Fault fracture zone stratum reinforcing material, preparation method thereof and grouting device

Abstract

The invention discloses a fault fracture zone stratum reinforcement material, a preparation method thereof and a grouting device, and belongs to the field of reinforcement materials.The fault fracture zone stratum reinforcement material comprises superfine sulphoaluminate cement, the D50 particle size A of the superfine sulphoaluminate cement ranges from 1.0 m to 1.5 m, and the D50 particle size A of the superfine sulphoaluminate cement ranges from 1.0 m to 1.5 m; the D50 particle size B of the superfine Portland cement is 2.5 to 3.5 m; the D50 particle size C of the ultrafine fly ash is 4-6 m, and the like. The superfine sulphoaluminate cement, the superfine Portland cement, the superfine fly ash and the red mud which meet the particle size limitation relationship are matched for use, and the filling capacity of the material on fine cracks of a fault fracture zone stratum is enhanced through a multi-stage filling effect; the compressive strength, the impermeability, the matching property of early strength and setting time and the like of the material are improved, so that the core requirement of rapid reinforcement of a fault fracture zone stratum is met.

Description

Technical Field

[0001] This application belongs to the field of reinforcement materials, specifically relating to a reinforcement material for fault fracture zones, its preparation method, and grouting device. Background Technology

[0002] Fault fracture zones are areas of fractured rock mass formed in and around the fault zone after the rock strata have fractured due to strong stress during crustal movement, resulting in relative displacement of the rock masses on both sides of the fracture surface. These areas are characterized by highly fractured rock masses with well-developed fissures, loose internal structure, and poor stability. This makes them highly susceptible to a series of serious disasters such as water and mud inrushes and surrounding rock instability, posing a significant threat to the construction safety and operational stability of underground engineering and mining operations. Grouting technology is a core method for mitigating disasters caused by fault fracture zones. By injecting specific grouting materials into the fault fracture zone, the fissures and pores in the rock mass are filled, enhancing the integrity and stability of the rock mass, thereby achieving the goal of disaster prevention and control.

[0003] In existing grouting technologies, grouting materials mostly employ cement-based or organic-inorganic composite systems. For example, industrial waste such as fly ash and slag are used to modify cement-based grouting materials to improve their performance, reduce material costs, and achieve resource utilization of industrial waste. Alternatively, organic materials such as polyurethane are added to enhance the sealing performance of the grouting material, making it better suited to complex geological conditions. However, existing grouting materials still have some problems that urgently need to be solved. On the one hand, the materials have limited penetration into micro-cracks, making it difficult to fully fill the tiny voids in fault fracture zones, thus affecting the grouting reinforcement effect. On the other hand, some materials do not perform well in matching early strength with setting time; either the early strength develops too quickly, reducing operability during grouting, or the setting time is too long, failing to form an effective support structure in time, posing a threat to engineering safety. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in related technologies. Therefore, the purpose of this application is to propose a reinforcement material for fault-fractured zones, its preparation method, and a grouting device. This application mainly utilizes a combination of ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash, and red mud that meet the aforementioned particle size constraints. Through a multi-stage filling effect, the material's ability to fill the fine fractures in fault-fractured zones is enhanced, improving its compressive strength, impermeability, and the matching of early strength and setting time, thereby meeting the core requirement for rapid reinforcement of fault-fractured zones.

[0005] The first aspect of this application discloses a fault fracture zone strata reinforcement material. According to an embodiment of this application, the fault fracture zone strata reinforcement material comprises: Ultrafine sulfoaluminate cement, wherein the D50 particle size A of the ultrafine sulfoaluminate cement is 1.0-1.5 µm; Ultrafine silicate cement, wherein the D50 particle size B of the ultrafine silicate cement is 2.5-3.5 µm; Ultrafine fly ash, wherein the D50 particle size C of the ultrafine fly ash is 4-6 µm; Red mud, wherein the D50 particle size D of the red mud is 6-8 µm; The D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement, and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: 4.0≤(C / A)×(B / A)≤6.5.

[0006] The fault fracture zone reinforcement material described in the above embodiments of this application mainly uses a combination of ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash, and red mud that meet the above-mentioned particle size limitation relationship. Through a multi-level filling effect, the material enhances its ability to fill the fine cracks in the fault fracture zone, improves the material's compressive strength, impermeability, and the matching of early strength and setting time, thereby meeting the core requirement of rapid reinforcement of fault fracture zone strata.

[0007] In addition, the fault fracture zone reinforcement material according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the fault fracture zone reinforcement material comprises the following raw materials by weight percentage: The composition is as follows: 40-50% ultrafine sulfoaluminate cement, 10-15% ultrafine silicate cement, 20-25% ultrafine fly ash, 8-12% red mud, 1-2% early strength agent, 1-1.5% water-reducing agent, 0.1-0.2% thickener, 0.8-1.2% quick-setting agent, and the balance is water.

[0008] In some embodiments of this application, the early strength agent is composed of calcium formate and aluminum sulfate in a mass ratio of (2~3):1.

[0009] In some embodiments of this application, the thickener is composed of guar gum and xanthan gum in a mass ratio of (1~2):(1~2).

[0010] In some embodiments of this application, the water-reducing agent includes a polycarboxylate-based water-reducing agent; And / or, the accelerator includes at least one of alkali-free liquid fluorosilicate accelerator, alumina clinker-red mud composite powder accelerator, and polycarboxylate-aluminum sulfate composite accelerator.

[0011] The second aspect of this application discloses a method for preparing the fault fracture zone strata reinforcement material described in the first aspect above. According to an embodiment of this application, the method for preparing the fault fracture zone strata reinforcement material includes the following steps: Ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash and red mud are mixed to obtain a dry mix; The remaining raw materials and water are added to the dry mixture and mixed to obtain the fault fracture zone stratum reinforcement material.

[0012] The method for preparing the fault fracture zone strata reinforcement material according to the above embodiments of this application is simple to operate, requires no additional specific equipment, and is suitable for industrial mass production.

[0013] In addition, the preparation method of the fault fracture zone strata reinforcement material according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the preparation of the early strength agent includes the following process: calcium formate and aluminum sulfate are weighed according to a mass ratio, and then ball-milled separately. When the fineness of both reaches D50≤10μm, they are mixed to obtain the early strength agent.

[0014] In some embodiments of this application, the preparation of the water-reducing agent includes the following process: Polyethylene glycol monomethyl ether and acrylic acid were esterified at a molar ratio of 1:(1.0~1.2) in the presence of a catalyst at 85-95℃ for 6-8 hours to obtain a macromolecular monomer. The macromonomer, acrylic acid, and sodium methacrylate sulfonate are dissolved in water at a mass ratio of (35~45):(3~5):1. Under the protection of an inert gas at 60-70°C, an initiator accounting for 0.8~1.5% of the total mass of the monomer is added dropwise, and the reaction is carried out for 3-4 hours. After the reaction is completed, the mixture is cooled and neutralized with alkali solution to pH=6.5~7.0 to obtain the water-reducing agent.

[0015] In some embodiments of this application, the preparation of the thickener includes the following process: Guar gum and xanthan gum were weighed according to the mass ratio, then dried and pulverized separately, passed through a 160-190 mesh sieve to obtain powder, and then mixed to obtain a mixed powder. Citric acid, accounting for 0.3-0.6 wt% of the total mass of the mixed powder, is added to the mixed powder and mixed to obtain the thickener.

[0016] The third aspect of this application provides a grouting device for performing grouting operations on the fault fracture zone stratum reinforcement material described in the first aspect or the fault fracture zone stratum reinforcement material prepared by the method described in the second aspect. The grouting device includes: Support components; and A slurry container is disposed above the support component, and the slurry container is conveyed to the spray head component through a mixing container, a delivery pipe and a pumping component; The slurry container is equipped with a flow sensor, the mixing container is equipped with a motor and a stirrer, and the pumping component is connected to a controller.

[0017] The grouting device described in the above embodiments of this application is used to perform grouting for the reinforcement of the fault fracture zone strata. It has a simple structure, strong practicality, and can achieve real-time adjustment of the grouting to ensure the grouting effect.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the grouting device provided in an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: Figure 1 In the middle: 1-support component; 2-agitator; 3-mixing container; 4-delivery pipe; 5-pumping component; 6-motor; 7-flow sensor; 8-slurry container; 9-controller; 10-spraying head component. Detailed Implementation

[0021] The embodiments of this application are described in detail below, and the embodiments described below with reference to the accompanying drawings are merely exemplary and intended to explain this application, and should not be construed as limiting this application.

[0022] The first aspect of this application discloses a fault fracture zone strata reinforcement material. According to an embodiment of this application, the fault fracture zone strata reinforcement material comprises: Ultrafine sulfoaluminate cement, wherein the D50 particle size A of the ultrafine sulfoaluminate cement is 1.0-1.5 µm, for example, it can be 1.0 µm, 1.2 µm, 1.5 µm or any range between the above values; Ultrafine silicate cement, wherein the D50 particle size B of the ultrafine silicate cement is 2.5-3.5 µm, for example, it can be 2.5 µm, 3.0 µm, 3.5 µm or any range between the above values; Ultrafine fly ash, wherein the D50 particle size C of the ultrafine fly ash is 4-6 µm, for example, it can be 4 µm, 5 µm, 6 µm or any range between the above values; Red mud, wherein the D50 particle size D of the red mud is 6-8 µm, for example, it can be 6 µm, 7 µm, 8 µm or any range between the above values; The D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement, and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: 4.0 ≤ (C / A) × (B / A) ≤ 6.5. For example, (C / A) × (B / A) can be 4.0, 4.5, 5.0, 6.0, 6.5, or any of the above values.

[0023] The fault fracture zone reinforcement material described in the above embodiments of this application mainly utilizes a combination of ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash, and red mud that meet the aforementioned particle size limitations. Through a multi-stage filling effect, it enhances the material's ability to fill the fine fractures in the fault fracture zone, improving its compressive strength, impermeability, and the matching of early strength and setting time, thereby meeting the core requirement for rapid reinforcement of fault fracture zones. Specifically: Ultrafine sulfoaluminate cement (D50=1.0-1.5μm), due to its micron-sized particle size, possesses a high specific surface area, which can accelerate the hydration reaction kinetics and achieve rapid early strength enhancement. Simultaneously, the penetration gradient advantage of micro- and nano-scale particles is beneficial for injection into micro-fractures in fault zones. Ultrafine silicate cement (D50=2.5-3.5μm), serving as a particle size transition range, assists the hydration process to balance the stability of later strength, avoiding the later strength reduction phenomenon caused by the rapid hydration of sulfoaluminate cement. The increasing particle size of ultrafine fly ash (D50=4-6μm) and red mud (D50=6-8μm) can fill the gaps between cement particles. Therefore, ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash, and red mud enhance material density through a multi-stage filling effect. The glassy microsphere structure of fly ash also enhances slurry fluidity, while finely ground red mud can activate potential activity and reduce the impact of harmful components. By quantifying the synergistic relationship of different particle sizes, it is ensured that the particle gradation forms a compact packing structure, which not only guarantees the injectability of grout to the fine cracks in the fault fracture zone, but also improves the strength and impermeability of the hardened body by reducing internal porosity, ultimately meeting the core requirement of rapid reinforcement.

[0024] It should be noted that D50 refers to the particle size value corresponding to 50% of the cumulative volume percentage in the cumulative particle size distribution curve of the substance. It can be determined using existing detection methods such as sieving (grading particles through sieves of different apertures, weighing the residual particles on each sieve, and calculating the cumulative distribution curve to determine D50) and laser diffraction / scattering (when a laser beam passes through the sample, the particles scatter the light; by detecting the intensity and angle of the scattered light, the particle size distribution is inverted using Mie scattering theory). Furthermore, in (C / A) × (B / A), "C / A" represents the ratio of C to A, and "B / A" represents the ratio of B to A.

[0025] According to some specific embodiments of this application, the fault fracture zone strata reinforcement material, by mass percentage, comprises the following raw materials: 40-50% ultrafine sulfoaluminate cement (e.g., 40%, 42%, 45%, 50%, or any range thereof), 10-15% ultrafine silicate cement (e.g., 10%, 12%, 14%, 15%, or any range thereof), 20-25% ultrafine fly ash (e.g., 20%, 22%, 23%, 25%, or any range thereof), and 8-12% red mud (e.g., 8%, 10%, 12%). The following are the possible values: (e.g., 1%, 1.2%, 1.5%, 2%, or any range of the above values); (e.g., 1%, 1.2%, 1.5%, 2%, or any range of the above values); (e.g., 1%, 1.2%, 1.5%, or any range of the above values); (e.g., 0.1%, 0.12%, 0.15%, 1.5%, or any range of the above values); (e.g., 0.8%, 1.2%, 0.8%, 1.0%, 1.2%, or any range of the above values); (e.g., 0.4~0.45); (e.g., 0.4~0.45); (e.g., 0.4~0.45). Preferably, the fault fracture zone strata reinforcement material comprises the following raw materials by mass percentage: 45% ultrafine sulfoaluminate cement, 13% ultrafine silicate cement, 22% ultrafine fly ash, 10% red mud, 1.5% early strength agent, 1.2% water-reducing agent, 0.15% thickener, 1.0% quick-setting agent, and a water-cement ratio of 0.4~0.45.

[0026] According to some specific embodiments of this application, the early strength agent is composed of calcium formate and aluminum sulfate in a mass ratio of (2~3):1, preferably composed of calcium formate and aluminum sulfate in a mass ratio of 2:1.

[0027] According to some specific embodiments of this application, the thickener is composed of guar gum and xanthan gum in a mass ratio of (1~2):(1~2), preferably composed of guar gum and xanthan gum in a mass ratio of 1:1.

[0028] According to some specific embodiments of this application, the water-reducing agent includes a polycarboxylate-based water-reducing agent, such as a polycarboxylate-based water-reducing agent with a water reduction rate of ≥28%; and / or, the quick-setting agent includes at least one of an alkali-free liquid fluorosilicate quick-setting agent, an alumina clinker-red mud composite powder quick-setting agent, and a polycarboxylate-aluminum sulfate composite quick-setting agent, preferably an alkali-free liquid fluorosilicate quick-setting agent.

[0029] The second aspect of this application provides a method for preparing the fault fracture zone strata reinforcement material as described in any one of the first aspects above. According to an embodiment of this application, the method for preparing the fault fracture zone strata reinforcement material includes the following steps: Ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash and red mud are mixed to obtain a dry mix; The remaining raw materials and water are added to the dry mixture and mixed to obtain the fault fracture zone stratum reinforcement material.

[0030] The method for preparing the fault fracture zone strata reinforcement material according to the above embodiments of this application is simple to operate, requires no additional specific equipment, and is suitable for industrial mass production.

[0031] In the embodiments of this application, the actual operation of preparing the above-mentioned fault fracture zone strata reinforcement material may include the following steps: (1) Raw material pretreatment a) The red mud is dried in an oven at 110℃ for 5-6 hours to remove free water, and then finely ground in a high-energy ball mill (ball-to-material ratio 10:1, speed 400r / min, time 3-4h) to control the fineness to reach the specified particle size. b) Ultrafine sulfoaluminate cement, ultrafine silicate cement, and ultrafine fly ash are respectively finely ground by air jet mill to reach the specified particle size.

[0032] (2) Dry mixing and homogenization Weigh out the finely ground ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash, and red mud according to the proportions, pour them into a planetary mixer, and mix at 300 r / min for 6-8 minutes until the mixed powder has no obvious color difference.

[0033] (3) Additive compound Add early strength agent, water reducing agent, thickener and quick-setting agent to dry mixed powder, adjust the speed to 500 r / min, stir for 4-5 min, so that the additives are evenly coated on the surface of the powder.

[0034] (4) Pulp making and molding Water is added slowly to prepare the grouting material (i.e., the stratum reinforcement material for the fault fracture zone). The water used is added separately, with a water-cement ratio of 0.40~0.45. First, stir at 800 r / min for 5 min, then stir at 1200 r / min for 3 min at high speed until the grout flows evenly and there are no lumps. The stratum reinforcement material for the fault fracture zone is then obtained.

[0035] According to some specific embodiments of this application, the preparation of the early strength agent includes the following process: calcium formate and aluminum sulfate are weighed according to the mass ratio, and then ball-milled separately. When the fineness of both reaches D50≤10μm, they are mixed to obtain the early strength agent.

[0036] In the embodiments of this application, the actual operation of preparing the early strength agent may include the following steps: a) Weigh industrial-grade calcium formate (purity ≥99%) and aluminum sulfate (purity ≥98%) according to the specified mass ratio; b) Grind the two raw materials separately in a ball mill (ball-to-material ratio 6:1, rotation speed 300 r / min, time 1.5 h) to ensure that the fineness reaches D50≤10μm; c) Pour the ground calcium formate and aluminum sulfate into a mixer and stir at 400 r / min for 30 min to obtain a uniformly mixed powdered early strength agent.

[0037] According to some specific embodiments of this application, the preparation of the water-reducing agent includes the following process: Polyethylene glycol monomethyl ether and acrylic acid were esterified at a molar ratio of 1:(1.0~1.2) in the presence of a catalyst at 85-95℃ for 6-8 hours to obtain a macromolecular monomer. The macromonomer, acrylic acid, and sodium methacrylate sulfonate are dissolved in water at a mass ratio of (35~45):(3~5):1. Under the protection of an inert gas at 60-70°C, an initiator accounting for 0.8~1.5% of the total mass of the monomer is added dropwise, and the reaction is carried out for 3-4 hours. After the reaction is completed, the mixture is cooled and neutralized with alkali solution to pH=6.5~7.0 to obtain the water-reducing agent.

[0038] In the embodiments of this application, the actual operation of preparing the water-reducing agent described above may include the following steps: First, polyethylene glycol monomethyl ether (MPEG-2400) and acrylic acid are esterified in a molar ratio of 1:(1.0~1.2) under the action of a catalyst to prepare the key intermediate - macromonomer (MPEG-AA). Then, the macromonomer, acrylic acid, and functional monomer sodium methacrylate are dissolved in water in a precise mass ratio of (35~45):(3~5):1. Under nitrogen protection, the copolymerization reaction is carried out for 3~4 hours by adding 0.8~1.5% of ammonium persulfate initiator by mass of total monomers. After the reaction, the system is cooled and neutralized with alkali to pH=6.5~7.0 to finally obtain a polycarboxylate superplasticizer with excellent dispersibility and stability.

[0039] According to some specific embodiments of this application, the preparation of the thickener includes the following process: Guar gum and xanthan gum were weighed according to the mass ratio, then dried and pulverized separately, passed through a 160-190 mesh sieve to obtain powder, and then mixed to obtain a mixed powder. Citric acid, accounting for 0.3-0.6 wt% of the total mass of the mixed powder, is added to the mixed powder and mixed to obtain the thickener.

[0040] In the embodiments of this application, the actual operation of preparing the thickener described above may include the following steps: a) Take food-grade guar gum and xanthan gum, weigh them at a mass ratio of 1:1, and dry them separately in an oven at 80℃ for 2 hours to remove free water; b) After drying, the two raw materials are crushed and sieved separately for later use; c) Pour the two powders into a three-dimensional mixer and stir at 200 r / min for 1 hour to ensure uniform mixing; d) Add 0.5% of citric acid (activator) of the total mass of the mixed powder, and continue stirring for 20 minutes to obtain the thickener.

[0041] The third aspect of this application proposes a grouting device, such as Figure 1 As shown ( Figure 1 In the middle: 1-support component; 2-mixer; 3-mixing container; 4-delivery pipe; 5-pumping component; 6-motor; 7-flow sensor; 8-slurry container; 9-controller; 10-spraying head component), the grouting device is used to realize the grouting operation of the fault fracture zone stratum reinforcement material described in the first aspect or the fault fracture zone stratum reinforcement material prepared by the preparation method of the fault fracture zone stratum reinforcement material described in the second aspect; The grouting device includes: Support component 1; and The slurry container 8 is disposed above the support component 1, and the slurry container 8 is conveyed to the spray head component 10 through the mixing container 3, the conveying pipe 4 and the pumping component 5; The slurry container 8 is equipped with a flow sensor 7, the stirring container 3 is equipped with a motor 6 and a stirrer 2, and the pumping component 5 is connected to a controller 9.

[0042] The grouting device described in the above embodiments of this application is used to perform grouting for the reinforcement of the fault fracture zone strata. It has a simple structure, strong practicality, and can achieve real-time adjustment of the grouting to ensure the grouting effect.

[0043] The embodiments of this application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0044] Example 1 This embodiment provides a fault fracture zone strata reinforcement material, which, by mass percentage, comprises the following raw materials: 45% ultrafine sulfoaluminate cement, 13% ultrafine silicate cement, 22% ultrafine fly ash, 10% red mud, 1.5% early strength agent, 1.2% water-reducing agent, 0.15% thickener, 1.0% quick-setting agent, and a water-cement ratio of 0.43. The D50 particle size A of the ultrafine sulfoaluminate cement is 1.4 µm, the D50 particle size B of the ultrafine silicate cement is 3.0 µm, the D50 particle size C of the ultrafine fly ash is 4.1 µm, and the D50 particle size D of the red mud is 7.0 µm; the D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement, and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: (C / A) × (B / A) = 6.28; The early strength agent is composed of calcium formate and aluminum sulfate in a mass ratio of 2:1. Its preparation includes the following steps: a) Weigh calcium formate and aluminum sulfate separately according to the specified mass ratio; b) Grind the two raw materials separately in a ball mill (ball-to-material ratio 6:1, rotation speed 300 r / min, time 1.5 h) and control the fineness to reach D50≤10μm; c) Pour the ground calcium formate and aluminum sulfate into a mixer and stir at 400 r / min for 30 min to obtain the early strength agent. The preparation of the water-reducing agent includes the following steps: First, polyethylene glycol monomethyl ether (MPEG-2400) and acrylic acid are esterified in a molar ratio of 1:1.1 under the action of a catalyst to prepare the key intermediate - macromonomer (MPEG-AA); then, the macromonomer, acrylic acid, and functional monomer sodium methacrylate are dissolved in water in a precise mass ratio of 40:4:1, and copolymerized for 3.5 hours by adding 1.0% of ammonium persulfate initiator by the total mass of monomers at 65°C under nitrogen protection; after the reaction, the system is cooled and neutralized with alkali to pH=6.8, finally obtaining a polycarboxylate water-reducing agent product with excellent dispersibility and stability.

[0045] The thickener is composed of guar gum and xanthan gum in a mass ratio of 1:1. Its preparation includes the following steps: a) Weigh food-grade guar gum and xanthan gum in a mass ratio of 1:1, and dry them separately in an oven at 80℃ for 2 hours to remove free water; b) Grind the two raw materials after drying and pass them through a 180-mesh sieve for later use; c) Pour the two powders into a three-dimensional mixer and stir at 200 r / min for 1 hour to ensure uniform mixing; d) Add 0.5% of citric acid (activator) of the total mass of the mixed powder and continue stirring for 20 minutes to obtain the thickener.

[0046] The accelerator is an alkali-free liquid fluorosilicate (specifically sodium fluorosilicate) accelerator.

[0047] The preparation of the above-mentioned fault fracture zone strata reinforcement material includes the following steps: (1) Raw material pretreatment a) The red mud was dried in an oven at 110℃ for 5.5 hours to remove free water, and then finely ground in a high-energy ball mill (ball-to-material ratio 10:1, rotation speed 400r / min, and fineness controlled to reach the specified particle size). b) Ultrafine sulfoaluminate cement, ultrafine silicate cement, and ultrafine fly ash are respectively finely ground by air jet mill to reach the specified particle size.

[0048] (2) Dry mixing and homogenization Weigh out the finely ground ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash, and red mud according to the proportions, pour them into a planetary mixer, and mix at 300 r / min for 7 min until the mixed powder has no obvious color difference.

[0049] (3) Additive compound Add an early strength agent, water-reducing agent, thickener, and quick-setting agent to the dry-mixed powder, adjust the speed to 500 r / min, and stir for 4.5 min to ensure that the additives uniformly coat the powder surface.

[0050] (4) Pulp making and molding Add water slowly, controlling the water-cement ratio to 0.43. Stir at 800 r / min for 5 minutes, then stir at 1200 r / min for 3 minutes until the slurry flows evenly without lumps, thus obtaining the stratum reinforcement material for the fault fracture zone.

[0051] Example 2 This embodiment provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Embodiment 1 in that: (1) The D50 particle size A of the ultrafine sulfoaluminate cement is 1.5µm, the D50 particle size B of the ultrafine silicate cement is 2.7µm, the D50 particle size C of the ultrafine fly ash is 4.2µm, and the D50 particle size D of the red mud is 6.5µm; the D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: (C / A)×(B / A)=5.04.

[0052] Example 3 This embodiment provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Embodiment 1 in that: (1) The D50 particle size A of the ultrafine sulfoaluminate cement is 1.45µm, the D50 particle size B of the ultrafine silicate cement is 2.6µm, the D50 particle size C of the ultrafine fly ash is 4.3µm, and the D50 particle size D of the red mud is 7.5µm; the D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: (C / A)×(B / A)=5.32.

[0053] Example 4 This embodiment provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Embodiment 1 in that: (1) By mass percentage, the reinforcement material for the fault fracture zone includes the following raw materials: 40% ultrafine sulfoaluminate cement, 10% ultrafine silicate cement, 20% ultrafine fly ash, 8% red mud, 1% early strength agent, 1% water-reducing agent, 0.1% thickener, 0.8% quick-setting agent, and the balance being water.

[0054] Example 5 This embodiment provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Embodiment 1 in that: (1) By mass percentage, the fault fracture zone stratum reinforcement material includes the following raw materials: 50% ultrafine sulfoaluminate cement, 15% ultrafine silicate cement, 25% ultrafine fly ash, 12% red mud, 2% early strength agent, 1.5% water-reducing agent, 0.2% thickener, 1.2% quick-setting agent, and the balance is water.

[0055] Example 6 This embodiment provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Embodiment 1 in that: (1) The early strength agent is a single calcium formate, and its preparation includes the following steps: a) weigh calcium formate according to the specified mass ratio; b) put the raw materials into a ball mill and grind them separately (ball-to-material ratio 6:1, rotation speed 300r / min, time 1.5h), and control the fineness to reach D50≤10μm to obtain the early strength agent; (2) The thickener is a single guar gum, and its preparation includes the following steps: a) Weigh food-grade guar gum according to the proportion, and dry it in an oven at 80°C for 2 hours to remove free water; b) Pass the dried raw material powder through a 180-mesh sieve for later use; c) Add 0.5% of citric acid (activator) of the total mass of the mixed powder, and continue stirring for 20 minutes to obtain the thickener.

[0056] Example 7 This embodiment provides a grouting device, such as... Figure 1 As shown, it includes: Support component 1; and The slurry container 8 is disposed above the support component 1, and the slurry container 8 is conveyed to the spray head component 10 through the mixing container 3, the conveying pipe 4 and the pumping component 5; The slurry container 8 is equipped with a flow sensor 7, the stirring container 3 is equipped with a motor 6 and a stirrer 2, and the pumping component 5 is connected to a controller 9.

[0057] Comparative Example 1 This comparative example provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Example 1 only in that: (1) The D50 particle size A of the ultrafine sulfoaluminate cement is 0.8µm, the D50 particle size B of the ultrafine silicate cement is 3.0µm, the D50 particle size C of the ultrafine fly ash is 5.0µm, and the D50 particle size D of the red mud is 7.0µm; the D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: (C / A)×(B / A)=23.44.

[0058] Comparative Example 2 This comparative example provides a stratum reinforcement material for fault fracture zones and its preparation method, which differs from Example 1 only in that: (1) By mass percentage, the reinforcement materials for the fault fracture zone include: ultrafine sulfoaluminate cement (D50=1.4μm), silicate cement (D50=10.0μm, accounting for 25%), ordinary secondary fly ash (D50=15.0μm, accounting for 15%), slag powder (D50=9.0μm, accounting for 15%), red mud (D50=13.0μm, accounting for 5%), aluminum sulfate early strength agent (1.5%), polycarboxylate water-reducing agent (1.2%), guar gum thickener (0.15%), alkali-containing aluminate quick-setting agent (1.0%), with the balance being water and the water-cement ratio set at 0.43.

[0059] Test case This test example performs performance tests on the fault fracture zone strata reinforcement materials provided in Examples 1-6 and Comparative Examples 1-2.

[0060] The testing method is as follows: 1. Setting time Test standard: GB / T 1346-2011 "Test methods for standard consistency water requirement, setting time and soundness of cement".

[0061] The measurements were performed using a Vicat apparatus.

[0062] The prepared standard consistency cement paste (referred to as reinforcing material paste in this application) was filled into a circular mold and cured in a standard curing chamber (temperature 20±1°C, relative humidity ≥90%). After curing, a Vicat apparatus was used for testing. Initial setting time: The time elapsed from the moment water is added until the test needle sinks into the neat paste to a distance of 4±1mm from the bottom plate. At this point, the paste begins to lose its plasticity.

[0063] Final setting time: The time elapsed from the moment water is added until the test needle sinks no more than 0.5 mm into the neat paste. At this point, the paste completely loses its plasticity and begins to develop strength.

[0064] 2. Compressive strength Test standard: GB / T 17671-2021 Cement mortar strength test method (ISO method)

[0065] Prepare prism specimens of 40 mm × 40 mm × 160 mm. Cure the specimens in a standard curing chamber (temperature 20 ± 1°C, relative humidity ≥ 90%) until the specified age (1 day and 28 days). Using a compressive strength testing machine, load the specimen at a uniform rate of 2400 N / s ± 200 N / s until failure, record the maximum load, and calculate the compressive strength value.

[0066] 3. Flowability Test standard: GB / T 2419-2005 "Determination of fluidity of cement mortar".

[0067] The test was conducted using a jumping table. The prepared slurry was poured into a truncated cone mold in one go, leveled, and then the mold was lifted vertically. The jumping table was then made to complete 25 jumps within 25 seconds at a frequency of once per second.

[0068] Initial spread: After the jump is over, use calipers to measure the diameter of the bottom of the slurry in two mutually perpendicular directions and take the average value (unit: mm).

[0069] 30-minute spread: Let the slurry stand in the container for 30 minutes, stirring gently at regular intervals to prevent settling, and then repeat the above agitation and measurement steps at the 30-minute mark.

[0070] 4. Permeability coefficient (28 days) Test standard: GB / T 50082-2009 Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete.

[0071] Maintaining a constant head difference between the upper and lower ends of the sample, and after the seepage reaches a steady state, measure the seepage flow rate per unit time, and calculate the permeability coefficient using Darcy's Law. Darcy's Law formula: ; k is the permeability coefficient, Q is the seepage flow rate, L is the sample height, A is the sample cross-sectional area, H is the head difference, and t is the time.

[0072] The test results are shown in Table 1.

[0073] Table 1

[0074] As shown in Table 1, the optimized multi-stage particle size distribution (4.0 ≤ (C / A) × (B / A) ≤ 6.5) and the selected composite additives significantly improved the overall performance of the material: the setting time was short (initial setting 16-25 minutes) and well matched with the early strength (1-day strength 9.0-13.2 MPa), the 28-day compressive strength was high (40.5-49.5 MPa), the fluidity was excellent and the impermeability was good, all of which were superior to the comparative example, proving that it can effectively meet the core requirements of rapid reinforcement and efficient impermeability of fault fracture zones.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A stratum reinforcement material for fault fracture zones, characterized in that, include: Ultrafine sulfoaluminate cement, wherein the D50 particle size A of the ultrafine sulfoaluminate cement is 1.0-1.5 µm; Ultrafine silicate cement, wherein the D50 particle size B of the ultrafine silicate cement is 2.5-3.5 µm; Ultrafine fly ash, wherein the D50 particle size C of the ultrafine fly ash is 4-6 µm; Red mud, wherein the D50 particle size D of the red mud is 6-8 µm; The D50 particle size A of the ultrafine sulfoaluminate cement, the D50 particle size B of the ultrafine silicate cement, and the D50 particle size C of the ultrafine fly ash satisfy the following relationship: 4.0≤(C / A)×(B / A)≤6.

5.

2. The fault fracture zone strata reinforcement material according to claim 1, characterized in that, The fault fracture zone strata reinforcement material, by mass percentage, comprises the following raw materials: The composition of the cement is as follows: 40-50% ultrafine sulfoaluminate cement, 10-15% ultrafine silicate cement, 20-25% ultrafine fly ash, 8-12% red mud, 1-2% early strength agent, 1-1.5% water-reducing agent, 0.1-0.2% thickener, and 0.8-1.2% quick-setting agent.

3. The fault fracture zone strata reinforcement material according to claim 2, characterized in that, The early strength agent is composed of calcium formate and aluminum sulfate in a mass ratio of (2~3):

1.

4. The fault fracture zone strata reinforcement material according to claim 2, characterized in that, The thickener is composed of guar gum and xanthan gum in a mass ratio of (1~2):(1~2).

5. The fault fracture zone strata reinforcement material according to claim 2, characterized in that, The water-reducing agent includes a polycarboxylate-based water-reducing agent; And / or, the accelerator includes at least one of alkali-free liquid fluorosilicate accelerator, alumina clinker-red mud composite powder accelerator, and polycarboxylate-aluminum sulfate composite accelerator.

6. A method for preparing a fault fracture zone strata reinforcement material according to any one of claims 1 to 5, characterized in that, Includes the following steps: Ultrafine sulfoaluminate cement, ultrafine silicate cement, ultrafine fly ash and red mud are mixed to obtain a dry mix; The remaining raw materials and water are added to the dry mixture and mixed to obtain the fault fracture zone stratum reinforcement material.

7. The method for preparing the fault fracture zone strata reinforcement material according to claim 6, characterized in that, The preparation of the early strength agent includes the following process: calcium formate and aluminum sulfate are weighed according to the mass ratio, and then ball-milled separately. When the fineness of both reaches D50≤10μm, they are mixed to obtain the early strength agent.

8. The method for preparing the fault fracture zone strata reinforcement material according to claim 6, characterized in that, The preparation of water-reducing agents includes the following processes: Polyethylene glycol monomethyl ether and acrylic acid were esterified at a molar ratio of 1:(1.0~1.2) in the presence of a catalyst at 85-95℃ for 6-8 hours to obtain a macromolecular monomer. The macromonomer, acrylic acid, and sodium methacrylate sulfonate are dissolved in water at a mass ratio of (35~45):(3~5):

1. Under the protection of an inert gas at 60-70°C, an initiator accounting for 0.8~1.5% of the total mass of the monomer is added dropwise, and the reaction is carried out for 3-4 hours. After the reaction is completed, the mixture is cooled and neutralized with alkali solution to pH=6.5~7.0 to obtain the water-reducing agent.

9. The method for preparing the fault fracture zone strata reinforcement material according to claim 6, characterized in that, The preparation of thickeners includes the following processes: Guar gum and xanthan gum were weighed according to the mass ratio, then dried and pulverized separately, passed through a 160-190 mesh sieve to obtain powder, and then mixed to obtain a mixed powder. Citric acid, accounting for 0.3-0.6 wt% of the total mass of the mixed powder, is added to the mixed powder and mixed to obtain the thickener.

10. A grouting device, characterized in that, Grouting operation for the fault fracture zone strata reinforcement material as described in any one of claims 1 to 5 or the fault fracture zone strata reinforcement material prepared by the preparation method of any one of claims 6 to 9; The grouting device includes: Support components; and A slurry container is disposed above the support component, and the slurry container is conveyed to the spray head component through a mixing container, a delivery pipe and a pumping component; The slurry container is equipped with a flow sensor, the mixing container is equipped with a motor and a stirrer, and the pumping component is connected to a controller.

Images