A fast-setting, high-strength, expansive leak sealing material, method, and application

Abstract

This invention discloses a rapid-setting, high-strength, expansive leak sealing material, method, and application, belonging to the field of cement-based material admixture technology. It is prepared using a mixing method, comprising a base material composed of cement, desulfurized gypsum, calcium oxide, basic alumina, calcium formate, hydrated calcium silicate, carboxycellulose, and solid polycarboxylate superplasticizer; an active component composed of polyaluminum sulfate, magnesium sulfate, disodium ethylenediaminetetraacetate, borax, and defoamer; and a structural regulating functional component composed of ultrafine fly ash, ultrafine silica, ultrafine hydroxyapatite, ultrafine zinc sulfate, nano-titanium dioxide, and ultrafine boron nitride. The three components are mixed with water and stirred evenly before being mixed with an activator for leak sealing and void filling. The leak sealing material of this invention has advantages such as scientifically reasonable composition, simple preparation and application methods, rapid curing, high strength, good durability, and micro-expansion, and is effective for sealing and filling water seepage, permeability, and gas leaks.

Description

Technical Field

[0001] This invention belongs to the field of cement-based material admixture technology, specifically relating to a fast-setting, high-strength, expansive leak-proof crack sealing material, method, and application. Background Technology

[0002] Coal mining generates numerous goaf areas and encounters problems such as water inrush, seepage, and gas accumulation due to cracks and voids around the mining area. Therefore, sealing water inrush cracks in the coal and rock strata surrounding the goaf, sealing seepage cracks in roadways, and grouting gas drainage holes are key measures to prevent mine water inrush, leakage, collapse, and gas explosions. To effectively seal these cracks and voids and eliminate water inrush, leakage, and gas leakage, the materials used for crack sealing and void filling must possess characteristics such as rapid curing (quick setting), slight volume expansion, impermeability resistance, and high strength and durability. Currently, quick-setting sealing materials used for sealing water-permeable cracks in coal mining include organic polymer sealing materials, silicate-modified organic polymer sealing materials, and inorganic sealing materials. Organic polymeric rapid-setting sealing materials mainly include polyurethane, phenolic resin, and epoxy resin. Their advantages include good fluidity, excellent sealing effect, high strength, high toughness, and the ability to bond to coal and rock masses. Their disadvantages include complex preparation processes, relatively high prices, spontaneous combustion, and the risk of igniting coal due to the large amount of heat released during curing. Inorganic rapid-setting sealing materials are mainly inorganic composites formed by combining ordinary silicate cement with sulfoaluminate cement, aluminum sulfate, calcium oxide, sodium aluminate, and calcium sulfate. Their advantages include simple preparation, low price, fast setting speed, low curing temperature, flame retardancy, and good stability. Their disadvantages include easy shrinkage and poor durability. Due to the numerous advantages of inorganic rapid-setting sealing materials, the current and future development trend of rapid-setting materials for coal mine crack sealing is towards inorganic rapid-setting sealing materials. The main problems to be solved are early strength, volume shrinkage, and durability. Currently, inorganic quick-setting materials mainly involve incorporating quick-setting agents into a cementitious matrix. During grouting, the cement-based material and quick-setting agent are mixed together and injected into the area requiring sealing and filling, allowing it to set rapidly. Therefore, quick-setting agents are the core and key component of current sealing and filling materials. Quick-setting agents mainly include powder quick-setting agents and liquid quick-setting agents. Powder quick-setting agents suffer from problems such as high dust content and significant later-stage strength loss during construction, leading to their gradual replacement by liquid quick-setting agents. Liquid quick-setting agents can be classified into alkali-containing and alkali-free liquid quick-setting agents based on their alkali content. Alkali-containing liquid quick-setting agents mainly include aluminate-type, sodium silicate-type, and sulfate-type liquid quick-setting agents. Alkali-containing liquid quick-setting agents have the advantages of low dust content and low dosage, but due to their high alkali content, the 28-day compressive strength retention rate of concrete is relatively low. Alkali-free liquid quick-setting agents are mainly aluminum sulfate-type liquid quick-setting agents, with aluminum sulfate as the main accelerator component, supplemented with other components. Aluminum sulfate-based alkali-free liquid accelerators avoid the drawbacks of alkali-based liquid accelerators, such as significant later-stage strength loss in concrete and alkali-aggregate reaction. Furthermore, they are non-corrosive and environmentally friendly. Therefore, alkali-free liquid accelerators are a key focus of current research and future development and application.However, alkali-free liquid accelerators still have some problems that need to be solved, such as large dosage, high cost, poor stability, easy flocculation, precipitation, crystallization and other phenomena, and poor adaptability to different cements. These defects limit their promotion and application.

[0003] Inorganic alkali-free liquid accelerators are currently a research hotspot, with a focus on their stability and application effects. Chen Yansheng et al. prepared an alkali-free liquid accelerator by reacting sodium oxalate, aluminum hydroxide, hydrofluoric acid, aluminum sulfate, ethanolamine, and diethanolamine. When the dosage was 6% of cement, the initial and final setting times were 134 seconds and 390 seconds, respectively, and the compressive strengths at 1 day and 28 days were 10.6 MPa and 98.5 MPa, respectively. This accelerator has the advantages of low dosage, low cost, good stability, no flocculation, precipitation, crystallization, simple preparation process, good adaptability, and good setting effect (Chen Yansheng, Zhang Yun, Wei Kai, et al., Preparation and application research of highly adaptable alkali-free liquid accelerators, New Building Materials, 2022, (7): 122-127). Li Chongzhi et al. prepared a diethanolamine carboxylic acid ester silica gel complex stabilizer by reacting diethanolamine and oxalic acid under concentrated sulfuric acid catalysis, and then reacted it with aluminum sulfate, diethanolamine, and magnesium sulfate to prepare an alkali-free liquid accelerator. When the dosage was 8% of the cement mass, the initial setting time was 200 seconds, the final setting time was 495 seconds, the 6-hour compressive strength was 1.2 MPa, the 1-day compressive strength was 13.5 MPa, and the 28-day compressive strength was 46.3 MPa. This overcomes the problems of poor stability, slow hardening speed, and poor compatibility with cement of traditional liquid alkali-free accelerators (Li Chongzhi, Deng Songwen, Dong Peng, et al., Research and Application of High-Performance Alkali-Free Liquid Accelerators, New Building Materials, 2023, (3): 59-62). Deng Lin et al. prepared an alkali-free liquid accelerator by reacting industrial titanium dioxide waste acid, hydrofluoric acid, and aluminum hydroxide. At a dosage of 7%, the initial setting time and final setting time were 190 seconds and 320 seconds, respectively, with a 1-day compressive strength of 11.2 MPa and a 28-day compressive strength of 48.5 MPa. This accelerator has the characteristics of fast setting time, low dosage, and high strength (Deng Lin, Mao Xuehua, Study on the performance and hydration mechanism of aluminum sulfate-type alkali-free accelerator prepared from industrial titanium dioxide waste acid, 2022, 42(11): 211-216). Zhang Guoli et al. prepared highly active aluminum hydroxide with aluminum sulfate and ammonia water, then reacted it with aluminum sulfate, oxalic acid, and triethanolamine to prepare polyaluminum sulfate, and then compounded it with sodium fluorosilicate, calcium formate, and EDTA to prepare a liquid alkali-free accelerator. When the dosage was 5%, the initial setting time was 200 seconds, the final setting time was 380 seconds, the 1-day strength was 7.3 MPa, and the 28-day strength was 43.5 MPa. It overcomes the problems of uneven mixing, different setting time, and poor strength and durability caused by the poor stability, flocculation, stratification and precipitation of aluminum sulfate-type quick-setting agents. (Zhang Guoli, Wu Zhihong, Deng Yue, et al. Preparation and stability of EDTA-modified aluminum sulfate alkali-free liquid quick-setting agent. Journal of Materials Science and Engineering, 2022, 40(3): 466-473).Liang Hui et al. prepared a liquid alkali-free accelerator by reacting aluminum sulfate, magnesium sulfate, diethanol, monoisopropanolamine, fluorosilicic acid, and glycolic acid. At a dosage of 6%, it enabled the reference cement to initially set in 210 seconds and finally set in 565 seconds, achieving a 1-day compressive strength of 11.5 MPa and a 28-day compressive strength of 48.6 MPa. This accelerator possesses Al content. 3+It has advantages such as high content, good stability, good reinforcing effect, and green environmental protection and safety (Liang Hui, Liao Wenjie, Long Caixia, et al., Preparation and performance study of liquid alkali-free quick-setting agent, New Building Materials, 2023, (3): 138-139). Wu Wenxian prepared a suspension stabilizer by reacting acrylamide, ammonium persulfate, acrylic acid, mercaptoacetic acid and potassium hydrogen tartrate; prepared a complexing reinforcing agent by reacting ethylenediaminetetraacetic acid, triethanolamine, p-toluenesulfonic acid and hydroquinone; and then prepared a new type of alkali-free liquid quick-setting agent by combining the prepared suspension stabilizer, complexing reinforcing agent, aluminum sulfate, hydroxymethyl cellulose and oxalic acid. It solved the problems of poor stability, low strength and prominent compatibility with cement of quick-setting agent. (Wu Wenxian, Development of new alkali-free liquid quick-setting agent, New Building Materials, 2022, (6): 124-129). Song Shaofei et al. prepared a fluorine-free and alkali-free liquid quick-setting agent using aluminum sulfate, modified triethanolamine, citric acid, disodium EDTA, phosphoric acid, glycerol, ferrous sulfate, and sodium carbonate. When the solid dosage was 2.8%, the initial setting time was 147 seconds, the final setting time was 390 seconds, and the 1-day compressive strength was 9.67 MPa. It has the advantages of low dosage, short setting time, and low cost (Song Shaofei, Qu Qiheng, Li Wenli, et al., Preparation and performance study of novel fluorine-free and alkali-free liquid quick-setting agent, New Building Materials, 2023, (3): 139-142). Deng Songwen prepared a high-performance, alkali-free liquid accelerator using aluminum sulfate, oxalic acid, diethanolamine, magnesium sulfate, and fumed silica. At an 8% dosage, the initial setting time of cement paste was 144 seconds, and the final setting time was 282 seconds. The cement's 6-hour compressive strength was 1.3 MPa, its 1-day compressive strength was 13.4 MPa, and its 28-day compressive strength was 49.2 MPa. It exhibits characteristics such as low alkali content, high early strength, and good adaptability (Deng Songwen, Research and Application of High-Performance Alkali-Free Liquid Accelerator for Tunnels, Master's Thesis, Beijing University of Civil Engineering and Architecture, 2023). Liu Yuan et al. prepared aluminum formate using formic acid and aluminum hydroxide, and then reacted it with fluorosilicic acid, triethanolamine, hydroxyapatite, and aluminum sulfate upon heating to obtain an alkali-free liquid accelerator. When the admixture dosage is 8%, the initial setting time is 159 seconds, the final setting time is 333 seconds, the 1-day compressive strength is 13.2 MPa, the 28-day compressive strength is 49.6 MPa, and the 90-day compressive strength is 53.5 MPa. Introducing aluminum formate into alkali-free liquid accelerators can reduce the sulfate content in the accelerators, mitigate the adverse effects on concrete durability, shorten the initial and final setting times of cement, and significantly enhance the early and later strengths of cement (Liu Yuan, Zhu Fangfang, Zhang Yuanyong, et al. Effect of aluminum formate-modified aluminum sulfate-based alkali-free liquid accelerators on cement performance, Bulletin of the Chinese Ceramic Society, 2024, 43(12): 4331-4339). Zhang Xuhua et al. reacted formic acid with aluminum sulfate and diethanolamine and added magnesium nitrate to obtain an alkali-free liquid quick-setting agent. At an 8% dosage, the initial setting and final setting times of cement mortar were 276 seconds and 492 seconds, respectively. The compressive strength of the cement mortar reached 20.23 MPa after 1 day and 49.6 MPa after 28 days.This quick-setting agent has good temperature adaptability and compatibility with admixtures. When used in synergy with naphthalene-based / polycarboxylate-based water-reducing agents, it can still exert a good coagulation-promoting effect. A small amount of Mg is introduced into the quick-setting agent. 2+ It can combine with OH- produced during cement hydration to form Mg(OH)2, which has a certain inhibitory effect on the volume shrinkage of cured cement mortar; the Al in it 3+ and SO4 2- It can induce a large amount of ettringite crystal deposition in the early stage of hydration reaction to form a spatial network structure, which promotes the rapid setting of cement paste (Zhang Xuhua, Tian Mingkun, Zhang Gaoyin, et al. Synthesis and performance evaluation of aluminum sulfate type alkali-free quick-setting agent, China Building Materials Science and Technology, 2024, 33(4): 21-24).

[0004] Analysis of the current research and application status of crack and pore quick-setting sealing and filling materials in coal mines in recent years reveals the following problems: (1) Current research and application mainly focuses on inorganic sealing and filling materials with silicate cement as the main component. The quick-setting effect is mainly achieved by adding liquid inorganic alkali-free quick-setting agent. In the construction process, quick-setting agent needs to be added again during grouting; (2) The quick-setting agent is mainly composed of aluminum sulfate and reacts with other components such as ethanolamine, diethanolamine, triethanolamine, oxalic acid, glycerol, etc. The preparation process of quick-setting agent is complicated and troublesome; (3) The quick-setting agent is liquid, and its transportation and storage are relatively troublesome. During the storage process, the liquid quick-setting agent is prone to layering, flocculation and precipitation, which affects the use effect; (4) The main problem of current crack sealing and filling materials is the existence of shrinkage defects, which makes the sealing and filling body easy to fall off at the crack. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a fast-setting, high-strength, expansive leak-proof crack sealing material, method, and application, so as to solve the technical problems of complex preparation, easy stratification and flocculation, and shrinkage defects of existing fast-setting sealing materials, and achieve a sealing effect of rapid setting, anti-shrinkage micro-expansion, high strength, and durability.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for preparing a rapid-setting, high-strength, expansive leak-sealing material, comprising the following steps:

[0008] Step 1: Mix cement, desulfurized gypsum, calcium oxide, basic alumina, calcium formate, hydrated calcium silicate, carboxycellulose and solid polycarboxylate superplasticizer evenly to obtain component A;

[0009] Step 2: Mix polyaluminum sulfate, magnesium sulfate, disodium ethylenediaminetetraacetate, borax and defoamer evenly to obtain component B;

[0010] Step 3: Mix ultrafine fly ash, ultrafine silica, ultrafine hydroxyapatite, ultrafine zinc sulfate, nano titanium dioxide and ultrafine boron nitride evenly to obtain component C;

[0011] Step 4: Mix component A with water and stir evenly to obtain component A slurry; mix component B with water and stir evenly to obtain component B slurry; mix component C with water and stir evenly to obtain component C slurry; mix component A slurry, component B slurry and component C slurry evenly, then add activator and stir evenly to obtain a fast-setting high-strength expansion-type leakage crack sealing material.

[0012] Preferably, in step 4, the mass ratio of component A, component B, component C and activator is (186.6~237.8):(51.6~68.9):(120~153):(6~9).

[0013] Based on mass parts, component A slurry is prepared by adding 75-95 parts of water to 186.6-237.8 parts of component A and stirring evenly; component B slurry is prepared by adding 21-28 parts of water to 51.6-68.9 parts of component B and stirring evenly; component C slurry is prepared by adding 48-61.2 parts of water to 120-153 parts of component C and stirring evenly.

[0014] The activator is aluminum carbonate powder with a purity of 98%.

[0015] Preferably, in step 1, the mass ratio of cement, desulfurized gypsum, calcium oxide, basic alumina, calcium formate, hydrated calcium silicate, carboxycellulose, and solid polycarboxylate superplasticizer is (85~95):(45~55):(20~30):(15~25):(10~15):(10~15):(0.1~0.3):(1.5~2.5).

[0016] In step 2, the mass ratio of polyaluminum sulfate, magnesium sulfate, disodium ethylenediaminetetraacetate, borax, and defoamer is (40~50):(10~15):(0.5~0.6):(1~3):(0.1~0.3).

[0017] In step 3, the mass ratio of ultrafine fly ash, ultrafine silica, ultrafine hydroxyapatite, ultrafine zinc sulfate, nano titanium dioxide and ultrafine boron nitride is (40~50): (30~35): (25~30): (10~15): (5~8): (10~15).

[0018] Preferably, in step 1, the cement is ordinary Portland cement P·O 42.5; the main component of the desulfurized gypsum is CaSO4·2H2O, with a content of 93% and an average particle size of 50μm.

[0019] Preferably, in step 1, calcium oxide, basic alumina, calcium formate, hydrated calcium silicate, carboxycellulose, and solid polycarboxylate superplasticizer are all powdered materials with a purity greater than 99%.

[0020] Preferably, in step 2, the polyaluminum sulfate, magnesium sulfate, disodium ethylenediaminetetraacetate, and borax are all powdered materials with a purity greater than 98%; the defoamer is a solid organosilicon defoamer with a purity of 99%.

[0021] Preferably, in step 3, the ultrafine fly ash has a particle size of 0.4~0.6 μm, a loss on ignition of no more than 3.2%, a water requirement of no more than 91%, a moisture content of no more than 0.2%, and an activity index of 85%~90%.

[0022] Preferably, in step 3, the purity of ultrafine silica, ultrafine hydroxyapatite, ultrafine zinc sulfate, and ultrafine boron nitride is greater than 99%, and the particle size is 1~5μm; the particle size of nano titanium dioxide is 30~50nm.

[0023] This invention also discloses a rapid-setting, high-strength, expansive leak-sealing material, prepared using the aforementioned method. The initial setting time of the rapid-setting, high-strength, expansive leak-sealing material is 2-3 minutes, and the final setting time is 4-6 minutes. Its 1-hour compressive strength is 7.55-7.93 MPa; its 1-day compressive strength is 26.54-31.52 MPa; its 28-day compressive strength is 53.46-56.62 MPa; its 90-day compressive strength is 58.81-63.68 MPa; its 28-day carbonization depth is 0.1-0.2 mm; and its 28-day volume shrinkage rate is 0.1%-0.11%.

[0024] This invention also discloses the application of the above-mentioned method for preparing rapid-setting high-strength expansive seepage crack sealing material in water and gas seepage, crack sealing, and void filling and repair in coal mines, tunnels, and dams.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention discloses a method for preparing a rapid-setting, high-strength, expansive leak-sealing material. The material comprises three material systems with different functions: a base material composed of ordinary silicate cement, desulfurized gypsum, calcium oxide, basic alumina, calcium formate, hydrated calcium silicate, carboxycellulose, and a solid polycarboxylate superplasticizer; an active component composed of polyaluminum sulfate, magnesium sulfate, disodium EDTA, borax, and an antifoaming agent, primarily used to accelerate the hydration and setting of the base material, achieving rapid setting; and a component composed of ultrafine fly ash, ultrafine silica, ultrafine hydroxyapatite, ultrafine zinc sulfate, nano-titanium dioxide, and ultrafine boron nitride, which regulates the hydration products and microstructure and macrostructure of the cured material, and possesses good thermal conductivity. This results in a dense, shrinkage-resistant, and micro-expanding structure after curing, achieving high-strength embedded locking and sealing of leak-sealing cracks and voids, resulting in permanent sealing and filling effects. In terms of preparation, all three functional components are compounded by mixing and blending selected materials, without the need for heating or prolonged chemical reactions. In terms of application, the three components are separately mixed with water, then mixed with an activator and injected into cracks and voids. After thorough mixing, the mixture is rapidly cured, exhibiting low heat release and low temperature during curing. The resulting sealing and filling material has a uniform structure, resistance to shrinkage and micro-expansion, high early strength, and good durability, resulting in excellent sealing and filling effects. The rapid-setting, high-strength, expansive leak-proof crack sealing material prepared by this invention has a scientifically sound composition, clearly defined functions, a simple and easy preparation method, and is convenient for packaging, transportation, and storage. The preparation process requires no heating, consumes little energy, is environmentally friendly, and exhibits significant sealing and filling effects. The initial setting time is 2-3 minutes, the final setting time is 4-6 minutes, the compressive strength is greater than 7 MPa at 1 hour, greater than 25 MPa at 1 day, and greater than 50 MPa at 28 days.

[0027] This invention also discloses a rapid-setting, high-strength, expansive seepage crack sealing material prepared by the above-mentioned method. It consists of three parts: a base material with cementitious materials as the main component; a rapid-setting accelerator constituting a setting-promoting component; and a component with anti-shrinkage, micro-expansion, microstructure regulation, and thermal conductivity. The entire material is formed through mixing and compounding, and the preparation process involves no heating or chemical reaction, resulting in low energy consumption and environmental friendliness. The rapid-setting, high-strength, expansive seepage crack sealing material has a uniform and dense structure, excellent anti-shrinkage performance, and significant micro-expansion characteristics. It maintains a stable shape during the curing process, effectively resisting the influence of external stress and is not prone to cracking or deformation. It not only has rapid setting characteristics of initial setting in 2-3 minutes and final setting in 4-6 minutes, but also high early strength, with a compressive strength reaching 7.55-7.93 MPa in 1 hour and as high as 26.54-31.52 MPa in 1 day, fully meeting the performance requirements for water seepage, permeability, and gas sealing materials. Meanwhile, the compressive strength reaches 53.46~56.62 MPa at 28 days and further increases to 58.81~63.68 MPa at 90 days, demonstrating excellent subsequent strengthening effect. It also possesses good durability; 28-day freeze-thaw tests and impermeability tests show its superior freeze-thaw resistance, with a carbonization depth of only 0.1~0.2 mm, and a 28-day volume shrinkage rate controlled at 0.1%~0.11%, demonstrating excellent volume stability. More importantly, its 28-day and 90-day shrinkage tests show that the material has excellent anti-shrinkage and micro-expansion properties. It exhibits extremely high early strength and excellent later durability, reaching the required strength standards in a very short time, meeting the stringent requirements of engineering projects for material performance. The initial and final setting times are very short, greatly improving construction efficiency, shortening the construction period, and reducing project costs. Its sealing and filling effects are extremely significant, providing a solid and reliable guarantee for the project.

[0028] This invention also discloses the application of the rapid-setting high-strength expansive seepage crack sealing material prepared by the above-mentioned method in water and gas seepage, crack sealing, and void filling and repair in coal mines, tunnels, and dams. Due to its extremely high embedded locking and sealing capability, this rapid-setting high-strength expansive seepage crack sealing material can effectively prevent the formation of water and gas seepage cracks, greatly improving the safety and durability of the project. Its dense microstructure and excellent anti-shrinkage and micro-expansion properties make the sealed structure more stable and reliable, capable of withstanding various external environmental tests for a long time. At the same time, this rapid-setting high-strength expansive seepage crack sealing material is convenient and quick to apply, and can quickly cure and form, greatly shortening the construction cycle and improving project efficiency. Furthermore, this rapid-setting high-strength expansive seepage crack sealing material also has good adaptability and compatibility, and can be perfectly combined with various engineering materials and structures, providing a strong guarantee for the overall performance and stability of the project. Therefore, this fast-setting, high-strength, expansive leak-sealing material has significant advantages and broad application prospects in sealing water and air leaks and filling voids in coal mines, tunnels, dams, and other engineering projects. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0031] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0032] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0033] In this invention, unless otherwise specified, the components involved or their preferred components can be combined to form new technical solutions.

[0034] In this invention, unless otherwise specified, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" indicates that all real numbers between "6~22" have been listed in this document, and "6~22" is simply a shortened representation of these numerical combinations.

[0035] The "scope" disclosed in this invention can be in the form of a lower limit and an upper limit, and can be one or more lower limits and one or more upper limits, respectively.

[0036] In this invention, the term "and / or" as used herein refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0037] In this invention, unless otherwise stated, the various reactions or operation steps may be performed sequentially or in a particular order. Preferably, the reaction methods described herein are performed sequentially.

[0038] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0039] This invention provides a method for preparing a rapid-setting, high-strength, expansive leak-sealing material, comprising the following steps:

[0040] Step 1: According to the mass fractions, mix 85-95 parts cement, 45-55 parts desulfurized gypsum, 20-30 parts calcium oxide, 15-25 parts alkaline alumina, 10-15 parts calcium formate, 10-15 parts hydrated calcium silicate, 0.1-0.3 parts carboxylic acid cellulose and 1.5-2.5 parts solid polycarboxylate superplasticizer evenly to obtain component A;

[0041] Step 2: According to the mass fractions, mix 40-50 parts of polyaluminum sulfate, 10-15 parts of magnesium sulfate, 0.5-0.6 parts of disodium ethylenediaminetetraacetate, 1-3 parts of borax and 0.1-0.3 parts of defoamer evenly to obtain component B;

[0042] Step 3: According to the mass fractions, mix 40-50 parts of ultrafine fly ash, 30-35 parts of ultrafine silica, 25-30 parts of ultrafine hydroxyapatite, 10-15 parts of ultrafine zinc sulfate, 5-8 parts of nano titanium dioxide and 10-15 parts of ultrafine boron nitride evenly to obtain component C.

[0043] Step 4: Add 75-95 parts of water to 186.6-237.8 parts of component A and stir until homogeneous to obtain component A slurry; add 21-28 parts of water to 51.6-68.9 parts of component B and stir until homogeneous to obtain component B slurry; add 48-61.2 parts of water to 120-153 parts of component C and stir until homogeneous to obtain component C slurry. Mix component A slurry, component B slurry, and component C slurry until homogeneous, then add an activator and stir until homogeneous to obtain a fast-setting, high-strength, expansive leakage crack sealing material, which is immediately injected into the leakage and voids that need to be sealed.

[0044] Furthermore, in step 1, the cement is ordinary Portland cement P·O 42.5.

[0045] Furthermore, in step 1, the main component of the desulfurized gypsum is CaSO4·2H2O, with a content of 93% and an average particle size of 50μm.

[0046] Furthermore, in step 1, the calcium oxide, alkaline alumina, calcium formate, hydrated calcium silicate, carboxycellulose, and solid polycarboxylate superplasticizer are all in powder form with a purity greater than 99%.

[0047] Furthermore, in step 2, the polyaluminum sulfate, magnesium sulfate, disodium ethylenediaminetetraacetate, and borax have a purity greater than 99% and are in powder form.

[0048] Furthermore, in step 2, the defoamer is a solid silicone defoamer with a purity of 99%.

[0049] Furthermore, in step 3, the particle size of the ultrafine fly ash is 0.4~0.6 μm, the loss on ignition is no more than 3.2%, the water requirement is no more than 91%, the moisture content is no more than 0.2%, and the activity index is 85%~90%.

[0050] Furthermore, in step 3, the purity of ultrafine silica, ultrafine hydroxyapatite, ultrafine zinc sulfate, and ultrafine boron nitride is greater than 99%, and the particle size is 1~5μm.

[0051] Furthermore, in step 3, the particle size of the nano-titanium dioxide is 30~50nm.

[0052] Furthermore, in step 4, the activator is 6-9 parts of aluminum carbonate powder with a purity of 98%.

[0053] The preparation method of this invention employs a mixing and compounding technique, scientifically and rationally proportioning the selected materials to prepare the desired sealing material without the need for heating or prolonged chemical reactions. This preparation method is not only simple and easy to implement but also significantly reduces energy consumption, aligning with the concept of green environmental protection. Furthermore, the packaging, transportation, and storage of this preparation method are relatively simple and convenient, reducing logistics costs and storage difficulties, enabling the material to be more widely applied in practical engineering projects.

[0054] The rapid-setting, high-strength, expansive leak-sealing material prepared by this invention has an initial setting time of 2-3 minutes and a final setting time of 4-6 minutes. This rapid-setting, high-strength, expansive leak-sealing material has a uniform structure, strong anti-shrinkage properties, and significant micro-expansion characteristics, enabling it to maintain a stable shape during the curing process and preventing cracks or deformation. The material exhibits high early strength and good later-stage durability, achieving high strength in a short time to meet engineering performance requirements. The short initial and final setting times significantly improve construction efficiency and reduce project costs. The 1-hour strength is greater than 7 MPa, the 1-day strength is greater than 25 MPa, and the 28-day strength can exceed 50 MPa, demonstrating significant sealing and filling effects and providing reliable protection for engineering projects.

[0055] The rapid-setting, high-strength, expansive leak-sealing material developed in this invention can be applied to water and gas seepage, crack sealing, and void filling and repair in coal mines, tunnels, and dams. It effectively prevents the formation of water and gas seepage cracks, improving the safety and durability of engineering projects. Its dense microstructure and anti-shrinkage, micro-expansion characteristics make the sealed structure more stable and reliable, less susceptible to external environmental influences. It is easy to apply, can quickly cure and solidify, significantly shortening the construction cycle and reducing project costs.

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described and shown herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0057] Example 1

[0058] A method for preparing a rapid-setting, high-strength, expansive leak-sealing material includes the following steps:

[0059] Step 1: According to the mass fractions, mix 85 parts of ordinary silicate cement P·O 42.5, 45 parts of desulfurized gypsum, 20 parts of calcium oxide, 15 parts of alkaline alumina, 10 parts of calcium formate, 10 parts of hydrated calcium silicate, 0.1 parts of carboxycellulose, and 1.5 parts of solid polycarboxylate superplasticizer evenly to obtain component A.

[0060] Step 2: According to the mass fractions, mix 40 parts of polyaluminum sulfate, 10 parts of magnesium sulfate, 0.5 parts of disodium ethylenediaminetetraacetate, 1 part of borax, and 0.1 parts of defoamer evenly to obtain component B;

[0061] Step 3: According to the mass fractions, mix 40 parts of ultrafine fly ash, 30 parts of ultrafine silica, 25 parts of ultrafine hydroxyapatite, 10 parts of ultrafine zinc sulfate, 5 parts of nano titanium dioxide and 10 parts of ultrafine boron nitride evenly to obtain component C.

[0062] Step 4: Add 75 parts water to 186.6 parts of component A and stir until homogeneous to obtain component A slurry; add 21 parts water to 51.6 parts of component B and stir until homogeneous to obtain component B slurry; add 48 parts water to 120 parts of component C and stir until homogeneous to obtain component C slurry. Mix component A slurry, component B slurry, and component C slurry until homogeneous, then add 6 parts aluminum carbonate powder activator and stir until homogeneous to obtain a fast-setting, high-strength, expansive leakage crack sealing material, which is immediately injected into the leaks and voids that need to be sealed.

[0063] Example 2

[0064] A method for preparing a rapid-setting, high-strength, expansive leak-sealing material includes the following steps:

[0065] Step 1: According to the mass fractions, mix 87 parts of ordinary silicate cement P·O 42.5, 47 parts of desulfurized gypsum, 23 parts of calcium oxide, 17 parts of alkaline alumina, 11 parts of calcium formate, 12 parts of hydrated calcium silicate, 0.15 parts of carboxycellulose, and 1.7 parts of solid polycarboxylate superplasticizer evenly to obtain component A.

[0066] Step 2: According to the mass fractions, mix 43 parts of polyaluminum sulfate, 11 parts of magnesium sulfate, 0.52 parts of disodium ethylenediaminetetraacetate, 1.5 parts of borax, and 0.15 parts of defoamer evenly to obtain component B;

[0067] Step 3: According to the mass fractions, mix 42 parts of ultrafine fly ash, 31 parts of ultrafine silica, 27 parts of ultrafine hydroxyapatite, 11 parts of ultrafine zinc sulfate, 6 parts of nano titanium dioxide and 12 parts of ultrafine boron nitride evenly to obtain component C.

[0068] Step 4: Add 80 parts of water to 198.85 parts of component A and stir until homogeneous to obtain component A slurry; add 23 parts of water to 56.17 parts of component B and stir until homogeneous to obtain component B slurry; add 51 parts of water to 129 parts of component C and stir until homogeneous to obtain component C slurry. Mix component A slurry, component B slurry, and component C slurry until homogeneous, then add 7 parts of aluminum carbonate powder activator and stir until homogeneous to obtain a fast-setting, high-strength, expansive leakage crack sealing material, which is immediately injected into the leakage and voids that need to be sealed.

[0069] Example 3

[0070] A method for preparing a rapid-setting, high-strength, expansive leak-sealing material includes the following steps:

[0071] Step 1: According to the mass fractions, mix 90 parts of ordinary silicate cement P·O 42.5, 50 parts of desulfurized gypsum, 25 parts of calcium oxide, 20 parts of alkaline alumina, 13 parts of calcium formate, 13 parts of hydrated calcium silicate, 0.2 parts of carboxycellulose, and 2.0 parts of solid polycarboxylate superplasticizer evenly to obtain component A;

[0072] Step 2: According to the mass fractions, mix 45 parts of polyaluminum sulfate, 13 parts of magnesium sulfate, 0.55 parts of disodium ethylenediaminetetraacetate, 2.5 parts of borax, and 0.25 parts of defoamer evenly to obtain component B;

[0073] Step 3: According to the mass fractions, mix 45 parts of ultrafine fly ash, 33 parts of ultrafine silica, 28 parts of ultrafine hydroxyapatite, 13 parts of ultrafine zinc sulfate, 7 parts of nano titanium dioxide and 13 parts of ultrafine boron nitride evenly to obtain component C.

[0074] Step 4: Add 85 parts water to 213.2 parts of component A and stir until homogeneous to obtain component A slurry; add 25 parts water to 61.3 parts of component B and stir until homogeneous to obtain component B slurry; add 55 parts water to 139 parts of component C and stir until homogeneous to obtain component C slurry. Mix component A slurry, component B slurry, and component C slurry until homogeneous, then add 7.5 parts aluminum carbonate powder activator and stir until homogeneous to obtain a fast-setting, high-strength, expansive leakage crack sealing material, which is immediately injected into the leakage and voids that need to be sealed.

[0075] Example 4

[0076] A method for preparing a rapid-setting, high-strength, expansive leak-sealing material includes the following steps:

[0077] Step 1: According to the mass fractions, mix 92 parts of ordinary Portland cement P·O 42.5, 53 parts of desulfurized gypsum, 27 parts of calcium oxide, 23 parts of alkaline alumina, 14 parts of calcium formate, 14 parts of hydrated calcium silicate, 0.25 parts of carboxycellulose, and 2.3 parts of solid polycarboxylate superplasticizer evenly to obtain component A;

[0078] Step 2: According to the mass fractions, mix 47 parts of polyaluminum sulfate, 14 parts of magnesium sulfate, 0.57 parts of disodium ethylenediaminetetraacetate, 2.5 parts of borax, and 0.25 parts of defoamer evenly to obtain component B;

[0079] Step 3: According to the mass fractions, mix 47 parts of ultrafine fly ash, 34 parts of ultrafine silica, 29 parts of ultrafine hydroxyapatite, 14 parts of ultrafine zinc sulfate, 7.5 parts of nano titanium dioxide and 14 parts of ultrafine boron nitride evenly to obtain component C;

[0080] Step 4: Add 90 parts water to 225.55 parts of component A and stir until homogeneous to obtain component A slurry; add 26 parts water to 64.32 parts of component B and stir until homogeneous to obtain component B slurry; add 58 parts water to 145.5 parts of component C and stir until homogeneous to obtain component C slurry. Mix component A slurry, component B slurry, and component C slurry until homogeneous, then add 8 parts aluminum carbonate powder activator and stir until homogeneous to obtain a fast-setting, high-strength, expansive leakage crack sealing material, which is immediately injected into the leaks and voids that need to be sealed.

[0081] Example 5

[0082] A method for preparing a rapid-setting, high-strength, expansive leak-sealing material includes the following steps:

[0083] Step 1: According to the mass fractions, mix 95 parts of ordinary silicate cement P·O 42.5, 55 parts of desulfurized gypsum, 30 parts of calcium oxide, 25 parts of alkaline alumina, 15 parts of calcium formate, 15 parts of hydrated calcium silicate, 0.3 parts of carboxycellulose, and 2.5 parts of solid polycarboxylate superplasticizer evenly to obtain component A.

[0084] Step 2: According to the mass fractions, mix 50 parts of polyaluminum sulfate, 15 parts of magnesium sulfate, 0.6 parts of disodium ethylenediaminetetraacetate, 3 parts of borax, and 0.3 parts of defoamer evenly to obtain component B;

[0085] Step 3: According to the mass fractions, mix 50 parts of ultrafine fly ash, 35 parts of ultrafine silica, 30 parts of ultrafine hydroxyapatite, 15 parts of ultrafine zinc sulfate, 8 parts of nano titanium dioxide and 15 parts of ultrafine boron nitride evenly to obtain component C.

[0086] Step 4: Add 95 parts water to 237.8 parts of component A and stir until homogeneous to obtain component A slurry; add 28 parts water to 68.9 parts of component B and stir until homogeneous to obtain component B slurry; add 61.2 parts water to 153 parts of component C and stir until homogeneous to obtain component C slurry. Mix component A slurry, component B slurry, and component C slurry until homogeneous, then add 9 parts aluminum carbonate powder activator and stir until homogeneous to obtain a fast-setting, high-strength, expansive leakage crack sealing material, which is immediately injected into the leaks and voids that need to be sealed.

[0087] The rapid-setting, high-strength, expansive seepage crack sealing material prepared in Examples 1-5 is not limited to sealing water inrush and seepage in coal mines, crack repair, and void filling. It can also be used for crack repair in buildings, roads, and bridges, and as a sprayed flocculation reinforcement material for tunnels and goaf areas.

[0088] Table 1 shows the performance comparison of the rapid-setting high-strength expansive seepage crack sealing materials prepared in Examples 1-5 of this invention. To facilitate the comparison of the influence of different material ratios on the sample performance, the performance of the rapid-setting high-strength expansive seepage crack sealing materials prepared in Examples 1-5 was tested according to GB / T17671-2021 "Test Method for Strength of Cement Mortar" and GB / T50082-2023 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete". The results are shown in Table 1. As can be seen from Table 1, the rapid-setting high-strength expansive seepage crack sealing materials prepared in Examples 1-5 have excellent mechanical properties and durability, specifically: 1) Initial setting in 2-3 minutes, final setting in 4-6 minutes, and a compressive strength of 7.55-7.93 MPa in 1 hour; the compressive strength in 1 day reaches 26.54-31.52 MPa; indicating that it has the characteristics of fast setting speed and high early strength, which meets the performance requirements as a material for sealing water inrush, permeability and gas. 2) The compressive strength after 28 days reached 53.46~56.62 MPa, indicating that the sealing material has high strength. The compressive strength after 90 days reached 58.81~63.68 MPa, indicating that the sealing material has good subsequent reinforcement effect. 3) The 28-day freeze-thaw test and anti-permeability test results show that this sealing material has good durability, indicating good freeze-thaw resistance and greater durability. 4) The carbonation depth is 0.1~0.2 mm, indicating good durability. 6) The 28-day volume shrinkage rate is 0.1%~0.11%, indicating good volume stability. 5) The 28-day and 90-day shrinkage test results show that this sealing material has good anti-shrinkage and micro-expansion effects. The rapid-setting high-strength expansion-type leakage crack sealing materials prepared in Examples 1~5 have excellent workability, volume stability, and durability, and are suitable for manufacturing different types of cement-based composite material components.

[0089] Table 1. Performance comparison of the rapid-setting, high-strength, expansive leak sealing materials prepared in Examples 1-5

[0090]

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a rapid setting high strength expansive crack sealing material, characterized in that, It comprises the following steps: Step 1, cement, desulfurization gypsum, calcium oxide, basic aluminum oxide, calcium formate, hydrated calcium silicate, carboxymethyl cellulose and solid polycarboxylic acid water reducing agent are mixed uniformly to obtain component A; Step 2, polyaluminum sulfate, magnesium sulfate, ethylenediaminetetraacetic acid disodium, borax and defoaming agent are mixed uniformly to obtain component B; Step 3, superfine fly ash, superfine silicon dioxide, superfine hydroxyapatite, superfine zinc sulfate, nanometer titanium dioxide and superfine boron nitride are mixed uniformly to obtain component C; Step 4, component A is mixed with water, stirred uniformly to obtain component A slurry; component B is mixed with water, stirred uniformly to obtain component B slurry; component C is mixed with water, stirred uniformly to obtain component C slurry; component A slurry, component B slurry and component C slurry are mixed uniformly, then an activator is added, stirred uniformly to obtain a rapid setting high strength expansion type leakage crack sealing material; In step 1, the mass fraction ratio of cement, desulfurization gypsum, calcium oxide, basic aluminum oxide, calcium formate, hydrated calcium silicate, carboxymethyl cellulose and solid polycarboxylic acid water reducing agent is (85-95):(45-55):(20-30):(15-25):(10-15):(10-15):(0.1-0.3):(1.5-2.5); the cement is ordinary Portland cement P·O 42.5; the calcium oxide, basic aluminum oxide, calcium formate, hydrated calcium silicate, carboxymethyl cellulose and solid polycarboxylic acid water reducing agent are all powder materials; In step 2, the mass fraction ratio of polyaluminum sulfate, magnesium sulfate, ethylenediaminetetraacetic acid disodium, borax and defoaming agent is (40-50):(10-15):(0.5-0.6):(1-3):(0.1-0.3); the polyaluminum sulfate, magnesium sulfate, ethylenediaminetetraacetic acid disodium and borax are all powder materials; the defoaming agent is solid silicone defoaming agent; In step 3, the mass fraction ratio of superfine fly ash, superfine silicon dioxide, superfine hydroxyapatite, superfine zinc sulfate, nanometer titanium dioxide and superfine boron nitride is (40-50):(30-35):(25-30):(10-15):(5-8):(10-15); In step 4, the mass fraction ratio of component A, component B, component C and activator is (186.6-237.8):(51.6-68.9):(120-153):(6-9); According to the mass fraction, 186.6-237.8 parts of component A are added into 75-95 parts of water to prepare component A slurry; 51.6-68.9 parts of component B are added into 21-28 parts of water to prepare component B slurry; 120-153 parts of component C are added into 48-61.2 parts of water to prepare component C slurry; the activator is aluminum carbonate powder.

2. The process for the production of a rapid setting high strength expanding crack- penetrating sealant material according to claim 1, characterized in that, In step 1, the main component of desulfurization gypsum is CaSO4·2H2O, the content is 93%, and the average particle size is 50 μm.

3. The method of preparing a rapid setting high strength expanding crack- penetrating sealant material as claimed in claim 1, wherein, In step 3, the superfine fly ash has a particle size of 0.4-0.6 μm, a loss on ignition of not more than 3.2%, a water demand of not more than 91%, a water content of not more than 0.2%, and an activity index of 85%-90%.

4. The process for the production of a rapid setting high strength expanding crack- penetrating sealant material as claimed in claim 1, wherein, In step 3, the superfine silica, superfine hydroxyapatite, superfine zinc sulfate and superfine boron nitride have a purity of more than 99% and a particle size of 1-5 μm; and the nano-titanium dioxide has a particle size of 30-50 nm.

5. A rapid setting high strength expanding crack sealing material characterized in that, The preparation method of the quick-setting high-strength expansive leakage crack sealing material is prepared by the method of any one of claims 1-4; the quick-setting high-strength expansive leakage crack sealing material has an initial setting time of 2-3 min, a final setting time of 4-6 min, a 1h compressive strength of 7.55-7.93 MPa, a 1-day compressive strength of 26.54-31.52 MPa, a 28-day compressive strength of 53.46-56.62 MPa, a 90-day compressive strength of 58.81-63.68 MPa, a 28-day carbonization depth of 0.1-0.2 mm, and a 28-day volume shrinkage rate of 0.1%-0.11%.

6. The application of the quick-setting high-strength expansive leakage crack sealing material prepared by the method of any one of claims 1-4 in the water and gas leakage, gap sealing and void filling repair of coal mines, tunnels and dams.

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