Early high-strength micro-expansion non-shrinkage grouting material and preparation method thereof

Abstract

This invention discloses an early-stage, high-strength, micro-expansion, non-shrinkage grouting material and its preparation method, belonging to the field of new materials technology. This invention prepares a high-performance grouting material through multi-scale nanomaterial synergy, gradation optimization, and hydration kinetic regulation. The preparation method includes pretreatment of gelling powder, preparation of dispersed sol, preparation of nano-expansion regulator, preparation of nano-filler system, and nano-reinforced mixing process. The main performance indicators are: 1-hour compressive strength ≥32MPa, 1-day compressive strength ≥62MPa, 28-day compressive strength ≥102MPa; 3-hour expansion rate 0.6-0.95%, 28-day shrinkage rate ≤0.015%; initial flowability ≥305mm, 30-minute retention ≥265mm; freeze-thaw mass loss ≤3.8%, chloride ion diffusion coefficient ≤1.8×10⁻⁶. ‑12 m 2 / s, coefficient of thermal expansion ≤1.2×10 ‑6 / ℃. This grouting material has the advantages of early strength and high strength, micro-expansion and no shrinkage, high fluidity, excellent durability and low thermal expansion, and is suitable for high-performance engineering scenarios such as nuclear power plant containment vessels and long-span bridge bearings.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, specifically, it relates to an early high-strength micro-expansion non-shrinkage grout and its preparation method. Background Technology

[0002] Grouting material is an important building material with an irreplaceable role in modern engineering construction. It is typically composed of various components such as cement, aggregates, admixtures, and additives, possessing good fluidity and binding properties. It can fill confined spaces and cure rapidly to form a high-strength structural layer. Grouting materials are widely used in construction, bridges, tunnels, and water conservancy projects, playing a crucial role, especially in equipment foundation reinforcement, structural repair, waterproofing, and prestressed pipe grouting. With the continuous advancement of engineering technology, the requirements for grouting material performance are increasing, particularly regarding early strength, shrinkage performance, and durability. However, traditional grouting materials have some significant shortcomings in practical applications, which limit their use in high-performance engineering projects.

[0003] A major problem with traditional grouting materials is insufficient early strength. In many engineering scenarios requiring rapid construction, such as emergency repairs, reinforcements, or precast component installations, the early strength of the grouting material directly determines the construction progress and structural safety. However, traditional grouting materials typically require a long curing time to reach their design strength, which not only prolongs the construction period but can also increase construction costs. Furthermore, shrinkage cracking is another prominent issue with traditional grouting materials. During the hardening process, the grouting material undergoes volume shrinkage due to moisture evaporation and chemical reactions, leading to cracks. These cracks not only affect the appearance but also weaken the structure's load-bearing capacity and durability, and can even pose safety hazards. In addition, traditional grouting materials also have shortcomings in terms of durability, such as poor freeze-thaw resistance and poor impermeability, which are particularly pronounced in harsh environments.

[0004] To overcome the aforementioned shortcomings of traditional grouting materials, researchers have proposed various improvement methods and technologies. Among these, adding expanding agents is a common method to address shrinkage issues. Expanding agents can generate micro-expansion during the hardening process of the grouting material, offsetting some of the shrinkage stress and thus reducing the risk of cracking. However, the effect of expanding agents is often unstable, greatly affected by environmental conditions and material batches, making precise control difficult. Furthermore, excessive use of expanding agents may lead to a decrease in the strength of the grouting material, affecting its mechanical properties. Another method is to add shrinkage-reducing agents, which can reduce the shrinkage rate of the grouting material and improve volume stability, but these are costly and may negatively impact flowability and other properties. In addition, the application of reinforcing fibers has been extensively studied; fibers can improve the crack resistance and toughness of grouting materials. However, fiber dispersibility and bonding with the matrix are key issues, and the complex and costly preparation process limits its large-scale application.

[0005] In recent years, the application of nanomaterials in grouting materials has attracted widespread attention. Due to their unique physical and chemical properties, nanomaterials can significantly improve the microstructure and performance of grouting materials. For example, nano-silica can promote the hydration reaction of cement and improve early strength; nano-calcium carbonate can fill micropores and increase density; and nano-graphene oxide can enhance mechanical properties and durability. However, the application of nanomaterials still faces challenges, such as the tendency of nanoparticles to agglomerate, insufficient compatibility with the matrix, and complex preparation processes. These issues limit their widespread adoption in grouting materials.

[0006] In terms of preparation technology, traditional grouting materials typically employ simple mechanical stirring methods to mix the components uniformly. However, this method struggles to achieve uniform dispersion of nanomaterials, hindering their full performance. Furthermore, traditional processes are insufficient in controlling flowability and workability, failing to meet the demands of high-performance grouting materials. Therefore, developing a novel preparation method that can both achieve uniform material dispersion and optimize performance is of great significance.

[0007] In summary, traditional grouting materials have shortcomings in early strength, shrinkage performance, and durability. While existing improvement methods have shown some effectiveness, they still face challenges related to stability and cost. This invention overcomes these difficulties through technological innovation, providing a new solution for the research and application of high-performance grouting materials, and possesses significant engineering value and market potential. Summary of the Invention

[0008] 1. The problem to be solved

[0009] To address the problems of insufficient early strength, cracking due to volume shrinkage, poor durability, and inadequate thermal stability in existing grouting materials, this invention aims to provide an early-strength, high-strength, micro-expansion, non-shrinkage grouting material and its preparation method to meet the needs of high-performance engineering scenarios such as nuclear power plant containment structures and long-span bridge bearings. Specifically, traditional grouting materials struggle to achieve a compressive strength of ≥32MPa within 1 hour in rapid construction scenarios, and their 28-day strength is typically below 100MPa, limiting construction efficiency and structural safety. Volume shrinkage during the hardening process (28-day shrinkage rate often ≥0.05%) easily leads to cracking, weakening structural durability. Furthermore, their freeze-thaw resistance and corrosion resistance are insufficient (chloride ion diffusion coefficient often ≥5×10⁻⁶). -12 m 2 / s, acid erosion strength retention rate ≤80%, making it difficult to cope with harsh environments; in addition, traditional grouting materials have a high coefficient of thermal expansion (usually ≥2×10). -6 In environments with large temperature differences (°C), thermal stress damage is easily generated. Existing improvement methods, such as adding expanding agents, shrinkage reducing agents, or fibers, have certain effects, but they suffer from problems such as unstable expansion, high cost, complex processes, or poor dispersibility of nanomaterials, making it difficult to fully meet high-performance requirements.

[0010] This invention solves the above problems through innovative material formulation and preparation process, developing a material with high early strength (compressive strength ≥32MPa at 1h, ≥62MPa at 1d, ≥102MPa at 28d), micro-expansion with no shrinkage (expansion rate 0.6-0.95% at 3h, shrinkage rate ≤0.015% at 28d), high fluidity (initial flowability ≥305mm), and excellent durability (freeze-thaw resistance ≤3.8%, chloride ion diffusion coefficient ≤1.8×10⁻⁶). -12 m 2 ( / s) and low thermal expansion (coefficient of thermal expansion ≤ 1.2 × 10⁻⁶). -6 Grouting materials with a temperature of / ℃ provide reliable material solutions for high-performance engineering.

[0011] 2. Technical Solution

[0012] To solve the above problems, the present invention adopts the following technical solution.

[0013] A method for preparing an early-strength, high-strength, micro-expansion, non-shrinkage grout includes the following steps: a. Pretreatment of the gelling powder: Silicate cement, sulfoaluminate cement, and nano-silica are mixed and then ball-milled at 500-800 rpm for 60-120 min under an inert atmosphere to obtain composite gelling powder with a particle size of 0.5-2 µm; b. Preparation of the dispersion sol: Nano-titanium dioxide, functionalized nano-calcium carbonate, and cellulose ether are dispersed in deionized water under ultrasonic conditions for 30-60 min to form a stable dispersion sol; c. Preparation of the nano-expansion regulator: Magnesium oxide micropowder, calcium sulfoaluminate, nano-graphene oxide, and deionized water are mixed... d. Preparation of the nano-filled system: Quartz sand aggregate, silica fume, and slag powder are selected and ball-milled and homogenized to obtain the nano-filled system; e. Nano-reinforced mixing process: The composite cementitious powder from step a and the nano-filled system from step d are dispersed and mixed in a high-speed disperser at 150-200 rpm for 2-3 min. Then, the nano-expansion regulator from step c is added, and dispersion and mixing are continued for 1-2 min. Then, the dispersing sol from step b is added, and the stirring speed is increased to 250-350 rpm for 5-8 min. Finally, 5-10 times the mass of the energy storage material is added and shear homogenization is performed to obtain the product.

[0014] Preferably, in step a, the mass ratio of silicate cement, sulfoaluminate cement, and nano-silica is (40-60):(8-15):(0.5-2); the particle size of the nano-silica in step a is 10-30 nm. For Portland Cement (PC), basic characteristics include: Strength grade: typically 42.5 or higher, indicating a 28-day compressive strength of 42.5 MPa or higher. Particle size: median particle size is approximately 11.74 µm, and specific surface area is approximately 356 m². 2 / kg. Chemical composition: The main components are CaO (62.8%), SiO2 (21.7%), Al2O3 (5.45%), Fe2O3 (3.41%), etc. For Calcium Sulfoaluminate Cement (CSA), basic characteristics: Strength grade: usually 42.5R, indicating rapid hardening characteristics, 28d compressive strength reaches or exceeds 42.5MPa. Particle size: Median particle size is about 13.56µm. Chemical composition: The main components are CaO (39.7%), Al2O3 (27.3%), SiO2 (13.8%), SO3 (10.9%), etc., with high sulfate and aluminate content. Synergistic strengthening mechanism of ternary composite cementitious system: (1) Silicate cement: dominates the later strength development, generates CSH gel and Ca(OH)2, specific surface area 356m 2 / kg ensures full hydration; Sulfoaluminate cement: rapidly generates ettringite (AFt) skeleton, 3h expansion rate 0.5-1.2%, 1d strength contribution ≥50%; Nano silica: volcanic ash reaction consumes Ca(OH)2 to generate CSH gel, filling pores (specific surface area ≥200m²). 2 / g). (2) Particle size matching and microstructure optimization: PC / CSA particle size synergy: PC (D50=11.74µm) and CSA (D50=13.56µm) form a continuous gradation, increasing the packing density by 12-15% and reducing water demand. Nano SiO2 effect: 10-30nm particle size enhances performance through the following mechanisms: nucleation effect: as a CSH heterogeneous nucleation site, it accelerates the hydration reaction rate by 3-5 times; micro-filling effect: fills 10-100nm pores, reducing the total porosity by ≥30%; chemical activation: surface silanol groups (Si-OH) and Ca 2+ The reaction generates CSH, and the strength increases by 20-35% in 1 day. (3) Hydration kinetics regulation: Early stage (0-12h): CSA rapidly hydrates to generate AFt, and nano SiO2 promotes the hydrolysis of C3S in PC. The strength in 10h can reach 40-50% of the strength in 28 days. Mid-stage (12h-7d): PC dominates the generation of CSH gel, and nano SiO2 continuously consumes Ca(OH)2. The Ca(OH)2 content decreases by 60-80% in 28 days. Long-term stage (7d-28d): AFt and CSH synergistically form an interlocked structure, with compressive strength ≥100MPa and shrinkage rate ≤0.02%. Scientific basis of key parameters: CSA:PC ratio (8-15:40-60): Ensure that the ratio of AFt to CSH generation is 1:2-1:3, which ensures early strength and avoids excessive expansion. Nano-SiO2 content (0.5-2%): When it exceeds 3%, the flowability decreases by 30-50% due to the agglomeration effect. This formulation balances activity and workability. Particle size control (10-30nm): 40nm particles have the best filling effect, but 10-30nm particles can achieve similar effects and better dispersibility through surface modification. This formulation achieves a high-performance grouting material system with 1-day compressive strength ≥60MPa, 28-day strength ≥100MPa, and volume change rate ≤0.02% through the triple synergy of particle size distribution optimization, hydration stage control, and nano-reinforcement technology.

[0015] Preferably, in step b, the mass ratio of nano-titanium dioxide, functionalized nano-calcium carbonate, cellulose ether (CAS No. 9004-32-4), and deionized water is (0.1-0.8):(0.05-0.3):(0.02-0.1):(15-22); the particle size of nano-titanium dioxide in step b is 5-15nm; the ultrasonic conditions in step b are as follows: power 200-400W, frequency 40kHz.

[0016] Preferably, the preparation method of functionalized nano-calcium carbonate in step b is as follows: A calcium chloride solution with a concentration of 0.5-1.5 mol / L and a sodium carbonate solution with a concentration of 0.5-1.5 mol / L are rapidly mixed at 20-30°C in a molar ratio of 1:(2-4), with the stirring speed controlled at 300-500 rpm and the reaction time at 30-60 min, to generate a nano-calcium carbonate suspension with a particle size controlled at 20-50 nm; 0.05-0.2 times its mass of silane coupling agent KH- is added to the above nano-calcium carbonate suspension. 570 or KH-550, and adjust the pH of the solution to 8.0-9.0, use ultrasonic dispersion with power of 200-400W and frequency of 40kHz for 30-60min to form a modified suspension; remove unreacted impurities by centrifugation, where the centrifugation speed is 5000-8000rpm and the centrifugation time is 10-20min, wash with deionized water 3-5 times, and then dry in a vacuum drying oven at 60-80℃ for 6-12h to obtain functionalized nano-calcium carbonate. The preparation method of functionalized nano-calcium carbonate achieves performance optimization through the following mechanism: (1) Nano-calcium carbonate synthesis stage: chemical precipitation control: using the molar ratio of CaCl2 to Na2CO3 1: (2-4), the excessive growth of particles is inhibited by the carbonate excess strategy (Ostwald ripening mechanism), combined with a stirring speed of 300-500rpm to form a uniform shear force field, which promotes the nucleation rate > growth rate, and achieves precise control of particle size of 20-50nm. Low-temperature reaction kinetics: At 20-30℃, the ion diffusion rate is slowed down to avoid local oversaturation and agglomeration, while promoting the transformation of amorphous precursors to calcite crystal form. (2) Surface functionalization modification: Silane coupling agent bonding mechanism: KH-570 (containing methacryloyloxy) or KH-550 (containing amino) hydrolyzes to silanol (Si-OH) at pH 8.0-9.0, which dehydrates and condenses with hydroxyl (-OH) on the surface of nano-calcium carbonate to form Si-O-Ca covalent bonds, constructing an organic-inorganic interface layer. Ultrasonic cavitation effect: 40kHz ultrasound generates microjets and cavitation bubbles break, destroying the van der Waals forces between particles, while promoting the directional adsorption of silane molecules to achieve monolayer coating (coverage rate > 90%). (3) Post-process optimization: Centrifugal purification: High-speed centrifugation at 5000-8000rpm selectively separates unreacted ions (such as Cl). - Na + This process avoids the formation of large-sized aggregates (>100nm) and ensures product monodispersity (PDI < 0.2). Vacuum drying prevents agglomeration: Low-temperature vacuum conditions at 60-80℃ suppress secondary agglomeration caused by capillary forces, preserving the nanoscale pore structure (BET specific surface area 40-60m²). 2 / g). (4) The role of functionalized nano-calcium carbonate in grouting materials: nucleating agent: surface silane groups provide high-energy active sites, accelerate the heterogeneous nucleation of CSH gel, and increase the compressive strength by ≥15% in 1 day; micro-expansion regulation: KH-550 amino groups and Ca 2+ Coordination delays the formation rate of AFt (ettringite), and the expansion rate stabilizes at 0.5-1.2% after 3 hours; interface enhancement: organic functional groups form hydrogen bonds with the polymer matrix (such as polycarboxylate superplasticizer), and the interfacial bonding strength is ≥8MPa. Scientific basis for key parameters: molar ratio 1:(2-4): excess carbonate ions inhibit CaCO3 dissolution-recrystallization through the common ion effect, limiting grain size (Langmuir adsorption model). Ultrasonic power 200-400W: at an energy density of 0.5-1.0W / mL, the cavitation threshold breaks through the particle aggregation energy barrier (≈10kT), achieving efficient dispersion. This process, through chemical-mechanical synergy, achieves controllable size and precise surface functionalization of nano-calcium carbonate, providing an optimized microstructure control method for early-stage high-strength grouting materials.

[0017] Preferably, in step c, the mass ratio of magnesium oxide micropowder (CAS No. 1309-48-4), calcium sulfoaluminate (CAS No. 960375-09-1), nano-graphene oxide, and deionized water is (1.5-4):(0.3-1.2):(0.1-0.5):(6-10). The parameters of the nano-graphene oxide are as follows: CAS No. 7782-42-5. Functionalized GO materials with a sheet thickness of 1-3 nm, with a doping content of 0.1-0.5%, can improve flexural strength by 30-50% (through crack bridging and interface reinforcement). MgO:CSA ratio (1.5-4:0.3-1.2): ensures an expansion pressure gradient ≤0.5 MPa / day to avoid structural damage. GO doping content (0.1-0.5%): exceeding 0.5% leads to agglomeration due to van der Waals forces, reducing the specific surface area from 263 m² / h. 2 / g decreased to 150m 2 / g. Particle size matching: MgO (5-20μm) and GO (1-3nm) form a multi-scale filling, reducing porosity by 40%. This formulation, through the combination of temporal and tertiary control of the expansion phase and nano-reinforcement technology, achieves a high-performance grouting material system with a 1-day compressive strength ≥60MPa and a 28-day shrinkage rate ≤0.03%, suitable for harsh environments such as nuclear power plant containment vessels.

[0018] Preferably, the mass ratio of quartz sand aggregate, silica fume and slag powder in step d is (100-150):(2-8):(1-5); the parameters of ball milling in step d are as follows: rotation speed 400-500 r / min, time 12-18 h; the parameters of homogenization in step d are as follows: pressure: 40-60 MPa, number of cycles: 3-5 times.

[0019] Synergistic effect of mass ratio (quartz sand aggregate: silica fume: slag powder = 100-150: 2-8: 1-5): Quartz sand aggregate: provides skeletal support, optimizes gradation (0.05-1.2mm continuous distribution), and increases bulk density to 75-80%. Silica fume: provides nanoscale filler (specific surface area ≥ 20000 m²). 2 / kg) reacts with volcanic ash, increasing strength by 15-25% in 1 day. Slag powder: potential activity activation (releasing Ca in an alkaline environment). 2+ The 28-day strength contribution rate is 10-15%, and the chloride ion diffusion coefficient is reduced by 50%. Micro-control of ball milling process (400-500 r / min, 12-18 h): The shear force generated by ball milling deagglomerates the slag glass, increasing the release of active SiO2 and Al2O3 by 2-3 times. Macro-optimization of high-pressure homogenization (40-60 MPa, 3-5 cycles): Pressure 40-60 MPa: eliminates >100 μm bubbles, reduces porosity from 8-10% to 3-5%, and improves impermeability by 2-3 grades (P≥P12). 3-5 cycles: destroys silica fume agglomerates (from 10 μm → <1 μm), reduces the thickness of the quartz sand-cement interface transition zone (ITZ) from 20 μm to 5 μm, and increases interfacial bonding strength from 5 MPa to 8 MPa. Temperature control <40℃: Prevents thermal activation leading to prehydration, ensures fluidity retention ≥90%, and extends the construction time window to 60-90 minutes. Multi-scale structural synergy: Nanoscale: Silica fume fills 10-100nm pores, increasing the density of CSH gel nucleation sites by 10%. 3 / cm 3 Micron-level: Ball-milled quartz sand creates an uneven surface, increasing mechanical interlocking force by 30%; Macro-level: High-pressure homogenization reduces defect size from 500μm to <50μm, increasing fracture toughness by 50%. This process, through precise control of gradation matching, activation, and defect elimination, achieves a high-performance grouting material system with a 1-day compressive strength ≥65MPa and a 28-day shrinkage rate ≤0.02%, suitable for demanding scenarios such as grouting of long-span bridge bearings.

[0020] Preferably, in step d, the mass ratio of the composite gel powder, dispersible sol, nano-expansion regulator and nano-filler system is (80-100):(8-12):(2-4):(1-2); the parameters of the shear homogenization treatment in step d are as follows: rotation speed 400-500 rpm, time 30-60 s. In step d, the composite gel powder (80-100 parts), dispersing sol (8-12 parts), nano-expansion regulator (2-4 parts), and nano-filler system (1-2 parts) achieve performance optimization through the following synergistic mechanism: the composite gel powder provides the main strength framework as the matrix (1-day compressive strength ≥60MPa); the dispersing sol ensures uniform dispersion of nanoparticles through electrostatic stabilization (Zeta potential ≥30mV); the nano-expansion regulator (magnesium oxide / calcium sulfoaluminate composite system) precisely regulates the 3-hour expansion rate (0.5-1.2%); and the nano-filler system (silica fume / GO composite) reduces porosity to ≤3% through size gradient filling (10nm-1μm). High-speed shear homogenization treatment at 400-500rpm for 30-60s, with an instantaneous shear rate ≥10... 3 s -1 The hydrodynamic action breaks down nano-aggregates (reducing the size from 500nm to <100nm) and forms chemical bonds at the interface (Ca-O-Si bond binding energy ≥530kJ / mol), ultimately achieving a performance balance of slurry fluidity ≥300mm and 28d shrinkage ≤0.02%.

[0021] Preferably, the preparation method of the energy storage material in step d is as follows: Paraffin (CAS No. 8002-74-2) and sodium sulfate decahydrate (CAS No. 7727-73-3) with a mass ratio of 1:(3-5) are selected as phase change materials; polymethyl methacrylate (CAS No. 9011-14-7) is dissolved in acetone at a mass ratio of 20-40 times to prepare a shell material solution; the phase change material is dispersed in deionized water at a mass ratio of 30-50 times, and then polyvinyl alcohol at a mass ratio of 5-10 times is added. Under high-speed stirring at 1200-1500 rpm, the shell material solution at a mass ratio of 2-3 times is added dropwise to form a water-in-oil emulsion. The temperature is raised to 70-80°C and the reaction is carried out for 4-6 hours to complete the shell polymerization. Then, the microcapsules are separated by centrifugation at 8000 rpm for 10 minutes, washed three times alternately with ethanol and deionized water, and dried under vacuum at 40°C for 24 hours to obtain the energy storage material.

[0022] Optimization of composite phase change materials: Paraffin provides high latent heat (180-220 J / g) but low thermal conductivity (0.2 W / m·K), while sodium sulfate decahydrate compensates for its low thermal conductivity (0.5 W / m·K) through the release / absorption of latent heat (250-300 J / g) from its water of crystallization. The combination of these two materials achieves a latent heat ≥200 J / g and improves cycle stability by 50% (capacity retention >90% after 500 thermal cycles). Microcapsule shell construction: Low-viscosity solutions (50-100 cP) in the shell material solution facilitate the formation of a uniform shell. A shell thickness of 2-5 μm is controlled by the dissolution concentration, and a glass transition temperature of 105℃ ensures high-temperature stability. Emulsification stabilization of polyvinyl alcohol: 5-10% addition forms an oil-in-water emulsion with an HLB value of 16-18, reducing interfacial tension to <10 mN / m, and controlling droplet size to 50-200 μm (laser particle size analysis). Interfacial polymerization reaction control: In-situ polymerization at 70-80℃: Thermal decomposition of the initiator generates free radicals, causing methyl methacrylate monomers to polymerize at the droplet interface. Reaction kinetics: Ensure monomer conversion >95% and shell crosslinking density ≥80% (determined by swelling method) within 4-6 hours.

[0023] A high-strength, low-expansion, non-shrink grouting material is obtained by the preparation method described above.

[0024] 3. Beneficial effects

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention achieves excellent properties of grouting material, such as early strength, high strength, micro-expansion, and no shrinkage, through multi-scale nanomaterial synergy, gradation optimization, and hydration kinetic regulation. The mechanism of its beneficial effects is analyzed in depth from three dimensions: material ratio, reaction mechanism, and microstructure: (1) Early strength and high strength mechanism: synergistic effect of nanomaterials, nano-silica (10-30nm) consumes Ca(OH)2 through volcanic ash reaction to generate CSH gel, increasing the strength by 20-35% in 1 day. Its specific surface area is ≥200m². 2 Its / g characteristic allows it to fill pores in the 10-100nm range, reducing total porosity by ≥30%. Functionalized nano-calcium carbonate surface silane groups provide high-energy active sites, accelerating CSH heterogeneous nucleation and increasing 1-day compressive strength by ≥15%. KH-550 amino groups and Ca... 2+Coordination delays the formation rate of ettringite, stabilizing the expansion rate at 0.5-1.2% over 3 hours. Hydration kinetic regulation: The formation of the sulfoaluminate cement / silicate cement composite system is time-controlled: in the early stage (0-12h), the ettringite skeleton is rapidly formed; in the middle stage (12h-7d), CSH gel dominates; and in the later stage (7-28d), an interlocking structure is formed. The strength in 1 hour reaches 40-50% of the strength in 28 days, and the compressive strength in 28 days is ≥102MPa. (2) Micro-expansion without shrinkage mechanism: the expansion source is synergistically controlled, and the magnesium oxide / calcium sulfoaluminate composite system generates gradient expansion: magnesium oxide hydrates to generate Mg(OH)2 (volume expansion of 2.1 times), and calcium sulfoaluminate generates ettringite (volume expansion of 1.5 times), with an expansion pressure gradient of ≤0.5MPa / day. Nano-graphene oxide (sheet thickness 1-3nm) inhibits shrinkage through crack bridging, and a dosage of 0.1-0.5% increases the flexural strength by 30-50%. Shrinkage compensation technology: Energy storage material microcapsules (paraffin / sodium sulfate composite phase change material) release latent heat (≥200J / g) when the temperature difference changes, controlling the coefficient of thermal expansion to ≤1.2×10 -6 / ℃. 28d drying shrinkage rate ≤0.015%, which is 70% lower than that of traditional grouting materials. (3) Durability improvement principle: Microstructure optimization, high pressure homogenization process (40-60MPa) reduces porosity from 8-10% to 3-5%, the thickness of the quartz sand-cement interface transition zone (ITZ) is reduced from 20μm to 5μm, and the interfacial bonding strength is increased from 5MPa to 8MPa. The nano-filling system (silica fume / GO composite) forms a 10nm-1μm size gradient filling, and the chloride ion diffusion coefficient ≤1.8×10 -12 m 2 / s, which is 64% lower than the national standard. Enhanced chemical stability: The organic functional groups of functionalized nano-calcium carbonate form a hydrogen bond network with polycarboxylate superplasticizer, and the acid erosion strength retention rate is ≥88%. After 50 freeze-thaw cycles, the mass loss is ≤3.8%, which is better than the requirements of GB / T50448 standard. (4) Contribution to process innovation: The nano-reinforced mixing process adopts high-speed shearing of 400-500rpm, and the instantaneous shear rate is ≥10 3 s -1 By breaking down nano-agglomerates (reducing size from 500nm to <100nm) and ensuring dispersion stability with a Zeta potential ≥30mV, this process achieves a slurry flowability ≥305mm while maintaining a 28-day shrinkage rate ≤0.015%, resolving the flowability-volume stability contradiction in traditional processes. Through this innovative mechanism, this invention achieves a breakthrough in performance, reaching a 1-hour compressive strength ≥32MPa and a 28-day strength ≥102MPa in harsh environments such as nuclear power plant containment structures. Compared to similar products (such as CN102351492A), this represents a 60% increase in early-stage strength and a 3-fold improvement in volume stability. Attached Figure Description

[0027] Figure 1 This is a photograph of the gelled powder prepared in Example 1.

[0028] Figure 2 This is a photograph of the nano-expanding agent prepared in Example 1.

[0029] Figure 3 This is a transmission electron microscope image of the energy storage material prepared in Example 1. Detailed Implementation

[0030] The present invention will now be described in detail through specific embodiments. However, these illustrative embodiments are for the purpose of illustrating the invention only and do not constitute any limitation on the actual scope of protection of the invention, nor are they intended to limit the scope of protection of the invention to these embodiments. For parameter ranges not mentioned, intermediate values ​​are selected. Furthermore, for mass percentages or weight percentages not explicitly stated or mentioned, they generally refer to the final concentration after addition.

[0031] Example 1

[0032] Pretreatment of cementitious powder: Take 40g of silicate cement (PC, strength grade 42.5, median particle size 11.74µm), 8g of sulfoaluminate cement (CSA, strength grade 42.5R, median particle size 13.56µm), and 0.5g of nano silica (particle size 10nm), mix them under an inert atmosphere (nitrogen) and ball mill at 500rpm for 60min to obtain composite cementitious powder with a particle size of 0.5-2µm.

[0033] Preparation of the dispersion sol: 0.1 g of nano-titanium dioxide (5 nm particle size), 0.05 g of functionalized nano-calcium carbonate (20 nm particle size), 0.02 g of cellulose ether (CAS No. 9004-32-4), and 15 g of deionized water were dispersed under ultrasonic conditions of 200 W and 40 kHz for 30 min to form a stable dispersion sol. Preparation of functionalized nano-calcium carbonate: 0.5 mol / L calcium chloride solution and 0.5 mol / L sodium carbonate solution were mixed at a molar ratio of 1:2 and stirred at 20℃ and 300 rpm for 30 min to generate a 20 nm nano-calcium carbonate suspension; 0.05 times the mass of silane coupling agent KH-570 was added to adjust the pH to 8.0, and the mixture was ultrasonically dispersed at 200 W and 40 kHz for 30 min; centrifuged at 5000 rpm for 10 min to remove impurities, washed three times with deionized water, and vacuum dried at 60℃ for 6 h. The prepared gel powder is as follows. Figure 1 As shown.

[0034] Preparation of nano-expansion regulator: Take 1.5g of magnesium oxide micro powder (CAS No. 1309-48-4), 0.3g of calcium sulfoaluminate (CAS No. 960375-09-1), 0.1g of nano-graphene oxide (GO, CAS No. 7782-42-5, sheet thickness 1-3nm), and 6g of deionized water, mix to form a nano-expansion regulator, such as... Figure 2 As shown.

[0035] Preparation of nanofiller system: Take 100g of quartz sand aggregate (particle size 0.05-1.2mm) and 2g of silica fume (specific surface area ≥20000m²). 2 The nanofilled system was prepared by ball milling 1g of slag powder at 400rpm for 12h and then homogenizing it three times under high pressure at 40MPa.

[0036] Nano-enhanced mixing process: Take 80g of composite gel powder and 1g of nanofiller system, disperse and mix in a high-speed disperser at 150rpm for 2min; add 2g of nano-expansion regulator, continue dispersion and mixing for 1min; add 8g of dispersing sol, increase the stirring speed to 250rpm, mix for 5min; add 40g of energy storage material (5 times the mass of the dispersed and dissolved material), and homogenize by shearing at 400rpm for 30s to obtain the product. Energy storage material (such as...) Figure 3 Preparation (as shown): Paraffin (CAS No. 8002-74-2) and sodium sulfate decahydrate (CAS No. 7727-73-3, mass ratio 1:3) were used as phase change materials; polymethyl methacrylate (PMMA, CAS No. 9011-14-7) was dissolved in 20 times acetone to prepare a shell material solution; the phase change material was dispersed in 30 times deionized water, 5 times polyvinyl alcohol was added, stirred at 1200 rpm, 2 times shell material solution was added dropwise, reacted at 70℃ for 4 h, centrifuged at 8000 rpm for 10 min, washed 3 times alternately with ethanol / deionized water, and vacuum dried at 40℃ for 24 h.

[0037] Example 2-18

[0038] Examples 2-18 refer to the process flow and experimental methods of Example 1, but some parameters (such as the mass of each component and process conditions) are adjusted according to the endpoint and intermediate values ​​of the claims, as shown in Table 1.

[0039] Comparative Example 1

[0040] Unlike Example 1, no functionalized nano-calcium carbonate was used. In step b, an equal amount of ordinary nano-calcium carbonate (particle size 20 nm, unmodified with silane coupling agent) was used instead, while keeping other conditions unchanged.

[0041] Comparative Example 2

[0042] Unlike Example 1, in step b, no functionalized nano-calcium carbonate is added; instead, an equal amount of deionized water is used, while keeping other conditions unchanged.

[0043] Comparative Example 3

[0044] Unlike Example 1, no energy storage material is added in step e, while other conditions remain unchanged.

[0045] Comparative Example 4

[0046] Unlike Example 1, in step e, only paraffin (without sodium sulfate decahydrate) is used as the energy storage material, and the mass is still 40g, while other conditions remain unchanged.

[0047] Comparative Example 5

[0048] Unlike Example 5, no functionalized nano-calcium carbonate was used. In step b, an equal amount of ordinary nano-calcium carbonate (30 nm particle size, unmodified by silane coupling agent) was used instead, while keeping other conditions unchanged.

[0049] Comparative Example 6

[0050] Unlike Example 5, in step b, no functionalized nano-calcium carbonate is added; instead, an equal amount of deionized water is used, while keeping other conditions unchanged.

[0051] Comparative Example 7

[0052] Unlike Example 5, no energy storage material is added in step e, while other conditions remain unchanged.

[0053] Comparative Example 8

[0054] Unlike Example 5, in step e, only paraffin (without sodium sulfate decahydrate) is used as the energy storage material, and the mass is still 60g, while other conditions remain unchanged.

[0055] Comparative Example 9

[0056] Unlike Example 10, no functionalized nano-calcium carbonate was used. In step b, an equal amount of ordinary nano-calcium carbonate (50 nm particle size, unmodified by silane coupling agent) was used instead, while keeping other conditions unchanged.

[0057] Comparative Example 10

[0058] Unlike Example 10, in step b, no functionalized nano-calcium carbonate is added; instead, an equal amount of deionized water is used, while keeping other conditions unchanged.

[0059] Comparative Example 11

[0060] Unlike Example 10, no energy storage material is added in step e, while other conditions remain unchanged.

[0061] Comparative Example 12

[0062] Unlike Example 10, in step e, only paraffin (without sodium sulfate decahydrate) is used as the energy storage material, and the mass is still 80g, while other conditions remain unchanged.

[0063] Comparative Example 13

[0064] Unlike Example 1, no nano-expansion regulator was used, and in step e, an equal amount of deionized water was substituted, while other conditions remained unchanged.

[0065] Comparative Example 14

[0066] Unlike Example 5, no nano-expansion regulator was used, and in step e, an equal amount of deionized water was substituted, while other conditions remained unchanged.

[0067] Comparative Example 15

[0068] Unlike Example 10, no nano-expansion regulator was used, and in step e, an equal amount of deionized water was used instead, while keeping other conditions unchanged.

[0069] Comparative Example 16

[0070] Unlike Example 1, the nano-enhanced mixing process in step e is not performed. Instead, the composite gel powder, dispersible sol, nano-expansion regulator, nano-filler system and energy storage material are simply mixed in the same mass ratio, stirred evenly and then left to stand, while keeping other conditions unchanged.

[0071] The following is a summary of the process parameters and proportions for Examples 1-18 and Comparative Examples 1-16, in grams (g). The process conditions cover the endpoint and intermediate values ​​of all parameters in the claims.

[0072] Table 1 Summary of process parameters for Examples 1-18

[0073]

[0074]

[0075] Table 2 Summary of process parameters for Comparative Examples 1-16

[0076]

[0077]

[0078]

[0079] Example Design: Examples 1-18 cover the endpoint values ​​(minimum, maximum) and intermediate values ​​of the parameters for each step in the claims, ensuring comprehensive verification of the feasibility of the formulation and process conditions. The parameters for steps a, b, c, d, and e are all adjusted proportionally, and the mass of the energy storage material is designed to be 5-10 times the mass of the dispersed and dissolved material.

[0080] Comparative Designs: Comparative Examples 1, 5, and 9: Verifying the role of functionalized nano-calcium carbonate, replacing it with ordinary nano-calcium carbonate, and examining the effect of surface modification on nucleation and interfacial strength. Comparative Examples 2, 6, and 10: Removing functionalized nano-calcium carbonate, verifying its necessity for micro-expansion regulation and strength. Comparative Examples 3, 7, and 11: Removing the energy storage material, verifying its contribution to thermal regulation and long-term stability. Comparative Examples 4, 8, and 12: Using only paraffin wax as the energy storage material, verifying the synergistic effect of paraffin wax and sodium sulfate decahydrate.

[0081] Comparative Examples 13-15: The nano-expansion regulator was removed to verify its effect on micro-expansion and volume stability. Comparative Example 16: The nano-reinforced mixing process was omitted to verify the importance of high-speed shear homogenization for dispersibility and interfacial bonding. Synergistic Effect Verification: By omitting key components or processes in the comparative examples, the synergistic contributions of functionalized nano-calcium carbonate (nucleation, interfacial reinforcement), energy storage materials (thermal regulation), nano-expansion regulator (volume stability), and nano-reinforced mixing process (uniform dispersion, chemical bonding) to early strength, micro-expansion, and shrinkage-free properties are highlighted.

[0082] Physical performance testing: The fluidity and setting time of the grouts prepared in Examples 1-18 and Comparative Examples 1-16 were tested as follows: Flowability: Initial fluidity and 30-minute retention value were measured using a truncated cone fluidity meter according to GB / T50448-2015. Water-to-material ratio: 0.14; ambient temperature: 20±2℃. Setting time: Initial and final setting times were measured using a Vicat apparatus to control the construction window period.

[0083] Mechanical property testing: Compressive strength and flexural strength were tested using the following methods: Compressive strength: According to JC / T986-2018, the compression loading rate was 2.4 kN / s, and the compressive strength was measured at 1 h, 3 h, 1 d, and 28 d. Flexural strength: The flexural strength was measured using the three-point bending method at 28 d.

[0084] Volume stability test: The vertical expansion rate and coefficient of thermal expansion were tested using the following methods: Vertical expansion rate: Dial gauge method, measuring the expansion rate over 3 hours and the contraction rate over 28 days, referring to GB / T50082-2009. Coefficient of thermal expansion: Thermomechanical analyzer (TMA), measuring the coefficient of thermal expansion in the range of 20-60℃.

[0085] Durability testing: Freeze-thaw resistance and corrosion resistance were tested using the following methods: Freeze-thaw resistance: 50 cycles of rapid freezing were performed, and mass loss and strength loss were measured. Corrosion resistance: Immersion in 5% NaCl solution for 90 days was performed, and the chloride ion diffusion coefficient was measured; erosion in 10% H2SO4 solution for 28 days was performed, and the strength retention rate was measured.

[0086] Microstructure analysis: The hydration products and pore structure were analyzed using the following methods: Hydration products: XRD analysis was used to determine the ratio of ettringite (AFt) to CSH gel, and thermogravimetric analysis (TGA) was used to determine the 28-day Ca(OH)2 content. Pore structure: Mercury intrusion porosimetry (MIP) was used to determine the total porosity and pore size distribution, and the dispersion state of the nanomaterials was observed.

[0087] The test results of Examples 1-18 and Comparative Examples 1-16 are summarized in Table 3.

[0088] Table 3 Performance test results of Examples 1-18 and Comparative Examples 1-16

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] Results Analysis

[0097] Examples 1-18: Physical properties: Initial flowability ≥305mm, 30min retention ≥265mm, initial setting time ≤40min, final setting time ≤220min, meeting construction requirements. Mechanical properties: 1h compressive strength ≥32MPa, 3h ≥52MPa, 1d ≥62MPa, 28d ≥102MPa, flexural strength ≥15.5MPa, indicating excellent early strength and long-term strength. Volume stability: 3h expansion rate 0.6-0.95%, 28d shrinkage rate ≤0.015%, coefficient of thermal expansion ≤1.2×10⁻⁶. -6 / ℃, achieving the goal of micro-expansion without shrinkage. Durability: Freeze-thaw resistance with mass loss ≤3.8%, strength loss ≤15%, and chloride ion diffusion coefficient ≤1.8×10. -12 m 2 / s, acid erosion strength retention rate ≥88%, excellent durability. Microstructure: total porosity ≤2.8%, Ca(OH)2 content ≤2.5%, indicating that the nanomaterials effectively fill the pores and optimize hydration products.

[0098] Comparative Examples 1-16: Comparative Examples 1, 5, and 9 (unfunctionalized nano-calcium carbonate): Initial flowability decreased to 287-290 mm, 1-day compressive strength decreased to 54-55 MPa, 28-day shrinkage increased to 0.030-0.032%, and total porosity increased to 4.0-4.1%. The absence of functionalized nano-calcium carbonate reduced the nucleation effect and interfacial bonding strength, leading to a decrease in strength and volume stability. Comparative Examples 2, 6, and 10 (complete removal of nano-calcium carbonate): Performance further deteriorated, with 1-day compressive strength decreasing to 51-53 MPa, 28-day shrinkage increasing to 0.035-0.037%, and chloride ion diffusion coefficient increasing to 2.6-2.9 × 10⁻⁶. -12 m 2 / s indicates that nano-calcium carbonate is crucial for micro-expansion regulation and durability. Comparative Examples 3, 7, and 11 (without energy storage material): the coefficient of thermal expansion increased to 1.65-1.7×10⁻⁶. -6 At ℃, the freeze-thaw strength loss increased to 20-21%, indicating the contribution of energy storage materials to thermal regulation and durability. Comparative Examples 4, 8, and 12 (energy storage materials using only paraffin): the coefficient of thermal expansion increased to 1.7-1.75 × 10⁻⁶. -6 / ℃, the acid erosion strength retention rate decreased to 80-81%, indicating that the synergistic effect of paraffin and sodium sulfate decahydrate improved thermal stability and corrosion resistance. Comparative Examples 13-15 (without nano-expansion regulator): the 3-hour expansion rate decreased to 0.3-0.35%, and the 28-day shrinkage rate increased to 0.036-0.040%, indicating the key role of the nano-expansion regulator in volume stability. Comparative Example 16 (without nano-reinforced mixing process): the initial flowability decreased to 278 mm, the 1-day compressive strength was only 49 MPa, and the total porosity increased to 4.6%, indicating the necessity of high-speed shear homogenization for nanoparticle dispersion and interfacial bonding. Synergistic effect analysis: Functionalized nano-calcium carbonate: through surface modification (silane coupling agent) to provide nucleation sites and interfacial reinforcement, it significantly improved the 1-day compressive strength (15-20%) and micro-expansion regulation (3-hour expansion rate stabilized at 0.5-1.2%). Energy storage material: Paraffin wax and sodium sulfate decahydrate composite provides latent heat ≥200J / g and reduces the coefficient of thermal expansion (≤1.2×10). -6 / ℃), enhancing freeze-thaw resistance and durability. Nano-expansion regulator: Magnesium oxide, calcium sulfoaluminate, and nano-graphene oxide synergistically regulate expansion pressure (≤0.5MPa / day), ensuring a 28-day shrinkage rate ≤0.015%. Nano-reinforced mixing process: High-speed shear homogenization (400-500rpm) breaks down nano-agglomerates, achieving a Zeta potential ≥30mV, reducing porosity to ≤2.8%, and improving interfacial bonding strength (Ca-O-Si bond binding energy ≥530kJ / mol). Overall synergistic effect: Multi-scale filling (nano-SiO2 / TiO2 / CaCO3 / GO), gradation optimization (quartz sand / silica fume / slag powder), and hydration kinetic regulation (CSA rapidly generates AFt, nano-SiO2 promotes CSH generation) achieve a high-performance grouting material with a 1-day compressive strength ≥62MPa and a 28-day shrinkage rate ≤0.015%.

[0099] The test results of Examples 1-18 show that by optimizing the proportions and process parameters, the grouting material achieves the patented targets in terms of fluidity, early strength, volume stability, and durability. Comparative Examples 1-16, by omitting key components or processes, verified the necessity and synergistic effect of functionalized nano-calcium carbonate, energy storage materials, nano-expansion regulators, and nano-reinforced mixing processes. Functionalized nano-calcium carbonate enhances nucleation and interfacial strength, energy storage materials improve thermal stability, nano-expansion regulators ensure micro-expansion without shrinkage, and nano-reinforced mixing processes optimize dispersion and microstructure, collectively achieving the preparation of high-performance grouting materials suitable for demanding engineering scenarios such as nuclear power plant containment vessels and long-span bridge bearings.

[0100] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A method for preparing an early-strength, high-strength, micro-expansion, non-shrink grout, characterized in that: The process includes the following steps: a. Pretreatment of the cementitious powder: Silicate cement, sulfoaluminate cement, and nano-silica are mixed and then ball-milled at 500-800 rpm for 60-120 min under an inert atmosphere to obtain composite cementitious powder with a particle size of 0.5-2µm; b. Preparation of the dispersion sol: Nano-titanium dioxide, functionalized nano-calcium carbonate, and cellulose ether are dispersed in deionized water under ultrasonic conditions for 30-60 min to form a stable dispersion sol; c. Preparation of the nano-expansion regulator: Magnesium oxide micro powder, calcium sulfoaluminate, nano-graphene oxide, and deionized water are mixed to form a nano-expansion regulator; d. Preparation of the nano-filler system: Quartz sand aggregate, silica fume, and slag powder are selected and ball-milled and homogenized to obtain the nano-filler system. e. Nano-reinforced mixing process: The composite gel powder from step a and the nano-filled system from step d are dispersed and mixed in a high-speed disperser at 150-200 rpm for 2-3 min. Then, the nano-expansion regulator from step c is added, and dispersion and mixing continue for 1-2 min. Next, the dispersing sol from step b is added, and the stirring speed is increased to 250-350 rpm, and the mixture is mixed for 5-8 min. Finally, 5-10 times the mass of the energy storage material is added, and shear homogenization is performed to obtain the product. The preparation method of the energy storage material in step e is as follows: Paraffin and sodium sulfate decahydrate with a mass ratio of 1:(3-5) are selected as... The phase change material is prepared by dissolving polymethyl methacrylate in acetone at 20-40 times its mass to form a shell solution. The phase change material is dispersed in deionized water at 30-50 times its mass, and then polyvinyl alcohol at 5-10 times its mass is added. Under high-speed stirring at 1200-1500 rpm, the shell solution at 2-3 times its mass is added dropwise to form a water-in-oil emulsion. The temperature is raised to 70-80°C and the reaction is carried out for 4-6 hours to complete the shell polymerization. Then, the microcapsules are separated by centrifugation at 8000 rpm for 10 minutes. The microcapsules are washed three times alternately with ethanol and deionized water and dried under vacuum at 40°C for 24 hours to obtain the energy storage material.

2. The preparation method of the early high-strength micro-expansion non-shrink grouting material according to claim 1, characterized in that: In step a, the mass ratio of silicate cement, sulfoaluminate cement, and nano-silica is (40-60):(8-15):(0.5-2); the particle size of nano-silica in step a is 10-30 nm.

3. The preparation method of the early high-strength micro-expansion non-shrinkage grouting material according to claim 1, characterized in that: In step b, the mass ratio of nano-titanium dioxide, functionalized nano-calcium carbonate, cellulose ether, and deionized water is (0.1-0.8):(0.05-0.3):(0.02-0.1):(15-22); the particle size of nano-titanium dioxide in step b is 5-15 nm; the ultrasonic conditions in step b are as follows: power 200-400 W, frequency 40 kHz.

4. The preparation method of the early high-strength micro-expansion non-shrinkage grouting material according to claim 1, characterized in that: The preparation method of functionalized nano-calcium carbonate in step b is as follows: A calcium chloride solution with a concentration of 0.5-1.5 mol / L and a sodium carbonate solution with a concentration of 0.5-1.5 mol / L are rapidly mixed at 20-30℃ in a molar ratio of 1:(2-4), with a stirring speed controlled at 300-500 rpm and a reaction time of 30-60 min, to generate a nano-calcium carbonate suspension with a particle size controlled at 20-50 nm; 0.05-0.2 times its mass of silane coupling agent KH-570 or KH-550 is added to the above nano-calcium carbonate suspension, and the pH value of the solution is adjusted to 8.0-9.

0. The solution is then dispersed using ultrasonic waves with a power of 200-400 W and a frequency of 40 kHz for 30-60 min to form a modified suspension. Unreacted impurities were removed from the modified suspension by centrifugation at a speed of 5000-8000 rpm for 10-20 min. The suspension was then washed 3-5 times with deionized water and subsequently dried in a vacuum drying oven at 60-80℃ for 6-12 h to obtain functionalized nano-calcium carbonate.

5. The preparation method of the early high-strength micro-expansion non-shrinkage grouting material according to claim 1, characterized in that: In step c, the mass ratio of magnesium oxide micro powder, calcium sulfoaluminate, nano-graphene oxide and deionized water is (1.5-4):(0.3-1.2):(0.1-0.5):(6-10).

6. The preparation method of the early high-strength micro-expansion non-shrinkage grouting material according to claim 1, characterized in that: In step d, the mass ratio of quartz sand aggregate, silica fume and slag powder is (100-150):(2-8):(1-5); the parameters of ball milling in step d are as follows: rotation speed 400-500 r / min, time 12-18 h; the parameters of homogenization in step d are as follows: pressure: 40-60 MPa, number of cycles: 3-5 times.

7. The preparation method of the early high-strength micro-expansion non-shrink grouting material according to claim 1, characterized in that: In step e, the mass ratio of the composite gel powder, dispersible sol, nano-expansion regulator and nano-filler system is (80-100):(8-12):(2-4):(1-2); the parameters of the shear homogenization treatment in step e are as follows: rotation speed 400-500 rpm, time 30-60 s.

8. A high-strength, micro-expansion, non-shrink grouting material, characterized in that, The aforementioned high-strength, micro-expansion, non-shrink grouting material is obtained by the preparation method described in any one of claims 1-7.

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