Grouting material for deeply cracked rock mass and preparation method thereof

Abstract

This invention belongs to the field of engineering materials technology and discloses a grouting material for deep-earth fractured rock masses and its preparation method. The raw material composition is as follows: 100 parts rapid-hardening sulfoaluminate cement, 30-60 parts fly ash microspheres, 20-50 parts highly active slag powder; 5-15 parts nano-silica, 10-30 parts metakaolin, 5-25 parts self-healing epoxy resin containing dynamic covalent bonds, 1-3 parts layered bimetallic hydroxide containing vanadate, 1-4 parts polyacrylamide, 5-9 parts water glass, 2-10 parts surface-treated ultrafine steel fibers; 1-3 parts high-efficiency water-reducing agent, 0-0.6 parts retarder / accelerator; and a water-cement ratio of 0.20-0.28. This invention provides a new solution to the challenge of reinforcing and repairing fractured rock masses in complex geological environments such as high stress, high water pressure, and high-chlorine groundwater in deep underground engineering.

Description

Technical Field

[0001] This invention relates to the field of engineering materials technology, and more specifically to a toughening, self-healing, anti-dispersion, anti-seepage, and active anti-corrosion grouting material for deep-earth fractured rock masses and its preparation method. Background Technology

[0002] In deep-earth engineering, the surrounding rock is often subjected to a severe environment of "high ground stress, high osmotic pressure, and high temperature." This necessitates that grouting materials possess comprehensive properties such as high strength and toughness, anti-dispersion and anti-seepage properties, and good self-healing and thermal stability to meet the reinforcement and sealing requirements under complex coupled conditions at depth. Furthermore, groundwater commonly contains corrosive chloride ions, which easily erode the grouting body and can even penetrate through it, corroding equipment within the tunnel / well. Traditional cement-based grouting materials suffer from insufficient performance, including slow setting, low early strength, and limited final strength. In water-rich environments, they are easily washed away and diluted, resulting in significant material loss and poor impermeability and durability. They lack intelligent response capabilities; when the grout body develops micro-cracks due to subsequent deformation, it cannot self-repair, leading to secondary leakage. Moreover, once corrosion occurs, traditional materials are difficult to actively prevent corrosion.

[0003] Existing technologies such as ultrafine cement, chemical grouts, fiber-reinforced composites, and microcapsule-based self-healing materials have fragmented functions and each has its own limitations, making it difficult to cope with the complex and harsh environments of deep environments: chemical grouts have low strength and pollute the environment; fiber reinforcement can only inhibit crack propagation; most self-healing materials have low strength and require harsh repair conditions; they lack anti-dispersion design, resulting in poor underwater grouting effects; and they lack resistance to chloride ion penetration and active corrosion protection.

[0004] If polyacrylamide (PAM) and water glass are added to the slurry material, the long-chain molecules of PAM will cause the slurry particles to aggregate and form a flocculent structure through adsorption and bridging. The added water glass will react with the calcium produced during cement hydration. 2+The rapid reaction generates calcium silicate gel (CSH), filling the gaps between flocs and providing a feasible solution for anti-dispersion and strength enhancement of materials in underground dynamic water conditions. Furthermore, the two work synergistically to construct a stable three-dimensional network structure, effectively reducing scouring losses of the grout material in dynamic water environments. However, excessive water glass content (>10%) leads to a loose structure and decreased mechanical properties in the grout, requiring strict control of the dosage. In addition, adding nano-silica and metakaolin to the system can further reduce micropores and prepare a denser grout to improve its strength. However, this system still does not solve the problems of toughening, self-healing, impermeability, and active corrosion prevention. Dynamic covalent bonds can undergo reversible fracture and recombination under thermal stimulation. This in-situ fracture and ex-situ recombination characteristic will endow the grout with self-healing function, and the ex-situ recombination of dynamic covalent bonds under external force can achieve toughening enhancement. In the high-temperature thermal stimulation environment of underground engineering, introducing epoxy resin containing dynamic covalent bonds (disulfide bonds) into the grout material will bring hope for achieving toughening and self-healing functions in the grout. Metal components or equipment (such as reinforcing bars and metal equipment) protected by grouting are susceptible to Cl- from groundwater. - The risk of ion erosion accelerates corrosion and can even penetrate grouting to corrode equipment inside the tunnel / well. In the past, hydrotalcite and montmorillonite were often added to form layered stacks, creating tortuous paths to block Cl. - Ion permeation, this passive physical barrier, is limited by the lack of active chemical protection; however, if vanadate is loaded onto layered bimetallic hydroxides, the pH drop during corrosion stimulates the instability of the layered bimetallic hydroxides in the nano-container, thereby releasing the inhibitory vanadate anions, forming a vanadate-iron inhibition film to isolate Cl-. - Ion corrosion.

[0005] In summary, existing grouting materials still face the following technical bottlenecks: rapid setting and high strength and toughness are difficult to achieve simultaneously; they are easily diluted and washed away in water-rich environments, leading to significant material loss; and they lack effective active protection against chloride ion corrosion in groundwater; they lack inherent self-healing capabilities, and micro-cracks cannot heal, causing secondary leakage. Therefore, to address these issues, there is an urgent need to develop a smart grouting material that can utilize solid waste resources, integrating early strength, high strength, excellent adhesion and toughness; inherent self-healing capabilities; and active corrosion protection functions such as anti-dispersion, seepage prevention, and chloride resistance in water. Summary of the Invention

[0006] In view of this, the present invention provides a grouting material for deep-seated fractured rock masses and its preparation method. The purpose of this invention is to provide a grouting material and its preparation method that integrates rapid setting, high strength, toughness, self-healing, anti-dispersion, impermeability, and active corrosion prevention functions, utilizing solid waste as a raw material that can be recycled. The grouting material is given toughness and self-healing properties by introducing epoxy resin containing dynamic covalent bonds; anti-dispersion properties by introducing polyacrylamide and water glass; impermeability and active corrosion prevention properties by introducing vanadate-containing layered bimetallic hydroxides; and the strength of the cement grout is enhanced through the synergistic effect of fly ash microspheres, highly active slag powder, nano-silica, and metakaolin. This invention provides an innovative solution to the challenges of reinforcing and repairing fractured rock masses in complex geological environments such as high stress, high water pressure, and high-chlorine groundwater in deep underground engineering, and has significant environmental, social, and economic benefits.

[0007] One objective of this invention is to provide a tough, self-healing, anti-dispersion, anti-seepage, and actively corrosion-resistant grouting material, comprising a cementitious matrix component, reinforcing and functional components, additives, and water. The raw material composition, by weight, is as follows:

[0008] Cementitious matrix components: 100 parts rapid-hardening sulfoaluminate cement, 30-60 parts fly ash microspheres, and 20-50 parts highly active slag powder; Reinforcing and functional components: 5-15 parts of nano-silica, 10-30 parts of metakaolin, 5-25 parts of self-healing epoxy resin containing dynamic covalent bonds, 1-3 parts of layered bimetallic hydroxide containing vanadate, 1-4 parts of polyacrylamide, 5-9 parts of water glass, and 2-10 parts of surface-treated ultrafine steel fiber. Admixtures: 1-3 parts of high-efficiency water-reducing agent, 0-0.6 parts of retarder / accelerator; Water: The water-to-binder ratio is 0.20-0.28, whereby the water-to-binder ratio is the ratio of the total mass of water to the cementitious matrix components.

[0009] Controlling the water glass content to 5-9 parts can effectively promote the formation of floc network and avoid the problems of loose stone structure and decreased mechanical properties caused by excessive content (>10%).

[0010] Furthermore, the self-healing epoxy resin containing dynamic covalent bonds is synthesized by a curing reaction between a small molecule diamine crosslinking agent containing dynamic covalent bonds and an epoxy resin monomer; wherein, the mass ratio of the small molecule diamine crosslinking agent containing dynamic covalent bonds to the epoxy resin monomer is 1:5 to 1:10. The small molecule diamine crosslinking agent containing dynamic covalent bonds is a crosslinking agent containing disulfide bonds.

[0011] Preferably, the crosslinking agent containing disulfide bonds is made of 2-aminothiophenol.

[0012] Furthermore, the method for preparing the vanadate-containing layered bimetallic hydroxide is as follows: Zinc-aluminum layered bimetallic hydroxides were prepared by thoroughly mixing a mixed solution of metal nitric acid and an alkaline solution and then placing the mixture in an oven. After washing, drying, grinding, and sieving, the zinc-aluminum layered bimetallic hydroxide powder was placed in a vanadate solution and vanadate-containing layered bimetallic hydroxides were prepared by ion exchange.

[0013] Preferably, the volume ratio of the metal nitric acid mixed solution to the alkaline solution is 1:1 to 1:2.

[0014] Preferably, the metal nitric acid mixed solution is a mixed solution of Zn(NO3)2 and Al(NO3)3; wherein the concentration of Zn(NO3)2 in the mixed solution is 0.20–0.50 mol / L, and the concentration of Al(NO3)3 is 0.10–0.25 mol / L; the alkaline solution is a NaOH solution; wherein the concentration of the NaOH solution is 0.80–1.20 mol / L; the concentration of the vanadate solution is 0.05–0.1 mol / L; and the solid-liquid ratio of the zinc-aluminum layered bimetallic hydroxide powder to the vanadate solution is 1:20–1:100 (g / mL).

[0015] Preferably, the vanadate-containing layered bimetallic hydroxide has a particle size of 50-200 nm, and its interlayer contains exchangeable anions (such as carbonate, nitrate, etc.) to capture chloride ions, and its interlayer is loaded with vanadate anions to form a corrosion inhibitor nanocontainer.

[0016] Furthermore, after the grouting material cures, it forms an internal multi-layered interpenetrating network structure consisting of hydrated calcium silicate gel, ettringite, vanadate-containing layered bimetallic hydroxide, and dynamically covalently bonded intelligent epoxy resin segments. The vanadate-containing layered bimetallic hydroxide is uniformly dispersed in the network structure as nanoscale sheets, forming a physical barrier and chemical active centers. The layered structure resists permeation, and the loaded vanadate anions are actively released to form a vanadate-iron inhibitory film with iron ions during corrosion, providing active corrosion protection.

[0017] Furthermore, under standard curing conditions, the grouting material exhibits a 1-day compressive strength of 42–55 MPa and a 28-day compressive strength of 65–82 MPa; a bond strength with granite ≥4.5 MPa; an underwater molding strength retention rate ≥80%; and a chloride ion permeability coefficient ≤1.8×10⁻⁶. -12 m 2 / s.

[0018] The second objective of this invention is to provide a method for preparing a tough, self-healing, anti-dispersion, anti-permeability, and actively corrosion-resistant grouting material, comprising the following steps: S1: Material preparation: Dry mix the cementitious matrix components, nano silica, metakaolin and surface-treated ultrafine steel fibers, and stir for 15-20 minutes until uniform to obtain dry mix A; S2: Add polyacrylamide to 40-60% of the total amount of mixing water, stir at 50 ℃ until completely dissolved, then add water glass and high-efficiency water-reducing agent, stir evenly to obtain premixed liquid B; the remaining mixing water is reserved for step S3 to adjust the consistency of the slurry; S3: Pour the premixed liquid B into the mixer, and gradually add the dry mixture A, retarder / accelerator and remaining mixing water while stirring, and continue stirring until a uniform slurry C is formed. S4: Add vanadate-containing layered bimetallic hydroxide, a small molecule diamine crosslinking agent with dynamic covalent bonds, and epoxy resin monomer to a homogeneous slurry C to obtain the grouting material.

[0019] The third objective of this invention is to provide the application of the tough, self-healing, anti-dispersion, anti-seepage, and active anti-corrosion grouting material in deep-earth cracked rock masses, specifically in the reinforcement and waterproofing of cracked rock masses in deep underground mining projects, water-rich strata, and high-chlorine groundwater environments.

[0020] As can be seen from the above technical solution, compared with the prior art, the beneficial effects achieved by the present invention include at least the following: 1) Synergistic Achievement of Rapid Setting and High Strength: This invention achieves early and rapid hydration and strength development through the synergistic effect of rapid-setting sulfoaluminate cement and nano-silica. C4A3S in the rapid-setting sulfoaluminate cement... - Anhydrous calcium sulfoaluminate reacts rapidly with water to form ettringite (AFt), providing early skeletal strength. Nano-silica (average particle size 15 nm) acts as a nucleating agent, significantly accelerating the formation of hydrated calcium silicate (CSH) gel while filling micropores and increasing density. Under low water-to-binder ratio (0.20-0.28), the close packing effect of fly ash microspheres and highly active slag powder further reduces material porosity, forming a denser material to improve strength. Furthermore, the bridging effect of dynamically covalently bonded smart epoxy resin on the surface of the inorganic slurry can encapsulate slurry particles, enhancing their shear strength. The nanofilling and interface modification effects of vanadate-containing layered bimetallic hydroxides allow them to penetrate the organic epoxy resin and inorganic slurry particle system, acting as nanofibers and enabling the organic-inorganic network to interpenetrate, jointly constructing an ultra-high density microstructure. The aforementioned synergistic effect enables the material to achieve high strength performance, with initial setting time of <40 min, 1-day compressive strength of 42–55 MPa, and 28-day compressive strength of 65–82 MPa, which is significantly better than traditional cement-based grouting materials (28-day strength is usually 40–50 MPa).

[0021] 2) Excellent anti-dispersion properties: This invention synergistically introduces water glass and polyacrylamide (PAM) into the grouting material system to construct a stable three-dimensional flocculation network. The amide groups in the long-chain PAM molecules hydrolyze to form carboxyl groups, which are irreversibly adsorbed onto the active sites (Ca) of cement particles through chelation. 2+ On the surface of PAM, a bridging structure is formed, causing particles to aggregate into flocs. Furthermore, the amide groups in the long-chain PAM molecules can form hydrogen bonds with the hydroxyl groups on the particle surface, further enhancing bridging flocculation and anti-dispersion capabilities. The Ca produced during the hydration of water glass and cement... 2+ The rapid reaction generates calcium silicate gel (CSH), filling the gaps between flocs and enhancing their strength. Therefore, the synergistic effect of PAM and water glass enables the grout to form a dense, flocculated protective layer in a dynamic water environment, effectively resisting groundwater erosion and dilution. With PAM dosage controlled at 1-4 parts and water glass dosage controlled at 5-9 parts, the two work synergistically to enhance erosion resistance, solving the problem of traditional grouting materials being easily dispersed and lost in water-rich strata. This makes it suitable for grouting reinforcement and water-stopping treatment in dynamic groundwater environments.

[0022] 3) Integration of Intelligent Self-Healing Function and Toughness: Epoxy resin containing dynamic covalent bonds (disulfide bonds) can bridge and encapsulate slurry particles on the surface of inorganic slurry. Once the epoxy resin is damaged and cracked, the dynamic covalent bonds undergo a reversible cross-linking reaction in the high-temperature environment of deep-earth engineering. This reversible reaction allows the broken bond sites to reconnect, achieving in-situ fracture and ex-situ reorganization. This causes the dynamic covalent bond network on both sides of the crack to re-cross-link, forming a new network structure, thereby effectively healing the crack, restoring the integrity of the material, and endowing the material with intelligent self-healing function. In addition, under external force, the epoxy resin containing dynamic covalent bonds undergoes stress-induced breakage of old dynamic covalent bonds and formation of new bonds. This mechanism of in-situ fracture and ex-situ formation of covalent bonds with tensile deformation endows the material with significant deformation resistance, locking the slurry in the dynamic network structure, and thus giving the material toughening properties.

[0023] 4) Impermeability and Active Corrosion Protection Design: This invention proposes a vanadate-supported layered bimetallic hydroxide LDH-V, constructing a triple protection mechanism of "physical barrier + chemical capture + intelligent slow release": The nanosheet structure (50-200 nm) of LDH-V is uniformly dispersed in the slurry, forming a maze effect, prolonging the diffusion path of water molecules and chloride ions, and significantly reducing the material's permeability (physical barrier); the LDH layers can exchange anions (such as carbonate ions, nitrate ions, etc.) with invading chloride ions (Cl... - An ion exchange reaction occurs, transferring Cl... - Fixed between LDH layers, reducing free Cl in the pore fluid. -The concentration inhibits chloride ion corrosion (chemical capture); when corrosion causes a decrease in the local microenvironment pH, the LDH structure becomes unstable, releasing the loaded vanadate anions. The vanadate anions react with iron ions to form an iron vanadate film that inhibits corrosion, thus playing an active anti-corrosion role (intelligent slow release). This additive achieves a synergistic effect through a triple mechanism of "physical barrier + chemical capture + intelligent slow release".

[0024] 5) Green Environmental Protection and Cost Advantages: This invention uses industrial solid waste such as fly ash microspheres and highly active slag powder as the main cementitious matrix components (total proportion ≥ 50%), realizing the high-value utilization of waste resources, reducing cement usage, and reducing CO2 emissions. Compared with existing technologies, the raw material cost of this invention is lower, resulting in significant economic, social, and environmental benefits.

[0025] This invention achieves rapid setting and high strength through a rapid-hardening sulfoaluminate cement-nano silica-slag powder system; it achieves anti-dispersion in water through a water glass-polyacrylamide synergistic system; it achieves self-healing and toughening through a dynamic covalent epoxy resin network; and it achieves seepage prevention and active corrosion protection through an LDH-V nano-container. These technologies enable synergistic and mutually reinforcing effects on underground functions within the same material system. Its core innovation lies in the construction of a multi-layered interpenetrating network structure: the water glass-PAM flocculation network provides a stable dispersion carrier for the dynamic covalent epoxy resin network; the nano-filling effect of LDH-V further reduces porosity, while the released vanadate anions synergistically enhance the interfacial bonding of steel fibers; and the toughness of the dynamic covalent network effectively compensates for the material's high strength but brittleness. This multi-functional synergistic integrated design makes the grouting material of this invention an ideal reinforcement and waterproofing material suitable for complex geological environments such as high stress, high water pressure, high-chlorine groundwater, and water-rich areas in deep underground engineering, with broad engineering application prospects and significant socio-economic benefits. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram illustrating the mechanism by which dynamic covalent epoxy resin imparts self-healing function to grouting materials in this invention.

[0028] Figure 2 The tortuous structure of the vanadate-containing layered bimetallic hydroxide in this invention provides impermeability and Cl... - Schematic diagram of ion capture and corrosion prevention mechanism involving the active release of vanadate anions.

[0029] Figure 3 This is a schematic diagram of an epoxy resin containing dynamic covalent bonds (disulfide bonds) and a grouting material containing LDH-V. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention discloses a tough, self-healing, anti-dispersion, anti-seepage, and active anti-corrosion grouting material for deep-earth fractured rock masses and its preparation method.

[0032] To better understand the present invention, the following specific embodiments are provided for further detailed description of the present invention, but they should not be construed as limiting the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above-described invention are also considered to fall within the protection scope of the present invention.

[0033] In this embodiment of the invention, the rapid-hardening sulfoaluminate cement is grade 42.5 or 52.5; the fly ash microspheres are hollow microspheres extracted from grade I fly ash; the highly active slag powder is grade S95 slag powder; the nano-silica has an average particle size of 15 nm; the metakaolin has an activity index ≥110; the polyacrylamide is non-ionic with a molecular weight of 8 million-12 million; and the water glass has a Baume degree of 38.5 and a modulus of 3.3. The surface-treated ultrafine steel fibers are surface-treated with silane coupling agent KH-550. The steel fibers are immersed in a 1 wt% KH-550 ethanol solution, treated at 60°C for 2 hours, filtered and dried, with a length of 6-8 mm and a diameter of 0.12-0.18 mm. The vanadate-containing layered double hydroxide is a vanadate-supported zinc-aluminum layered double hydroxide (LDH-V), prepared by ion exchange, in which vanadate is loaded onto the surface or interlayer of LDH, with a particle size of approximately 100 nm; the preparation method is as follows: (1) Dissolve Zn(NO3)2·6H2O and Al(NO3)3·9H2O in deionized water to prepare Zn 2+ Concentration of 0.32 mol / L, Al 3+ A mixed salt solution with a concentration of 0.16 mol / L; (2) Dissolve NaOH in deionized water to prepare a 1.0 mol / L NaOH solution; (3) Under vigorous stirring, slowly add NaOH solution dropwise to the mixed salt solution, adjust the pH to 9.0-10.0, and obtain a suspension; (4) The suspension was transferred to a hydrothermal reactor and crystallized at 120°C for 12-24 hours. After centrifugation, the suspension was washed with deionized water until neutral, dried at 60°C for 12 hours, and ground through a 200-mesh sieve to obtain the Zn-Al-NO3-LDH precursor. (5) Disperse the precursor in a 0.05-0.1 mol / L sodium metavanadate (NaVO3) solution with a solid-liquid ratio of 1:20-1:100 (g / mL). In the example, the preferred ratio is 1:50 g / mL. Adjust the pH to 8.0-9.0 with dilute nitric acid or NaOH. Stir the reaction at 60-80°C for 12-24 hours. Centrifuge, wash three times with deionized water, dry at 60°C for 12 hours, and grind through a 200-mesh sieve to obtain LDH-V.

[0034] The self-healing epoxy resin containing dynamic covalent bonds is synthesized by curing epoxy resin monomers with a small-molecule diamine crosslinking agent containing dynamic covalent bonds. The small-molecule diamine crosslinking agent is a disulfide-containing crosslinking agent, prepared as follows: 2-aminothiophenol (0.2 mol) is dissolved in 300 mL of anhydrous tetrahydrofuran and stirred to obtain solution A; iodine (0.1 mol) is dissolved in 200 mL of anhydrous tetrahydrofuran and stirred to obtain solution B. Under ice bath and nitrogen atmosphere protection, solution B is slowly added dropwise to solution A, and the reaction is continued for 2 hours after the addition is complete. After the reaction is complete, 150 mL of 10% Na₂S₂O₃ solution is added to the reaction solution to quench the reaction, and the mixture is extracted three times with ethyl acetate (200 mL each time). The organic phases are combined, and anhydrous sodium sulfate is added as a dehydrating agent and dried overnight. The dehydrating agent is removed by suction filtration, and the solvent is removed by rotary evaporation under reduced pressure to obtain a crude solid product. The crude product was dissolved by heating 200 mL of ethanol to boiling, filtered while hot, and the filtrate was cooled in an ice bath to crystallize. After crystals precipitated, they were filtered under vacuum, washed three times with cold ethanol, and dried under vacuum for 24 hours to obtain the aromatic diamine crosslinking agent containing disulfide bonds (DNS). Raman spectroscopy was used to test the SS bonds (wavenumber approximately 500 cm⁻¹). -1 The characteristic peaks at the point of origin are used to verify the formation of disulfide bonds.

[0035] The high-efficiency water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of ≥30%. The retarder / accelerator is selected from at least one of citric acid, sodium gluconate, aluminum sulfate, and lithium carbonate, with a dosage range of 0-0.6 parts.

[0036] Example 1 A tough, self-healing, anti-dispersion, anti-permeability, and actively corrosion-resistant grouting material, by weight, is prepared from the following raw materials: 100 parts of rapid-hardening sulfoaluminate cement, 60 parts of fly ash microspheres, 50 parts of highly active slag powder, 15 parts of nano-silica, 30 parts of metakaolin, 25 parts of self-healing epoxy resin containing dynamic covalent bonds (2.5 parts of crosslinking agent + 22.5 parts of epoxy resin), 3 parts of layered bimetallic hydroxide (LDH-V) containing vanadate, 4 parts of polyacrylamide, 9 parts of water glass, 10 parts of surface-treated ultrafine steel fiber, 3 parts of polycarboxylate-based high-efficiency water-reducing agent, 0.6 parts of aluminum sulfate, and a water-binder ratio of 0.28.

[0037] Preparation method: S1: Dry mix the cementitious matrix components, nano-silica, metakaolin and ultrafine steel fibers, and stir for 15-20 minutes until uniform to obtain dry mix A; S2: Add polyacrylamide to 40-60% of the total amount of mixing water, stir at 50 ℃ until completely dissolved, then add water glass and high-efficiency water-reducing agent, stir evenly to obtain premixed liquid B; the remaining mixing water is reserved for step S3 to adjust the consistency of the slurry. S3: Pour the premixed liquid B into the mixer, and gradually add the dry mixture A, aluminum sulfate and the remaining mixing water while stirring, and continue stirring until a uniform slurry C is formed. S4: Add vanadate-containing layered bimetallic hydroxide, disulfide bond-containing small molecule diamine crosslinking agent, and epoxy resin monomer to homogeneous slurry C to obtain the multifunctional grouting material.

[0038] Example 2 A tough, self-healing, anti-dispersion, anti-permeability, and actively corrosion-resistant grouting material, by weight, is prepared from the following raw materials: 100 parts of rapid-hardening sulfoaluminate cement, 30 parts of fly ash microspheres, 20 parts of highly active slag powder, 5 parts of nano-silica, 10 parts of metakaolin, 5 parts of self-healing epoxy resin containing dynamic covalent bonds (0.5 parts of crosslinking agent + 4.5 parts of epoxy resin), 1 part of vanadate layered bimetallic hydroxide (LDH-V), 1 part of polyacrylamide, 5 parts of water glass, 2 parts of surface-treated ultrafine steel fiber, 1 part of polycarboxylate-based high-efficiency water-reducing agent, and a water-binder ratio of 0.20.

[0039] The preparation method is the same as in Example 1.

[0040] Example 3 A tough, self-healing, anti-dispersion, anti-permeability, and actively corrosion-resistant grouting material, by weight, is prepared from the following raw materials: 100 parts of rapid-hardening sulfoaluminate cement, 45 parts of fly ash microspheres, 35 parts of highly active slag powder, 10 parts of nano-silica, 20 parts of metakaolin, 15 parts of self-healing epoxy resin containing dynamic covalent bonds (1.5 parts of crosslinking agent + 13.5 parts of epoxy resin), 2 parts of vanadate layered bimetallic hydroxide (LDH-V), 2.5 parts of polyacrylamide, 7 parts of water glass, 6 parts of surface-treated ultrafine steel fiber, 2 parts of polycarboxylate-based high-efficiency water-reducing agent, and a water-binder ratio of 0.24.

[0041] The preparation method is the same as in Example 1.

[0042] Performance testing The performance of the grouting materials prepared in Examples 1-3 was tested using the following methods: Setting time: Refer to GB / T 1346-2011.

[0043] Compressive strength: Refer to GB / T 17671-2021, specimen size 40 mm × 40 mm × 160 mm.

[0044] Bond strength: Using a granite substrate, pull-out method as per JC / T 907-2018.

[0045] Underwater molding strength retention rate: the ratio of the specimen's strength after 28 days of underwater molding and curing to its strength after 28 days of standard curing, multiplied by 100%.

[0046] Chloride ion permeability coefficient: Refer to the RCM method in GB / T 50082-2009.

[0047] Self-healing strength recovery rate: After curing for 28 days, the specimen was compressed to produce a through crack with a width of 0.5 mm. After unloading, it was placed in water for curing for 7 days, and the compressive strength recovery rate at the crack was tested (strength after repair / original strength × 100%).

[0048] The test results are shown in the table below: Table 1

[0049] The above data show that Examples 1-3 of the present invention all achieved rapid setting (initial setting ≤ 38 min), high strength (28 days ≥ 65 MPa), good adhesion (≥ 4.5 MPa), good anti-dispersion (underwater strength retention rate ≥ 80%), self-healing (recovery rate ≥ 65%), and low chloride ion penetration (≤ 1.8 × 10⁻¹² m³). 2 The comprehensive performance of the samples was as follows: Example 1 showed the best comprehensive performance, with a 28-day compressive strength of 82 MPa, a self-healing recovery rate of 75%, and a chloride ion permeability coefficient of 1.2 × 10⁻⁶.-12 m 2 / s. Compared with the traditional cement-based grouting materials described in the background art (28-day strength is usually 40-50 MPa, and there is no self-healing, anti-dispersion and active anti-corrosion ability), the present invention has achieved significant technical progress.

[0050] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A grouting material, characterized in that, The raw material composition, including the gelling matrix component, reinforcing and functional components, additives, and water, is as follows by weight: Cementitious matrix components: 100 parts rapid-hardening sulfoaluminate cement, 30-60 parts fly ash microspheres, and 20-50 parts highly active slag powder; Reinforcing and functional components: 5-15 parts of nano-silica, 10-30 parts of metakaolin, 5-25 parts of self-healing epoxy resin containing dynamic covalent bonds, 1-3 parts of layered bimetallic hydroxide containing vanadate, 1-4 parts of polyacrylamide, 5-9 parts of water glass, and 2-10 parts of surface-treated ultrafine steel fiber. Admixtures: 1-3 parts of high-efficiency water-reducing agent, 0-0.6 parts of retarder / accelerator; Water: The water-to-binder ratio is 0.20-0.

28.

2. The grouting material according to claim 1, characterized in that, The rapid-hardening sulfoaluminate cement is grade 42.5 or 52.5; the fly ash microspheres are hollow microspheres extracted from grade I fly ash; the highly active slag powder is grade S95 slag powder. The average particle size of the nano-silica is 15 nm; the activity index of the metakaolin is ≥110; the polyacrylamide is non-ionic with a molecular weight of 8 million to 12 million; the water glass has a Baumé degree of 38.5 ± 1 and a modulus of 3.0 to 3.5; the surface-treated ultrafine steel fibers are surface-treated with 1 wt% silane coupling agent KH-550, with a length of 6-8 mm and a diameter of 0.12-0.18 mm. The high-efficiency water-reducing agent is a polycarboxylate-based high-performance water-reducing agent with a water reduction rate of ≥30%; the retarding / accelerating regulator is selected from at least one of citric acid, sodium gluconate, aluminum sulfate, and lithium carbonate; The water-cement ratio is the ratio of the total mass of water to the cementitious matrix components.

3. The grouting material according to claim 1, characterized in that, The self-healing epoxy resin containing dynamic covalent bonds is synthesized by curing reaction between a small molecule diamine crosslinking agent containing dynamic covalent bonds and an epoxy resin monomer; wherein, the mass ratio of the small molecule diamine crosslinking agent containing dynamic covalent bonds to the epoxy resin monomer is 1:5 to 1:

10. The small molecule diamine crosslinking agent containing dynamic covalent bonds is a crosslinking agent containing disulfide bonds.

4. The grouting material according to claim 3, characterized in that, The crosslinking agent containing disulfide bonds is made of 2-aminothiophenol.

5. The grouting material according to claim 1, characterized in that, The method for preparing the vanadate-containing layered bimetallic hydroxide is as follows: Zinc-aluminum layered bimetallic hydroxides were prepared by thoroughly mixing a mixed solution of metal nitric acid and an alkaline solution and then placing the mixture in an oven. After washing, drying, grinding, and sieving, the zinc-aluminum layered bimetallic hydroxide powder was placed in a vanadate solution and vanadate-containing layered bimetallic hydroxides were prepared by ion exchange.

6. The grouting material according to claim 5, characterized in that, The volume ratio of the metal nitric acid mixed solution and the alkaline solution is 1:1 to 1:

2.

7. The grouting material according to claim 5, characterized in that, The metal nitric acid mixed solution is a mixed solution of Zn(NO3)2 and Al(NO3)3; wherein the concentration of Zn(NO3)2 in the mixed solution is 0.20–0.50 mol / L, and the concentration of Al(NO3)3 is 0.10–0.25 mol / L; the alkaline solution is a NaOH solution; wherein the concentration of the NaOH solution is 0.80–1.20 mol / L; the concentration of the vanadate solution is 0.05–0.1 mol / L; and the solid-liquid ratio of the zinc-aluminum layered bimetallic hydroxide powder to the vanadate solution is 1:20–1:100 (g / mL).

8. The grouting material according to claim 5, characterized in that, The vanadate-containing layered bimetallic hydroxide has a particle size of 50-200 nm.

9. A method for preparing a grouting material, characterized in that, Includes the following steps: S1: Prepare the grouting material according to any one of claims 1-8 by dry mixing the cementitious matrix component, nano silica, metakaolin and surface-treated ultrafine steel fiber, and stirring evenly to obtain dry mixture A. S2: Add polyacrylamide to part of the mixing water, stir at 50 ℃ until completely dissolved, then add water glass and high-efficiency water-reducing agent, stir evenly to obtain premixed solution B; S3: Pour the premixed liquid B into the mixer, and gradually add the dry mixture A, retarder / accelerator and remaining mixing water while stirring, and continue stirring until a uniform slurry C is formed. S4: Add vanadate-containing layered bimetallic hydroxide, a small molecule diamine crosslinking agent with dynamic covalent bonds, and epoxy resin monomer to a homogeneous slurry C to obtain the grouting material.

10. The application of the grouting material obtained by the preparation method according to claim 9 in deep-ground fractured rock masses.

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