A lost circulation material and a method of making the same

Abstract

This invention belongs to the technical field of building waterproofing and leak-stopping materials, specifically relating to a leak-stopping material and its preparation method. The leak-stopping material of this invention comprises: powder and liquid components. The liquid component includes water. By mass parts, the powder comprises: 40-60 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 15-25 parts of composite filler, 3.0-5.0 parts of ettringite precursor, 0.04-0.1 parts of water-reducing agent, 0.05-0.1 parts of hydroxypropyl methylcellulose ether, and 1.0-3.0 parts of penetrating crystallizing active powder. By mass parts, the liquid component comprises: 50-95 parts of deionized water and 5-50 parts of silicone-acrylic anti-permeability emulsion. The composite filler is fly ash modified with a silane coupling agent, and the particle size of the composite filler is 5-10 μm. The leak-stopping material of this invention has low water absorption, excellent corrosion resistance, good mechanical properties, and durability.

Description

Technical Field

[0001] This invention belongs to the technical field of building waterproofing and leak-stopping materials, specifically relating to a leak-stopping material and its preparation method. Background Technology

[0002] During construction and service, concrete structures are prone to developing micro-cracks due to factors such as temperature stress, load changes, and shrinkage deformation. If these cracks are not sealed in time, moisture can seep into the structure, leading to steel corrosion and concrete carbonation, severely impacting the structure's durability and safety. As the core material for solving leakage problems, the performance of leak-sealing materials directly determines the durability of the sealing effect.

[0003] There are many types of existing leak-sealing materials. Traditional cement-based leak-sealing materials, while low in cost and compatible with concrete substrates, have high porosity and water absorption, making them susceptible to erosion in humid or corrosive environments, leading to leak-sealing failure. Polyurethane materials, although possessing certain impermeability, lack chemical stability in harsh corrosive environments such as strong acids and alkalis, and are prone to aging and degradation with long-term use. Furthermore, some products exhibit significant brittleness and poor deformation resistance after curing. Acrylic grouting materials have limited temperature resistance, making it difficult to maintain stable leak-sealing effects in high-temperature corrosive environments.

[0004] Developing a leak-sealing material that combines extremely low water absorption, excellent corrosion resistance, good mechanical properties, and durability to adapt to complex and harsh leakage environments has become an urgent technical problem to be solved in this field.

[0005] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0006] The purpose of this invention is to provide a sealing material and its preparation method, so as to help solve or improve the problem of poor sealing effect of existing cement-based sealing materials in complex leakage environments.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a sealing material, comprising: powder and liquid; by mass parts, the powder comprises: 40-60 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 15-25 parts of composite filler, 3.0-5.0 parts of ettringite precursor, 0.04-0.1 parts of water-reducing agent, 0.05-0.1 parts of hydroxypropyl methylcellulose ether, and 1.0-3.0 parts of penetrating crystallizing active powder; by mass parts, the liquid comprises: 50-95 parts of deionized water and 5-50 parts of silicone-acrylic anti-permeability emulsion; the composite filler is fly ash modified with a silane coupling agent, and the particle size of the composite filler is 5-10 μm.

[0008] Preferably, the composite filler is prepared by a method including the following steps: mixing fly ash with a silane coupling agent solution, adding an ethanol solution, stirring and reacting at 60-70°C for 2-3 hours, filtering and drying to obtain the composite filler.

[0009] Preferably, the silane coupling agent is KH-570, the concentration of the silane coupling agent solution is 0.5wt%-2.0wt%, and the mass ratio of fly ash to the silane coupling agent solution is 100:3; the volume ratio of ethanol to water in the ethanol solution is 3:1, and the volume ratio of the ethanol solution to the silane coupling agent solution is 100:5. Preferably, the sulfoaluminate cement grade is 42.5, the grade of ordinary Portland cement is 42.5; The mass ratio of sulfoaluminate cement to ordinary silicate cement is (3.0-5.0):1.

[0010] Preferably, the ettringite precursor is a mixture of anhydrous aluminum sulfate and calcium hydroxide, with a mass ratio of anhydrous aluminum sulfate to calcium hydroxide of (1.3-1.5):1; the permeation crystallization active powder is obtained by mixing the following raw materials in the following mass percentages: sodium sulfate 35%-40%, sodium carbonate 5%-10%, lithium carbonate 10%-15%, tetrasodium ethylenediaminetetraacetate 8%-12%, sodium silicate 30%-35%, and sodium diisobutylnaphthalenesulfonate 0.1%-0.5%.

[0011] Preferably, the mass ratio of the liquid to the powder is 0.30-0.35.

[0012] Preferably, the silicone-acrylic antipermeability emulsion is prepared by a method comprising the following steps: A1, adding KH-570 silane coupling agent solution dropwise to a silane emulsion at 25-30°C; A2, heating to 70-80°C, adding an acrylic emulsion dropwise, and continuing to stir after the addition is complete to obtain a compound emulsion; A3, cooling to 60-70°C, adding a n-propyl zirconate solution to the compound emulsion, and stirring to react; A4, cooling and adding a thickener to adjust the viscosity, and aging to obtain the silicone-acrylic antipermeability emulsion.

[0013] Preferably, in step A1, the silane emulsion is n-butyltriethoxysilane emulsion, and the acrylic emulsion is styrene-acrylic emulsion; in step A1, the mass of the KH-570 silane coupling agent solution is 0.5%-1.5% of the sum of the masses of the silane emulsion and the acrylic emulsion, and the concentration of the KH-570 silane coupling agent solution is 0.5wt%-2.0wt%; in step A2, when adding the acrylic emulsion, 20% of the total amount of acrylic emulsion is added each time, and the time between two consecutive additions is... The interval is 10-15 min; after the addition is completed, continue stirring for 1-1.5 h; in step A3, the concentration of the n-propyl zirconate solution is 70 wt%, and the mass of the n-propyl zirconate solution is 0.2% of the sum of the masses of the silane emulsion and the acrylic emulsion, and the stirring time is 1-1.5 h; in step A4, the mass of the thickener is 0.1% of the sum of the masses of the silane emulsion and the acrylic emulsion; the mass percentage of the silicone-acrylic antipermeable emulsion in the liquid is 20%-40%.

[0014] The present invention also provides a method for preparing a sealing material, which adopts the following technical solution: The method for preparing the sealing material as described above includes the following steps: (1) adding sulfoaluminate cement, ordinary silicate cement, composite filler, ettringite precursor, penetrating crystallizing active powder, water reducing agent and hydroxypropyl methylcellulose ether into a mixer and mixing them evenly to obtain powder; (2) mixing liquid and powder in proportion to obtain the sealing material.

[0015] Preferably, in step (1), the mixing speed is 500-700 r / min and the mixing time is 10-15 min; the permeation crystallization active powder is obtained by adding sodium sulfate, sodium carbonate, lithium carbonate, sodium ethylenediaminetetraacetate, sodium silicate and sodium diisobutylnaphthalenesulfonate into a mixer and mixing at a speed of 500-700 r / min for 10-15 min.

[0016] Beneficial effects: The sealing material of this invention has low water absorption, excellent corrosion resistance, good mechanical properties and durability, so as to adapt to complex and harsh leakage environments.

[0017] The sealing material of this invention has an initial setting time of ≤5min, a final setting time of ≤10min, a compressive strength of ≥15MPa at 1h, a compressive strength of ≥40MPa at 3d, a bonding strength of ≥2.0MPa, and a seepage resistance pressure of ≥4.0MPa at 7d. At the same time, the material itself has a water absorption rate of ≤2%, a low sulfate erosion resistance coefficient and a low chloride ion diffusion coefficient, and possesses long-term seepage resistance and corrosion resistance properties. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0019] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0020] This invention addresses the problem that existing cement-based sealing materials have poor sealing performance in complex leakage environments by providing a sealing material.

[0021] The leak-sealing material of this invention includes: powder and liquid; by weight, the powder includes: 40-60 parts of sulfoaluminate cement (e.g., 40, 45, 50, 55, or 60 parts), 10-20 parts of ordinary silicate cement (e.g., 10, 13, 16, 18, or 20 parts), 15-25 parts of composite filler (e.g., 15, 17, 20, 23, or 25 parts), and ettringite precursor. 3.0-5.0 parts (e.g., 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts), 0.04-0.1 parts (e.g., 0.04 parts, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, or 0.1 parts) of water-reducing agent, and 0.05-0.1 parts (e.g., 0.05 parts, 0.06 ... 7 parts, 0.08 parts, 0.09 parts, or 0.1 parts) and 1.0-3.0 parts (e.g., 1.0, 1.5, 2.0, 2.5, or 3.0 parts) of penetrating crystallizing active powder; by weight, the liquid component includes: 50-95 parts (e.g., 50, 60, 70, 80, 85, or 95 parts) of deionized water and 5-50 parts (e.g., 5, 10, 20, 30, or 40 parts) of silicone-acrylic antipermeation emulsion. (or 50 parts); the composite filler is fly ash modified with a silane coupling agent (the fly ash modified with a silane coupling agent forms chemical bonds on a smooth surface, which helps to prevent agglomeration; and it can form physical and chemical crosslinks with organic materials and substrates to form an organic-inorganic interpenetrating network structure, reducing total porosity and enhancing interfacial strength), and the particle size of the composite filler is 5-10 μm (e.g., 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm).

[0022] In the sealing material of this invention, the core mineral of sulfoaluminate cement, anhydrous calcium sulfoaluminate (C4A3S), hydrates upon contact with water to form aluminum gel, while the tricalcium silicate (C3S) and dicalcium silicate (C2S) in ordinary silicate cement hydrate rapidly to generate calcium hydroxide (Ca(OH)2). This calcium hydroxide participates in the conversion reaction of aluminum gel to hydrated calcium sulfoaluminate (CAH) gel, accelerating the hydration process of anhydrous calcium sulfoaluminate and disrupting the hydration balance of ordinary silicate cement due to the consumption of calcium hydroxide. This further promotes the hydration of its own C3S, C2S, and other minerals, significantly increasing the overall hydration rate of the system and shortening the setting time. Furthermore, sulfoaluminate cement suffers from the problem of easy strength reduction in the later stages, while ordinary silicate cement exhibits stable strength development and continuous strength growth in the later stages. When ordinary silicate cement is used to replace part of sulfoaluminate cement, the CSH gel generated by its hydration can fill the tiny cracks that may be generated later, improving the density of the sealing material. On the other hand, it can make up for the lack of hydration power of sulfoaluminate cement in the later stage, so that the composite system not only has high early strength, but also steadily improves mechanical properties at long-term ages such as 28 days, avoiding strength shrinkage.

[0023] In the sealing material of this invention, the silicone-acrylic anti-permeability emulsion can form an organic-inorganic interpenetrating network structure within the cement-based material. This organic-inorganic interpenetrating network structure can fill the capillary channels of the cement-based material, allowing corrosive media (H...) to... + OH - Cl - The infiltration path of (etc.) becomes tortuous and narrow, the diffusion rate is greatly reduced, and a physical barrier is formed.

[0024] In a preferred embodiment of the sealing material of the present invention, the composite filler is prepared by a method comprising the following steps: mixing fly ash with a silane coupling agent solution, adding an ethanol solution, stirring and reacting at 60-70°C (e.g., 60°C, 62°C, 64°C, 66°C, 68°C or 70°C) for 2-3 hours (e.g., 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours), filtering and drying to obtain the composite filler.

[0025] In a preferred embodiment of the sealing material of the present invention, the silane coupling agent is KH-570, the concentration of the silane coupling agent solution is 0.5wt%-2.0wt% (e.g., 0.5wt%, 1wt%, 1.5wt%, or 2wt%), and the mass ratio of fly ash to silane coupling agent solution is 100:3; the volume ratio of ethanol to water in the ethanol solution is 3:1, and the volume ratio of ethanol solution to silane coupling agent solution is 100:5. If the amount of silane coupling agent is too small, the surface activation degree will be low; if the amount of silane coupling agent is too large, the cost will increase, and multilayer physical adsorption will form on the fly ash surface, resulting in a weak layer between the fly ash and the organic polymer, which will prevent the fly ash from functioning as a single-molecule bridge.

[0026] In a preferred embodiment of the sealing material of the present invention, the sulfoaluminate cement grade is [missing information]. 42.5, the grade of ordinary Portland cement is 42.5; The mass ratio of sulfoaluminate cement to ordinary silicate cement is (3.0-5.0):1 (e.g., 3.0:1, 3.5:1, 4.0:1, 4.5:1 or 5.0:1).

[0027] In a preferred embodiment of the sealing material of the present invention, the ettringite precursor is a mixture of anhydrous aluminum sulfate and calcium hydroxide, wherein the mass ratio of anhydrous aluminum sulfate to calcium hydroxide is (1.3-1.5):1 (e.g., 1.3:1, 1.4:1, or 1.5:1). The ettringite precursor acts as a nucleation site for ettringite, accelerating the hydration reaction process, promoting the rapid formation of hydration products, and shortening the setting time. If the amount of ettringite precursor is too small, the rapid hardening and setting effect will not be achieved. If the amount of ettringite precursor is too large, the setting time will be too fast, causing expansion cracking, structural damage, and affecting the sealing effect.

[0028] In a preferred embodiment of the sealing material of the present invention, the penetrating crystallizing active powder is obtained by mixing the following raw materials in the following mass percentages: 35%-40% sodium sulfate (e.g., 35%, 36%, 37%, 38%, 39% or 40%), 5%-10% sodium carbonate (e.g., 5%, 6%, 7%, 8%, 9% or 10%), 10%-15% lithium carbonate (e.g., 10%, 11%, 12%, 13%, 14% or 15%), 8%-12% tetrasodium ethylenediaminetetraacetate (e.g., 8%, 9%, 10%, 11% or 12%), 30%-35% sodium silicate (e.g., 30%, 31%, 32%, 33%, 34% or 35%), and 0.1%-0.5% sodium diisobutylnaphthalenesulfonate (e.g., 0.1%, 0.2%, 0.3%, 0.4% or 0.5%).

[0029] In the sealing material of this invention: cement hydration produces a large amount of Ca(OH)2, and Ca(OH)2 crystals dissolve upon contact with water, thereby ionizing Ca... 2+ The active chemicals in the penetrating crystallizing active powder (e.g., sodium sulfate, lithium carbonate, anhydrous sodium silicate), carried by water, penetrate into the interior of the sealing material through the capillaries and microcracks. Simultaneously, sodium diisobutylnaphthalene sulfonate reduces the surface tension of water, allowing the active chemicals to disperse more quickly and evenly into the pores and cracks within the sealing material. There, they react chemically with free calcium ions in the pore water solution, forming water-insoluble crystals such as CSH gel, CAH gel, and CaCO3 crystals. At the same time, the complexing agent (tetrasodium ethylenediaminetetraacetate) in the penetrating crystallizing active powder diffuses into the concrete and first reacts with free calcium ions... 2+The mixture combines to form unstable, water-soluble complexes. When these complexes encounter free silicate or aluminate ions, the active chemical groups are replaced, leading to the formation of CSH and CAH gels that block pores and cracks. The released active chemical groups then penetrate deeper into the concrete with water molecules, combining again with calcium ions to form complexes. This process repeats, continuously generating crystals that enhance the density of the sealing material, reduce its water absorption, and achieve long-lasting waterproofing.

[0030] In a preferred embodiment of the sealing material of the present invention, the mass ratio of liquid to powder is 0.30-0.35 (e.g., 0.30, 0.31, 0.32, 0.33, 0.34 or 0.35).

[0031] In a preferred embodiment of the sealing material of the present invention, the silicone-acrylic anti-permeability emulsion is prepared by a method comprising the following steps: A1. KH-570 silane coupling agent solution is added dropwise to a silane emulsion at 25-30°C (e.g., 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C); A2. The temperature is raised to 70-80°C (e.g., 70°C, 72°C, 74°C, 76°C, 78°C, or 80°C), and an acrylic emulsion is added dropwise. After the addition is completed, stirring is continued (to promote local cross-linking of some silane and acrylic molecules) to obtain a compound emulsion; A3. The temperature is lowered to 60-70°C (e.g., 60°C, 62°C, 64°C, 66°C, 68°C, or 70°C), and a n-propyl zirconate solution is added to the compound emulsion and stirred to react; A4. After cooling, a thickener is added to adjust the viscosity, and the mixture is allowed to mature to obtain the silicone-acrylic anti-permeability emulsion.

[0032] Among them, silicone-acrylic antipermeable emulsions possess excellent resistance to acid, alkali, and salt corrosion. The core principle is the synergistic effect of physical barrier properties and chemical stabilization mechanisms. Silicone-acrylic antipermeable emulsions can form an organic-inorganic interpenetrating network structure within cement-based materials. For example, when n-butyltriethoxysilane is used as the silane emulsion, the hydrolysis of n-butyltriethoxysilane generates silanol groups (-SiOH), which undergo condensation reactions with the hydroxyl groups of cement hydration products (such as CSH gel and Ca(OH)2) to form stable Si-O-Ca chemical bonds. Simultaneously, the silanol groups themselves condense to form a Si-O-Si inorganic network (forming a siloxane hydrophobic layer), filling the capillary pores of the cement-based material. Acrylic emulsions (preferably styrene-acrylic emulsions) form a continuous organic polymer film in the pores of the cement-based material, interpenetrating with the inorganic network of silanes, further blocking the pores (cutting off the channels between the pores and the outside, acting as a seal), reducing the porosity and connectivity of the material (reducing the channels for water to penetrate into the concrete). The interpenetrating network structure allows corrosive media (H... + OH - Cl - The infiltration path of (etc.) becomes tortuous and narrow, the diffusion rate is greatly reduced, and a physical barrier is formed.

[0033] In a preferred embodiment of the sealing material of the present invention, in step A1, the silane emulsion is n-butyltriethoxysilane emulsion, and the acrylic emulsion is styrene-acrylic emulsion; in step A1, the mass percentage of the n-butyltriethoxysilane emulsion is 15%-20%, the mass of the KH-570 silane coupling agent solution is 0.5%-1.5% of the mass of the silane emulsion, and the concentration is 0.5wt%-2.0wt% (e.g., 0.5wt%, 1.0wt%, 1.5wt%, or 2.0wt%); in step A2, when adding the acrylic emulsion, 20% of the total amount of acrylic emulsion is added each time, and the time interval between two adjacent additions is 10-15 minutes (e.g., 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, or 15 minutes). After the addition is complete, continue stirring for 1-1.5 hours (e.g., 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, or 1.5 hours); in step A3, the concentration of the n-propyl zirconate solution is 70 wt%, the mass of the n-propyl zirconate solution is 0.2% of the sum of the masses of the silane emulsion and the acrylic emulsion, and the stirring reaction time is 1-1.5 hours (to promote partial cross-linking of some silane and acrylic molecules; e.g., 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, or 1.5 hours); in step A4, the mass of the thickener is 0.1% of the sum of the masses of the silane emulsion and the acrylic emulsion; the mass percentage of the silicone-acrylic antipermeable emulsion in the liquid is 20%-40% (e.g., 20%, 25%, 30%, 35%, or 40%).

[0034] Preferably, the acrylic emulsion has a mass percentage of 40%-50%, and the mass ratio of the acrylic emulsion to the n-butyltriethoxysilane emulsion is 5:2.

[0035] The Si-O bond energy of n-butyltriethoxysilane (452 ​​kJ / mol) is much higher than that of C-C bonds (347 kJ / mol) and CO bonds (358 kJ / mol), making it less prone to breakage in acidic and alkaline environments. The hydrophobic n-butyl long chains are oriented along the pore walls, reducing contact between the corrosive medium and the substrate. Styrene-acrylic emulsion is used as the acrylic emulsion; the conjugated structure of the benzene ring enhances the polymer's chemical stability, exhibiting stronger alkali resistance and oxidation resistance compared to pure acrylic emulsion. The Si-O network of the compounded silane protects the acrylic acid molecular chains, preventing saponification and hydrolysis in strongly alkaline environments. The silane coupling agent (KH-570) forms a chemical bridge between the silane and acrylic acid, while the chemical bonding between the silane and the cementitious material enhances interfacial adhesion. Even under long-term immersion in corrosive media, the coating or modified layer will not peel off, preventing the corrosive medium from penetrating through the interface.

[0036] The present invention also proposes a method for preparing a sealing material. The method for preparing the sealing material in the embodiment of the present invention includes the following steps: (1) adding sulfoaluminate cement, ordinary silicate cement, composite filler, ettringite precursor, water-reducing agent and hydroxypropyl methylcellulose ether into a mixer and mixing them evenly to obtain powder; (2) mixing the liquid material and the powder material in proportion to obtain the sealing material.

[0037] In a preferred embodiment of the method for preparing the sealing material of the present invention, in step (1), the mixing speed is 500-700 r / min (e.g., 500 r / min, 550 r / min, 600 r / min, 650 r / min or 700 r / min), and the mixing time is 10-15 min (e.g., 10 min, 11 min, 12 min, 13 min, 14 min or 15 min); the penetrating crystallizing active powder is obtained by adding sodium sulfate, sodium carbonate, lithium carbonate, sodium ethylenediaminetetraacetate, sodium silicate and sodium diisobutylnaphthalenesulfonate into a mixer and mixing at a speed of 500-700 r / min (e.g., 500 r / min, 550 r / min, 600 r / min, 650 r / min or 700 r / min) for 10-15 min (e.g., 10 min, 11 min, 12 min, 13 min, 14 min or 15 min).

[0038] The sealing material and its preparation method of the present invention will be described in detail below through specific embodiments.

[0039] Unless otherwise specified, all raw materials used in the following experiments are commercially available; the sources of the main raw materials used in the following examples are: Jianwen Grade 42.5, manufactured by Zhengzhou Jianwen Special Materials Technology Co., Ltd.; Tianrui Grade 42.5, produced by Zhengzhou Cement Co., Ltd. of Tianrui Group; the ettringite precursor is a mixture of anhydrous aluminum sulfate and calcium hydroxide, with a mass ratio of 1.3:1; anhydrous aluminum sulfate, produced by Shanghai Yuanye Biotechnology Co., Ltd.; calcium hydroxide, produced by Henan Mingtai Chemical Co., Ltd.; fly ash microspheres (particle size 5-10 μm), produced by Zhengzhou Hollilight New Materials; hydroxypropyl methylcellulose ether (HPMC, viscosity 100,000) The following products are listed: (1) Hebei Guanxiang New Material Technology Co., Ltd.; (2) Powdered polycarboxylate superplasticizer with a water reduction rate ≥32%, Jiangxi Yingshan Supermaterial Technology Co., Ltd.; (3) Anhydrous sodium sulfate, industrial grade purity, Jiangsu Yinzhu Chemical Group Co., Ltd.; (4) Industrial calcium formate, sodium carbonate, lithium carbonate, and sodium diisobutylnaphthalene sulfonate, industrial grade purity, Shandong Yousuo Chemical Technology Co., Ltd.; (5) Tetrasodium ethylenediaminetetraacetate, analytical grade, Tianjin Dengfeng Chemical Reagent Factory; (6) Instantly soluble sodium silicate, modulus 2.8, Henan Borun New Material Co., Ltd.; (7) n-propyl zirconate solution, concentration 70wt%, Hubei Kewode Chemical Co., Ltd.; (8) Silane coupling agent KH-570, concentration 0.5wt%-2wt%. The thickener, model TT-935 (a high-content, low-viscosity polyacrylic acid modified alkali-soluble emulsion), is produced by Nantong Hantai Chemical Co., Ltd.; the acrylic emulsion is a styrene-acrylic emulsion, with a mass percentage of 40%-50% and a pH value of 7.5-8.5, produced by Jiangxi Chenguang New Material Co., Ltd.; the n-butyltriethoxysilane emulsion, with a mass percentage of 30%-40% and a pH value of 5-6, is produced by Hubei Xinhongli Chemical Co., Ltd.

[0040] Performance testing methods: The setting time, flexural strength, compressive strength, seepage pressure, bond strength, water absorption, wet-dry cycle, freeze-thaw cycle, sulfate attack resistance coefficient, and chloride ion diffusion coefficient of the sealing materials in the following examples were tested according to the test methods in GB 23440-2009 "Inorganic Waterproofing and Leak-stopping Materials", DL / T 5126-2021 "Test Procedure for Polymer Modified Cement Mortar" and GB / T 50082-2024 "Standard for Test Methods of Long-term Performance and Durability of Concrete".

[0041] Example 1 The sealing material in this embodiment comprises powder and liquid components; By weight, the powder comprises: sulfoaluminate cement, ordinary silicate cement, 20 parts of composite filler, 3.5 parts of ettringite precursor, 0.05 parts of polycarboxylate superplasticizer, 0.05 parts of hydroxypropyl methylcellulose ether, and 2 parts of penetrating crystallizing active powder; wherein, the total weight of sulfoaluminate cement and ordinary silicate cement is 74.4 parts, and the weight ratio of sulfoaluminate cement to ordinary silicate cement is 4.5:1; The composite filler was prepared by the following steps: fly ash microspheres with a particle size of 5-10 μm were mixed with a 1.0 wt% KH-570 silane coupling agent solution at a mass ratio of 100:3, and an ethanol aqueous solution was added (ethanol to water volume ratio of 3:1, and ethanol aqueous solution to silane coupling agent solution volume ratio of 100:5). The mixture was stirred at 70℃ for 3 h. After the reaction was completed, the mixture was filtered and dried to obtain the composite filler. The penetrating crystallization active powder, by weight percentage, includes: sodium sulfate 38%, sodium carbonate 7.5%, lithium carbonate 12%, tetrasodium ethylenediaminetetraacetate 12%, sodium silicate 30%, and sodium diisobutylnaphthalene sulfonate 0.5%.

[0042] In this embodiment, the mass ratio of powder to liquid is 1:0.35; the liquid consists of deionized water and silicone-acrylic antipermeability emulsion; in this embodiment, the mass ratio of silicone-acrylic antipermeability emulsion to deionized water is 1:9, and the liquid is obtained by stirring evenly with a high-speed mixer. The silicone-acrylic antipermeable emulsion is prepared by a method including the following steps: A1. At 25-30℃, take 100g of n-butyltriethoxysilane emulsion (mass percentage of 30%-40%) and deionized water at a mass ratio of 1:1 and stir evenly to obtain diluted n-butyltriethoxysilane emulsion (to reduce the emulsion concentration and reduce viscosity abrupt changes during emulsion mixing); start stirring and slowly add 10g of KH-570 silane coupling agent solution with a concentration of 1.0wt% to 200g of diluted n-butyltriethoxysilane emulsion. After the addition is completed, keep warm for 1h to allow the two to fully combine. A2. Heat to 70℃ and add 500g of acrylic emulsion (mass concentration of 40%-50%, the acrylic emulsion solution is added dropwise in several batches, each time adding 20% ​​of the total amount of acrylic emulsion, with an interval of 10-15 minutes between two consecutive additions). After the addition is completed, continue stirring for 1 hour to obtain the compound emulsion. A3. Cool down to 60℃, add 70wt% n-propylzirconate solution to the compound emulsion, the amount of which is 0.2% of the total mass of silane emulsion and acrylic emulsion, and stir to react for 1 hour; A4. After cooling, add 0.1% of the total mass of silane emulsion and acrylic emulsion as a thickener to adjust the viscosity to the construction requirements. Let it stand at room temperature for 24 hours to mature, and the silicone-acrylic anti-permeability emulsion is obtained.

[0043] The preparation method of the sealing material in this embodiment includes the following steps: (1) Weigh sodium sulfate, sodium carbonate, lithium carbonate, tetrasodium ethylenediaminetetraacetate, sodium silicate and sodium diisobutylnaphthalene sulfonate according to the ratio, add them to the mixer and dry mix them at 700 r / min for 15 min to uniformly prepare penetrating crystallizing active powder; (2) Weigh sulfoaluminate cement, ordinary silicate cement, composite filler, ettringite precursor, penetrating crystallizing active powder, polycarboxylate superplasticizer and hydroxypropyl methylcellulose ether according to the ratio, add them to the mixer and dry mix them at 700 r / min for 15 min to obtain powder; (3) Mix the powder and liquid in proportion to obtain the sealing material of this embodiment.

[0044] Example 2 The only difference between this embodiment and Embodiment 1 is that the mass ratio of silicone-acrylic antipermeable emulsion to deionized water is 1:4; all other aspects are the same as in Embodiment 1.

[0045] Example 3 The only difference between this embodiment and Embodiment 1 is that the mass ratio of silicone-acrylic antipermeable emulsion to deionized water is 1:14; all other aspects are the same as in Embodiment 1.

[0046] Example 4 The only difference between this embodiment and Embodiment 1 is that the mass ratio of silicone-acrylic antipermeable emulsion to deionized water is 1:19; all other aspects are the same as in Embodiment 1.

[0047] Comparative Example 1 The components of the sealing material in this comparative example include powder and liquid. By mass, the powder materials include: sulfoaluminate cement, ordinary silicate cement, 20 parts fly ash, 3.5 parts ettringite precursor, 0.05 parts polycarboxylate superplasticizer, and 0.05 parts hydroxypropyl methylcellulose ether; the total mass of sulfoaluminate cement and ordinary silicate cement is 76.4 parts. The mass ratios of sulfoaluminate cement to ordinary silicate cement were respectively 3:1, 3.5:1, 4:1, 4.5:1, and 5:1; Liquid material: deionized water; the mass ratio of powder to liquid material is 1:0.35.

[0048] The performance of the sealing material in this comparative example was tested, and the test results are shown in Table 1 below: Table 1

[0049] Note: In the wet-dry cycle test results, "cracking", "peeling" and "detachment" represent three different degrees of damage.

[0050] Comparative Example 2 In this comparative example of a penetrating crystallization sealing material, the powder, by mass parts, includes: fly ash (the mass of fly ash is set to 10 parts, 5 parts, 0 parts, 0 parts, and 0 parts respectively), composite filler (the corresponding mass of composite filler is 10 parts, 15 parts, 20 parts, 25 parts, and 30 parts respectively), 3.5 parts of ettringite precursor, 0.05 parts of polycarboxylate superplasticizer, and 0.05 parts of hydroxypropyl methylcellulose ether. Correspondingly, the sum of the masses of sulfoaluminate cement and ordinary silicate cement is 76.4 parts, 76.4 parts, 76.4 parts, 71.4 parts (when the amount of composite filler is 25 parts), and 66.4 parts (when the amount of composite filler is 30 parts), with a mass ratio of sulfoaluminate cement to ordinary silicate cement of 4.5:1.

[0051] The composite filler was prepared by the following steps: fly ash microspheres with a particle size of 5-10 μm were mixed with a KH-570 silane coupling agent solution with a concentration of 1.0 wt% at a mass ratio of 100:3. An ethanol aqueous solution was added (ethanol to water volume ratio of 3:1, and ethanol aqueous solution to silane coupling agent solution volume ratio of 100:5). The mixture was stirred and reacted at 70°C for 3 hours. After the reaction was completed, the mixture was filtered and dried to obtain the composite filler.

[0052] Liquid material: deionized water; the mass ratio of powder to liquid material is 1:0.35.

[0053] The performance of the sealing material in this comparative example was tested, and the test results are shown in Table 2 below: Table 2

[0054] Comparative Example 3 The components of the sealing material in this comparative example include powder and liquid. By weight percentage, the powder comprises: 20 parts of sulfoaluminate cement, ordinary silicate cement, composite filler (the same as the composite filler in Example 3), 3.5 parts of ettringite precursor, 0.05 parts of polycarboxylate superplasticizer, 0.05 parts of hydroxypropyl methylcellulose ether, and penetrating crystallizing active powder. The mass fractions of the penetrating crystallizing active powder were set to 1.0, 1.5, 2, 2.5, and 3.0 parts, respectively, and the corresponding total mass fractions of sulfoaluminate cement and ordinary silicate cement (the mass ratio of sulfoaluminate cement to ordinary silicate cement was 4.5:1) were set to 75.45, 74.95, 74.4, 73.95, and 73.45 parts, respectively. The penetrating crystallization active powder includes: 38% sodium sulfate, 7.5% sodium carbonate, 12% lithium carbonate, 12% tetrasodium ethylenediaminetetraacetate, 30% sodium silicate, and 0.5% sodium diisobutylnaphthalene sulfonate. Liquid material: deionized water; the mass ratio of powder to liquid material is 1:0.35.

[0055] The performance of the sealing material in this comparative example was tested, and the test results are shown in Table 3 below: Table 3

[0056] Comparative Example 4 The only difference between this comparative example and Example 1 is that the liquid used is different (the components of the liquid in this comparative example include deionized water and silicone-acrylic antipermeable emulsion; in the liquid of this comparative example, the mass ratio of silicone-acrylic antipermeable emulsion to deionized water is 1:1); all other aspects are the same as in Example 1.

[0057] The mass ratio of powder to liquid is 1:0.35.

[0058] The performance of the sealing materials in Examples 1-4 and this comparative example was tested, and the test results are shown in Table 4 below: Table 4

[0059] Comparative Example 5 The only difference between this comparative example and Example 1 is the liquid used. The liquid in this comparative example consists of deionized water and acrylic emulsion (the mass ratio of acrylic emulsion to deionized water in this comparative example is 1:1, 1:4, 1:9, 1:14, and 1:19). Everything else is the same as in Example 1.

[0060] The mass ratio of powder to liquid is 1:0.35.

[0061] The performance of the sealing material in this comparative example was tested, and the test results are shown in Table 5 below: Table 5

[0062] Comparative Example 6 The only difference between this comparative example and Example 1 is the liquid used. The liquid in this comparative example consists of deionized water and n-butyltriethoxysilane emulsion. (In this comparative example, the mass ratio of n-butyltriethoxysilane emulsion to deionized water is 1:1, 1:4, 1:9, 1:14, and 1:19. The liquid is obtained by stirring evenly with a high-speed mixer.) All other aspects are the same as in Example 1.

[0063] The mass ratio of powder to liquid is 1:0.35.

[0064] The performance of the sealing material in this comparative example was tested, and the test results are shown in Table 6 below: Table 6

[0065] Comparative Examples 5-6 were used to test various properties of the materials when acrylic emulsion and n-butyltriethoxysilane emulsion were used instead of the silicone acrylic emulsion in Example 1. The water absorption performance of Comparative Examples 5-6 was significantly worse than that of Example 1, and the performance of wet-dry cycle and freeze-thaw cycle was also poor when the amount of emulsion was small. This proves that the silicone acrylic antipermeable emulsion technology in this invention can better improve water absorption and enhance durability.

[0066] Experiments were conducted on Comparative Example 1 (mass ratio of sulfoaluminate cement to ordinary silicate cement was 4.5:1), Comparative Example 2 (20 parts of composite filler), Comparative Example 3 (2 parts of penetrating crystallizing active powder), Example 1 and Comparative Example 5 (mass ratio of acrylic emulsion to deionized water was 1:14), and Comparative Example 6 (mass ratio of n-butyltriethoxysilane emulsion to deionized water was 1:19) to test the 90-day sulfate attack resistance coefficient and 28-day chloride ion diffusion coefficient of each group of materials. The test results are shown in Table 7: Table 7

[0067] As can be seen from the test results in the table above, after the combined effects of composite filler, penetrating crystallizing active powder, and silicone-acrylic antipermeable emulsion, Example 1, compared to Comparative Example 1, showed a 33.8% increase in sulfate resistance coefficient and an 88.5% decrease in chloride ion diffusion coefficient. This indicates that the modified plugging material has a dense internal porosity and that the silicone-acrylic antipermeable emulsion outperforms both single acrylic emulsions and n-butyltriethoxysilane emulsions. The resulting polymer film effectively blocks the penetration channels of corrosive media, resisting the intrusion of external moisture, chloride ions, sulfate ions, and other corrosive media, thus significantly enhancing the material's antipermeability and durability. This is consistent with the high sulfate resistance coefficient and low chloride ion diffusion coefficient results shown in Example 1 in Table 7, further verifying the crucial role of the liquid composition and ratio in improving the overall protective effect of the material.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A leak-sealing material, characterized in that, include: Powder and liquid materials; By weight, the powder comprises: 40-60 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 15-25 parts of composite filler, 3.0-5.0 parts of ettringite precursor, 0.04-0.1 parts of water-reducing agent, 0.05-0.1 parts of hydroxypropyl methylcellulose ether, and 1.0-3.0 parts of penetrating crystallizing active powder; The liquid material comprises, by weight, 50-95 parts of deionized water and 5-50 parts of silicone-acrylic antipermeability emulsion; The composite filler is fly ash modified with a silane coupling agent, and the particle size of the composite filler is 5-10 μm.

2. The sealing material as described in claim 1, characterized in that, The composite filler is prepared by a method comprising the following steps: The fly ash and silane coupling agent solution are mixed, and an ethanol solution is added. The mixture is stirred and reacted at 60-70℃ for 2-3 hours. After filtration and drying, the composite filler is obtained.

3. The sealing material as described in claim 2, characterized in that, The silane coupling agent is KH-570, the concentration of the silane coupling agent solution is 0.5wt%-2.0wt%, and the mass ratio of fly ash to the silane coupling agent solution is 100:

3. The volume ratio of ethanol to water in the ethanol solution is 3:1, and the volume ratio of the ethanol solution to the silane coupling agent solution is 100:

5.

4. The sealing material as described in claim 1, characterized in that, The grade of the sulfoaluminate cement is: 42.5, the grade of ordinary Portland cement is 42.5; The mass ratio of sulfoaluminate cement to ordinary silicate cement is (3.0-5.0):

1.

5. The sealing material as described in claim 1, characterized in that, The precursor of ettringite is a mixture of anhydrous aluminum sulfate and calcium hydroxide, with a mass ratio of anhydrous aluminum sulfate to calcium hydroxide of (1.3-1.5):

1. The permeation crystallization active powder is obtained by mixing the following raw materials in the indicated mass percentages: sodium sulfate 35%-40%, sodium carbonate 5%-10%, lithium carbonate 10%-15%, tetrasodium ethylenediaminetetraacetate 8%-12%, sodium silicate 30%-35%, and sodium diisobutylnaphthalene sulfonate 0.1%-0.5%.

6. The sealing material as described in claim 1, characterized in that, The mass ratio of the liquid to the powder is 0.30-0.

35.

7. The sealing material as described in claim 1, characterized in that, The silicone-acrylic antipermeable emulsion is prepared by a method comprising the following steps: A1. Add KH-570 silane coupling agent solution dropwise to the silane emulsion at 25-30℃; A2. Heat to 70-80℃, add acrylic emulsion dropwise, and continue stirring after the addition is complete to obtain a compound emulsion; A3. Cool to 60-70℃, add n-propyl zirconate solution to the compound emulsion, and stir to react; A4. After cooling, add a thickener to adjust the viscosity and allow it to mature to obtain the silicone-acrylic anti-permeability emulsion.

8. The sealing material as described in claim 7, characterized in that, In step A1, the silane emulsion is n-butyltriethoxysilane emulsion, and the acrylic emulsion is styrene-acrylic emulsion; In step A1, the mass of the KH-570 silane coupling agent solution is 0.5%-1.5% of the sum of the masses of the silane emulsion and the acrylic emulsion, and the concentration of the KH-570 silane coupling agent solution is 0.5wt%-2.0wt%. In step A2, when adding acrylic emulsion, add 20% of the total amount of acrylic emulsion each time, with a time interval of 10-15 minutes between two consecutive additions; after the addition is completed, continue stirring for 1-1.5 hours. In step A3, the concentration of the n-propyl zirconate solution is 70 wt%, the mass of the n-propyl zirconate solution is 0.2% of the sum of the masses of the silane emulsion and the acrylic emulsion, and the stirring time is 1 h to 1.5 h; In step A4, the mass of the thickener is 0.1% of the sum of the masses of the silane emulsion and the acrylic emulsion; The mass percentage of silicone-acrylic antipermeable emulsion in the liquid material is 20%-40%.

9. The method for preparing the sealing material according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Add sulfoaluminate cement, ordinary silicate cement, composite filler, ettringite precursor, penetrating crystallization active powder, water-reducing agent and hydroxypropyl methylcellulose ether into a mixer and mix evenly to obtain powder; (2) Mix the liquid and powder materials in a certain proportion to obtain the sealing material.

10. The method for preparing the sealing material as described in claim 9, characterized in that, In step (1), the mixing speed is 500-700 r / min and the mixing time is 10-15 min; The permeation crystallization active powder is obtained by adding sodium sulfate, sodium carbonate, lithium carbonate, sodium ethylenediaminetetraacetate, sodium silicate, and sodium diisobutylnaphthalenesulfonate into a mixer and mixing them at a speed of 500-700 r / min for 10-15 min.

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