trifluoropentanol is 1:(1.4-1.7).

7. The shotcrete material according to claim 5, characterized in that, In step B2, the mass ratio of the compound to styrene is (0.1-0.4):

1.

8. The shotcrete material according to claim 1, characterized in that, The aggregate is ordinary quartz sand with a particle size of 10-40 mesh.

9. The shotcrete material according to claim 1, characterized in that, By weight parts, the admixture contains the following raw materials: 0.8-1 part of guar gum, 25-30 parts of copolymer, 2-5 parts of modifier, 0.2-0.4 part of initiator, and 90-100 parts of solvent.

10. A method for preparing the shotcrete material according to any one of claims 1-9, characterized in that, It comprises the following steps: Stir cement, aggregate, fiber composition, polymer emulsion and admixture at 30-45 °C for 1-2 h to obtain the product.