Anti-flowing water grouting material, preparation method, application and underground crack repairing method

Abstract

The invention provides a flowing-water-resistant grouting material, a preparation method, application and an underground crack repairing method. The anti-flowing water grouting material comprises the following components in parts by weight: 8-12 parts of Portland cement; 48 to 92 parts by weight of clay; 0-42 parts by weight of modified fly ash and 95-105 parts by weight of water; wherein the clay is prepared from the following components in percentage by mass: 12.8% of quartz; 8% of calcite; 37% of illite; 8% of albite; 1.8% of potassium feldspar; 11.4% of kaolinite; 18.9% of clinoptilolite by weight; 2.1% of pyrite; the modified fly ash is obtained by crushing fly ash. And good flowing water resistance can be achieved without adding extra additives. The method also has the advantages of simple pulping process, low cost, environmental friendliness and the like.

Description

Technical Field

[0001] This application relates to the field of grouting materials technology, and in particular to a grouting material resistant to dynamic water, its preparation method, its application, and a method for repairing underground cracks. Background Technology

[0002] Grouting involves using pressure conveying equipment to inject cementitious materials into underground fissures, allowing them to diffuse, gel, and solidify to fill cavities, reinforce strata, or prevent seepage and leakage. In some mining faces, water-rich areas exist with large volumes and high flow velocities, posing significant challenges to coal seam mining. Current grouting materials in related technologies do not provide sufficient water-blocking capabilities to meet the water-blocking requirements of water-rich environments. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a grouting material resistant to dynamic water, its preparation method, its application, and a method for repairing underground cracks.

[0004] For the purposes described above, this application provides a grouting material for resisting dynamic water flow, comprising: 8-12 parts by weight of silicate cement; 48-92 parts by weight of clay; 0-42 parts by weight of modified fly ash and 95-105 parts by weight of water;

[0005] The clay is composed of the following components by mass percentage: 12.8% quartz; 8% calcite; 37% illite; 8% albite; 1.8% potassium feldspar; 11.4% kaolinite; 18.9% chlorite; and 2.1% pyrite. The modified fly ash is obtained by crushing fly ash.

[0006] In some embodiments, the modified fly ash comprises the following components by weight percentage: 14.4% amorphous material, 78.9% mullite, and 6.7% quartz; the grouting material comprises: 48-52 parts by weight of clay and 38-42 parts by weight of modified fly ash.

[0007] In some embodiments, the clay has a D10 particle size of 0.958-0.962 μm, a D50 particle size of 3.080-3.084 μm, and a D90 particle size of 10.20-10.24 μm.

[0008] In some embodiments, the modified fly ash has a D10 particle size of 1.78-1.82 μm, a D50 particle size of 11.38-11.42 μm, and a D90 particle size of 47.88-48.82 μm.

[0009] In some embodiments, the silicate cement is PO42.5 silicate cement; the grouting material further includes: 0.1-0.2 parts by weight of water-reducing agent and 0.1-0.2 parts by weight of flocculant.

[0010] In some embodiments, the water-reducing agent is a polycarboxylate water-reducing agent, and the flocculant is a polyacrylamide flocculant.

[0011] This application embodiment also provides a method for preparing a grouting material resistant to dynamic water flow as described in any of the preceding embodiments, comprising:

[0012] A base material is obtained by mixing 8-12 parts by weight of silicate cement, 48-92 parts by weight of clay, and 0-42 parts by weight of modified fly ash; wherein the clay is composed of the following components in weight percentage: 12.8% quartz; 8% calcite; 37% illite; 8% albite; 1.8% potassium feldspar; 11.4% kaolinite; 18.9% chlorite; and 2.1% pyrite; the modified fly ash is obtained by crushing fly ash.

[0013] Add 95-105 parts by weight of water to the base material and stir to obtain the grouting material.

[0014] In some embodiments, the preparation method further includes adding 0.1-0.2 parts by weight of water-reducing agent and 0.1-0.2 parts by weight of flocculant to the grouting material.

[0015] This application also provides an example of a grouting material resistant to dynamic water flow as described above, or a grouting material resistant to dynamic water flow prepared by any of the methods described above, for use in the repair of underground fissures.

[0016] This application also provides a method for repairing underground fissures, which involves injecting a water-resistant grouting material as described above or a water-resistant grouting material prepared by a method as described above into the underground fissures using a pumping device; the underground fissures are underground fissures in coal mining. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the clay particle size distribution curve in an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the particle size distribution curve of the modified fly ash in an embodiment of this application;

[0020] Figure 3This is a schematic flowchart illustrating the preparation method of the grouting material resistant to dynamic water according to an embodiment of this application;

[0021] Figure 4 This is a schematic diagram of the particle size distribution curve of secondary clay.

[0022] Figure 5 This is a schematic diagram of the particle size distribution curve of secondary fly ash;

[0023] Figure 6 This is a schematic diagram of the test results for resistance to dynamic water erosion in Examples 1-5;

[0024] Figure 7 This is a schematic diagram showing the test results of resistance to dynamic water erosion in Comparative Examples 1-4;

[0025] Figure 8 This is a schematic diagram showing the results of the dynamic water erosion resistance test for comparative examples 5-8.

[0026] Figure 9 Electron micrographs of the grouting materials in Examples 1-5;

[0027] Figure 10 Electron micrographs of the grouting materials in Comparative Examples 1-4;

[0028] Figure 11 Electron micrographs of the grouting materials in Comparative Examples 5-8;

[0029] Figure 12a Electron microscopy of clay as an embodiment of this application Figure 1 ;

[0030] Figure 12b Electron microscopy of clay as an embodiment of this application Figure 2 ;

[0031] Figure 13 Electron micrograph of secondary clay;

[0032] Figure 14a Electron microscopy of modified fly ash Figure 1 ;

[0033] Figure 14b Electron microscopy of modified fly ash Figure 2 ;

[0034] Figure 15 Electron micrograph of secondary fly ash;

[0035] Figure 16 This is an electron microscope image of the grouting material for resisting dynamic water flow according to an embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0037] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by a person skilled in the art to which this application pertains. The terms "upper," "lower," "left," and "right," etc., used in the embodiments of this application are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0038] In coal mining, cracks may appear at the top of the coal seam after extraction. Repairing these cracks serves two purposes: firstly, it reinforces the strata, preventing post-mining loosening; secondly, it prevents groundwater seepage, thus conserving water. However, some mining faces contain water-rich areas characterized by large volumes and high flow velocities. Therefore, repairing cracks after coal seam extraction requires high resistance to dynamic water erosion, and also must not cause irreversible damage to groundwater. However, current grouting materials do not perform well enough to block water under dynamic water conditions, failing to meet the requirements of water-rich areas. Furthermore, some grouting materials contain toxic substances, which could cause irreversible damage to natural groundwater if applied in water-rich areas, making them unsuitable. Therefore, developing environmentally friendly grouting materials with good dynamic water resistance is crucial for solving the challenges of coal mining in water-rich areas.

[0039] Based on this, the present application provides a grouting material that resists dynamic water flow. By selecting PO42.5 silicate cement, local clay, and modified fly ash, it can reduce costs as much as possible while maintaining the effect of resisting dynamic water flow, and has the advantages of being environmentally friendly and having a simple grouting process.

[0040] This application provides a grouting material resistant to dynamic water flow, comprising: 8-12 parts by weight of silicate cement; 48-92 parts by weight of clay; 0-42 parts by weight of modified fly ash; and 95-105 parts by weight of water. The clay may be composed of the following components by weight percentage: 12.8% quartz; 8% calcite; 37% illite; 8% albite; 1.8% potassium feldspar; 11.4% kaolinite; 18.9% chlorite; and 2.1% pyrite, as shown in Table 1. The modified fly ash is obtained by crushing / pulverizing fly ash produced in industry (e.g., coal-fired power plants). Compared to unmodified fly ash, the modified fly ash has a smaller particle size and a larger specific surface area. Compared to the same quality of unmodified fly ash (i.e., traditional fly ash), modified fly ash particles have a larger contact area with the grouting material and greater internal friction, which makes the grout more stable and has stronger resistance to water erosion.

[0041] Table 1 Clay composition

[0042]

[0043] The grouting material for resisting dynamic water flow in this application embodiment is shown in the electron microscope image below. Figure 16 As shown, good resistance to dynamic water flow can be achieved by using 8-12 parts by weight of silicate cement, 48-92 parts by weight of clay, 0-42 parts by weight of modified fly ash, and 95-105 parts by weight of water without the addition of additional additives. Tests showed that at a water flow rate of 0.075 m / s... 3 Under the condition of / h, the retention rate is as high as 89%. At the same time, the grouting material for resisting dynamic water in the embodiments of this application also has the advantages of simple grouting process, low cost and environmental friendliness.

[0044] In some embodiments, the silicate cement can be ordinary silicate cement, such as ordinary PO42.5 silicate cement. The weight parts of the silicate cement can be 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, or 12 parts, etc. The water can be ordinary tap water.

[0045] In some embodiments, the particle size distribution of the clay in this application may specifically include D10 particle size of 0.958-0.962 μm, D50 particle size of 3.080-3.084 μm, and D90 particle size of 10.20-10.24 μm. The specific particle size distribution of the clay may be, for example... Figure 1 As shown in Table 2, for example, the D10 particle size is 0.960 μm, the D50 particle size is 3.082 μm, and the D90 particle size is 10.22 μm. The weight parts of the clay in the embodiments of this application can be 48 parts, 48.5 parts, 49 parts, 49.5 parts, 50 parts, 50.5 parts, 51 parts, 51.5 parts, 52 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 88 parts, 88.5 parts, 89 parts, 89.5 parts, 90 parts, 90.5 parts, 91 parts, 91.5 parts, or 92 parts, etc.

[0046] Table 2 Clay particle size distribution

[0047] Particle size (µm) content% 0.100 0.00 0.200 0.00 0.500 1.85 1.000 10.74 2.000 31.22 5.000 70.23 10.00 89.61 20.00 97.75 45.00 99.95 75.00 100.00

[0048] In some embodiments, the modified fly ash may consist of the following components by mass percentage: 14.4% amorphous material, 78.9% mullite, and 6.7% quartz, as shown in Table 3. Specifically, the particle size distribution of the modified fly ash may include D10 particles with a diameter of 1.78-1.82 μm, D50 particles with a diameter of 11.38-11.42 μm, and D90 particles with a diameter of 47.88-48.82 μm. The specific particle size distribution of the clay may be, for example... Figure 2As shown, for example, the D10 particle size is 1.8 μm, the D50 particle size is 11.4 μm, and the D90 particle size is 48 μm. The modified fly ash in the embodiments of this application can be 0 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 38 parts, 38.5 parts, 39 parts, 39.5 parts, 40 parts, 40.5 parts, 41 parts, 41.5 parts, or 42 parts by weight, etc.

[0049] Table 3. Composition of modified fly ash

[0050] Element amorphous Mullite quartz Quality percentage (%) 14.4 78.9 6.7

[0051] In some embodiments, the grouting material for resisting dynamic water flow may include: 8-12 parts by weight of silicate cement; 48-52 parts by weight of clay; 38-42 parts by weight of modified fly ash; and 95-105 parts by weight of water. Specifically, the parts by weight of silicate cement may be 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, or 12 parts, etc. The parts by weight of clay may be 48, 48.5, 49, 49.5, 50, 50.5, 51, 51.5, or 52 parts. The parts by weight of modified fly ash may be 38, 38.5, 39, 39.5, 40, 40.5, 41, 41.5, or 42 parts, etc. In this way, by partially replacing clay with modified fly ash, more modified fly ash can be used without reducing the erosion resistance of the grouting material, thus lowering the cost. For example, compared to using only 48-92 parts by weight of clay, the cost of the grouting material can be reduced from 497.74 yuan / m³. 3 Reduced to 400 yuan / m 3 the following.

[0052] In some embodiments, the grouting material further includes 0.1-0.2 parts by weight of a water-reducing agent and 0.1-0.2 parts by weight of a flocculant, etc. By adding these two additives, the grouting material can be easily injected into underground fissures in the water-rich areas of the coal mining area.

[0053] In some embodiments, the water-reducing agent may be a polycarboxylate water-reducing agent, and the flocculant may be a polyacrylamide flocculant.

[0054] Based on the same inventive concept, this application also provides a method for preparing a grouting material resistant to dynamic water as described in any of the preceding embodiments.

[0055] See Figure 3 The method for preparing the grouting material resistant to dynamic water flow according to the embodiments of this application may include:

[0056] Step S100: Mix 8-12 parts by weight of silicate cement, 48-92 parts by weight of clay, and 0-42 parts by weight of modified fly ash to obtain a base material; wherein the clay is composed of the following components by weight percentage: 12.8% quartz; 8% calcite; 37% illite; 8% albite; 1.8% potassium feldspar; 11.4% kaolinite; 18.9% chlorite; and 2.1% pyrite; the modified fly ash is obtained by crushing fly ash.

[0057] Step S200: Add 95-105 parts by weight of water to the base material and stir to obtain the grouting material.

[0058] In some embodiments, in step S100, the silicate cement can be commercially available PO42.5 silicate cement. The clay can be obtained by pulverizing and then mixing clay minerals with a mass percentage of 12.8% quartz, 8% calcite, 37% illite, 8% albite, 1.8% potassium feldspar, 11.4% kaolinite, 18.9% chlorite, and 2.1% pyrite, respectively. The modified fly ash can be obtained by pulverizing and re-crushing fly ash; this crushing process reduces the particle size of the fly ash, resulting in modified fly ash with a smaller particle size.

[0059] In some embodiments, when mixing 8-12 parts by weight of silicate cement, 48-92 parts by weight of clay and 0-42 parts by weight of modified fly ash, a stirring process may be performed to obtain a uniformly mixed base material.

[0060] In some embodiments, in step S200, when adding water to the base material, the mixture can be stirred while adding water. For example, after adding all the water, the mixture can be placed on a vibrating table and vibrated for 30 seconds to ensure it is thoroughly mixed.

[0061] In some embodiments, the method may further include adding 0.1-0.2 parts by weight of a water-reducing agent and 0.1-0.2 parts by weight of a flocculant to the grouting material. Typically, after addition, stirring can be performed to ensure that the water-reducing agent and flocculant are uniformly mixed with the grouting material.

[0062] In some embodiments, the water-reducing agent may be a polycarboxylate water-reducing agent, and the flocculant may be a polyacrylamide flocculant.

[0063] It should be understood that the method for preparing the grouting material resistant to dynamic water in the embodiments of this application is used to prepare the grouting material resistant to dynamic water as described in any of the previous embodiments, and has the same effect as the grouting material resistant to dynamic water as described in any of the previous embodiments, which will not be repeated here.

[0064] Based on the same inventive concept, this application also provides the use of the water-resistant grouting material described in any of the above-described technical solutions or the water-resistant grouting material prepared by the preparation method described in any of the above-described technical solutions in the repair of underground fissures. The underground fissures can be underground fissures in coal mining operations.

[0065] It should be understood that the purpose of the embodiments of this application is to have the same effect as the grouting material for resisting dynamic water as described in any of the previous embodiments, and will not be repeated here.

[0066] Based on the same inventive concept, this application also provides a method for repairing underground fissures, which involves injecting the water-resistant grouting material described in any of the above-mentioned technical solutions or the water-resistant grouting material prepared by the preparation method described in any of the above-mentioned technical solutions into the underground fissures using a pressure conveying device; wherein the underground fissures are underground fissures in coal mining.

[0067] It should be understood that the underground crack repair method of this application embodiment has the same water-resistant grouting material as described in any previous embodiment, and has the same water-resistant grouting material effect as described in any previous embodiment, which will not be repeated here.

[0068] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0069] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0070] Unless otherwise specified, all experimental materials used in the following examples were purchased from conventional biochemical reagent stores.

[0071] Example 1: Preparation of grouting material resistant to dynamic water flow

[0072] Weigh out 10 parts of ordinary PO42.5 silicate cement, 50 parts of clay, 40 parts of modified fly ash, 100 parts of water, 0.15 parts of polycarboxylate superplasticizer, and 0.15 parts of polyacrylamide flocculant.

[0073] Ordinary PO42.5 silicate cement, clay, and modified fly ash are mixed and stirred evenly to form the base material.

[0074] Pour water evenly into the mixed base material while stirring. After adding all the water, place it on a vibrating table and vibrate for 30 seconds to ensure it is evenly mixed.

[0075] Pour in the water-reducing agent and flocculant of the above-mentioned weights and stir evenly.

[0076] Example 2: Preparation of grouting material resistant to dynamic water flow

[0077] The only difference from Example 1 is that the clay is 60 parts by weight and the modified fly ash is 30 parts by weight.

[0078] Example 3: Preparation of grouting material resistant to dynamic water flow

[0079] The only difference from Example 1 is that the clay is 70 parts by weight and the modified fly ash is 20 parts by weight.

[0080] Example 4: Preparation of grouting material resistant to dynamic water flow

[0081] The only difference from Example 1 is that the clay is 80 parts by weight and the modified fly ash is 10 parts by weight.

[0082] Example 5: Preparation of grouting material resistant to dynamic water flow

[0083] The only difference from Example 1 is that the clay has 90 parts by weight and the modified fly ash has 0 parts by weight.

[0084] Comparative Example 1: Preparation of grouting material resistant to dynamic water flow

[0085] The only difference from Example 1 is that the clay content is 80 parts by weight, the modified fly ash content is 0 parts, and it also contains 10 parts of secondary clay. The secondary clay has a D10 particle size of 0.896 μm, a D50 particle size of 3.070 μm, and a D90 particle size of 13.53 μm. The composition of the secondary clay is shown in Table 4, and the particle size distribution curve is shown in... Figure 4 As shown.

[0086] Table 4. Components of Secondary Clay

[0087]

[0088] Comparative Example 2: Preparation of grouting material resistant to dynamic water flow

[0089] The only difference from Comparative Example 1 is that the clay has 70 parts by weight and the secondary clay has 20 parts by weight.

[0090] Comparative Example 3: Preparation of grouting material resistant to dynamic water flow

[0091] The only difference from Comparative Example 1 is that the clay has a weight of 60 parts and the secondary clay has a weight of 30 parts.

[0092] Comparative Example 4: Preparation of grouting material resistant to dynamic water flow

[0093] The only difference from Comparative Example 1 is that the clay has 50 parts by weight and the secondary clay has 40 parts by weight.

[0094] Comparative Example 5: Preparation of grouting material resistant to dynamic water flow

[0095] The only difference from Comparative Example 1 is that it does not contain secondary clay, but includes 10 parts by weight of secondary fly ash. The composition of the secondary fly ash is shown in Table 5, and the particle size distribution curve is shown in... Figure 5 As shown.

[0096] Table 5 Composition of Secondary Fly Ash

[0097] Element amorphous Mullite quartz Quality percentage (%) 11.0 73.7 15.3

[0098] Comparative Example 6: Preparation of a grouting material resistant to dynamic water flow

[0099] The only difference from Comparative Example 5 is that the clay has a weight of 70 parts and the secondary fly ash has a weight of 20 parts.

[0100] Comparative Example 7: Preparation of grouting material resistant to dynamic water flow

[0101] The only difference from Comparative Example 1 is that the clay has a weight of 60 parts and the secondary fly ash has a weight of 30 parts.

[0102] Comparative Example 8: Preparation of grouting material resistant to dynamic water flow

[0103] The only difference from Comparative Example 1 is that the clay has a weight of 50 parts and the secondary fly ash has a weight of 40 parts.

[0104] Test case

[0105] Test Methods: The properties of the grouting materials prepared in Examples 1-5 and Comparative Examples 1-8 were tested respectively. Specific Test Methods: For the erosion resistance test, a custom-made acrylic mold was used. 1000g of sand was poured into the mold, and an appropriate amount of grout was poured in at a distance of 30cm from the outlet. The grout was covered with sand near the outlet, and then 500ml of clean water was poured in evenly to fully wet the sand. A water pump outlet was inserted into the container, the pump was adjusted to speed 3, and a total of 4000ml of water was used for rinsing for 192s at a flow rate of 2.93m / s. After the rinsing test, the experimental sample was placed back on a tray and dried in an oven at 120℃. Scanning Electron Microscopy (SEM) Test Procedure: First, the sample section was placed on the sample stage. The sample stage was then placed in an ion sputtering instrument to deposit gold for 1 minute to enhance the sample's conductivity and improve imaging quality. The gold-plated sample stage with the sample was then placed in the stage of an SS-60 scanning electron microscope for image scanning.

[0106] Specifically, for Example 1, the retention rate of the grouting material for resisting dynamic water was calculated as follows: Retention rate = Mass of the grouting material for resisting dynamic water after scouring / Mass of the grouting material for resisting dynamic water before scouring x 100%.

[0107] Test results: The results of the dynamic water erosion resistance tests in Examples 1-5 are as follows: Figure 6 As shown. Among them, Figure 6In the examples, number 1 corresponds to Example 5, number 2 corresponds to Example 4, number 3 corresponds to Example 3, number 4 corresponds to Example 2, and number 5 corresponds to Example 1. Example 5 shows the results of the resistance test to dynamic water erosion for comparative examples 1-4. Figure 7 As shown. Among them, Figure 7 In the table, number 1 corresponds to Example 5, number 2 corresponds to Comparative Example 1, number 3 corresponds to Comparative Example 2, number 4 corresponds to Comparative Example 3, and number 5 corresponds to Comparative Example 4. The results of the dynamic water erosion resistance test for Examples 5-8 in Example 5 are as follows: Figure 8 As shown. Among them, Figure 8 In the middle, number 1 corresponds to embodiment 5, number 2 corresponds to embodiment 5, number 3 corresponds to embodiment 6, number 4 corresponds to embodiment 7, and number 5 corresponds to embodiment 8.

[0108] Electron micrographs of the grouting materials in Examples 1-5 are shown below. Figure 9 As shown. Among them, Figure 9 In Example 5, number 1 corresponds to Example 5, number 2 to Example 4, number 3 to Example 3, number 4 to Example 2, and number 5 to Example 1. Example 5 shows electron micrographs of the grouting materials used in Comparative Examples 1-4. Figure 10 As shown. Among them, Figure 10 In the diagram, number 1 corresponds to Example 5, number 2 corresponds to Comparative Example 1, number 3 corresponds to Comparative Example 2, number 4 corresponds to Comparative Example 3, and number 5 corresponds to Comparative Example 4. Electron micrographs of the grouting materials in Example 5 and Comparative Examples 5-8 are shown below. Figure 11 As shown. Among them, Figure 11 In the middle, number 1 corresponds to embodiment 5, number 2 corresponds to embodiment 5, number 3 corresponds to embodiment 6, number 4 corresponds to embodiment 7, and number 5 corresponds to embodiment 8.

[0109] Electron micrograph of clay as shown Figure 12a and Figure 12b As shown, the electron micrograph of the secondary clay is as follows. Figure 13 As shown in the electron microscope image of the modified fly ash, Figure 14a and Figure 14b As shown in the figure, the electron micrograph of secondary fly ash is as follows. Figure 15 As shown.

[0110] Results Analysis: Figure 6 It can be seen that when the amount of modified fly ash added to the substrate reaches 10%, the slurry aggregate is a single block, without dispersion or scouring diffusion; however, when the amount of modified fly ash added further increases, the slurry aggregate itself does not disperse, only local diffusion occurs. Figure 9 It can be seen that although the amount of modified fly ash added was continuously increasing, the overall slurry did not change significantly, the surface remained relatively intact, and there were few pores. Only when the addition amount was 30% did a tiny crack appear. This indicates that the modified fly ash has good compatibility with high-quality clay, and no large-area cracks or pores appeared.

[0111] Therefore, the grouting materials with resistance to dynamic water prepared in Examples 1 to 5 of this application have good resistance to dynamic water.

[0112] Comparing Comparative Examples 1-4 with Example 5, by Figure 7 It can be seen that when secondary clay replaces part of the high-quality clay, when the amount of secondary clay added to the substrate reaches 10%, the slurry aggregate does not disperse, but its scouring area increases; when the amount of secondary clay added further increases, although the slurry aggregate does not show large-scale dispersion, the scouring area gradually expands. However, under the scouring of water flow, some slurry moves with the direction of water flow, thus increasing its overall diffusion area. Figure 10 It can be seen that without the addition of secondary clay, the slurry surface is extremely smooth. When the amount of secondary clay added reaches 10%, small cracks appear on the surface, while the unbroken areas remain relatively intact. When the amount of secondary clay added reaches 20%, the surface begins to break, no longer forming a complete surface, and small cracks appear. When the amount of secondary clay added reaches 30%, obvious cracks appear in the slurry, with small pores appearing around the cracks. When the amount of secondary clay added reaches 40%, the surface becomes rough and uneven, with numerous small pores present.

[0113] Therefore, with the same amount of secondary clay and modified fly ash added, the diffusion of the aggregate in the grout with modified fly ash is significantly better than that with secondary clay. Therefore, using only the clay and modified fly ash from the embodiments of this application will not affect the water resistance of the grouting material.

[0114] Comparing each of Comparative Examples 5-8 with Example 5, by Figure 9 It can be seen that when the amount of secondary fly ash added is 0%, the slurry aggregate after scouring and drying remains intact without dispersion, indicating excellent scouring resistance. When the amount of secondary fly ash added reaches 10%, most of the slurry remains intact after scouring and drying, with a small portion showing dispersion, indicating good scouring resistance. When the amount of secondary fly ash added reaches 20% or more, large areas of fragmented slurry aggregate appear, scattered throughout the tray, indicating that the slurry aggregate has been dispersed and its scouring resistance has been largely lost. Figure 11It can be seen that without the addition of fly ash, the slurry surface is extremely smooth, with no pores, preventing water from passing through the slurry through the tiny pores, thus providing excellent water-blocking properties. When the fly ash content reaches 10%, the surface becomes uneven, with small cracks appearing, but the main body remains intact, without the presence of fine particles. When the fly ash content reaches 20%, numerous small pores begin to appear on the surface. When the fly ash content reaches 30%, large cracks begin to appear on the surface. When the fly ash content reaches 40%, the surface becomes uneven, the number of pores increases, and many fine particles are present. SEM results of high-quality clay slurries with different contents of secondary fly ash show that as the secondary fly ash content increases, the number of pores and cracks increases accordingly, the slurry surface becomes less intact, and the water-blocking effect deteriorates.

[0115] Will Figure 12a and Figure 13 In comparison, under the same electron microscope magnification of 1000x, it can be seen that modified fly ash has significantly more smaller particles than secondary fly ash, and the gaps between secondary fly ash particles are larger, while the gaps between modified fly ash particles are significantly smaller. Figure 2 and Figure 5 In comparison, the particle size of modified fly ash is significantly smaller than that of secondary fly ash, and the difference in D90 reaches 33.6 μm. The D90 of modified fly ash is 41.2% lower than that of secondary fly ash, which is consistent with the SEM results.

[0116] Therefore, by using only the clay and modified fly ash from the embodiments of this application, the cost of the grouting material can be reduced without affecting its resistance to dynamic water. Changing the clay or fly ash will reduce the resistance to dynamic water of the grouting material to varying degrees.

[0117] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the embodiments of this disclosure as described above, which are not provided in detail for the sake of brevity.

[0118] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0119] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A grouting material resistant to dynamic water flow, characterized in that, include: 8-12 parts by weight of silicate cement; 48-92 parts by weight of clay; 0-42 parts by weight of modified fly ash and 95-105 parts by weight of water; The clay is composed of the following components by mass percentage: 12.8% quartz; 8% calcite; 37% illite; 8% albite; 1.8% potassium feldspar; 11.4% kaolinite; 18.9% chlorite; and 2.1% pyrite. The modified fly ash is obtained by crushing fly ash.

2. The grouting material for resisting dynamic water flow according to claim 1, characterized in that, The modified fly ash is composed of the following components by weight percentage: 14.4% amorphous material, 78.9% mullite, and 6.7% quartz; the grouting material comprises: 48-52 parts by weight of clay and 38-42 parts by weight of modified fly ash.

3. The grouting material for resisting dynamic water flow according to claim 1, characterized in that, The clay has a D10 particle size of 0.958-0.962 μm, a D50 particle size of 3.080-3.084 μm, and a D90 particle size of 10.20-10.24 μm.

4. The grouting material for resisting dynamic water flow according to claim 2, characterized in that, The modified fly ash has a D10 particle size of 1.78-1.82 μm, a D50 particle size of 11.38-11.42 μm, and a D90 particle size of 47.88-48.82 μm.

5. The grouting material for resisting dynamic water flow according to any one of claims 1-4, characterized in that, The silicate cement is PO42.5 silicate cement; the grouting material also includes: 0.1-0.2 parts by weight of water-reducing agent and 0.1-0.2 parts by weight of flocculant.

6. The grouting material for resisting dynamic water flow according to claim 5, characterized in that, The water-reducing agent is a polycarboxylate water-reducing agent, and the flocculant is a polyacrylamide flocculant.

7. A method for preparing a grouting material resistant to dynamic water flow as described in any one of claims 1-6, characterized in that, include: Use 8-12 parts by weight of silicate cement; A base material is obtained by mixing 48-92 parts by weight of clay and 0-42 parts by weight of modified fly ash; wherein the clay is composed of the following components in mass percentage: 12.8% quartz; 8% calcite; 37% illite; 8% albite; 1.8% potassium feldspar; 11.4% kaolinite; 18.9% chlorite; and 2.1% pyrite; the modified fly ash is obtained by crushing fly ash. Add 95-105 parts by weight of water to the base material and stir to obtain the grouting material.

8. The method for preparing the grouting material resistant to dynamic water flow according to claim 7, characterized in that, The preparation method further includes adding 0.1-0.2 parts by weight of water-reducing agent and 0.1-0.2 parts by weight of flocculant to the grouting material.

9. The use of a water-resistant grouting material as described in any one of claims 1 to 6, or a water-resistant grouting material prepared by the preparation method as described in any one of claims 7 to 8, in the repair of underground fissures.

10. A method for repairing underground cracks, characterized in that, The grouting material resistant to dynamic water as described in any one of claims 1 to 6, or the grouting material resistant to dynamic water prepared by the preparation method as described in any one of claims 7 to 8, is injected into the underground fissure using a pressure conveying device; the underground fissure is an underground fissure in coal mining.

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