High-toughness impervious polymer modified cement-based grouting material and preparation method thereof

Abstract

The invention discloses a high-toughness impervious polymer modified cement-based grouting material and a preparation method thereof, and belongs to the technical field of building repair materials. The component A is prepared from a cementing material, an admixture, a fine aggregate, a composite expanding agent, a polymer for concrete modification, fibers, an early strength agent, a water reducing agent, a composite retarder, a defoaming agent, an air entraining agent, a nano material and a functional component. The system solves the technical contradiction of toughness-strength-impermeability in the polymer modified cement-based material, and the material has excellent comprehensive performance: the initial fluidity is greater than or equal to 330 mm, the 28d compressive strength is greater than or equal to 82 MPa, the breaking strength is greater than or equal to 16.8 MPa, the bending-compression ratio is greater than or equal to 0.19, the impermeability pressure value is greater than or equal to 2.6 MPa, and the material is suitable for the fields of prefabricated buildings, tunnel engineering and the like.

Description

Technical Field

[0001] This invention belongs to the field of building repair materials technology, specifically relating to a high-toughness, impermeable polymer-modified cement-based grouting material and its preparation method. Background Technology

[0002] Grouting material is a building repair material made from cementitious materials, high-strength aggregates, and high-performance admixtures in a specific mix ratio. When mixed with water, it exhibits excellent properties such as high fluidity, high strength, low shrinkage, and micro-expansion. Grouting material is widely used in various construction fields, including prefabricated buildings, tunnel lining repair, and sleeve grouting.

[0003] Polymer-modified grouting materials, as a key direction for optimizing the performance of cement-based materials, are widely used in building reinforcement, tunnel seepage prevention, and other projects. However, existing polymer-modified cement-based materials suffer from significant technical contradictions and performance defects. Cement-based materials themselves have a porous and brittle structure, exhibiting a high compressive-flexural ratio and susceptibility to cracking during hardening. The core technical challenge in polymer modification is that at low dosages, the polymer struggles to form a continuous film, filling pores only as a dispersed phase. While this slightly improves toughness, it fails to effectively block seepage channels, resulting in limited improvement in impermeability. High dosages, while forming a three-dimensional network structure to improve impermeability, cause the polymer to completely encapsulate cement particles, severely hindering hydration reactions and leading to a significant decrease in strength. This contradiction between toughness, impermeability, and strength restricts the reliability of engineering projects.

[0004] In the prior art, Chinese patent application publication number CN115650681A discloses a grouting material comprising epoxy resin, reactive diluent, toughening agent, coupling agent, leveling agent, defoamer, nonionic waterborne epoxy curing agent, ordinary silicate cement, sulfoaluminate cement, expanding agent, organic mineral composite agent, silica fume, and other components. While the grouting material prepared by this technical solution possesses certain compressive strength and toughness, it suffers from the following technical defects: First, the use of a large amount of liquid components (epoxy resin, reactive diluent, etc.) makes the material difficult to carry and use on-site, increasing construction complexity and transportation costs; second, the patent does not clearly specify the material's impermeability and its technical indicators, posing a risk of leakage in applications such as underground engineering and tunnel engineering where impermeability is required; third, epoxy resin materials are costly, and their interfacial compatibility with the cement matrix may lead to long-term performance degradation; finally, this technical solution does not systematically address the balance problem among toughness, strength, and impermeability that is commonly found in polymer-modified cement-based materials.

[0005] From a technical mechanism analysis, existing polymer-modified cement-based materials mainly suffer from the following scientific problems: First, the coupling and regulation of polymer film formation and cement hydration kinetics are insufficient, resulting in a mismatch between the polymer film formation and cement hardening time, making it difficult to simultaneously obtain a dense structure and sufficient hydration; Second, the synergistic effect mechanism between nanomaterials and polymers has not been fully utilized, and the role of nanomaterials in improving the matrix microstructure, providing additional nucleation sites, and enhancing interfacial bonding has not been systematically developed; Third, the design of the expansion compensation mechanism is not refined enough, and existing technologies mostly use a single expansion agent, making it difficult to achieve segmented expansion control in the plastic stage and the later stage of hardening, and unable to effectively compensate for shrinkage throughout the entire age; Fourth, the interaction mechanism between multi-component materials is unclear, and there is a lack of a systematic methodology for formula optimization.

[0006] Furthermore, existing technologies face a contradiction between flowability and mechanical properties in engineering applications. To ensure the self-leveling properties of the grout, a high dosage of water-reducing agent is usually required, but this reduces the early strength development rate; conversely, increasing the dosage of early-strength agent to improve early strength may shorten the setting time, affecting construction operation time and grout filling. These technical contradictions make it difficult for existing grouts to simultaneously meet the comprehensive performance requirements of high flowability, high toughness, high strength, and high impermeability.

[0007] Therefore, there is an urgent need to develop a new type of high-toughness, impermeable polymer-modified cementitious grouting material. Through systematic formulation design and component synergistic optimization, the above-mentioned technical problems can be solved, and a comprehensive balance improvement in toughness, strength, impermeability and workability can be achieved. Summary of the Invention

[0008] To address the aforementioned problems in existing technologies, the present invention aims to provide a high-toughness, impermeable polymer-modified cementitious grouting material and its preparation method. This material, through multi-component synergistic design and refined proportioning optimization, systematically resolves the technical contradictions between toughness, strength, and impermeability in polymer-modified cementitious materials, achieving excellent comprehensive performance.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The first aspect of this invention provides a high-toughness, impermeable polymer-modified cementitious grouting material, comprising component A and water. Based on the total mass of component A, component A comprises the following components: 10-80 wt% cementitious material, 1-50 wt% admixture, 10-80 wt% fine aggregate, 0.01-15 wt% expansive agent, 0.01-10 wt% polymer for concrete modification, 0.01-5 wt% fiber, 0.01-14 wt% early-strength agent, 0.1-25 wt% water-reducing agent, 0.01-16 wt% retarder, 0.04-20 wt% defoamer, 0.01-0.05 wt% air-entraining agent, 0.01-10 wt% nanomaterials, and 0.01-5 wt% functional components.

[0011] In the preferred technical solution, the cementitious material is cement, preferably silicate cement, including but not limited to P.O42.5 cement, P.Ⅰ42.5 cement, P.Ⅱ42.5 cement, P.MSR42.5 cement, P.HSR42.5 cement, P.O52.5 cement, P.Ⅰ52.5 cement, P.Ⅱ52.5 cement, etc.

[0012] In a preferred embodiment, the admixture is selected from at least one of silica fume, mineral powder, fly ash, blast furnace slag, metakaolin, steel slag powder, zeolite powder, phosphorus slag powder, and limestone powder. More preferably, the admixture is a combination of silica fume, mineral powder, and fly ash. Even more preferably, based on the total mass of the silica fume, mineral powder, and fly ash, the content of silica fume is 0.1-41 wt%, the content of mineral powder is 0.1-68 wt%, and the content of fly ash is 0.1-36 wt%. The silica fume is preferably 96% silica fume with a silicon content ≥96%; the fly ash is preferably Grade I fly ash with a density of 2.0–2.6 g / cm³.

[0013] In a preferred embodiment, the fine aggregate is selected from at least one of quartz sand, manufactured sand, and artificial sand. More preferably, the fine aggregate is quartz sand. Even more preferably, based on the total mass of the quartz sand, the content of 20-40 mesh quartz sand is 27.3-33.3 wt%, the content of 40-70 mesh quartz sand is 29.4-38.7 wt%, and the content of 70-120 mesh quartz sand is 29.4-38.7 wt%. This multi-graded quartz sand system can form a densely packed structure, effectively reducing porosity and improving the density and impermeability of the grout.

[0014] In a preferred embodiment, the expanding agent is a combination of a plastic expanding agent and a post-expanding agent. Based on the total mass of the expanding agent, the content of the plastic expanding agent is 0.01-40 wt%, and the content of the post-expanding agent is 60-99.99 wt%. The plastic expanding agent is selected from at least one of azodicarbonamide, aluminum powder, EP-2 plastic expanding agent, sodium percarbonate, sodium acetate, and ammonia water. The concentration of the ammonia water is 25-28 wt%. The post-expanding agent is selected from at least one of MgO expanding agent, CaO expanding agent, calcium vanadium-based expanding agent, and composite expanding agent. More preferably, the expanding agent is a combination of azodicarbonamide and the composite expanding agent HP-CSA in a mass ratio of 1:(50-200). The innovation of this composite expansive agent system lies in the following: azodicarbonamide begins to decompose and generate gas during the plastic stage after the grout is mixed, providing early expansion and effectively compensating for plastic shrinkage; while the composite expansive agent HP-CSA generates expansive hydration products such as ettringite during cement hydration, providing continuous expansion in the later stages and compensating for hardening shrinkage. The sequential combination of these two expansion mechanisms achieves shrinkage compensation throughout the entire lifespan, while avoiding the risk of cracking caused by excessive expansion.

[0015] In a preferred embodiment, the polymer for concrete modification is selected from at least one of water-soluble polymers, polymer emulsions, and redispersible polymer powders. The water-soluble polymer is selected from at least one of polyvinyl alcohol, cellulose derivatives, polyacrylamide, acrylates, and furanylaniline resins. The cellulose derivative is preferably methylcellulose and / or hydroxyethylcellulose. The polymer emulsion is selected from at least one of polyacrylate emulsions, styrene-butadiene emulsions, carboxylated styrene-butadiene emulsions, styrene-acrylic emulsions, vinyl polyvinyl acetate emulsions, vinyl acetate-acrylic acid copolymer emulsions, polyvinyl propionate emulsions, vinylidene chloride-vinyl chloride, waterborne epoxy resin emulsions, rubber asphalt emulsions, styrene-butadiene rubber emulsions, styrene-acrylic acid copolymer emulsions, and polystyrene acrylates. The redispersible polymer powder is selected from at least one of ethylene-vinyl acetate copolymer, polystyrene-acrylate latex powder, polyethylene-vinyl acetate latex powder, polyacrylate latex powder, vinyl acetate, polyacrylate-styrene, polyethylene-vinyl chloride-vinyl laurate, polyvinyl acetate-ethylene-higher fatty acid vinyl ester, and vinyl acetate-higher fatty acid vinyl ester. Most preferably, the polymer for concrete modification is ethylene-vinyl acetate copolymer (EVA copolymer). EVA copolymer has excellent film-forming properties and flexibility, enabling it to form a continuous polymer film layer during cement hydration, effectively filling capillary pores. Simultaneously, through the physical entanglement and chemical interaction between polymer segments and cement hydration products, it significantly improves the toughness and impermeability of the material.

[0016] In a preferred embodiment, the nanomaterial is selected from nanomaterials. Carbon nanotubes, nano ,nanometer Graphene, nano At least one of the following. More preferably, the nanomaterial is graphene. Graphene has an extremely high specific surface area (theoretical value 2630 m² / g) and excellent mechanical properties (tensile strength about 130 GPa, elastic modulus about 1 TPa), and can play multiple roles in cement-based materials: first, as a nano-reinforcement, it improves the fracture toughness of the material through bridging and pull-out mechanisms; second, its two-dimensional sheet structure can deflect and block crack propagation paths, improving crack resistance; third, the nano-network structure formed in cement paste can refine the pore structure, reduce porosity, and significantly improve impermeability; fourth, it provides additional nucleation sites, accelerates cement hydration reaction, and promotes the uniform distribution of hydration products.

[0017] In a preferred embodiment, the retarder is a carbohydrate compound, sodium gluconate, borax, orthophosphoric acid, etc. , , , Sodium polyphosphate, sodium tripolyphosphate, sodium pyrophosphate, citric acid, tartaric acid, salicylic acid, and polyols and their derivatives, or a combination thereof. More preferably, when a combination of saccharide compounds, sodium gluconate, and borax is used, the mass ratio is (0.8-1.2):(0.8-1.2):(0.8-1.2). The saccharide compounds are preferably glucose and / or sucrose. The mechanism of action of this composite retarder system is that sucrose adsorbs... Ions reduce the concentration of hydroxide ions in the liquid phase and inhibit tricalcium silicate ( Solubility of sodium gluconate; sodium gluconate is dissolved through chelation. Ions, delaying the reaction of calcium hydroxide ( Crystal formation; further adsorption of borax It forms a dense adsorption layer on the surface of cement particles, hindering the diffusion of water molecules and the precipitation of hydration products. The three retarders work synergistically to inhibit the cement hydration reaction through multiple pathways, achieving excellent retarding effect, while providing sufficient time for polymer film formation and nanomaterial dispersion.

[0018] In a preferred embodiment, the fiber is selected from at least one of polyvinyl alcohol fiber, steel fiber, polypropylene fiber, basalt fiber, carbon fiber, polyacrylonitrile fiber, wood fiber, and glass fiber. The steel fiber is selected from at least one of plain carbon steel fiber, stainless steel fiber, aluminum fiber, copper fiber, titanium fiber, and alloy fiber. The role of the fiber in the grout is to limit crack propagation through a bridging effect, thereby improving the material's crack resistance and toughness. Different types of fibers have different toughening mechanisms: polyvinyl alcohol fiber has good hydrophilicity and interfacial bonding performance with the cement matrix; steel fiber has the highest tensile strength and modulus, suitable for applications requiring high strength; polypropylene fiber can effectively control plastic shrinkage cracks; basalt fiber and carbon fiber combine high strength and corrosion resistance.

[0019] In a preferred embodiment, the early-strength agent is selected from at least one of calcium formate, sodium acetate, ethylene glycol, glycerol, triethanolamine, triisopropanolamine, lithium carbonate, gypsum dihydrate, sodium nitrite, calcium nitrate, sodium nitrate, calcium chloride, aluminum chloride, calcium sulfate, and sodium sulfate. The early-strength agent accelerates the cement hydration reaction, increases the early strength development rate of the grout, shortens the demolding time, and meets the requirements of rapid construction.

[0020] In a preferred embodiment, the water-reducing agent is selected from at least one of naphthalene-based water-reducing agents, aliphatic water-reducing agents, lignin water-reducing agents, melamine-based water-reducing agents, aminosulfonate water-reducing agents, and polycarboxylate water-reducing agents. More preferably, the water-reducing agent is a polycarboxylate water-reducing agent. Polycarboxylate water-reducing agents form an adsorption layer on the surface of cement particles through the steric hindrance effect of their side chains and the electrostatic repulsion of the carboxyl groups on the main chain. This allows the cement particles to be fully dispersed, significantly reducing the yield stress and plastic viscosity of the cement paste and improving its fluidity. Simultaneously, polycarboxylate water-reducing agents have a relatively small retardation effect on cement hydration, ensuring fluidity without excessively prolonging the setting time.

[0021] In a preferred embodiment, the defoamer is selected from at least one of fatty defoamers, polyether defoamers, silicone defoamers, and polyether-modified silicone defoamers. The fatty defoamer is preferably a mineral oil defoamer. The function of the defoamer is to reduce the number and stability of air bubbles generated during the mixing of the grouting material, reduce the porosity in the hardened body, and improve its density and strength.

[0022] In a preferred embodiment, the air-entraining agent is selected from at least one of rosin resin-based air-entraining agents, alkyl-based air-entraining agents, fatty alcohol sulfonate-based air-entraining agents, saponin-based air-entraining agents, and protein salt-based air-entraining agents. More preferably, the air-entraining agent is a saponin-based air-entraining agent, and even more preferably a triterpenoid saponin air-entraining agent. Triterpenoid saponins contain a hydrophilic hydroxy glycoside group and a hydrophobic pentacyclic triterpenoid aglycone in their molecular structure, exhibiting excellent surface activity. In grouting materials, triterpenoid saponin air-entraining agents can significantly reduce the surface tension of the grout, easily forming stable microbubbles during stirring. These uniformly distributed microbubbles play multiple roles in the grouting material: firstly, they act as ball bearings, improving the rheological properties of the grout and increasing its fluidity; secondly, under stress, they act as termination points for microcracks, preventing continuous crack propagation and improving toughness; and thirdly, the tortuous channels formed between the microbubbles significantly extend the penetration path, improving impermeability. Compared with other types of air-entraining agents, triterpenoid saponin air-entraining agents have advantages such as low dosage (only 0.01-0.05wt%), small bubble size (50-200μm), uniform distribution, good compatibility with other additives, and minimal loss of strength.

[0023] In a preferred embodiment, the functional component is a whisker, selected from one or more of silicon carbide, silicon nitride, alumina, titanate, zinc oxide, magnesium oxide, aluminum boron, glass, talc, mica, carbon, graphite, titanium oxide, and sulfides. As a one-dimensional nanomaterial, whiskers possess high aspect ratios (typically >20) and mechanical properties approaching theoretical strength. In cement-based materials, whiskers consume crack propagation energy through bridging and pull-out mechanisms, significantly improving the material's fracture toughness and crack resistance.

[0024] In a preferred embodiment, the mass ratio of water to component A is (0.03-0.4):1. The water-cement ratio (or water-material ratio) is a key parameter affecting the performance of grouting materials. An excessively low water-material ratio leads to insufficient fluidity, making self-leveling and thorough grouting difficult; while an excessively high water-material ratio improves fluidity, it increases porosity, reducing strength and impermeability. This invention achieves excellent fluidity performance under low water-material ratio conditions by optimizing the synergistic effect of admixtures such as water-reducing agents and air-entraining agents.

[0025] The second aspect of the present invention provides a method for preparing the above-mentioned high-toughness impermeable polymer-modified cementitious grouting material, comprising: mixing raw materials including cementitious materials, admixtures, fine aggregates, expansion agents, polymers for concrete modification, fibers, early-strength agents, water-reducing agents, retarders, defoamers, air-entraining agents, functional components and nanomaterials in the presence of water, thereby obtaining the grouting material.

[0026] In a preferred embodiment, the preparation method specifically includes the following steps:

[0027] (1) The cementitious materials and admixtures are first mixed to obtain powder A; and the expansive agent, concrete modifier polymer, fiber, early strength agent, water-reducing agent, retarder, defoamer, air-entraining agent and nanomaterials are second mixed to obtain powder B;

[0028] (2) Mix the powder A with the powder B and fine aggregate in a third mixing process to obtain grouting powder;

[0029] (3) Mix the grouting powder with water to obtain the final product.

[0030] The innovation of this preparation method lies in its stepwise mixing strategy, dividing the raw materials into three parts: powder A, powder B, and fine aggregates. Powder A contains the main cementitious materials and admixtures, which have similar particle size distributions, facilitating uniform mixing. Powder B contains expanding agents, polymers, fibers, and various additives; these functional components, through premixing, can form a uniform coating layer on the surface of the fine aggregates. Finally, the three parts of the raw materials are mixed, ensuring the uniform distribution of each component in the grout powder. Compared to one-time mixing, this stepwise mixing process significantly improves mixing uniformity, reduces agglomeration and segregation, and enhances the performance stability and batch reproducibility of the grout.

[0031] The beneficial effects of this invention are as follows:

[0032] I. Excellent Comprehensive Performance. The initial flowability of the grouting material of this invention reaches over 330 mm, and remains above 310 mm after 30 minutes. It achieves self-leveling without vibration, meeting the grouting requirements of complex structures. After 28 days of curing, the compressive strength reaches 85 MPa, the flexural strength reaches 17 MPa, and the flexural-compression ratio reaches over 0.2, indicating that the material has excellent toughness. The impermeability pressure value is significantly improved, meeting the engineering applications with high impermeability requirements. This comprehensive balance and improvement in toughness, strength, and impermeability is difficult to achieve with existing technologies.

[0033] II. Innovation of Multi-Component Synergistic Mechanism. This invention achieves synergistic effects among multiple components through systematic formulation design: polymers form a three-dimensional network structure in the cement matrix, filling capillary pores and providing toughness and impermeability; nanomaterials (especially graphene) improve fracture toughness through bridging and pull-out mechanisms, while refining the pore structure; fibers limit macroscopic crack propagation through bridging effects; composite expansion agents achieve full-age shrinkage compensation; and composite retarder provides sufficient time for polymer film formation and nanomaterial dispersion. The synergistic effect of these components breaks through the performance bottleneck of traditional single modification methods.

[0034] III. Segmented Expansion Control Mechanism. This invention employs a composite system of plastic expanding agent and post-expansion agent to achieve precise expansion control of the grout throughout its entire lifespan. The plastic expanding agent begins to expand by generating gas during the plastic stage of the grout, effectively compensating for plastic shrinkage and reducing plastic cracks. The post-expansion agent generates expansive products during hydration, compensating for hardening shrinkage and ensuring close contact between the grout and the substrate. This sequential segmented expansion mechanism avoids the problems of insufficient or excessive expansion caused by a single expanding agent, improving the volume stability and long-term performance of the grout.

[0035] IV. The composite retarding system is scientifically sound and reasonable. This invention employs a composite retarder system of carbohydrate compounds, sodium gluconate, and borax, which synergistically inhibits cement hydration through multiple mechanisms: sucrose adsorption... Sodium gluconate and borax chelate This composite retarding mechanism achieves precise control of the hydration rate, providing a sufficient time window for polymer film formation, nanomaterial dispersion, and the action of the expanding agent, while avoiding excessive delay in hydration and ensuring normal early strength development.

[0036] V. Nano-Polymer-Fiber Three-Level Toughening System. This invention constructs a multi-level toughening mechanism from the nanoscale to the microscale and then to the macroscale: nanomaterials (graphene) deflect and block microcrack propagation at the nano and submicron scales; polymer networks fill pores and provide a tough matrix at the microscale; and fibers bridge macroscopic cracks at the millimeter to centimeter scale. This cross-scale synergistic toughening mechanism enables the grout to maintain excellent crack resistance under different stress levels and crack scales, significantly improving the reliability and durability of the material.

[0037] VI. Simple and easy-to-implement process. This invention adopts a dry mixing process, with all components being powders or dispersible powders, avoiding the inconveniences of transportation, storage, and construction associated with liquid components. The step-by-step mixing process is simple, easy to control, and suitable for industrial production and on-site construction. It only requires the addition of water and stirring before use, offering high construction convenience and suitability for various engineering applications.

[0038] VII. Reasonable cost control. Compared with existing technologies that use high-cost polymers such as epoxy resin, this invention mainly uses cost-effective polymer materials such as ethylene-vinyl acetate copolymer. At the same time, through multi-component synergistic optimization, the amount of single component is reduced, thereby controlling material costs while achieving excellent performance and improving economic efficiency and market competitiveness.

[0039] In summary, this invention, through innovative formulation design and preparation methods, systematically solves the technical contradictions between toughness, strength, and impermeability in polymer-modified cement-based grouting materials, achieving a comprehensive improvement in overall performance. It provides a high-performance, easy-to-construct, and cost-effective new grouting material for prefabricated buildings, tunnel engineering, underground engineering, and other fields. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below through specific embodiments. Obviously, the embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0042] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0043] The raw materials used in the embodiments of this invention are described below:

[0044] Cementing material: P.O42.5 silicate cement, conforming to GB175-2007 standard.

[0045] Silica fume: 96 silica fume, silicon content ≥96%, specific surface area ≥15m² / g, average particle size 0.1-0.3μm.

[0046] Mineral powder: S95 grade slag powder, specific surface area ≥400m² / g, activity index ≥95%.

[0047] Fly ash: Grade I fly ash, density 2.0~2.6g / cm³, fineness (45μm sieve residue) ≤12%, water requirement ≤95%.

[0048] Quartz sand: 20-40 mesh, 40-70 mesh, 70-120 mesh quartz sand, SiO2 content ≥99%.

[0049] Azodicarbonamide: chemically pure, decomposition temperature 200-210℃.

[0050] HP-CSA composite expansion agent: calcium vanadium stone-hard gypsum-quicklime composite expansion agent, with a vertical expansion rate of 0.1% to 0.5%.

[0051] EVA redispersible latex powder: Ethylene-vinyl acetate copolymer redispersible powder, with vinyl acetate content of 18% to 20%, ash content of 10% to 12%, and bulk density of 400 to 500 g / L.

[0052] Polyvinyl alcohol fiber: 40μm in diameter, 12mm in length, tensile strength ≥1600MPa, elastic modulus ≥40GPa.

[0053] Calcium formate: chemically pure, content ≥98%.

[0054] Polycarboxylate superplasticizer: solid content 40%, water reduction rate ≥25%, pH value 6-8.

[0055] Glucose: chemically pure. Content ≥99%.

[0056] Sodium gluconate: chemically pure. Content ≥98%.

[0057] Borax: chemically pure. The content is ≥99.5%.

[0058] Mineral oil defoamer: Fatty defoamer, with an effective ingredient content of ≥98% and a surface tension of ≤25mN / m.

[0059] Triterpenoid saponin gas-entraining agent: Saponin-based gas-entraining agent with triterpenoid saponin content ≥75% and surface tension ≤30mN / m, recommended dosage 0.01%~0.05%.

[0060] Graphene: Single-layer graphene nanosheets, with 1-3 layers, average particle size of 1-5 μm, specific surface area of ​​500-700 m² / g, and purity >98%.

[0061] Silicon carbide whiskers: diameter 0.5-1.0μm, length 10-50μm, aspect ratio 20-100, tensile strength ≥3GPa.

[0062] Example 1

[0063] The cementitious materials and admixtures are first mixed (at a temperature of 20±2℃ for 30s) to obtain powder A; and the expansive agent, concrete modifier polymer, fiber, accelerator, water reducer, retarder, defoamer, air-entraining agent and nanomaterials are second mixed (at a temperature of 20±2℃ for 30s) to obtain powder B;

[0064] The powder A is mixed with the powder B and fine aggregate in a third mixing process (temperature 20±2℃, time 60s) to obtain grouting powder.

[0065] The grout powder is mixed with water to obtain a high-toughness, impermeable polymer-modified cement-based grouting material.

[0066] For details on the types and amounts of raw materials used in this embodiment, please refer to Table 1.

[0067] Unless otherwise specified, the remaining embodiments are carried out with reference to the method of Embodiment 1. The difference is that the types and amounts of substances used in each embodiment are as listed in Table 1.

[0068] In the following examples, the total mass of component A is 2 kg.

[0069] Table 1. Formulation composition of Examples 1-4

[0070] Components Example 1 Example 2 Example 3 Example 4 Cementitious materials / wt% 39.28 42.53 40.05 39.26 Silica fume / wt% 2.4 1.4 2.4 2.4 Mineral powder / wt% 1.8 1.9 0.9 1.8 fly ash / wt% 4.8 2.4 4.8 4.8 20-40 mesh quartz sand / wt% 14 15 14.8 14 40-70 mesh quartz sand / wt% 17 17 16.5 17 70-120 mesh quartz sand / wt% 17 17 16.5 17 azodicarbonamide / wt% 0.01 0.02 0.01 0.01 HP-CSA composite expander / wt% 2.39 1.38 2.39 2.39 Ethylene-vinyl acetate copolymer / wt% 0.28 0.2 0.3 0.2 Polyvinyl alcohol fiber / wt% 0.04 0.05 0.14 0.04 Calcium formate / wt% 0.7 0.7 0.8 0.7 Polycarboxylate superplasticizer / wt% 0.28 0.29 0.29 0.28 Total retarder dosage / wt% 0.01 0.01 0.01 0.02 Specific types and dosages of retarder Sucrose, sodium gluconate, and borax in a mass ratio of 1:1:1 Sucrose, sodium gluconate, and borax in a mass ratio of 1:1:1 Sucrose, sodium gluconate, and borax in a mass ratio of 1:1:1 Sodium gluconate and borax in a mass ratio of 2:1 DF770DD defoamer / wt% 0.04 0.05 0.05 0.04 Triterpenoid saponin gas-entraining agent / wt% 0.04 0.05 0.05 0.04 Graphene / wt% 0.01 0.02 0.01 0.02

[0071] Example 5

[0072] This embodiment is carried out in a similar manner to Example 1, except that the total amount of retarder is kept constant, and the retarder is adjusted to a mass ratio of glucose, sodium gluconate and borax of 1:0.8:1.

[0073] Example 6

[0074] This embodiment is carried out using a similar method to Embodiment 1, except that the nanomaterial is adjusted to be carbon nanotubes of equal mass.

[0075] Comparative Example 1

[0076] This comparative example uses only cement, quartz sand, and water-reducing agent, with cement content of 49.9 wt%, quartz sand content of 49.9 wt% (quartz sand gradation unchanged), and water-reducing agent content of 0.2 wt%.

[0077] Comparative Example 2

[0078] This comparative example was carried out using a similar method to Example 1, except that polyvinyl alcohol fiber was not added.

[0079] Comparative Example 3

[0080] This comparative example was conducted using a similar method to Example 1, except that the total amount of retarder remained constant, and the type of retarder was adjusted to use only sodium gluconate.

[0081] Comparative Example 4

[0082] This comparative example was carried out using a similar method to Example 1, except that no nanomaterials were added in this comparative example.

[0083] The flowability, flexural strength, compressive strength, flexural-compression ratio, vertical expansion rate, and anti-seepage pressure value of the cement-based grouting materials prepared in the above embodiments were tested. The specific results are shown in Tables 2 and 3.

[0084] The test methods for truncated cone flowability and the standard values ​​for compressive strength and vertical expansion rate shall be performed in accordance with the standard GB / T50448-2015 "Technical Specification for Application of Cement-based Grouting Materials"; the test methods for flexural strength and compressive strength shall be performed in accordance with the standard GB / T 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)"; the test method for vertical expansion rate shall be performed in accordance with the standard GB50119-2013 "Technical Specification for Application of Concrete Admixtures"; the test method for impermeability pressure value shall be performed in accordance with the standard GB / T50082-2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete"; for ease of testing, the flexural-compression ratio is used to reflect the toughness of the grout. The flexural-compression ratio is the ratio of flexural strength to compressive strength, and it is generally considered that a flexural-compression ratio higher than 0.2 indicates good toughness.

[0085] Table 2 Performance test results of Examples 1-6

[0086] Performance indicators Standard value Example 1 Example 2 Example 3 Example 4 Example 5 Initial flowability / mm 290 345 340 348 342 340 30min flowability / mm 260 340 332 331 335 329 1d flexural strength / MPa - 4.2 4.06 3.5 4.1 4.0 3d flexural strength / MPa - 12.3 11.76 9.8 13.9 11.5 28-day flexural strength / MPa - 17.6 17.1 16.1 17.1 17.1 1d compressive strength / MPa 20 20.6 20.1 20.2 20.3 20.2 3d compressive strength / MPa 40 53.4 50.25 50.3 50.2 52.6 28-day compressive strength / MPa 60 85.1 88.7 84.3 86.6 83.2 1d folding ratio - 0.20 0.20 0.17 0.20 0.20 3D bending ratio - 0.23 0.23 0.19 0.27 0.22 28d folding ratio - 0.21 0.19 0.19 0.20 0.21 3h vertical expansion rate / % 0.1-3.5 0.105 0.153 0.121 0.101 0.110 Difference in expansion values ​​between 24h and 3h / % 0.02-0.5 0.489 0.356 0.474 0.448 0.491 Anti-seepage pressure value / MPa - 1.0 0.9 0.9 1.0 0.9

[0087] Table 3 Performance test results of Example 6 and Comparative Examples 1-4

[0088] Performance indicators Standard value Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Initial flowability / mm 290 344 326 349 339 341 30min flowability / mm 260 338 288 344 327 336 1d flexural strength / MPa - 4.1 3.4 3.9 4.2 3.5 3d flexural strength / MPa - 11.9 7.5 10.9 11.4 12.3 28-day flexural strength / MPa - 17.1 9.8 16.2 16.9 16.6 1d compressive strength / MPa 20 20.4 20.4 20.1 20.3 20.4 3d compressive strength / MPa 40 50.1 45.9 51.3 52.4 52.4 28-day compressive strength / MPa 60 83.2 68.3 79.1 82.6 81.3 1d folding ratio - 0.20 0.17 0.19 0.21 0.18 3D bending ratio - 0.23 0.16 0.21 0.22 0.23 28d folding ratio - 0.20 0.14 0.20 0.20 0.25 3h vertical expansion rate / % 0.1-3.5 0.104 0 0.107 0.112 0.104 Difference in expansion values ​​between 24h and 3h / % 0.02-0.5 0.477 -0.001 0.487 0.493 0.433 Anti-seepage pressure value / MPa - 0.9 0.3 0.9 0.9 0.8

[0089] As can be seen from the results in Tables 2 and 3, Examples 1, 2, and 3 using the grouting material of the present invention have significantly better effects in terms of fluidity, mechanical properties, impermeability, and toughness.

[0090] The initial flowability of Examples 1-6 all reached over 340 mm, and the flowability remained above 329 mm after 30 minutes, far exceeding the standard value (initial value 290 mm, value after 30 minutes 260 mm), indicating that the grouting material has excellent workability and slump retention, and can meet the requirements of self-leveling grouting. The 28-day compressive strength of Examples 1-6 all reached over 83.2 MPa, far exceeding the standard value of 60 MPa, and the 28-day flexural strength all reached over 16.1 MPa, with a 28-day flexural-compression ratio in the range of 0.19-0.21, indicating that the material possesses both high strength and good toughness. The 3-hour vertical expansion rate and the difference between the expansion values ​​at 24 hours and 3 hours of Examples 1-6 were all within the standard range, indicating that the composite expansion agent system can effectively compensate for the shrinkage of the grouting material and ensure the volume stability of the material.

[0091] Comparative Example 1, using only a simple formula (cement, quartz sand, and water-reducing agent), exhibited a 28-day compressive strength of only 68.3 MPa, a 28-day flexural strength of only 9.8 MPa, and a 28-day flexural-compression ratio of only 0.14, indicating significantly insufficient mechanical properties and toughness. More importantly, Comparative Example 1 showed a 3-hour vertical expansion rate of 0, and the difference between the 24-hour and 3-hour expansion values ​​was -0.001%, indicating shrinkage. This could potentially lead to gaps between the grout and the substrate, affecting the grouting effect. The impermeability pressure value of Comparative Example 1 was only 0.3 MPa, far lower than that of the examples (0.9-1.0 MPa), demonstrating that polymer modification and multi-component synergistic optimization significantly improved the density and impermeability of the grout.

[0092] In Comparative Example 2, although the 28-day compressive strength remained at a high level (79.1 MPa) due to the absence of added fibers, the 28-day flexural strength decreased to 16.2 MPa, which was lower than most examples, indicating that fibers contribute to improving the flexural properties of the grout.

[0093] Comparative Example 3 used only a single retarder (sodium gluconate), and the fluidity dropped to 327 mm after 30 minutes, which was lower than 340 mm in Example 1, indicating that the composite retarder system has an advantage in maintaining fluidity.

[0094] In Comparative Example 4, without the addition of nanomaterials, the 28-day compressive strength decreased to 81.3 MPa, the 28-day flexural strength decreased to 16.6 MPa, and the impermeability pressure decreased to 0.8 MPa, all of which were lower than those of the example with added nanomaterials. This indicates that nanomaterials make a significant contribution to improving the overall performance of the grouting material.

[0095] Compared with Example 1, Example 5 showed a slight difference in performance after the retarder ratio was adjusted (mass ratio 1:0.8:1), but the overall performance remained excellent, indicating that the retarder ratio can be adjusted within a certain range.

[0096] Example 6 uses carbon nanotubes instead of graphene, and the performance is similar to that of Example 1, indicating that different types of nanomaterials can have a positive impact on the performance of grouting materials.

[0097] In summary, this invention, through multi-component synergistic design and refined proportioning optimization, successfully prepared a polymer-modified cement-based grouting material with high fluidity, high strength, high toughness, and excellent impermeability, with all performance indicators significantly superior to existing technologies.

[0098] The superior performance of the high-toughness, impermeable polymer-modified cementitious grouting material of this invention stems from the following synergistic mechanism:

[0099] I. Polymer Network Formation Mechanism. EVA redispersible latex powder rapidly disperses into an emulsion after mixing with water, with polymer particles adsorbing onto the surfaces of cement particles and aggregates. As the cement hydration reaction proceeds, water is gradually consumed, and polymer particles come into contact and fuse, forming a continuous polymer film. These polymer films fill the capillary pores and interfacial transition zones in the cement paste, significantly reducing porosity and pore size, and increasing the material's density. Simultaneously, polymer segments interact with cement hydration products (such as...) Polymers (such as ettringite) form a physical cross-linked network through non-covalent interactions such as hydrogen bonds and van der Waals forces. The flexible segments of the polymer endow the material with good toughness and deformability. Under stress, it can dissipate energy through the slippage and unentanglement of the segments, thus delaying crack propagation.

[0100] II. Enhancement and toughening mechanism of nanomaterials. The two-dimensional sheet structure and extremely high specific surface area of ​​graphene enable it to play multiple roles in cement-based materials: (1) Crack deflection mechanism: When microcracks encounter graphene sheets, due to the high elastic modulus and strength of graphene, the cracks are forced to deflect around the graphene, which prolongs the crack propagation path and increases the fracture energy; (2) Bridging mechanism: Graphene sheets span both sides of the crack and delay crack propagation by tensile stress; (3) Pull-out mechanism: When crack propagation causes graphene to be pulled out of the matrix, the interfacial friction consumes a lot of energy; (4) Pore structure refinement: Graphene forms a nano-network in cement paste, which refines the pore structure, reduces pore connectivity, and significantly improves impermeability; (5) Nucleation sites: The surface of graphene provides additional heterogeneous nucleation sites, which promotes the uniform generation and distribution of hydration products and improves the microstructure.

[0101] Silicon carbide whiskers, as one-dimensional nanomaterials, possess high aspect ratios and mechanical properties approaching theoretical strength. The whiskers, randomly distributed within the matrix, form a three-dimensional reinforcing network that bears stress through bridging and prevents crack propagation. When a crack encounters a whisker during propagation, the whisker is pulled out, fractures, or debonds from the matrix. These processes consume a significant amount of energy, significantly improving the material's fracture toughness.

[0102] III. Fiber Toughening Mechanism. Polyvinyl alcohol (PVA) fibers play a macroscopic toughening role in grouting materials. Hydrogen bonds are formed between the hydroxyl groups (-OH) on the fiber surface and cement hydration products, ensuring good interfacial bonding. When the grouting material is subjected to tensile or bending stress, microcracks first form in the matrix. The fibers bridge these cracks, bearing part of the stress and delaying crack propagation. As the stress increases, the cracks continue to propagate, and the fibers gradually pull out of the matrix or break. This process consumes a large amount of energy, significantly improving the material's toughness and crack resistance. The presence of fibers transforms the material's failure mode from brittle fracture to ductile failure, enabling the material to maintain a certain load-bearing capacity even after reaching its ultimate stress, thus improving the structural safety and reliability.

[0103] IV. Synergistic Mechanism of Composite Expanding Agents. Azodicarbonamide decomposes at 200-210℃ to produce nitrogen gas (…). ), carbon monoxide ( ) and ammonia ( While azodicarbonamide can initially contain gases like gypsum, during the mixing process, due to localized frictional heat from mechanical stirring and the catalytic effect of the alkaline environment, it begins to slowly decompose at relatively low temperatures (40-60℃), generating microbubbles during the plastic stage of the grout. This provides early expansion and effectively compensates for plastic shrinkage. The calcium sulfoaluminate in the composite expanding agent HP-CSA reacts with gypsum to form ettringite (…). ), quicklime hydrated to form These expansive hydration products are continuously generated during and after the cement hardening process, providing post-hardening expansion and compensating for hardening and drying shrinkage. The temporal complementarity of the two expansion mechanisms ensures the volumetric stability of the grout throughout its entire lifespan, guarantees close contact between the grout and the substrate, and improves grouting effectiveness and long-term performance.

[0104] V. Synergistic Mechanism of Composite Retarder. The composite retarder system of carbohydrate compounds (glucose / sucrose), sodium gluconate, and borax used in this invention synergistically inhibits cement hydration through multiple mechanisms:

[0105] (1) Mechanism of action of sucrose: The hydroxyl groups in sucrose molecules have strong nucleophilicity and can adsorb sucrose in solution. Ions lower the pH of the liquid phase, thereby inhibiting tricalcium silicate ( The dissolution and hydration of ). Hydration rate and liquid phase Concentration is closely related, decreasing Concentration can effectively slow down the hydration reaction.

[0106] (2) Mechanism of action of sodium gluconate: gluconate ions ( The multiple hydroxyl and carboxyl groups in ) can interact with Ions form stable chelate complexes, reducing the amount of free ions in the liquid phase. Concentration, inhibition The nucleation and growth of crystals slows down the precipitation of hydration products. In addition, gluconate ions adsorb on the surface of cement particles to form a protective layer, which hinders the diffusion of water molecules into the interior of the cement particles, further slowing down the hydration reaction.

[0107] (3) Mechanism of action of borax: Borax hydrolyzes in alkaline solution to generate metaborate ions ( This ion can also interact with... It forms a complex. More importantly, borax forms a dense, gel-like adsorption layer on the surface of cement particles, further hindering the hydration reaction. This adsorption layer has a certain degree of selective permeability, allowing small water molecules to pass through but hindering the diffusion of ions, thereby finely controlling the hydration rate.

[0108] The synergistic effect of the three retarders not only prolongs the setting time of the grout, providing sufficient time for polymer dispersion, film formation and uniform dispersion of nanomaterials, but also avoids the problem of excessive delay or even non-hydration of cement hydration that may be caused by the use of a single retarder at high dosage, thus ensuring the normal development of early strength.

[0109] VI. Mechanism of Toughening and Impermeability Enhancement by Microbubbles in Air-Entraining Agent. Triterpenoid saponin air-entraining agent introduces a large number of microbubbles (50-200 μm in diameter) by reducing the surface tension of the grout during the mixing process. These microbubbles are uniformly distributed in the hardened body and play multiple roles: (1) Ball effect: The bubbles in the freshly mixed grout are similar to tiny balls, reducing the frictional resistance between particles and improving fluidity; (2) Stress concentration and slow release: Under stress, the microbubbles, as stress concentration points, preferentially deform or rupture, consuming some energy. At the same time, the microcracks formed around the bubbles are confined to the vicinity of the bubbles and will not expand into macrocracks, thus playing the role of crack termination; (3) Tortuous penetration channel: The presence of bubbles makes the penetration path tortuous, greatly extending the effective penetration distance and reducing the permeability coefficient. It is worth noting that the dosage of the air-entraining agent in this invention has been carefully optimized (0.01-0.05 wt%), and the introduced bubbles are small in size, moderate in number, and uniformly distributed. While improving toughness and impermeability, the negative impact on strength is controlled within an acceptable range (strength loss <5%).

[0110] VII. Multi-level Synergistic Toughening System. This invention constructs a multi-level toughening mechanism from the nanoscale to the macroscale: nanomaterials (graphene and whiskers) deflect and block microcrack initiation and early propagation at the nanoscale and submicron scale; polymer networks fill pores and provide a tough matrix at the micron scale, and enhance the interface through interaction with hydration products; microbubbles act as stress concentration easing points and crack termination points at the tens to hundreds of micrometer scale; fibers bridge macrocracks at the millimeter to centimeter scale, delaying final failure. This cross-scale synergistic toughening mechanism ensures that the grouting material maintains excellent crack resistance and toughness under different stress levels, loading rates, and environmental conditions.

[0111] VIII. Interface Enhancement Mechanism. The performance of grouting materials depends not only on the properties of each phase material itself, but also on the interface properties. This invention enhances interface properties through multiple means: (1) Pozzolanic effect of admixtures such as silica fume and mineral powder: the active... and With cement hydration products A secondary hydration reaction occurs, generating additional calcium silicate hydration gel (CSH gel), which not only improves the strength of the slurry, but more importantly, fills and improves the interfacial transition zone, reduces the porosity of the region, and enhances the bonding between the aggregate and the slurry; (2) Interface regulation of nanomaterials: nano Nanomaterials such as graphene are enriched in the interface region, and the interface microstructure is improved through the filling effect and nucleation effect, thereby improving the interface strength and toughness; (3) Polymer interface bridging: one end of the polymer chain segment is adsorbed or bonded to the surface of the aggregate, and the other end is embedded in the cement stone matrix to form a flexible bridging layer, which alleviates the stress concentration at the interface and improves the deformation coordination ability of the interface; (4) Fiber interface reinforcement: the interaction between the chemical groups on the fiber surface and the hydration products improves the fiber-matrix interface bonding strength, ensuring that the fiber toughening effect is fully utilized.

[0112] Through the synergistic effect of the above-mentioned multi-component materials and the cross-scale reinforcement and toughening mechanism, the grouting material of this invention achieves a comprehensive balance improvement in toughness, strength, impermeability and workability, providing a new technical path for the development of high-performance building repair materials.

[0113] The specific embodiments of the present invention have been described in detail above. However, these embodiments are only for illustrating the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Any equivalent substitutions, simple changes, or modifications made to the technical solutions of the present invention within the scope of the inventive concept shall fall within the scope of protection of the present invention.

Claims

1. A high-toughness, impermeable polymer-modified cementitious grouting material, characterized in that, It includes component A and water; based on the total mass of component A, component A comprises the following components: Cementitious materials 10-80wt%; 1-50wt% of admixtures; Fine aggregate 10-80wt%; Expanding agent 0.01-15wt%; Polymers for concrete modification: 0.01-10 wt%; Fiber 0.01-5wt%; Early strength agent 0.01-14wt%; Water-reducing agent 0.1-25wt%; Retarder 0.01-16wt%; Defoamer 0.04-20wt%; Air-entraining agent 0.01-0.05wt%; Nanomaterials 0.01-10 wt%; Functional components 0.01-5 wt%; The nanomaterials are selected from nanomaterials. Carbon nanotubes, nano ,nanometer Graphene, nano At least one of them; The retarder is a carbohydrate compound, sodium gluconate, borax, orthophosphoric acid, etc. , , , Sodium polyphosphate, sodium tripolyphosphate, sodium pyrophosphate, citric acid, tartaric acid, salicylic acid, and one or a combination of polyols and their derivatives; The expanding agent is a combination of a plastic expanding agent and a post-expanding agent. Based on the total mass of the expanding agent, the content of the plastic expanding agent is 0.01-40 wt%, and the content of the post-expanding agent is 60-99.99 wt%. The plastic expanding agent is selected from at least one of azodicarbonamide, aluminum powder, EP-2 plastic expanding agent, sodium percarbonate, sodium acetate, and ammonia water. The post-expanding agent is selected from at least one of MgO expanding agent, CaO expanding agent, calcium vanadium stone expanding agent, and composite expanding agent. The polymer used for concrete modification is selected from at least one of water-soluble polymers, polymer emulsions, and redispersible polymer powders.

2. The high-toughness, impermeable polymer-modified cementitious grouting material according to claim 1, characterized in that: The admixture is selected from at least one of silica fume, mineral powder, fly ash, blast furnace slag, metakaolin, steel slag powder, zeolite powder, phosphorus slag powder, and limestone powder.

3. The high-toughness, impermeable polymer-modified cementitious grouting material according to claim 1, characterized in that: The fine aggregate is selected from at least one of quartz sand, manufactured sand and artificial sand.

4. The high-toughness, impermeable polymer-modified cementitious grouting material according to claim 1, characterized in that: When a combination of carbohydrates, sodium gluconate and borax is used, the mass ratio is (0.8-1.2):(0.8-1.2):(0.8-1.2); and / or, the carbohydrates are glucose and / or sucrose.

5. The high-toughness, impermeable polymer-modified cementitious grouting material according to claim 1, characterized in that: The water-soluble polymer is selected from at least one of polyvinyl alcohol, cellulose derivatives, polyacrylamide, acrylates, and furanylamine resin; the polymer emulsion is selected from at least one of polyacrylate emulsion, styrene-butadiene emulsion, carboxylated styrene-butadiene emulsion, styrene-acrylic emulsion, vinyl polyvinyl acetate emulsion, vinyl acetate-acrylic acid copolymer emulsion, polyvinyl propionate emulsion, vinylidene chloride-vinyl chloride, waterborne epoxy resin emulsion, rubber asphalt emulsion, styrene-butadiene rubber emulsion, styrene-acrylic acid copolymer emulsion, and polystyrene acrylate; the redispersible polymer powder is selected from at least one of ethylene-vinyl acetate copolymer, polystyrene-acrylate latex powder, polyethylene-vinyl acetate latex powder, polyacrylate latex powder, vinyl acetate, polyacrylate-styrene, polyethylene-vinyl chloride-vinyl laurate, polyvinyl acetate-ethylene-higher fatty acid vinyl ester, and vinyl acetate-higher fatty acid vinyl ester.

6. The high-toughness, impermeable polymer-modified cementitious grouting material according to claim 1, characterized in that: The early strength agent is selected from at least one of calcium formate, sodium acetate, ethylene glycol, glycerol, triethanolamine, triisopropanolamine, lithium carbonate, gypsum dihydrate, sodium nitrite, calcium nitrate, sodium nitrate, calcium chloride, aluminum chloride, calcium sulfate, and sodium sulfate; and / or, the water-reducing agent is selected from at least one of naphthalene-based water-reducing agents, aliphatic water-reducing agents, lignin water-reducing agents, melamine-based water-reducing agents, aminosulfonate water-reducing agents, and polycarboxylate water-reducing agents; and / or, the defoamer is selected from at least one of aliphatic defoamers, polyether defoamers, silicone defoamers, and polyether-modified silicone defoamers; and / or, the air-entraining agent is selected from at least one of rosin resin air-entraining agents, alkyl air-entraining agents, fatty alcohol sulfonate air-entraining agents, saponin air-entraining agents, and protein salt air-entraining agents.

7. The high-toughness, impermeable polymer-modified cementitious grouting material according to claim 1, characterized in that: The fiber is selected from at least one of polyvinyl alcohol fiber, steel fiber, polypropylene fiber, basalt fiber, carbon fiber, polyacrylonitrile fiber, wood fiber, and glass fiber; and / or, the functional component is a whisker, which is selected from one or more of silicon carbide, silicon nitride, alumina, titanate, zinc oxide, magnesium oxide, aluminum boron, glass, talc, mica, carbon, graphite, titanium oxide, and sulfides.

8. A method for preparing a high-toughness, impermeable polymer-modified cementitious grouting material according to any one of claims 1-7, characterized in that: The raw materials, including cementitious materials, admixtures, fine aggregates, expansive agents, polymers for concrete modification, fibers, early-strength agents, water-reducing agents, retarders, defoamers, air-entraining agents, functional components, and nanomaterials, are mixed in the presence of water to obtain the final product.

9. The preparation method according to claim 8, characterized in that, Includes the following steps: (1) The cementitious materials and admixtures are mixed in the first step to obtain powder A; Furthermore, an expansion agent, a concrete modifier polymer, fibers, an early-strength agent, a water-reducing agent, a retarder, a defoamer, an air-entraining agent, and nanomaterials are mixed in a second step to obtain powder B; (2) Mix the powder A with the powder B and fine aggregate in a third mixing process to obtain grouting powder; (3) Mix the grouting powder with water to obtain the final product.

10. The preparation method according to claim 8 or 9, characterized in that: The mass ratio of water to component A is (0.03-0.4):1.