An impermeable shield inert synchronous grouting material and its preparation method

Abstract

The present invention discloses an impermeable shield inert synchronous grouting material and a preparation method thereof, which are composed of raw materials with the following mass percentages: inert cementitious material: 19% - 28%, river sand 45% - 50%, sodium-based bentonite 7% - 10%, strengthening and impermeability composite agent 4% - 8%, water 11.8% - 15.7%, water reducer 0.1 - 1%, and the total content of the above raw materials is 100%; wherein: the inert cementitious material is a mixture of slag powder, fly ash, and silica fume, and the mass ratio of the slag powder, fly ash, and silica fume is (14 - 18):(3 - 5):(2 - 5). The preparation method is based on the recycling of solid waste resources. The prepared shield inert synchronous grouting material has good workability and pumpability, and excellent waterproof and impermeability performance, ensuring the durability and structural stability of tunnel precast segments.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of solid waste resources, and particularly relates to an impermeable shield inert synchronous grouting material and a preparation method thereof. Background Art

[0002] Slag is a vitreous substance produced during blast furnace ironmaking. 0.3 - 0.9 tons of slag can be discharged for every 1 ton of pig iron smelted. Currently, the utilization rate of slag is 70 - 85%. The main chemical components of slag include calcium oxide, silicon dioxide, alumina, etc., accounting for more than 90% of the total mass. Fly ash is a solid waste discharged from coal-fired power plants. 0.25 - 0.3 tons of fly ash can be produced for every 1 ton of coal burned, and the emissions are increasing year by year. It has become one of the industrial waste slags with a large discharge in China at present. The main components of fly ash include silicon dioxide, alumina, iron oxide, etc., accounting for more than 75% of the total mass. Silica fume is an amorphous powder material produced during the smelting of ferrosilicon alloy and industrial silicon. 0.12 - 0.2 tons of silica fume can be produced for every 1 ton of industrial silicon smelted, and its annual output has exceeded 40 million tons. The main component of silica fume is silicon dioxide, accounting for more than 85% of the total mass. Therefore, how to comprehensively utilize slag, fly ash and silica fume efficiently, with high added value and on a large scale, prevent environmental pollution, and achieve sustainable development and circular economy is an inevitable choice.

[0003] During the shield tunneling method construction of tunnel engineering, a synchronous grouting liquid needs to be poured into the tail gap between precast segments and the soil body to maintain the stability of the tunnel structure. At the same time, it is also the first barrier for tunnel waterproofing and impermeability, and the quality of its impermeability performance will directly affect the durability and structural stability of precast segments. Synchronous grouting materials can be divided into active grouting materials containing cement and inert grouting materials without cement according to whether there is cement in the slurry. In engineering applications, in order to meet the strength requirements, the cement content in active grouting materials usually needs to be 10% - 15%. And cement is a high-energy-consuming and highly polluting building material, and there are problems such as pipe blockage caused by poor workability and poor pumpability in cement-based grouting materials. Compared with the relatively widely used active slurry, the research and application of inert grouting materials are less, and there is almost no research on their impermeability performance. Therefore, based on the reuse of solid waste resources, researching a shield inert synchronous grouting material with good impermeability performance has become an optimal solution to solve the tunnel grouting problem. Summary of the Invention

[0004] The purpose of the invention is to provide an impermeable shield inert synchronous grouting material and a preparation method thereof. Based on the reuse of solid waste resources, the prepared shield inert synchronous grouting material has good workability, good pumpability, and excellent waterproof and impermeability performance, ensuring the durability and structural stability of tunnel precast segments.

[0005] The present invention adopts the following technical solution: An impermeable shield inert synchronous grouting material, which is composed of raw materials with the following mass percentages: inert cementitious material: 19% - 28%, river sand 45% - 50%, sodium-based bentonite 7% - 10%, strengthening and impermeability composite agent 4% - 8%, water 11.8% - 15.7%, water reducing agent 0.1 - 1%, and the total content of the above raw materials is 100%; wherein: the inert cementitious material is a mixture of slag powder, fly ash, and silica fume, and the mass ratio of the slag powder, fly ash, and silica fume is (14 - 18):(3 - 5):(2 - 5).

[0006] Further, the strengthening and impermeability composite agent is a mixture of sodium silicate, sodium meta-aluminate, and calcium hydroxide, and the mass ratio of the sodium silicate, sodium meta-aluminate, and calcium hydroxide is 10:(1 - 4):(2 - 3).

[0007] Further, the slag powder is S95 grade granulated blast furnace slag powder, the fly ash is grade I fly ash, and the specific surface area of the fly ash is 380 - 420 m 2 / kg, and the particle size grade is 400 mesh;

[0008] Meanwhile, the specific surface area of the slag powder is 370 - 400 m 2 / kg, and the particle size grade is 400 mesh; meanwhile, the specific surface area of the silica fume is 27 - 23700 m 2 / kg, and the particle size grade is 1000 - 10000 mesh.

[0009] Further, the particle size of the river sand is all within 0.2 - 0.5 mm.

[0010] Further, the water reducing agent is a powdered polycarboxylate water reducing agent.

[0011] The present invention also discloses a preparation method of the above impermeable shield inert synchronous grouting material, and the preparation method is as follows:

[0012] Step 1: Mix the slag powder, fly ash, and silica fume at room temperature, and carry out constant temperature magnetic stirring to obtain an inert cementitious material powder;

[0013] Step 2: Mix the inert cementitious material powder, river sand, sodium-based bentonite, and water reducing agent obtained in Step 1 at room temperature, and carry out constant temperature magnetic stirring to obtain a powder mixture;

[0014] Step 3: Mix the strengthening and impermeability composite agent and water at room temperature, and carry out constant temperature magnetic stirring to obtain a mixed solution;

[0015] Step 4: Mix the powder mixture obtained in Step 2 with the mixed solution obtained in Step 3, and carry out constant temperature magnetic stirring to obtain an impermeable shield inert synchronous grouting material.

[0016] Further, in Step 1, Step 2, Step 3 and Step 4, the stirring speed of the constant-temperature magnetic stirring is 150 r / min to 180 r / min, and the stirring time is 20 min to 30 min.

[0017] The beneficial effects of the present invention are as follows: 1. Since blast furnace slag powder, fly ash, and silica fume all belong to silicate substances, the inert cementitious material composed of the above materials is similar in properties to the traditional cementitious material cement. Under the action of the strength and impermeability enhancer, it can not only increase the strength to replace cement, but also improve the impermeability of the grouting material. 2. The components of the strength and impermeability enhancer include sodium silicate, sodium meta-aluminate, and calcium hydroxide. Among them, sodium silicate forms a network structure with the inert cementitious material to improve its strength and durability; sodium meta-aluminate and calcium hydroxide are both alkaline substances, which can synergistically increase the strength of the fly ash in the inert cementitious material. At the same time, the meta-aluminate ion forms a complex-like substance with the calcium ions precipitated from the inert cementitious material, and combines with silica fume through a complexation-dissociation reaction. The formed calcium-based meta-aluminate can improve the mechanical properties of the material. The calcium-based meta-aluminate-silica fume has a dense structure and can achieve the impermeability effect by reverse migration along the water leakage line. 3. The fineness of silica fume is 8000 to 10000 mesh, and it has the characteristics of a large specific surface area and good dispersibility. Both silica fume and calcium-based meta-aluminate are inorganic materials, and they have good compatibility. Therefore, silica fume can combine with calcium-based meta-aluminate and fill into the structure of calcium-based meta-aluminate to form a dense structure with good interfacial compatibility. Specific Embodiments

[0018] The present invention will be described in detail below in conjunction with specific embodiments.

[0019] An impermeable shield inert synchronous grouting material of the present invention uses an inert cementitious material and a strength and impermeability enhancer as basic raw materials. The inert cementitious material is selected from solid waste blast furnace slag, fly ash, and silica fume. Since blast furnace slag powder, fly ash, and silica fume all belong to silicate substances, the inert cementitious material composed of the above materials is similar in properties to the traditional cementitious material cement. Under the action of the strength and impermeability enhancer, it can not only increase the strength to replace cement, but also improve the impermeability of the grouting material.

[0020] The selected strength and impermeability enhancer is a mixture of sodium silicate, sodium meta-aluminate, and calcium hydroxide. Among them, sodium silicate forms a network structure with the inert cementitious material to improve the strength and durability of the grouting material; sodium meta-aluminate and calcium hydroxide are both alkaline substances, which can synergistically increase the strength of the fly ash in the inert cementitious material. At the same time, the meta-aluminate ion forms a complex-like substance with the calcium ions precipitated from the inert cementitious material, and combines with silica fume through a complexation-dissociation reaction. The formed calcium-based meta-aluminate can improve the mechanical properties of the grouting material. The calcium-based meta-aluminate-silica fume has a dense structure and can achieve the impermeability effect by reverse migration along the water leakage line.

[0021] The fineness of silica fume is 8,000 - 10,000 mesh, and it has the characteristics of large specific surface area and good dispersibility. Both silica fume and calcium-based aluminates are inorganic materials, and they have good compatibility. Therefore, silica fume can combine with calcium-based aluminates and fill into the structure of calcium-based aluminates to form a dense structure with good interfacial compatibility.

[0022] In order to further verify the technical effects of an impermeable shield inert synchronous grouting material in the present invention, specific embodiments are described in detail. Each embodiment takes the preparation of 100 g of the product in the present invention as an example, and is specifically as follows:

[0023] Example 1

[0024] An impermeable shield inert synchronous grouting material is composed of the following raw materials by mass: 14 g of slag powder, 3 g of fly ash, 2 g of silica fume, 50 g of sand, 7 g of sodium-based bentonite, 0.3 g of water reducing agent, 15.7 g of water, and 8 g of an enhancing and impermeability composite agent, among which there are 5.16 g of sodium silicate, 1.55 g of sodium aluminate, and 1.29 g of calcium hydroxide.

[0025] The preparation method of the impermeable shield inert synchronous grouting material is as follows:

[0026] Using a constant temperature magnetic stirrer, mix the slag powder, fly ash, and silica fume at room temperature. The stirring speed is 150 r / min and the stirring time is 30 min to obtain an inert cementitious material powder.

[0027] Using a constant temperature magnetic stirrer, mix the inert cementitious material powder, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at room temperature. The stirring speed is 170 r / min and the stirring time is 20 min to obtain a powder mixture.

[0028] Using a constant temperature magnetic stirrer, mix the enhancing and impermeability composite agent and water at room temperature. The stirring speed is 160 r / min and the stirring time is 25 min to obtain a mixed solution.

[0029] Using a constant temperature magnetic stirrer, mix the powder mixture prepared above and the mixed solution at room temperature. The stirring speed is 180 r / min and the stirring time is 30 min to obtain an impermeable shield inert synchronous grouting material.

[0030] Example 2

[0031] An impermeable shield inert synchronous grouting material is composed of raw materials with the following masses: 15 g of slag powder, 4 g of fly ash, 3 g of silica fume, 48 g of sand, 8 g of sodium-based bentonite, 0.5 g of water reducer, 14.5 g of water, and 7 g of an enhancing and impermeability composite agent, among which there are 4.67 g of sodium silicate, 0.93 g of sodium metaaluminate, and 1.4 g of calcium hydroxide.

[0032] The preparation method of the impermeable shield inert synchronous grouting material is as follows:

[0033] Using a constant-temperature magnetic stirrer, mix the slag powder, fly ash, and silica fume at room temperature. The stirring speed is 160 r / min and the stirring time is 25 min to obtain an inert cementitious material powder.

[0034] Using a constant-temperature magnetic stirrer, mix the inert cementitious material powder, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at room temperature. The stirring speed is 150 r / min and the stirring time is 20 min to obtain a powder mixture.

[0035] Using a constant-temperature magnetic stirrer, mix the enhancing and impermeability composite agent and water at room temperature. The stirring speed is 160 r / min and the stirring time is 30 min to obtain a mixed solution.

[0036] Using a constant-temperature magnetic stirrer, mix the prepared powder mixture and the prepared mixed solution at room temperature. The stirring speed is 160 r / min and the stirring time is 25 min to obtain the impermeable shield inert synchronous grouting material.

[0037] Example 3

[0038] An impermeable shield inert synchronous grouting material is composed of raw materials with the following masses: 16 g of slag powder, 4 g of fly ash, 4 g of silica fume, 47 g of sand, 9 g of sodium-based bentonite, 0.4 g of water reducer, 13.6 g of water, and 6 g of an enhancing and impermeability composite agent, among which there are 4 g of sodium silicate, 0.8 g of sodium metaaluminate, and 1.2 g of calcium hydroxide.

[0039] The preparation method of the impermeable shield inert synchronous grouting material is as follows:

[0040] Using a constant-temperature magnetic stirrer, mix the slag powder, fly ash, and silica fume at room temperature. The stirring speed is 160 r / min and the stirring time is 25 min to obtain an inert cementitious material powder.

[0041] Using a constant-temperature magnetic stirrer, mix the inert cementitious material powder, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at room temperature. The stirring speed is 150 r / min and the stirring time is 20 min to obtain a powder mixture.

[0042] Using a constant temperature magnetic stirrer at room temperature, mix the strengthening and impermeability composite agent with water at a stirring speed of 160 r / min for 30 min to obtain a mixed solution.

[0043] Using a constant temperature magnetic stirrer at room temperature, mix the prepared powder mixture with the mixed solution at a stirring speed of 160 r / min for 25 min to obtain an impermeable shield inert synchronous grouting material.

[0044] Example 4

[0045] An impermeable shield inert synchronous grouting material is composed of the following raw materials by mass: 17 g of slag powder, 5 g of fly ash, 4 g of silica fume, 47 g of sand, 10 g of sodium-based bentonite, 0.2 g of water reducing agent, 11.8 g of water, and 5 g of strengthening and impermeability composite agent, among which, 3.23 g of sodium silicate, 0.97 g of sodium meta-aluminate, and 0.8 g of calcium hydroxide.

[0046] The preparation method of the impermeable shield inert synchronous grouting material is as follows:

[0047] Using a constant temperature magnetic stirrer at room temperature, mix the slag powder, fly ash and silica fume at a stirring speed of 170 r / min for 25 min to obtain an inert cementitious material powder.

[0048] Using a constant temperature magnetic stirrer at room temperature, mix the inert cementitious material powder, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at a stirring speed of 150 r / min for 30 min to obtain a powder mixture.

[0049] Using a constant temperature magnetic stirrer at room temperature, mix the strengthening and impermeability composite agent with water at a stirring speed of 160 r / min for 25 min to obtain a mixed solution.

[0050] Using a constant temperature magnetic stirrer at room temperature, mix the prepared powder mixture with the mixed solution at a stirring speed of 180 r / min for 25 min to obtain an impermeable shield inert synchronous grouting material.

[0051] Example 5

[0052] An impermeable shield inert synchronous grouting material is composed of the following raw materials by mass: 18 g of slag powder, 5 g of fly ash, 5 g of silica fume, 45 g of sand, 10 g of sodium-based bentonite, 0.1 g of water reducing agent, 12.9 g of water, and 4 g of strengthening and impermeability composite agent, among which, 2.58 g of sodium silicate, 0.65 g of sodium meta-aluminate, and 0.77 g of calcium hydroxide.

[0053] The preparation method of the anti-seepage shield inert synchronous grouting material is as follows:

[0054] Using a constant-temperature magnetic stirrer, mix slag powder, fly ash and silica fume at room temperature. The stirring speed is 170 r / min and the stirring time is 30 min to obtain an inert cementitious material powder.

[0055] Using a constant-temperature magnetic stirrer, mix the inert cementitious material powder, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at room temperature. The stirring speed is 150 r / min and the stirring time is 25 min to obtain a powder mixture.

[0056] Using a constant-temperature magnetic stirrer, mix the reinforcement and anti-seepage compound agent with water at room temperature. The stirring speed is 150 r / min and the stirring time is 25 min to obtain a mixed solution.

[0057] Using a constant-temperature magnetic stirrer, mix the prepared powder mixture with the mixed solution at room temperature. The stirring speed is 180 r / min and the stirring time is 25 min to obtain the anti-seepage shield inert synchronous grouting material.

[0058] In the above Examples 1 - 5, room temperature refers to the temperature in the experimental environment, that is, no additional heating device is required for heating.

[0059] In the above Examples 1 - 5, the slag powder is S95 grade granulated blast furnace slag powder, with a mesh number of 400 meshes and a specific surface area of about 380 m 2 / kg. The fly ash is Class I fly ash, with a mesh number of 400 meshes and a specific surface area of about 420 m 2 / kg. The silica fume has a grade of 10,000 meshes and a specific surface area of 23,700 m 2 / kg. The particle size of the river sand is in the range of 0.2 mm - 0.5 mm. The superplasticizer is a powdered polycarboxylate superplasticizer.

[0060] In order to verify the functions and effects of the raw materials of the anti-seepage shield inert synchronous grouting material of the present invention, the following comparative examples are designed:

[0061] Comparative Example 1

[0062] An inert synchronous grouting material, and its preparation method includes the following steps:

[0063] Taking the preparation of 100 g of the product as an example, the mass of each component is as follows: 14 g of slag powder, 3 g of fly ash, 2 g of silica fume, 50 g of sand, 7 g of sodium-based bentonite, 15.7 g of water, 0.3 g of superplasticizer, 8 g of reinforcement and anti-seepage compound agent, among which, 6.4 g of sodium silicate, 0 g of sodium meta-aluminate, and 1.6 g of calcium hydroxide.

[0064] Comparative Example 2

[0065] An inert synchronous grouting material. Taking the preparation of 100 g of the product as an example, the masses of each component are as follows: 14 g of slag powder, 3 g of fly ash, 2 g of silica fume, 50 g of sand, 7 g of sodium-based bentonite, 15.7 g of water, 0.3 g of water reducer, and 8 g of strength and impermeability composite agent. Among them, there are 8 g of sodium silicate, 0 g of sodium metaaluminate, and 0 g of calcium hydroxide.

[0066] Comparative Example 3

[0067] An inert synchronous grouting material. Taking the preparation of 100 g of the product as an example, the masses of each component are as follows: 14 g of slag powder, 3 g of fly ash, 2 g of silica fume, 50 g of sand, 7 g of sodium-based bentonite, 15.7 g of water, 0.3 g of water reducer, and 8 g of strength and impermeability composite agent. Among them, there are 6.15 g of sodium silicate, 1.85 g of sodium metaaluminate, and 0 g of calcium hydroxide.

[0068] Comparative Example 4

[0069] An inert synchronous grouting material. Taking the preparation of 100 g of the product as an example, the masses of each component are as follows: 19 g of portland cement, 50 g of sand, 7 g of sodium-based bentonite, 15.7 g of water, 0.3 g of water reducer, and 8 g of strength and impermeability composite agent. Among them, there are 5.16 g of sodium silicate, 1.55 g of sodium metaaluminate, and 1.29 g of calcium hydroxide.

[0070] Comparative Example 5

[0071] An inert synchronous grouting material. Taking the preparation of 100 g of the product as an example, the masses of each component are as follows: 16 g of slag powder, 3 g of fly ash, 50 g of sand, 7 g of sodium-based bentonite, 15.7 g of water, 0.3 g of water reducer, and 8 g of strength and impermeability composite agent. Among them, there are 5.16 g of sodium silicate, 1.55 g of sodium metaaluminate, and 1.29 g of calcium hydroxide.

[0072] In the above Comparative Example 1 - Comparative Example 5, the slag powder has a mesh number of 400 mesh and a specific surface area of 380 m 2 / kg. The fly ash has a mesh number of 400 mesh and a specific surface area of about 420 m 2 / kg. The silica fume has a mesh number of 10,000 mesh and a specific surface area of 23,700 m 2 / kg. The particle size of the river sand is in the range of 0.2 mm to 0.5 mm. The water reducer is a powdered polycarboxylate superplasticizer.

[0073] In the above Comparative Example 1 - Comparative Example 5, the preparation methods of each inert synchronous grouting material are as follows:

[0074] Use a constant-temperature magnetic stirrer to mix slag powder, fly ash and silica fume at room temperature. The stirring speed is 150 r / min and the stirring time is 30 min to obtain an inert cementitious material powder. When there is no silica fume in the components of the example, silica fume is not added.

[0075] Use a constant-temperature magnetic stirrer to mix the inert cementitious material powder, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at room temperature. The stirring speed is 170 r / min and the stirring time is 20 min to obtain a powder mixture. When the inert cementitious material powder is not used, that is, use a constant-temperature magnetic stirrer to mix portland cement, river sand, sodium-based bentonite, and powdered polycarboxylate superplasticizer at room temperature. The stirring speed is 170 r / min and the stirring time is 20 min to obtain a powder mixture.

[0076] Use a constant-temperature magnetic stirrer to mix the strengthening and anti-seepage compound agent and water at room temperature. The stirring speed is 160 r / min and the stirring time is 25 min to obtain a mixed solution.

[0077] Mix the powder mixture prepared by a constant-temperature magnetic stirrer at room temperature with the mixed solution. The stirring speed is 180 r / min and the stirring time is 30 min to obtain an inert synchronous grouting material.

[0078] In the above Comparative Examples 1 - 5, room temperature refers to the temperature in the experimental environment where no additional heating device is required for heating.

[0079] According to T-CECS 563-2018, GB / T1761-1999, JGJ / T 70-2009 and GB 18445-2012, test the performance of an anti-seepage shield inert synchronous grouting material in each example and an inert synchronous grouting material in the comparative example. Conduct setting time test, consistency test, cube compressive strength test and anti-seepage performance test respectively. The test results are as follows:

[0080] Table 1. Performance of Anti-seepage Shield Inert Synchronous Grouting Material

[0081]

[0082]

[0083] As can be seen from the data in Table 1, the 3d compressive strength of Examples 1 to 5 is 10.23 to 12.35 MPa, the 28d compressive strength is 22.51 to 25.93 MPa, the initial setting time is 4.6 to 5.2 h, the final setting time is 5.5 to 6.2 h, and the 28d impermeability pressure is 1.2 to 1.4 MPa, all of which are superior to Comparative Examples 1 to 3 and Comparative Example 5. In particular, the 28d impermeability pressure is much higher than that of Comparative Examples 1 to 3 and Comparative Example 5, and is similar to the 28d impermeability pressure of Comparative Example 4, indicating that the impermeable shield inert synchronous grouting material prepared with a cement-free formula can achieve an impermeability pressure close to that of the active slurry (containing cement). According to the requirements for 3d compressive strength ≥0.5 and 28d compressive strength ≥2.5 in T-CECS 563-2018, Examples 1 to 5 using the method of the present invention far exceed the relevant mechanical property requirements in the specification. The active grouting material containing Portland cement prepared in Comparative Example 4 has a consistency of 6.7 cm, while the inert synchronous grouting materials prepared in each example of the present invention have good consistency, good workability and good pumpability.

Claims

1. An impermeable shield inert synchronous grouting material, characterized in that, it is composed of raw materials with the following mass percentages: inert cementitious material: 19% - 28%, river sand 45% - 50%, sodium-based bentonite 7% - 10%, reinforcement - impermeability composite agent 4% - 8%, water 11.8% - 15.7%, water reducer 0.1 - 1%, and the total content of the above raw materials is 100%; among them: the inert cementitious material is a mixture of slag powder, fly ash, and silica fume, and the mass ratio of the slag powder, fly ash, and silica fume is (14 - 18):(3 - 5):(2 - 5); the reinforcement - impermeability composite agent is a mixture of sodium silicate, sodium metaaluminate, and calcium hydroxide, and the mass ratio of the sodium silicate, sodium metaaluminate, and calcium hydroxide is 10:(1 - 4):(2 - 3).

2. An impermeable shield inert synchronous grouting material according to claim 1, characterized in that, The slag powder is S95 grade granulated blast furnace slag powder, and the fly ash is Class I fly ash. The specific surface area of the fly ash is 380 - 420 m 2 / kg, and the particle size grade is 400 mesh; Meanwhile, the specific surface area of the slag powder is 370 - 400 m 2 / kg, and the particle size grade is 400 mesh; meanwhile, the specific surface area of the silica fume is 27 - 23700 m 2 / kg, and the particle size grade is 1000 - 10000 mesh.

3. An impermeable shield inert synchronous grouting material according to claim 2, characterized in that, the particle size of the river sand is all within 0.2 - 0.5 mm.

4. An impermeable shield inert synchronous grouting material according to claim 3, characterized in that, the water reducer is a powdered polycarboxylate water reducer.

5. A preparation method of an impermeable shield inert synchronous grouting material according to any one of claims 1 - 4, characterized in that, the preparation method is as follows: Step 1: Mix slag powder, fly ash, and silica fume at room temperature, and carry out constant - temperature magnetic stirring to obtain an inert cementitious material powder; Step 2: Mix the inert cementitious material powder, river sand, sodium - based bentonite, and water reducer obtained in Step 1 at room temperature, and carry out constant - temperature magnetic stirring to obtain a powder mixture; Step 3: Mix the reinforcement - impermeability composite agent and water at room temperature, and carry out constant - temperature magnetic stirring to obtain a mixed solution; Step 4: Mix the powder mixture in Step 2 with the mixed solution in Step 3, and carry out constant - temperature magnetic stirring to obtain an impermeable shield inert synchronous grouting material.

6. A preparation method of an impermeable shield inert synchronous grouting material according to claim 5, characterized in that, in Step 1, Step 2, Step 3, and Step 4, the stirring speed of the constant - temperature magnetic stirring is 150 r / min - 180 r / min, and the stirring time is 20 min - 30 min.

Images