Shield muck synchronous grouting material and preparation method thereof

Abstract

The invention provides a shield muck synchronous grouting material and a preparation method thereof. The grouting material comprises the following raw materials in parts by weight: 30-40 parts of a cementing material, 50-65 parts of shield muck, 4-6 parts of a polymer emulsion, 2-4 parts of an exciting agent, 0.1-0.3 part of an early strength agent, 1-2 parts of a mud-resistant polycarboxylate superplasticizer, 3-5 parts of quaternary ammonium salt coupling agent modified nano magnesium oxide and 18-32 parts of water. The mud-resistant polycarboxylate superplasticizer is prepared by copolymerizing a monoalkenyl polyether macromonomer, an acrylate derivative and sucrose monoallyl ether according to a molar ratio of 1: (0.1-0.3): (0.15-0.35). Under the synergistic effect of the quaternary ammonium salt coupling agent modified nano magnesium oxide and the anti-mud polycarboxylic acid water reducer, the grouting material has excellent anti-permeability performance.

Description

Technical Field

[0001] The invention belongs to the technical field of grouting materials, and in particular relates to a shield slag synchronous grouting material and a preparation method thereof. Background Art

[0002] During the construction of tunnel projects, on the one hand, it is necessary to improve construction technology to cope with numerous technical difficulties, including passing through soft and water-rich strata, weathered rock strata, soft clay layers, sand layers, corrosive water environments, and various underground pipelines; on the other hand, it is also necessary to prevent tunnel seepage and ground subsidence in subway tunnels. Synchronous grouting technology is to inject grouting materials with appropriate early and final strength into the tunnel while the shield is being excavated to fill the gap at the shield tail. It can inhibit natural soil deformation, control ground subsidence, and ensure environmental safety. It is the first line of defense for tunnel lining waterproofing, has a certain waterproof function, and serves as a reinforcement layer for the lining structure to improve its durability.

[0003] With the vigorous development of shield tunnel projects in my country, the amount of shield slag has increased dramatically. Due to the limited construction site, the slag often needs to be discharged. However, the transportation and treatment costs of a large amount of slag are high, and the transportation and treatment process is very likely to have an adverse impact on the surrounding ecological environment. During the excavation process, a shield machine will encounter a variety of rock and soil types, and will produce various types of shield slag, including sandy slag, clayey slag, mixed slag, organic slag, etc. Among them, using sandy slag as the sand source of synchronous grouting material has the advantages of being harmless and realizing effective resource utilization, and can also achieve the effect of reducing costs and increasing efficiency. It has now attracted widespread attention and become a research hotspot. For example, patent CN111072347B discloses a method for preparing wall grouting material using waste diorite slag by an earth pressure shield, which includes the following steps: (1) washing and drying the slag discharged during shield excavation in diorite formations; (2) sending the slag treated in step (1) to a screening machine for screening to remove large particles; (3) replacing part of the medium sand in the original wall grouting material with the sieved slag, and then adding bentonite, fly ash, cement and water to prepare the wall grouting material. Patent CN101928122B discloses a synchronous grouting material for tunnels and a preparation method thereof. The grouting material is made of slag slurry with a clay and fine sand content of 30%-65% and a soil-sand weight ratio of 0.1-0.18:1 as the main raw material. 80kg-120kg of cement, 300kg-450kg of fly ash, 200kg-500kg of water or muddy water, and 3kg-10kg of sodium carboxymethyl cellulose are added to each cubic meter of slag slurry to prepare a slurry with a slurry density of 1.85-2.05g / cm 3 ; The slurry consistency is between 10.5-12cm.

[0004] The above is a technology for partially or completely replacing fine aggregate with sandy slag, which can not only significantly reduce material costs, realize waste resource utilization, and alleviate the shortage of natural sand resources. However, in order to reduce processing costs and shorten construction periods, the mud content of sandy slag will not be reduced to a very low level (the mud content of Class III sand in GB / T 14684-2011 is ≤5%), resulting in loose internal structure of the grouting material stone body, increased porosity, and decreased impermeability. Therefore, it is necessary to improve the grouting material that partially or completely replaces fine aggregate with sandy slag to improve the impermeability of the grouting material. Summary of the invention

[0005] In order to overcome the problem that the internal structure of the grouting material stone body is loose, the porosity is increased, and the anti-seepage performance is reduced due to the high mud content of shield slag, the present invention provides a shield slag synchronous grouting material and a preparation method thereof. The raw material of the grouting material contains a quaternary ammonium salt coupling agent modified nano magnesium oxide with a cationic quaternary ammonium salt grafted on the surface. Because the mud particles have a preferential adsorption effect on cations, the quaternary ammonium salt coupling agent modified nano magnesium oxide will be adsorbed to the surface of the mud particles, on the one hand, it plays the role of a sacrificial agent to reduce the adsorption of the mud particles on the polycarboxylate water reducer, and on the other hand, as the As the hydration reaction of the cementitious material proceeds, the magnesium oxide also hydrates and expands in volume. The expansion force compresses the surrounding water-absorbing and expanding mud particles, making the mud particles more compact, thereby reducing the risk of loose internal structure of the stone body. In addition, the grouting material also includes an anti-mud polycarboxylic acid water-reducing agent copolymerized with monoolefin polyether macromonomers, acrylate derivatives, and sucrose monoallyl ether as polymerization monomers, which can make the hydration reaction of the cementitious material more complete, and has the effect of synergizing with quaternary ammonium salt coupling agent-modified nano-magnesium oxide to further improve the anti-seepage performance of the grouting material.

[0006] In order to achieve the above objectives, the following specific technical solutions are adopted:

[0007] A shield slag synchronous grouting material comprises the following raw materials in parts by weight: 30-40 parts of cementitious material, 50-65 parts of shield slag, 4-6 parts of polymer emulsion, 2-4 parts of activator, 0.1-0.3 parts of early strength agent, 1-2 parts of anti-mud polycarboxylate water reducer, and 3-5 parts of quaternary ammonium salt coupling agent modified nano magnesium oxide; the anti-mud polycarboxylate water reducer is copolymerized by monoalkenyl polyether macromonomer, acrylate derivative, and sucrose monoallyl ether in a molar ratio of 1:0.1-0.3:0.15-0.35.

[0008] Sucrose monoallyl ether can increase the steric hindrance of polycarboxylic acid water reducer, prevent the adsorption of mud particles in shield slag on the water reducer, weaken the interaction between the water reducer and mud particles, and improve the dispersibility and collapse protection effect of the water reducer.

[0009] The monoalkenyl polyether macromonomer has a number average molecular weight of 2000-4000 and is selected from one or a combination of two or more of allyl polyoxyethylene ether, methyl allyl polyoxyethylene ether and isopentenyl polyoxyethylene ether.

[0010] The acrylate derivative is selected from one or a combination of two or more of methyl methacrylate, methyl acrylate, ethyl acrylate and ethyl methacrylate.

[0011] The anti-mud type polycarboxylate water reducer is prepared by a method comprising the following steps:

[0012] 1) adding monoalkenyl polyether macromonomer and sucrose monoallyl ether into water and stirring until completely dissolved to obtain a solution;

[0013] 2) In an inert atmosphere, the solution obtained in step 1) is heated, and the initiator solution and the acrylate derivative solution are added dropwise at the same time. After the addition, the reaction is carried out at a constant temperature. After the reaction is completed, the solution is cooled to room temperature and the solid content is adjusted to obtain an anti-mud polycarboxylate water-reducing agent.

[0014] The amount of water used in step 1) is 5-8 times the total mass of the monoalkenyl polyether macromonomer and sucrose monoallyl ether.

[0015] Step 2) The temperature is raised to 60-80°C. The drop-adding time is 0.5-1h. The constant temperature reaction time is 1-3h. The initiator is selected from one or a combination of two or more of sodium persulfate, potassium persulfate, and ammonium persulfate. The amount of the initiator is 0.1-0.3wt% of the sum of the mass of the monoalkenyl polyether macromonomer, the acrylate derivative, and the sucrose monoallyl ether. The solid content is adjusted to 35-40wt% by adding water or distillation. The solvent of the initiator solution is water and the concentration is 10-15wt%. The solvent of the acrylate derivative solution is water and the concentration is 0.1-0.2mol / L.

[0016] The quaternary ammonium salt coupling agent is selected from one or a combination of two or more of trimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, N, N, N-tri-n-butyl-N-trimethoxysilyl propyl ammonium chloride, and trimethyl [3- (triethoxysilyl) propyl] ammonium chloride.

[0017] The average particle size of the nano magnesium oxide is 50-100 nm. The dosage of the quaternary ammonium salt coupling agent is 3-5 wt % of the nano magnesium oxide.

[0018] The quaternary ammonium salt coupling agent modified nano magnesium oxide is prepared by a method comprising the following steps:

[0019] The nano-magnesium oxide is dispersed in an alcohol solution, a quaternary ammonium salt coupling agent is added, and the mixture is stirred to react. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the quaternary ammonium salt silane coupling agent-modified nano-magnesium oxide.

[0020] The alcohol solution is a mixture of alcohol and water in a mass ratio of 1-4:1. The mass ratio of the nano magnesium oxide to the alcohol solution is 1:18-20. The stirring temperature is 20-40°C. The reaction time is 12-24h. The washing is 1-3 times of washing with water. The alcohol is selected from one or a combination of two or more of methanol, ethanol and isopropanol.

[0021] The shield slag has a fineness modulus of 1-2, a mud content of 15-20%, a moisture content of 5-15%, and a pH of 7-8.

[0022] The cementitious material is prepared by mixing red mud, high-sulfur tailings powder, slag and steel slag in a mass ratio of 1-2:2-4:1-2:1-2.

[0023] The polymer emulsion has a solid content of 40-55% and is selected from one or a combination of two or more of styrene-acrylic emulsion, styrene-butadiene emulsion, polyvinyl acetate-ethylene copolymer emulsion and water-based epoxy resin emulsion.

[0024] The early strength agent is selected from one or a combination of two or more of sodium silicate, sodium nitrate, sodium acetate, triethanolamine, triisopropanolamine, and methanol.

[0025] The activator is selected from one or a combination of two or more of calcium hydroxide, sodium carbonate, calcium oxide or calcium sulfate.

[0026] The red mud is Bayer red mud with an average particle size of 10-30 μm and a specific surface area of ​​800-1200 m 2 / kg.

[0027] The high-sulfur tailings powder has a 45 μm square hole sieve residue of less than 20% and a specific surface area of ​​400-500 m 2 / kg, SO3 content 10-15%, Fe2O3 content 15-20%, SiO2 content 35-45%.

[0028] The slag is selected from one of S95 grade slag powder and S105 grade slag powder or a combination of the two.

[0029] The steel slag powder is selected from one of G85 grade steel slag powder and G95 grade steel slag powder or a combination of the two.

[0030] The present invention also provides a method for preparing the above-mentioned shield slag synchronous grouting material, comprising the following steps:

[0031] The cementitious material, shield slag, quaternary ammonium coupling agent modified nano magnesium oxide, activator and early strength agent are uniformly mixed to obtain mixture A, and polymer emulsion, anti-mud polycarboxylate water reducer and water are uniformly mixed to obtain mixture B, and then mixture B is added into mixture A and stirred to prepare slurry, so as to obtain shield slag synchronous grouting material.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The raw material of the grouting material of the present invention comprises a quaternary ammonium salt coupling agent modified nano magnesium oxide with a cationic quaternary ammonium salt grafted on the surface. Since mud particles have a preferential adsorption effect on cations, the quaternary ammonium salt coupling agent modified nano magnesium oxide will be adsorbed on the surface of the mud particles, and on the one hand, it plays a role of a sacrificial agent to reduce the adsorption of the mud particles on the polycarboxylic acid water reducer. On the other hand, as the hydration reaction of the cementitious material proceeds, the magnesium oxide is also hydrated and produces volume expansion. The expansion force will produce a compression effect on the surrounding water-absorbing and swollen mud particles, making the mud particles more compact, thereby reducing the risk of loose internal structure of the stone body. In addition, the grouting material also includes a kind of anti-mud polycarboxylic acid water reducer copolymerized with a monoolefin polyether macromonomer, an acrylate derivative, and a sucrose monoallyl ether as polymerization monomers, which can make the hydration reaction of the cementitious material more complete and has the effect of cooperating with the quaternary ammonium salt coupling agent modified nano magnesium oxide to further improve the anti-seepage performance of the grouting material. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with specific embodiments, but is not limited to the contents of the specification. Unless otherwise specified, the "parts" described in the embodiments of the present invention are all parts by weight. The reagents used are all commercially available reagents in the art.

[0035] The average particle size of nano-magnesium oxide was 50 nm and it was purchased from Qinghe Chaotai Metal Materials Co., Ltd.

[0036] Dow PRIMAL DC-420 styrene acrylic emulsion, solid content 48%, was purchased from Qingdao Pintel Trading Co., Ltd.

[0037] The number average molecular weight of allyl polyoxyethylene ether APEG-2400 is 2400 and it was purchased from Jiangsu Haian Petrochemical Co., Ltd.

[0038] The number average molecular weight of isopentenyl polyoxyethylene ether TPEG-4000 is 4000 and was purchased from Liaoning Aoke Chemical Co., Ltd.

[0039] The shield slag has a fineness modulus of 1.6, a mud content of 17.5%, a moisture content of 10.5%, and a pH of 7.6. It comes from the shield sand of Beijing Metro Line 3.

[0040] Bayer red mud was purchased from Shandong Aluminum Co., Ltd. with an average particle size of 17.3 μm and a specific surface area of ​​1180 m2 / kg.

[0041] High-sulfur tailings powder was purchased from Zibo Qirong Building Materials Co., Ltd., with a 45 μm square hole sieve residue of 14.5% and a specific surface area of ​​450 m 2 / kg, SO3 content is 13.5%, Fe2O3 content is 16.0%, and SiO2 content is 40%.

[0042] Example 1

[0043] 1) Add 1 mol TPEG-4000 and 0.35 mol sucrose monoallyl ether to the weight of two monomers and 5 times the weight of water and stir until completely dissolved to obtain a solution;

[0044] 2) Under nitrogen atmosphere, the solution obtained in step 1) was heated to 80°C, and a 10wt% aqueous solution of ammonium persulfate (40min dripping, the mass of ammonium persulfate is 0.3wt% of the mass of TPEG-4000, sucrose monoallyl ether, and methyl acrylate) and 1.5L of 0.2mol / L aqueous solution of methyl acrylate (60min dripping) were added dropwise at the same time. The reaction was carried out at a constant temperature for 3h after the dripping. After the reaction was completed, the solution was cooled to room temperature, and the solid content was adjusted to 45wt% by distillation to obtain an anti-mud polycarboxylate water reducer. The weight average molecular weight measured by GPC method was 58,000.

[0045] 3) Disperse 1 kg of nano-magnesium oxide in 20 kg of an alcohol solution prepared by mixing ethanol and water in a mass ratio of 4:1, add 50 g of trimethyl[3-(triethoxysilyl)propyl]ammonium chloride, and react with stirring at 25° C. for 24 h. After the reaction is completed, filter, wash with water three times, and dry at 80° C. to constant weight to obtain quaternary ammonium salt silane coupling agent-modified nano-magnesium oxide.

[0046] 4) 4 kg of a cementitious material prepared by mixing red mud, high-sulfur tailings powder, S95-grade slag powder, and G85-grade steel slag powder in a mass ratio of 2:4:1:1, 6.5 kg of shield slag, 0.5 kg of quaternary ammonium coupling agent-modified nano-magnesium oxide, 0.4 kg of calcium hydroxide, and 0.03 kg of triethanolamine were uniformly mixed to obtain a mixture A, and 0.6 kg of PRIMAL DC-420 styrene-acrylic emulsion, 0.2 kg of anti-mud polycarboxylate water-reducing agent, and 3.2 kg of water were uniformly mixed to obtain a mixture B, and then the mixture B was added to the mixture A and stirred to prepare a slurry, thereby obtaining a synchronous grouting material for shield slag.

[0047] Example 2

[0048] The rest is the same as Example 1, except that in step 1), the amount of sucrose monoallyl ether is 0.15 mol. The weight average molecular weight of the obtained anti-mud polycarboxylate water-reducing agent measured by GPC method is 54,000.

[0049] Example 3

[0050] The rest is the same as Example 1, except that in step 1), an equimolar amount of APEG-2400 is used to replace TPEG-4000. The weight average molecular weight of the anti-mud polycarboxylate water-reducing agent measured by GPC method is 56,000.

[0051] Example 4

[0052] The rest is the same as Example 1, except that in step 3), the amount of trimethyl[3-(triethoxysilyl)propyl]ammonium chloride used is 30 g.

[0053] Example 5

[0054] The rest is the same as Example 1, except that in step 4), the amount of quaternary ammonium salt coupling agent modified nano magnesium oxide is 0.3 kg.

[0055] Example 6

[0056] The rest is the same as Example 1, except that in step 4), the amount of anti-mud polycarboxylate water-reducing agent is 0.1 kg.

[0057] Example 7

[0058] 1) Add 1 mol APEG-2400 and 0.35 mol sucrose monoallyl ether to the weight of two monomers and 5 times the weight of water and stir until completely dissolved to obtain a solution;

[0059] 2) Under nitrogen atmosphere, the solution obtained in step 1) was heated to 80°C, and a 10wt% aqueous solution of ammonium persulfate (40min dripping, the mass of ammonium persulfate is 0.3wt% of the mass of TPEG-4000, sucrose monoallyl ether, and methyl acrylate) and 1.5L of 0.2mol / L aqueous solution of methyl acrylate (60min dripping) were added dropwise at the same time. The reaction was carried out at a constant temperature for 3h after the dripping. After the reaction was completed, the solution was cooled to room temperature, and the solid content was adjusted to 45wt% by distillation to obtain an anti-mud polycarboxylate water reducer. The weight average molecular weight measured by GPC method was 56,000.

[0060] 3) Disperse 1 kg of nano-magnesium oxide in 20 kg of an alcohol solution prepared by mixing ethanol and water in a mass ratio of 4:1, add 50 g of trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride, and react with stirring at 25° C. for 24 h. After the reaction is completed, filter, wash with water three times, and dry at 80° C. to constant weight to obtain quaternary ammonium salt silane coupling agent-modified nano-magnesium oxide.

[0061] 4) 3 kg of a cementitious material prepared by mixing red mud, high-sulfur tailings powder, S95-grade slag powder, and G85-grade steel slag powder in a mass ratio of 1:2:2:2, 5 kg of shield slag, 0.3 kg of quaternary ammonium coupling agent-modified nano-magnesium oxide, 0.2 kg of calcium hydroxide, and 0.03 kg of triethanolamine are uniformly mixed to obtain a mixture A; at the same time, 0.6 kg of PRIMAL DC-420 styrene-acrylic emulsion, 0.2 kg of anti-mud polycarboxylate water reducer, and 2.4 kg of water are uniformly mixed to obtain a mixture B; then, the mixture B is added to the mixture A and stirred to prepare a slurry, thereby obtaining a synchronous grouting material for shield slag.

[0062] Comparative Example 1

[0063] The rest is the same as Example 1, except that in step 3), an equal mass of 3-aminopropyltrimethoxysilane is used to replace trimethyl[3-(triethoxysilyl)propyl]ammonium chloride.

[0064] Comparative Example 2

[0065] The rest is the same as Example 1, except that sucrose monoallyl ether is not added in step 1), and the amount of 0.2 mol / L methyl acrylate aqueous solution in step 2) is 3.25 L (120 min dripping). The weight average molecular weight measured by GPC method is 53,000.

[0066] Comparative Example 3

[0067] The rest is the same as Example 1, except that in step 4), an equal mass of conventional polycarboxylate water reducer - BASF polycarboxylate water reducer RHEOPLUS 413 is used to replace the anti-mud polycarboxylate water reducer.

[0068] The grouting materials prepared in the above embodiments and comparative examples were subjected to the following performance tests:

[0069] Cement mortar fluidity: The test was conducted with reference to the standard GB / T 2419-2005 cement mortar fluidity determination method, and the mortar composition was determined according to the specific embodiments and comparative examples.

[0070] Anti-seepage performance: The test was carried out in accordance with the standard JGJ / T 70-2009 Test method for basic properties of building mortar. The anti-seepage grade of the sample is calculated as follows: P=10H-1, where P represents the anti-seepage grade of the sample, and H represents the water pressure (MPa) when water seepage occurs in 3 of the 6 samples.

[0071] Compressive strength: Tested in accordance with standard GB / T 177-85 cement mortar strength test method, the molding mold specification is 40mm×40mm×160mm; specimen curing conditions require curing in air, room temperature 20℃, relative humidity 85%.

[0072] Table 1 Performance test results

[0073]

[0074]

[0075] It can be seen from Table 1 that under the synergistic effect of the anti-mud polycarboxylate water-reducing agent and the quaternary ammonium coupling agent modified nano magnesium oxide, the grouting material prepared by the present invention has excellent dispersibility and dispersion retention performance, indicating that the cementitious material particles can maintain a good dispersion state, the mud particles have no adverse effect on the normal hydration of the cementitious material particles, the internal structure of the stone body is dense, and the anti-seepage performance is excellent.

[0076] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A shield slag synchronous grouting material, characterized in that: The invention comprises the following raw materials in parts by weight: 30-40 parts of cementitious material, 50-65 parts of shield slag, 4-6 parts of polymer emulsion, 2-4 parts of activator, 0.1-0.3 parts of early strength agent, 1-2 parts of anti-mud polycarboxylic acid water reducer, 3-5 parts of quaternary ammonium salt coupling agent modified nano magnesium oxide, and 18-32 parts of water; the anti-mud polycarboxylic acid water reducer is copolymerized by monoalkenyl polyether macromonomer, acrylate derivative and sucrose monoallyl ether in a molar ratio of 1:0.1-0.3:0.15-0.

35.

2. The shield slag synchronous grouting material according to claim 1, characterized in that: The monoalkenyl polyether macromonomer has a number average molecular weight of 2000-4000 and is selected from one or a combination of two or more of allyl polyoxyethylene ether, methallyl polyoxyethylene ether, and isopentenyl polyoxyethylene ether; the acrylate derivative is selected from one or a combination of two or more of methyl methacrylate, methyl acrylate, ethyl acrylate, and ethyl methacrylate.

3. The shield slag synchronous grouting material according to claim 1, characterized in that: The anti-mud type polycarboxylate water reducer is prepared by a method comprising the following steps: 1) adding monoalkenyl polyether macromonomer and sucrose monoallyl ether into water and stirring until completely dissolved to obtain a solution; 2) In an inert atmosphere, the solution obtained in step 1) is heated, and the initiator solution and the acrylate derivative solution are added dropwise at the same time. After the addition, the reaction is carried out at a constant temperature. After the reaction is completed, the solution is cooled to room temperature and the solid content is adjusted to obtain an anti-mud polycarboxylate water-reducing agent.

4. The shield slag synchronous grouting material according to claim 3, characterized in that: The amount of water used in step 1) is 5-8 times the total mass of the monoalkenyl polyether macromonomer and sucrose monoallyl ether.

5. The shield slag synchronous grouting material according to claim 3, characterized in that: Step 2) the initiator is selected from one or a combination of two or more of sodium persulfate, potassium persulfate, and ammonium persulfate; the amount of the initiator is 0.1-0.3wt% of the total mass of the monoalkenyl polyether macromonomer, the acrylate derivative, and the sucrose monoallyl ether.

6. The shield slag synchronous grouting material according to claim 1, characterized in that: The quaternary ammonium salt coupling agent modified nano magnesium oxide is prepared by a method comprising the following steps: The nano-magnesium oxide is dispersed in an alcohol solution, a quaternary ammonium salt coupling agent is added, and the mixture is stirred to react. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the quaternary ammonium salt silane coupling agent-modified nano-magnesium oxide.

7. The shield slag synchronous grouting material according to claim 6, characterized in that: The quaternary ammonium salt coupling agent is selected from one or a combination of two or more of trimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, N, N, N-tri-n-butyl-N-trimethoxysilyl propyl ammonium chloride, and trimethyl [3- (triethoxysilyl) propyl] ammonium chloride; the average particle size of the nano magnesium oxide is 50-100 nm; and the amount of the quaternary ammonium salt coupling agent is 3-5wt% of the nano magnesium oxide.

8. The shield slag synchronous grouting material according to claim 6, characterized in that: The alcohol solution is a mixed solution of alcohol and water in a mass ratio of 1-4:1; the mass ratio of the nano magnesium oxide to the alcohol solution is 1:18-20.

9. The shield slag synchronous grouting material according to claim 1, characterized in that: The shield slag has a fineness modulus of 1-2, a mud content of 15-20%, a moisture content of 5-15%, and a pH of 7-8.

10. The method for preparing the shield slag synchronous grouting material according to any one of claims 1 to 9, characterized in that: The steps include: The cementitious material, shield slag, quaternary ammonium coupling agent modified nano magnesium oxide, activator and early strength agent are uniformly mixed to obtain mixture A, and polymer emulsion, anti-mud polycarboxylate water reducer and water are uniformly mixed to obtain mixture B, and then mixture B is added into mixture A and stirred to prepare slurry, so as to obtain shield slag synchronous grouting material.

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