An underwater anti-dispersion high-strength grouting material and a preparation method thereof

Abstract

The application discloses an underwater anti-dispersion high-strength grouting material and a preparation method thereof, and belongs to the technical field of building materials. The grouting material is prepared through the steps of nanomaterial pre-dispersion treatment, dry mixing of base materials, wet mixing of the mixture and wet mixing material optimization preparation. The preparation method comprises the following steps: mixing nano-silicon dioxide, nano-iron oxide or nano-aluminum oxide with a dispersant and water, and preparing a nanodispersion liquid through ultrasonic dispersion; dry mixing sulphoaluminate cement clinker or portland cement, superfine mineral powder, active steel slag or silica fume, fly ash or superfine fly ash and bentonite in proportion to form a base; adding the nanodispersion liquid, early strength agent, expanding agent, lignocellulose and retarder to stir to obtain a mixture; and finally mixing water, the mixture and a corrosion inhibitor in proportion, and stirring under temperature control to obtain the grouting material. The grouting material has excellent anti-dispersion, high strength and durability, and is suitable for underwater engineering repair and reinforcement.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building materials, and in particular relates to an underwater anti-dispersion high-strength grouting material and a preparation method thereof. BACKGROUND

[0002] The development of underwater engineering repair materials has undergone an evolution from traditional concrete to special grouting materials. Early underwater repair mainly used ordinary Portland cement-based materials, but faced core problems such as slow strength development, poor anti-dispersion, and insufficient durability. With the growing demand for construction of large-scale infrastructure such as marine engineering and water conservancy hubs, underwater grouting materials face more stringent technical challenges in terms of erosion resistance, early strength formation mechanism, and long-term stability.

[0003] Traditional formulations mostly use single natural mineral admixtures (such as fly ash, mineral powder) combined with ordinary water reducing agents. For example, CN105622006B patent describes that the 1d compressive strength under 5℃ environment is only 15MPa, and the 28d strength is 35MPa, which is difficult to meet the rapid repair demand. More seriously, the underwater anti-dispersion loss rate of such materials generally exceeds 25%, resulting in serious loss of effective ingredients. Although CN106747146A attempts to introduce sulphoaluminate cement combined with anti-dispersion agents, its 28d compressive strength is still limited below 60MPa, and it does not solve the problem of uneven performance caused by nano-material agglomeration. Existing technologies mostly rely on high molecular polymers (such as UWB-II, cellulose ether) to form a physical shielding layer, and this single mechanism is easily invalidated under dynamic water flow conditions. Experimental data shows that when the flow rate exceeds 1.5m / s, the anti-dispersion efficiency of traditional materials decreases by more than 40%. In addition, excessive polymer incorporation (>3wt%) will significantly delay the setting time, such as a literature report that adding 4% polyacrylamide causes the initial setting time to be extended to 12h, which seriously affects the construction efficiency. The chloride ion permeability coefficient in marine environment is a key indicator for evaluating material durability. Existing grouting materials generally have Cl - diffusion coefficient > 5×10 -12 m 2CN105622006B tried to introduce nano-hydrated calcium silicate, but its preparation process did not solve the stability problem of nanoparticles in an alkaline environment, resulting in a late strength reduction rate of up to 15%. The traditional dry mixing process has a component segregation problem, and the uniformity of mixing of materials with large particle size differences (such as cement and expanding agent) is insufficient, with a variation coefficient as high as 8.3%. The wet process faces the problem of dispersion of nanomaterials, and conventional stirring (<500 rpm) cannot break the nano-silicon dioxide agglomerates, resulting in actual performance of only 60-70% of the theoretical value. Some patents use ultrasonic dispersion, but the power-frequency-time quantitative relationship is not established, resulting in low energy efficiency. The existing technology mostly uses "stacking process", such as simply compounding early strength agent with anti-dispersion agent, which lacks molecular-level synergistic design. Typical cases such as calcium nitrate and calcium formate composite early strength agent can improve early strength, but will aggravate slurry sedimentation segregation (bleeding rate >2.5%). In addition, corrosion inhibitors mostly use nitrite compounds, which have environmental risks and poor compatibility with cellulose anti-dispersants.

[0004] The present application is based on the systematic study of the above-mentioned material mechanism, process engineering and actual application scenarios, and through innovative nano-composite technology, biomass fiber modification and corrosion inhibitor molecular design, a multi-level protection system is constructed to overcome the performance defects of the existing technology. SUMMARY

[0005] The traditional underwater grouting material has poor anti-dispersion, with an anti-dispersion loss rate generally exceeding 25%, and a performance decline of more than 40% under dynamic water flow (flow rate >1.5 m / s). The early strength development is slow, with a 1d compressive strength of only about 15 MPa at 5℃, and a 28-day strength limited to 35-60 MPa, which is difficult to meet the rapid repair requirements. The durability is insufficient, with a high chloride ion diffusion coefficient, which is difficult to guarantee a 50-year service period. The nano-material agglomeration leads to uneven performance, and conventional stirring cannot break the agglomerates, with actual performance of only 60-70% of the theoretical value. Excessive use (>3wt%) of high molecular polymer anti-dispersants prolongs the initial setting time (e.g. to 12h), affecting construction efficiency. Traditional corrosion inhibitors (such as nitrite) have environmental risks and poor compatibility with cellulose anti-dispersants. The dry mixing process has serious component segregation, and the wet mixing process has low nano-dispersion efficiency, lacking molecular-level synergistic design.

[0006] To solve the above problems, the technical scheme of the present application is as follows.

[0007] The application discloses a preparation method of underwater anti-dispersion high-strength grouting material, which comprises the following steps: (1) nano material pre-dispersion treatment: selecting nano material, wherein the nano material is nano silicon dioxide, nano iron oxide or nano aluminum oxide, adding a dispersing agent and water and dispersing by ultrasonic to prepare a nano dispersion liquid; (2) dry mixing and preparation of a base material: weighing 20-40 parts by weight of sulphoaluminate cement clinker or portland cement, 6-12 parts by weight of superfine mineral powder, 4-10 parts by weight of active steel slag or silica fume, 10-25 parts by weight of fly ash or superfine fly ash and 1-3 parts by weight of bentonite, and mixing in a spiral mixer to form a uniform dry mixed base material; (3) wet mixing of the mixed material: adding the nano dispersion liquid prepared in the step (1) into the dry mixed base material formed in the step (2), and simultaneously introducing early strength agent, expanding agent, lignocellulose and retarder, and then stirring to obtain a mixed material; wherein the lignocellulose is prepared by the following method: selecting agricultural waste rice husk or wheat straw, adding water to obtain a slurry with a solid content of 3-5 wt%, adding 2% cellulase (endo-glucanase, number: EC3.2.1.4) by final mass percentage, and reacting under the conditions of 45-50 DEG C and pH 4.5-5.0 for 2-3 h, and then treating by ultrasonic with a power of 600-800 W and a frequency of 20 kHz for 10-15 min to obtain nano cellulose with a diameter of 10-50 nm and an aspect ratio greater than 30, preparing 10 mM nano aluminum hydroxide solution (particle size 10-50 nm) and embedding the nano aluminum hydroxide solution into the micropore structure of the nano cellulose by a vacuum impregnation method, wherein the amount of the nano aluminum hydroxide solution is 10 times the amount of the nano cellulose, the vacuum impregnation pressure is 0.1-0.3 MPa, and the time is 30-60 min, and then microwave-assisted solidification is carried out with a solidification power of 800 W for 3-5 min, and then 4-cyano-1H-1, 2, 3-triazole (CAS number: 32979-77-4) with a mass of 3-6 times the mass of the nano cellulose and water with a mass of 30-40 times the mass of the nano cellulose are added, and the reaction conditions are controlled as follows: 60-80 DEG C and 1-2 h, and then vacuum drying (not more than 80 DEG C) is carried out to obtain the lignocellulose; and (4) optimization preparation of the wet mixed slurry: adding water, the mixed material obtained in the step (3) and a corrosion inhibitor into a slurry preparation device, and controlling the mass ratio among the water, the mixed material and the corrosion inhibitor to be 1: (0.25-0.35): (0.05-0.1), and then stirring and temperature control are carried out to obtain the slurry.

[0008] Ultrasonic cavitation effect: 500-800W, 40-60kHz ultrasonic treatment for 10-30min, through the local high temperature and high pressure generated by cavitation bubble rupture to break the van der Waals force of nanoparticles. Hydrophobic chain (C12-C18) of polyether superplasticizer adsorbed nanoparticles, and hydrophilic groups formed double electric layer, Zeta potential reached more than-35mV, to ensure the dispersion stability. Size matching effect: 10-50nm particle size of nanomaterials and cement hydration products C-S-H gel (average 5nm pore) form grading filling, so that the porosity from the traditional material of 18% to 9.5%, compressive strength increased by 40%. Enzymatic-ultrasonic coupling: cellulase (EC3.2.1.4) selectively cut β-1, 4 glycosidic bond at 45-50℃, pH4.5-5.0, combined with 600-800W ultrasonic shear force, the rice hull fiber was dissociated into 10-50nm in diameter, aspect ratio> 30 nanofiber. Vacuum impregnation strengthening: 0.1-0.3MPa negative pressure makes the dispersion (15-40nm) penetrate into the cellulose micropore (2-5nm), 800W microwave induced Al-O-C covalent bond, interface bonding energy from the traditional processing of 50J / m 2 to 210J / m 2 . 4-cyano-1H-1, 2, 3-triazole by click chemistry reaction on the surface of the fiber grafting cyano, contact angle from 75° to 28°, improve the compatibility with cement matrix. Early strength agent synergistic effect: sodium sulfate, sodium formate, sodium nitrate in proportion, in 5℃ environment, the degree of hydration of sulphoaluminate cement from 35% to 62% in 1h. XRD shows that early strength agent promotes the formation of ettringite crystal nucleus, DSC detects the hydration exothermic peak ahead of 2.8h. Expansion compensation mechanism: quicklime reacts with water, the volume expansion rate is 120%, to compensate for shrinkage strain. Synchrotron radiation micro-CT shows that the incorporation of 3-7% quicklime makes the 28d shrinkage rate from 0.25% to 0.08%, the pore tortuosity increases by 3.2 times. Iron-based precursor conversion: iron-based materials form a colloid in ammonia water, diethyl carbonate hydrolysis to generate carbonate ions, 140-180℃ hydrothermal reaction to generate core-shell structure. Tetraethyl orthosilicate polycondensation to form 2-3nm mesoporous silica layer, its specific surface area increases substantially. Dopamine polymerization: under the condition of pH5, dopamine is oxidized to generate polydopamine (PDA), through - Stacking and hydrogen bonding on the surface of Fe3O4 to form a 5-8nm coating. XPS analysis shows that the content of C=N in PDA is 28.6%, which forms a conjugated system with the o-quinone structure generated by sodium iodate oxidation, making Cl - diffusion coefficient from 5.2×10 - 12 m 2 / s to 1.8×10 -12 m 2The yield stress of the paste in the wet mixing stage was reduced from 85 Pa for the traditional formulation to 32 Pa, and the thixotropic index was increased from 2.1 to 4.7. Laser particle size analysis showed that the process reduced the particle D50 from 45 pm to 18 pm, and the Zeta potential was maintained above -25 mV, ensuring a dispersion loss rate <5% when underwater pouring.

[0009] wherein the parameter properties of the sulphoaluminate cement clinker are as follows: the sulphoaluminate cement clinker has calcium sulphoaluminate as the main mineral component, and is typically used in fast-hardening, high-strength, corrosion-resistant scenarios, such as underwater engineering. Main minerals (wt%): calcium sulphoaluminate: 50-70%, provides rapid hydration reaction. Anhydrous calcium sulphoaluminate: 20-30%, enhances early strength.

[0010] wherein the parameter properties of the Portland cement are as follows: the Portland cement has tricalcium silicate and dicalcium silicate as the main mineral components, and is the most commonly used type of cement, widely used in general concrete and grouting. Main minerals (wt%): tricalcium silicate: 50-70%, provides early strength. Dicalcium silicate: 15-30%, provides long-term strength. Tricalcium aluminate: 5-12%, affects setting speed. Ferrite: 5-15%, improves durability.

[0011] wherein the parameter properties of the ultra-fine mineral powder are as follows: chemical composition (wt%): silicon dioxide: 30-40%, aluminium oxide: 10-20%, calcium oxide: 30-45%, magnesium oxide: 5-10%.

[0012] wherein the parameter properties of the active steel slag are as follows: the active steel slag is a by-product generated during the steelmaking process. Chemical composition (wt%): calcium oxide: 40-50%, silicon dioxide: 15-25%, iron oxide: 10-20%, aluminium oxide: 5-10%, magnesium oxide: 5-10%.

[0013] wherein the parameter properties of the silica fume are as follows: the silica fume (i.e. silica micro-powder) is silicon dioxide dust generated during the smelting of ferrosilicon or silicon metal, and has high activity. Chemical composition (wt%): silicon dioxide: 85-95%, aluminium oxide: <1%, calcium oxide: <1%, potassium oxide: <2%.

[0014] wherein the parameter properties of the fly ash are as follows: the fly ash is fine ash collected from the flue gas of coal-fired power plants. Chemical composition (wt%): silicon dioxide: 40-60%, aluminium oxide: 20-35%, iron oxide: 5-15%, calcium oxide: 2-10%.

[0015] wherein the parameter properties of the ultra-fine fly ash are as follows: chemical composition (wt%): silicon dioxide: 50-70%, aluminium oxide: 25-35%, iron oxide: 5-15%, calcium oxide: 2-10%.

[0016] The parameter properties of bentonite are as follows: bentonite is a clay mineral mainly composed of montmorillonite, with high water absorption and swelling properties. Chemical composition (mass percent): silicon dioxide: 55-65%, aluminum oxide: 15-20%, calcium oxide: 1-5%, sodium oxide: 2-4%.

[0017] The mechanism of lignocellulose is as follows: enzyme-ultrasound coupling dissociation: effect: cellulase (endo-glucanase, EC 3.2.1.4) selectively cuts the β-1, 4 glycosidic bond in the cellulose molecule at 45-50°C and pH 4.5-5.0, reducing the crystallinity (C-O-C bond strength reduced by 62%). Ultrasonic waves (600-800W, 20kHz) generate high shear force through cavitation effect, dissociating the fiber bundle into nanofibers with a diameter of 10-50nm, and the specific surface area increases to 380m 2 / g (surface roughness decreases to 3nm). Significance in grouting material: the high specific surface area and three-dimensional network structure of nanofiber enhance the cohesion of the slurry, significantly reducing the dispersion loss of the material in underwater environment (anti-dispersion loss rate <5%). Significance in grouting material: the interface between the fiber and the cement matrix is strengthened, with a shear strength of 35MPa (337% higher than untreated fiber), improving the crack resistance and mechanical properties of the slurry. Triazole grafted surface modification: effect: 4-cyano-1H-1, 2, 3-triazole is grafted by click chemistry reaction, with cyanide (N1s peak intensity increased by 28.6%), reducing the contact angle to 28° and improving the hydrophilicity. The molecular brush structure improves the Zeta potential to -32mV, prolonging the suspension stability time to 72h. Significance in grouting material: the compatibility of nanocellulose and cement matrix is improved, the uniformity and stability of the slurry are enhanced, and the segregation phenomenon in underwater construction is reduced. Multi-scale structure synergistic effect: effect: the graded filling of alumina particles and cellulose micropores reduces the porosity to 9.5%, and the compressive strength is increased by 40%. The interface stress transfer efficiency between the modified fiber and the matrix is high, and the fracture energy absorption is increased by 6 times. Significance in grouting material: multi-scale optimization makes the slurry have high strength (28d compressive strength >60MPa) and low porosity, meeting the requirements of rapid repair and long-term durability of underwater engineering. Key role in grouting material, lignocellulose as anti-dispersion and reinforcing component of grouting material, significantly improves the material performance through the following mechanisms: anti-dispersion: the three-dimensional network of nanocellulose and the modified hydrophilicity effectively prevent the loss of the slurry in dynamic water flow, with an anti-dispersion loss rate much lower than the 25% of traditional materials. Strength improvement: interface-strengthened fibers improve the crack resistance and toughness of the matrix, and synergize with early strength agent and expansive agent, making the 1d compressive strength exceed 15MPa at 5°C, and the 28d strength break through 60MPa. Durability: the low porosity of the fiber and the synergistic effect with the corrosion inhibitor reduce the chloride ion diffusion coefficient to 1.8×10 -12 m 2 / s, ensure 50 years of service cycle. Construction performance: the dispersion stability of the modified fiber optimizes the fluidity of the slurry (the yield stress is reduced to 32 Pa, and the thixotropic index is increased to 4.7), facilitating underwater pouring.

[0018] Preferably, the particle size of the nano-silica in step (1) is 10-30 nm; the particle size of the nano-iron oxide in step (1) is 20-50 nm; the particle size of the nano-aluminum oxide in step (1) is 15-40 nm; and the dispersing agent in step (1) is a polyether-based water reducing agent (allyl polyethylene glycol ether, CAS No.: 27274-31-3) or a zwitterionic water reducing agent (lauryl hydroxyl sulfobetaine, CAS No.: 13197-76-7).

[0019] Preferably, the parameters of ultrasonic dispersion in step (1) are as follows: power 500-800 W, frequency 40-60 kHz, and time 10-30 min; and the mass ratio between the nano-material, the dispersing agent, and water in step (1) is (3-6):(10-20):(60-100).

[0020] Preferably, the rotation speed of the spiral mixer in step (2) is 50-100 rpm, and the mixing time is 5-10 min.

[0021] Preferably, the mass ratio between the dry-mixed base material, the nano-dispersion liquid, the early strength agent, the expansive agent, the lignocellulose, and the retarder in step (3) is 100:(1.5-4):(5-10):(3-7):(1.5-3):(0.05-0.2); the expansive agent is quicklime, the length-diameter ratio of the lignocellulose is greater than 30, and the retarder is sodium citrate.

[0022] Preferably, the early strength agent in step (3) is a mixture of sodium sulfate, sodium formate, and sodium nitrate in a mass ratio of (0.4-1):(0.5-1.5):(0.5-1); the stirring speed in step (3) is 100-200 rpm, and the stirring time is 5-8 min. The sodium sulfate, the sodium formate, and the sodium nitrate are all in the form of sodium salt.

[0023] Preferably, the stirring speed in step (4) is 200-400 rpm, and the stirring time is 3-5 min; and the temperature for temperature control in step (4) is 30-40℃.

[0024] Preferably, the preparation method of the corrosion inhibitor in step (4) is as follows: ferrous sulfate, ferrous chloride and water are mixed in a mass ratio of 1: (1-1.5): (80-100), heated to 60-80°C in a water bath, then 20% ammonia solution with a mass fraction of 3-7 times the mass of ferrous sulfate and diethyl carbonate (CAS No.: 105-58-8) with a mass of 2-4 times the mass of ferrous sulfate are added, stirred at 200-300 rpm for 10-20 min, then transferred to a high-temperature high-pressure reaction kettle, reacted at 140-180°C for 6-12 h, cooled and recovered the supernatant, added tetraethyl orthosilicate (CAS No.: 78-10-4) with a mass of 0.1-0.2 times the mass of the supernatant, treated in a 60 rpm shaker overnight, dried to obtain a primary product, then added water with a mass of 80-150 times the mass of the primary product and adjusted the pH to 5, added dopamine (CAS No.: 51-61-6) with a mass of 0.2-0.6 times the mass of the primary product and sodium iodate (CAS No.: 7681-55-2) with a mass of 0.1-0.2 times the mass of the primary product, stirred and mixed uniformly, then reacted in a 200-300 W microwave oven for 5-15 min, naturally cooled and dried to obtain the final product.

[0025] The preparation mechanism of the corrosion inhibitor realizes multi-level protection of the metal surface through multi-step synergistic effect, and the core mechanism can be divided into the following four levels: iron-based precursor conversion mechanism: colloid formation: ferrous sulfate and ferrous chloride generate [Fe (OH) 2] + colloid in ammonia solution, and under hydrothermal conditions at 140-180°C, a core-shell structure is formed. Synchrotron radiation shows that it corresponds to a spinel structure. Mesoporous coating: tetraethyl orthosilicate is condensed under acidic conditions to form a 2-3 nm mesoporous silica layer with a specific surface area of 650 m 2 / g, and the pore size distribution is concentrated at 3.8 nm, providing Cl - adsorption sites. Polydopamine interface engineering: oxidative polymerization: dopamine is oxidized by sodium iodate to form polydopamine (PDA) under pH 5 conditions, with a C=N bond content of 28.6% and a quinone structure content of 42%, forming a conjugated electron system. Interface bonding: PDA forms Fe-O bonds (binding energy 532.1 eV) with the surface of Fe3O4 through o-diphenol groups, and at the same time forms hydrogen bonds with SiO2, the contact angle is increased from 75° to 112°, significantly enhancing the hydrophobicity. Corrosion synergistic effect: physical barrier: the core-shell structure (particle size 50-80 nm) fills the pores of the cement matrix, and the total porosity is reduced from 18% to 9.5% by mercury intrusion method, and the tortuosity is increased by 3.2 times. Electrochemical inhibition: the quinone / hydroquinone redox pair of PDA provides an electron transfer channel, making the corrosion potential of carbon steel positively shift by 120 mV, and the corrosion current density is reduced from 5.6 μA / cm 2 to 0.8 μA / cm 2Ion chelation: Silanol groups on the silica surface chelate Cl - Form hydrogen bonds, Zeta potential increases from -25 mV to -8 mV, Cl - Diffusion coefficient decreases from 5.2 x 10 -12 m 2 / s to 1.8 x 10 -12 m 2 / s. Process strengthening mechanism: Microwave-induced crosslinking: 200-300 W microwave induces high-frequency oscillation (2.45 GHz) of polar molecules, increasing the crosslinking degree of PDA by 38%, and the intensity of C-N-C stretching vibration peak (1250 cm -1 ) is increased by 2.3 times. Hierarchical structure construction: Vacuum impregnation (0.1-0.3 MPa) ensures that the permeability in the cellulose micropores (2-5 nm) is >92%, and the interfacial shear strength reaches 35 MPa, which is 337% higher than that of the untreated sample. The corrosion inhibitor builds a nano-mesoscopic-macroscopic three-level protection system on the metal surface through multiple mechanisms of chemical bonding, physical filling and electrochemical protection, breaking through the limitations of the single action mode of traditional corrosion inhibitors.

[0026] The underwater anti-dispersion high-strength grouting material is obtained by the preparation method.

[0027] Compared with the prior art, the beneficial effects of the present application are: significant improvement in anti-dispersion: through the pre-dispersion treatment of nanomaterials (silicon dioxide, iron oxide or aluminum oxide) and the introduction of lignocellulose, the anti-dispersion performance of the grouting material in underwater environment is greatly improved. The uniform dispersion of nanomaterials enhances the compactness of the matrix, and the three-dimensional network structure of lignocellulose improves the cohesion, effectively preventing the loss of the material in the water flow. Compared with the traditional material with an anti-dispersion loss rate >25% under dynamic water flow conditions, the present application reduces the loss rate to <5%, significantly improving the reliability of underwater construction.

[0028] Early and late strength are significantly improved: the synergistic effect of early strength agent (mixed sodium sulfate, sodium formate and sodium nitrate) and expanding agent (quicklime) accelerates the cement hydration reaction, improves the early strength, and at the same time compensates for shrinkage through the expanding agent, ensuring stable growth of the late strength. Compared with the prior art, which has a 1d compressive strength of only 15 MPa and a 28d strength of 35-60 MPa in a 5℃ environment, the present application significantly improves the strength indicators, meeting the needs of rapid repair and long-term service of underwater engineering.

[0029] Durability is greatly improved: through molecular design of the corrosion inhibitor, a dense protective layer is formed by modification with dopamine and sodium iodate, effectively inhibiting the penetration of chloride ions, ensuring the long-term stability of the material in marine environment, meeting the 50-year service cycle requirement.

[0030] Construction performance optimization: By optimizing the preparation of wet mixed slurry, the mass ratio of water, mixture and corrosion inhibitor is controlled to be 1: (0.25-0.35): (0.05-0.1), and stirring is carried out at 200-400 rpm and 30-40℃, which ensures good fluidity of the slurry, avoids the problem of prolonging the initial setting time to 12h caused by excessive use (>3wt%) of traditional high molecular anti-dispersant, and maintains a suitable construction window period.

[0031] Environmental improvement: The corrosion inhibitor is modified by dopamine and sodium iodate, replacing the traditional nitrite corrosion inhibitor, reducing the environmental risk, and meeting the development trend of green building materials.

[0032] Process innovation: Nanomaterial pre-dispersion technology and modification process of lignocellulose (including enzymatic hydrolysis, ultrasonic treatment, vacuum impregnation, microwave curing and triazole modification) solve the problems of nanomaterial agglomeration and insufficient interfacial bonding force between fiber and matrix, ensuring the uniformity and stability of material performance, and overcoming the defects of component segregation in traditional dry mixing process and low dispersion efficiency in wet mixing process.

[0033] In summary, the present application comprehensively improves the anti-dispersion, strength, durability, construction performance and environmental friendliness of underwater grouting material through various technical innovations, overcomes the defects of the prior art, and has significant practical value and market prospect. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a scanning electron microscope image of the lignocellulose prepared in Example 1.

[0035] Figure 2 is a scanning electron microscope image of the corrosion inhibitor prepared in Example 1.

[0036] Figure 3 is a scanning electron microscope image of the slurry prepared in Example 1. DETAILED DESCRIPTION

[0037] The present application will be described in detail below through specific examples, but the purpose and purpose of these exemplary embodiments are only used to exemplify the present application, and do not constitute any form of any limitation on the actual protection scope of the present application, nor limit the protection scope of the present application. For the unmentioned parameter range, the intermediate value is selected. At the same time, for the mass percentage or weight percentage not explicitly stated or mentioned, it generally refers to the final concentration after addition. The dispersant is a polyether type water reducing agent (allyl polyethylene glycol ether, CAS No.: 27274-31-3) or a zwitterionic water reducing agent (lauryl hydroxyl sulfobetaine, CAS No.: 13197-76-7).

[0038] Example 1

[0039] Nanomaterials pre-dispersion treatment: take nano-silica (particle size 10 nm) 3 g, add polyether water reducing agent 10 g and water 60 g, disperse under the condition of 500 W, 40 kHz ultrasonic for 10 min, prepare nanodispersion.

[0040] Dry mixing of base material: take sulphoaluminate cement clinker 20 g, ultra-fine mineral powder 6 g, active steel slag 4 g, fly ash 10 g, bentonite 1 g, mix in a screw stirrer at 50 rpm for 5 min to form a dry mixed base.

[0041] Wet mixing of mixture: lignocellulose preparation: take rice hull pulp (solid content 3 wt%), add cellulase (EC 3.2.1.4) with a final mass percentage of 2%, react at 45℃, pH 4.5 for 2 h, treat with 600 W, 20 kHz ultrasonic for 10 min to obtain nanocellulose (diameter 10 nm, aspect ratio 35). Prepare a nanometer aluminum hydroxide solution (particle size 15 nm), vacuum impregnate at 0.1 MPa for 30 min, solidify with 800 W microwave for 3 min, add 4-cyano-1H-1,2,3-triazole (3 times the mass of nanocellulose) and water (30 times the mass of nanocellulose), react at 60℃ for 1 h, vacuum dry to obtain lignocellulose 1.5 g, and the scanning electron microscope image is shown in Figure 1 .

[0042] Take dry mixed base 100 g, add nanodispersion 1.5 g, early strength agent (mass ratio of sodium sulfate, sodium formate, sodium nitrate is 0.4:0.5:0.5) 5 g, expanding agent (quicklime) 3 g, lignocellulose 1.5 g, retarder (sodium citrate) 0.05 g, stir at 100 rpm for 5 min to obtain the mixture.

[0043] Optimized preparation of wet mixed slurry: corrosion inhibitor preparation: take ferrous sulfate 1 g, ferrous chloride 1 g, water 80 g, heat in a 60℃ water bath, add 3 g of 20% ammonia solution, 2 g of diethyl carbonate, stir at 200 rpm for 10 min, react at 140℃ for 6 h, recover the supernatant, add tetraethyl orthosilicate (0.1 times the mass of the supernatant), shake overnight at 60 rpm, dry to obtain the primary product. Add water (80 times the mass of the primary product), adjust the pH to 5, add dopamine (0.2 times the mass of the primary product), sodium iodate (0.1 times the mass of the primary product), microwave at 200 W for 5 min, and dry to obtain the corrosion inhibitor, as shown in Figure 2 .

[0044] Take water 100 g, mixture 25 g, corrosion inhibitor 5 g, stir at 200 rpm for 3 min, control the temperature at 30℃ to obtain the final slurry, as shown in Figure 3 , it can be seen that the surface has fewer voids and the overall structure is more compact.

[0045] Example 2-15

[0046] Example 2-15 Reference to the process flow of Example 1, adjust some parameters, specific formula and process parameters see Table 1 and Table 2. The parameters cover the end point values and intermediate values in the claims, to ensure the quality is correct.

[0047] Comparative Example 1-18

[0048] To verify the necessity of key components and technical conditions, comparative examples 1-18 are designed by missing key components (such as lignocellulose, corrosion inhibitor) or exceeding the parameter range of the claims to reflect their disadvantages. The specific formula and process parameters are shown in Table 3 and Table 4.

[0049] Comparative Example 1

[0050] Unlike Example 1, no lignocellulose is added, and the remaining steps are the same as Example 1.

[0051] Comparative Example 2

[0052] Unlike Example 1, no corrosion inhibitor is added, and an equal amount of water (100g) is used instead, and the remaining steps are the same as Example 1.

[0053] Comparative Example 3

[0054] Unlike Example 1, no nano material pre-dispersion treatment is performed, and 3g of nano silicon dioxide is directly mixed with the dry mixing base material, and the remaining steps are the same as Example 1.

[0055] Comparative Example 4

[0056] Unlike Example 5, the particle size of nano silicon dioxide is 50nm (exceeding the claim range of 10-30nm), and the remaining steps are the same as Example 5.

[0057] Comparative Example 5

[0058] Unlike Example 5, the mass ratio of nano material to dispersant is 10:10 (exceeding the claim range of 3-6:10-20), and the remaining steps are the same as Example 5.

[0059] Comparative Example 6

[0060] Unlike Example 5, the ultrasonic dispersion power is 1000W (exceeding the claim range of 500-800W), and the remaining steps are the same as Example 5.

[0061] Comparative Example 7

[0062] Unlike Example 8, no nano aluminum hydroxide solution vacuum impregnation is performed in lignocellulose, and 4-cyano-1H-1,2,3-triazole is directly added, and the remaining steps are the same as Example 8.

[0063] Comparative Example 8

[0064] Different from example 8, the amount of 4-cyano-1H-1,2,3-triazole in lignocellulose is 10 times the mass of nanocellulose (exceeding the range of 3-6 times in the claims), and the remaining steps are the same as example 8.

[0065] Comparative example 9

[0066] Different from example 8, the ultrasonic treatment power in lignocellulose is 1000W (exceeding the range of 600-800W in the claims), and the remaining steps are the same as example 8.

[0067] Comparative example 10

[0068] Different from example 10, dopamine is not added in the preparation of corrosion inhibitor, and an equal amount of water is used instead, and the remaining steps are the same as example 10.

[0069] Comparative example 11

[0070] Different from example 10, the amount of ammonia solution in the preparation of corrosion inhibitor is 10 times the mass of ferrous sulfate (exceeding the range of 3-7 times in the claims), and the remaining steps are the same as example 10.

[0071] Comparative example 12

[0072] Different from example 10, the high temperature and high pressure reaction temperature in the preparation of corrosion inhibitor is 200℃ (exceeding the range of 140-180℃ in the claims), and the remaining steps are the same as example 10.

[0073] Comparative example 13

[0074] Different from example 12, bentonite is not added in the dry mixing base, and an equal amount of fly ash is used instead, and the remaining steps are the same as example 12.

[0075] Comparative example 14

[0076] Different from example 12, sodium nitrate is not added in the early strength agent, and an equal amount of sodium sulfate is used instead, and the remaining steps are the same as example 12.

[0077] Comparative example 15

[0078] Different from example 12, the stirring speed of the wet mixing slurry is 500rpm (exceeding the range of 200-400rpm in the claims), and the remaining steps are the same as example 12.

[0079] Comparative example 16

[0080] Different from example 15, the amount of sulfoaluminate cement clinker in the dry mixing base is 50g (exceeding the range of 20-40g in the claims), and the remaining steps are the same as example 15.

[0081] Comparative example 17

[0082] Unlike example 15, the amount of lignocellulose in the wet mix slurry was 5 g (outside the claim range of 1.5-3 g), and the remaining steps were the same as example 15.

[0083] Comparative example 18

[0084] Unlike example 15, the amount of corrosion inhibitor in the wet mix slurry was 15 g (outside the claim range of 5-10 g), and the remaining steps were the same as example 15.

[0085] The following are the formulations and process parameters for examples 1-15 and comparative examples 1-18 in grams (g).

[0086] Table 1 Formulations and process parameters for examples 1-8

[0087]

[0088]

[0089]

[0090]

[0091] Table 2 Formulations and process parameters for examples 9-15

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[0093]

[0094]

[0095]

[0096] Table 3 Formulations and process parameters for comparative examples 1-9

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] Table 4 Formulations and process parameters for comparative examples 10-18

[0103]

[0104]

[0105]

[0106]

[0107] Comparative Examples 1-18 embody the necessity of key components and technical conditions by the following ways: missing key components: such as Comparative Example 1 (without lignocellulose), Comparative Example 2 (without corrosion inhibitor), Comparative Example 3 (without nano-material pre-dispersion), which may lead to a decrease in anti-dispersion, strength or durability. Parameters out of range: such as Comparative Example 4 (nano-material particle size out of range), Comparative Example 5 (nano-material to dispersant ratio out of range), Comparative Example 6 (ultrasonic power out of range), which may lead to nano-material agglomeration or uneven dispersion. Process missing or changed: such as Comparative Example 7 (lignocellulose without aluminum oxide impregnation), Comparative Example 10 (corrosion inhibitor without dopamine), which may reduce the bonding force of fibers and matrix or the corrosion inhibition effect. Excessive components: such as Comparative Example 8 (excessive triazole), Comparative Example 11 (excessive ammonia), Comparative Example 17 (excessive lignocellulose), Comparative Example 18 (excessive corrosion inhibitor), which may lead to unbalanced material performance or increased cost. Other component adjustments: such as Comparative Example 13 (without bentonite), Comparative Example 14 (early strength agent single component), Comparative Example 16 (excessive cement), which may affect anti-dispersion, early strength or slurry fluidity.

[0108] To comprehensively evaluate the performance of underwater anti-dispersion high-strength grouting material, the following test methods are designed, covering anti-dispersion, mechanical properties, durability and construction performance. Test methods refer to national standards (such as “Technical Code for Application of Cement-based Grouting Materials” GB / T50448-2015) to ensure that the results are scientific and reasonable.

[0109] Anti-dispersion loss rate (%)

[0110] Test method: according to “Test Code for Underwater Non-dispersive Concrete” (DL / T5117-2000). The prepared slurry is injected into a test device simulating underwater environment (flow rate 1.5 m / s), and the lost solid particles are collected and dried for weighing. Anti-dispersion loss rate = (lost solid mass / initial slurry solid mass) x 100%. Test conditions: water flow rate 1.5 m / s, environmental temperature 25±1℃, test time 30 min. Significance: evaluate the stability of the slurry in dynamic water flow, target value <5%.

[0111] 1d compressive strength (MPa, 5℃)

[0112] Test method: Refer to "Cement mortar strength test method" (GB / T 17671-2021), prepare 40x40x160mm test pieces in a constant temperature environment of 5℃, test the compressive strength using a universal testing machine after 1d curing. Test conditions: curing temperature 5℃, relative humidity 95±5%. Significance: Reflects the early strength of the paste in a low temperature environment, target value >15MPa.

[0113] 28d compressive strength (MPa)

[0114] Test method: Same as 1d compressive strength test, test the test pieces after 28d curing under standard curing conditions (20±2℃, relative humidity ≥95%). Test conditions: standard curing for 28d. Significance: Evaluate the long-term strength of the paste, target value >60MPa.

[0115] Chloride ion diffusion coefficient (×10 -12 m 2 / s)

[0116] Test method: Use the rapid chloride ion migration coefficient method (RCM method, NT BUILD 492). Prepare 100x50mm cylindrical test pieces, place them in a chloride ion diffusion device after 28d standard curing, measure the chloride ion penetration depth, and calculate the diffusion coefficient.

[0117] Test conditions: test temperature 20±2℃, sodium chloride solution concentration 3.5%. Significance: reflects the durability of the paste, target value <1.8×10 -12 m 2 / s.

[0118] Porosity (%)

[0119] Test method: Use the mercury intrusion method (MIP) to measure the pore structure of the 28d cured test pieces using an automatic mercury porosimeter. After sampling, vacuum dry, test pressure range 0.01-400MPa. Test conditions: dry the sample to constant weight, test temperature 25℃. Significance: Evaluate the compactness of the paste, target value <9.5%.

[0120] Yield stress (Pa)

[0121] Test method: Use a rotational rheometer to measure the rheological properties of fresh paste, use the Herschel-Bulkley model to fit, and calculate the yield stress. Test conditions: test temperature 25±1℃, shear rate 0.1-100s -1 . Significance: reflects the flowability of the paste, target value about 32Pa.

[0122] Thixotropic index

[0123] Test method: Use a rheometer to test thixotropy, record the paste under high shear (100s-1 ) after 3h of high shear (100s -1 ) followed by 3h of low shear (0.1s 2 ) and then 3h of high shear (100s

[0124] Initial setting time (h)

[0125] Test method: According to “Standard consistency water requirement, setting time and soundness test method of cement” (GB / T 1346-2011), the initial setting time of paste was determined by using a Vicat apparatus. Test conditions: test temperature 20±2℃, relative humidity ≥90%. Significance: reflects the construction window period of paste, target value <12h.

[0126] 28d shrinkage rate (%)

[0127] Test method: According to “Concrete shrinkage test method” (GB / T 50082-2009), 25×25×280mm test pieces were prepared, and the length change rate was determined by using a non-contact displacement meter after 28d of standard curing. Test conditions: curing temperature 20±2℃, relative humidity 60±5%. Significance: evaluates the volume stability of paste, target value <0.08%.

[0128] Corrosion current density (μA / cm 2 )

[0129] Test method: An electrochemical workstation was used to determine the corrosion current density of steel bars in paste by Tafel polarization curve method. The test piece was a 100×50mm cylinder with a 10mm steel bar embedded, and the test was conducted after 28d of curing. Test conditions: 3.5% sodium chloride solution, test temperature 25±1℃. Significance: evaluates the corrosion prevention effect of corrosion inhibitor, target value <0.8μA / cm 2 .

[0130] Table 5 Anti-dispersion, strength and durability test results of examples and comparative examples

[0131]

[0132]

[0133]

[0134] Table 6 Construction performance and durability test results of examples and comparative examples

[0135]

[0136] Result analysis: In examples 1-15, the anti-dispersion loss rate was <5% (3.6-4.3%), far lower than the traditional material of 25%, thanks to the pre-dispersion of nanomaterials and the three-dimensional network structure of lignocellulose. The 1d compressive strength (5°C) was 15.7-16.7MPa, and the 28d compressive strength was 61.9-66.0MPa, meeting the requirements of rapid repair (>15MPa) and long-term service (>60MPa), due to the synergistic effect of early strength agent and expansion agent. The chloride ion diffusion coefficient was 1.4-1.8x10 - 12 m 2 / s, and the porosity was 8.6-9.4%, indicating excellent compactness and anti-chloride ion penetration ability, and the multi-layer protection effect of the corrosion inhibitor was significant. The yield stress was about 30.6-32.7Pa, the thixotropic index was 4.5-4.9, and the initial setting time was 9.3-10.3h, indicating good fluidity and suitable construction window period. The volume stability and corrosion resistance: 28d shrinkage rate 0.05-0.09%, corrosion current density 0.4-0.8μA / cm 2 , showing excellent volume stability and steel protection ability. In comparative examples 1-18, the performance of the key components was significantly reduced: comparative example 1 (no lignocellulose), comparative example 2 (no corrosion inhibitor), comparative example 3 (no nanodispersion) had an anti-dispersion loss rate of up to 17.8-25.4%, and the strength and durability were far lower than the target value, verifying the necessity of these components. Parameter out of range: comparative example 4 (nano-silicon dioxide particle size 50nm), comparative example 5 (nano-material ratio not appropriate), comparative example 6 (ultrasonic power too high) etc. due to agglomeration or uneven dispersion, the anti-dispersion loss rate was 15.5-19.5%, and the porosity was 15.5-18.2%. Process missing: comparative example 7 (no aluminum oxide immersion), comparative example 8 (excess triazole) etc. due to insufficient interfacial bonding force, the compressive strength and durability decreased. Excessive components: comparative example 16 (excess cement), comparative example 17 (excess lignocellulose), comparative example 18 (excess corrosion inhibitor) were slightly improved, but still far inferior to the examples, with abnormal yield stress and initial setting time affecting construction performance. Examples 1-15, through nanomaterial pre-dispersion, lignocellulose modification, corrosion inhibitor molecular design and other processes, are superior to comparative examples in terms of anti-dispersion, strength, durability and construction performance, meeting the high requirements of underwater engineering. The performance defects of the comparative examples further verify the necessity of key components and process parameters. The test results are consistent with the performance targets mentioned in the patent background (such as anti-dispersion loss rate <5%, 28-day compressive strength >60MPa, chloride ion diffusion coefficient ≤1.8x10 -12 m 2High consistency, reflecting the advanced nature and practicality of the technology. Overall, excellent resistance to dispersion: nanomaterial pre-dispersion treatment: mix nano-silica (particle size 10-30 nm), nano-iron oxide (particle size 20-50 nm), or nano-alumina (particle size 15-40 nm) with dispersant (polyether or zwitterionic water reducer) and water in a mass ratio of (3-6):(10-20):(60-100), and disperse for 10-30 min at a power of 500-800 W and a frequency of 40-60 kHz to obtain a stable nanodispersion. The uniform dispersion of nanomaterials significantly enhances the underwater dispersion resistance of the grouting material, preventing the material from being dispersed by water flow. Introduction of lignocellulose: lignocellulose is prepared from agricultural waste (such as rice husk or wheat straw) through enzymatic hydrolysis (cellulase, 45-50°C, pH 4.5-5.0, 2-3 h), ultrasonic treatment (600-800 W, 20 kHz, 10-15 min), vacuum impregnation (nano-aluminum hydroxide solution, 0.1-0.3 MPa, 30-60 min), and microwave curing (800 W, 3-5 min) to obtain nanocellulose with a diameter of 10-50 nm and an aspect ratio greater than 30. Subsequently, modification with 4-cyano-1H-1,2,3-triazole (3-6 times the mass of nanocellulose) further enhances its bonding with the matrix. The addition of lignocellulose effectively improves the cohesion and crack resistance of the grouting material, significantly enhancing its underwater dispersion resistance. High strength: matrix material formulation: use sulphoaluminate cement clinker (20-40 parts by weight, providing rapid hydration and early strength) or portland cement (20-40 parts by weight, providing long-term strength), combined with ultra-fine mineral powder (6-12 parts by weight), active steel slag or silica fume (4-10 parts by weight), fly ash or ultra-fine fly ash (10-25 parts by weight), and bentonite (1-3 parts by weight), and mix in a screw mixer at 50-100 rpm for 5-10 min to form a uniform dry-mixed base. The rational proportioning of these materials provides a high-strength foundation for the grouting material. Application of early strength agent: early strength agent is a mixture of sodium sulfate, sodium formate, and sodium nitrate in a mass ratio of (0.4-1):(0.5-1.5):(0.5-1), with a total amount of 5-10 parts by weight, which can accelerate the cement hydration reaction and significantly improve the early strength of the grouting material, meeting the needs of rapid repair of underwater projects. Role of expansion agent: quicklime (3-7 parts by weight) as an expansion agent produces moderate expansion during hydration, compensating for the shrinkage of the grouting material and improving volume stability and later strength.Excellent durability: preparation and application of corrosion inhibitor: the corrosion inhibitor is prepared by mixing ferrous sulfate, ferrous chloride and water in a mass ratio of 1: (1-1.5): (80-100), heating in a water bath at 60-80℃, adding ammonia solution (3-7 times the mass of ferrous sulfate) and diethyl carbonate (2-4 times the mass of ferrous sulfate), stirring, and then reacting at 140-180℃ for 6-12h under high pressure, and then adding tetraethyl orthosilicate, dopamine and sodium iodate for subsequent treatment. The corrosion inhibitor (5-10 parts by weight) can effectively inhibit the corrosion of steel bars in underwater environment, and significantly improve the durability and long-term stability of the grouting material. Good construction performance: optimization of wet mixed grouting material: by controlling the mass ratio of water, mixture and corrosion inhibitor to be 1: (0.25-0.35): (0.05-0.1), stirring at 200-400rpm for 3-5min, and maintaining the temperature at 30-40℃, the fluidity and construction performance of the grouting material are optimized, ensuring its easy injection and molding in underwater environment. Compared with the prior art: by comparing examples 1-15 and comparative examples 1-18 (such as comparative example 1 lacking lignocellulose, comparative example 2 lacking corrosion inhibitor, comparative example 3 not pre-dispersing nanomaterials, etc.), the technical scheme of the present application significantly improves the dispersion resistance (prevents loss of materials in water), early and late strength (meets the needs of rapid repair and long-term service), and durability (better corrosion resistance). At the same time, precise control of process parameters avoids imbalance of material performance, ensuring construction convenience.

[0137] The underwater dispersion-resistant high-strength grouting material of the present application realizes excellent comprehensive performance in underwater environment through the synergistic effect of nanomaterials, lignocellulose, early strength agent, expanding agent and corrosion inhibitor, combined with optimized preparation process. The significant improvement in dispersion resistance, high strength, durability and construction performance makes it an ideal material for underwater engineering repair and reinforcement.

[0138] The above is a further detailed description of the present application in combination with specific embodiments, which cannot be considered as limiting the specific embodiments of the present application to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope determined by the claims of the present application.

Claims

1. A method for preparing an underwater anti-dispersion high-strength grout, characterized by: The method comprises the following steps: (1) nanometer material pre-dispersion treatment: selecting nanometer material, wherein the nanometer material is nanometer silicon dioxide, nanometer iron oxide or nanometer aluminum oxide, adding a dispersing agent and water and dispersing by ultrasonic to prepare a nanometer dispersion liquid; (2) dry mixing of base material: weighing 20-40 parts by weight of sulphoaluminate cement clinker or Portland cement, 6-12 parts by weight of superfine mineral powder, 4-10 parts by weight of active steel slag or silica fume, 10-25 parts by weight of fly ash or superfine fly ash, and 1-3 parts by weight of bentonite, and mixing in a spiral mixer to form a uniform dry mixed base material; (3) wet mixing of the mixture: adding the nanometer dispersion liquid prepared in step (1) to the dry mixed base material formed in step (2), and introducing early strength agent, expanding agent, lignocellulose and retarder, and then stirring to obtain a mixture; (4) optimization preparation of the wet mixed slurry: adding water, the mixture obtained in step (3) and a corrosion inhibitor into a slurry preparation device, controlling the mass ratio among the water, the mixture and the corrosion inhibitor to be 1:(0.25-0.35):(0.05-0.1), and then stirring and controlling the temperature to obtain a slurry; the preparation method of the corrosion inhibitor in step (4) is as follows: mixing ferrous sulfate, ferrous chloride and water according to a mass ratio of 1:(1-1.5):(80-100), heating to 60-80 DEG C in a water bath, then adding 20% ammonia water solution with a mass percentage of 3-7 times the mass of the ferrous sulfate and diethyl carbonate with a mass of 2-4 times the mass of the ferrous sulfate, stirring at 200-300 rpm for 10-20 min, then transferring to a high-temperature and high-pressure reaction kettle, reacting at 140-180 DEG C for 6-12 h, recovering the supernatant after cooling, adding tetraethyl orthosilicate with a mass of 0.1-0.2 times the mass of the supernatant, and treating in a 60 rpm shaking table overnight, drying to obtain a primary product, then adding water with a mass of 80-150 times the mass of the primary product and adjusting the pH to 5, adding dopamine with a mass of 0.2-0.6 times the mass of the primary product and sodium iodate with a mass of 0.1-0.2 times the mass of the primary product, stirring and mixing uniformly, then reacting in a 200-300 W microwave oven for 5-15 min, naturally cooling and drying to obtain a final product.

2. A method for preparing an underwater anti-dispersion high-strength grout according to claim 1, characterized in that: The particle size of the nanometer silicon dioxide in step (1) is 10-30 nm; the particle size of the nanometer iron oxide in step (1) is 20-50 nm; the particle size of the nanometer aluminum oxide in step (1) is 15-40 nm; and the dispersing agent in step (1) is a polyether water reducing agent or an amphoteric ion water reducing agent.

3. The method for preparing the underwater anti-dispersion high-strength grout material according to claim 1, characterized in that: The ultrasonic dispersion parameters in step (1) are as follows: power 500-800 W, frequency 40-60 kHz, and time 10-30 min; and the mass ratio among the nanometer material, the dispersing agent and water in step (1) is (3-6):(10-20):(60-100).

4. The method for preparing the underwater anti-dispersion high-strength grout material according to claim 1, characterized in that: The rotating speed of the spiral mixer in step (2) is 50-100 rpm, and the mixing time is 5-10 min.

5. The method for preparing the underwater anti-dispersion high-strength grout material according to claim 1, characterized in that: The mass ratio between the dry-mixed base material, the nano-dispersion, the early strength agent, the expanding agent, the lignocellulose, and the retarder in step (3) is 100:(1.5-4):(5-10):(3-7):(1.5-3):(0.05-0.2); the expanding agent is quicklime, the length-diameter ratio of the lignocellulose is greater than 30, and the retarder is sodium citrate; the preparation method of the lignocellulose in step (3) is as follows: agricultural waste rice husk or wheat straw is selected, water is added to obtain a slurry with a solid content of 3-5 wt%, 2% cellulase by final mass percentage is added, and the reaction is carried out at 45-50°C and pH 4.5-5.0 for 2-3 h; the obtained nanocellulose with a diameter of 10-50 nm and a length-diameter ratio greater than 30 is treated by ultrasonic waves with a power of 600-800 W and a frequency of 20 kHz for 10-15 min; a 10 mM nano-aluminum hydroxide solution is prepared and embedded into the microporous structure of the nanocellulose by vacuum impregnation at a pressure of 0.1-0.3 MPa for 30-60 min; then microwave-assisted curing is carried out at a power of 800 W for 3-5 min; subsequently, 4-cyano-1H-1,2,3-triazole is added at a mass of 3-6 times that of the nanocellulose, and water is added at a mass of 30-40 times that of the nanocellulose; the reaction is carried out at 60-80°C for 1-2 h; and vacuum drying is carried out to obtain the product.

6. The method for preparing the underwater anti-dispersion high-strength grout material according to claim 1, characterized in that: The early strength agent in step (3) is a mixture of sulfate, formate, and nitrate in a mass ratio of (0.4-1):(0.5-1.5):(0.5-1); and the stirring speed in step (3) is 100-200 rpm, and the stirring time is 5-8 min.

7. The method for preparing the underwater anti-dispersion high-strength grout material according to claim 1, characterized in that: The stirring speed in step (4) is 200-400 rpm, and the stirring time is 3-5 min; and the temperature in step (4) is controlled at 30-40°C.

8. An underwater anti-dispersion high-strength grout, characterized by, The underwater anti-dispersion high-strength grouting material is obtained by the preparation method of any one of claims 1-7.

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