Ultra-high performance repair grout for underwater construction, its preparation method and application

Abstract

This invention relates to the field of cement-based building materials technology, and in particular to an ultra-high performance repair grout for underwater construction, its preparation method, and its application. It uses fast-setting and fast-hardening high-belite sulfoaluminate cement as the main cementing material, adds amorphous calcium aluminate to promote hydration, and adds ultrafine fly ash, ultrafine mineral powder, and silica fume as auxiliary cementing materials to ensure the later-stage strength of the repair grout. Combined with compound admixtures, it prepares an ultra-high performance repair grout with crack resistance, high adhesion, ultra-high strength, underwater anti-dispersion properties, and high durability.

Description

Technical Field

[0001] This invention relates to the field of cement-based building materials technology, and in particular to an ultra-high performance repair grout for underwater construction, its preparation method, and its application. Background Technology

[0002] With the rapid development of road and transportation construction, more and more cross-sea and cross-river bridges are being put into use. As the service life of ordinary concrete extends, problems such as steel corrosion and concrete spalling seriously affect the structural safety of bridges.

[0003] Existing technologies often employ reinforcement measures that use fiberglass sleeves to encase underwater epoxy grout, but the high price of epoxy grout and its mismatch in elastic modulus with ordinary concrete limit its application.

[0004] Cement-based grouting materials have advantages such as low cost and service synergy, and have received increasing attention. However, there is limited research on existing technologies for grouting materials used in underwater structure repair. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an ultra-high performance repair grout for underwater construction, its preparation method, and its application. Specifically, it uses fast-setting and fast-hardening high-belite sulfoaluminate cement as the main cementing material, adds amorphous calcium aluminate to promote hydration, and adds ultrafine fly ash, ultrafine mineral powder, and silica fume as auxiliary cementing materials to ensure the later strength of the repair grout. It is also combined with compound admixtures to prepare an ultra-high performance repair grout with crack resistance, high adhesion, ultra-high strength, underwater anti-dispersion, and high durability.

[0006] Specifically, the ultra-high performance repair grouting material for underwater construction of this invention is composed of the following raw materials in parts by weight: 23-30 parts of fast-setting and fast-hardening high-belite sulfoaluminate cement, 0.5-4.5 parts of calcium aluminate amorphous phase, 0.01-0.03 parts of retarder, 3-8 parts of ultrafine fly ash, 5-10 parts of ultrafine mineral powder, 2-6 parts of silica fume, 43-55 parts of fine aggregate, 0.01-0.15 parts of sodium nitrite, 0.3-0.6 parts of high-performance polycarboxylate superplasticizer, 0.03-0.06 parts of defoamer, 0.02-0.5 parts of expansion agent, 0.6-1.1 parts of ethylene / vinyl laurate / vinyl chloride terpolymer powder, 0.5-1 part of anti-dispersing agent, and 2-6 parts of copper-plated steel fiber.

[0007] The anti-dispersant is composed of a viscosity modifier, disodium ethylenediaminetetraacetate, sodium sulfoaluminate, glyceryl polyoxyethylene ether, sodium phosphate, and sodium dodecylbenzenesulfonate in a mass ratio of 1:(0.1-0.2):(0.8-1):(0.5-0.8):(0.3-0.6):(0.2-0.3). The viscosity modifier is prepared by dissolving 85 parts of water-soluble acrylic acid and 15 parts of ethyleneimine in a sodium hydroxide alkaline solution, stirring at 90°C until uniformly dissolved, and then adding 0.02 parts of sodium thiosulfate solution dropwise to the solution to induce a polymerization reaction.

[0008] Preferably, the fast-setting and fast-hardening high belite sulfoaluminate cement is composed of fast-setting and fast-hardening high belite sulfoaluminate clinker, anhydrite, and admixtures. The fast-setting and fast-hardening high belite sulfoaluminate cement clinker contains 0.5-4.6% f-CaO and 14-26.3% CaSO4.

[0009] This invention uses fast-setting and fast-hardening high-belite sulfoaluminate cement as the main cementitious material. Its high free gypsum content ensures that all C4A3 minerals are hydrated to form AFt, ensuring good volume stability. Compared with ordinary calcium aluminate minerals, amorphous calcium aluminate has greater hydration activity, which can cooperate with the hydration of fast-setting and fast-hardening high-belite sulfoaluminate cement and promote the hydration of ultrafine mineral admixtures, providing high early strength and stable later strength. The addition of sodium nitrite also promotes cement hydration, improves the pore structure of cement stone, increases structural density, and has the effect of lowering the freezing point and inhibiting steel corrosion.

[0010] Preferably, the retarder is composed of sodium citrate, citric acid, tartaric acid, and boric acid in a mass ratio of 1:1:1:1 or 2:1:1:2.

[0011] Preferably, the high-performance polycarboxylate superplasticizer is a powder with a water reduction rate of ≥32%.

[0012] Preferably, the defoamer is a polyether-based defoamer.

[0013] Preferably, the expanding agent is at least one of a plastic expanding agent and a CaO-C4A3 mineral expanding agent. More preferably, the expanding agent is a composite of a plastic expanding agent and a CaO-C4A3 mineral expanding agent at a mass ratio of 0.5:(8-12). Even more preferably, the mineral expanding agent is of type ZY-II.

[0014] Preferably, the fine aggregate is calcined corundum, composed of continuous gradation within four particle size ranges: 70-120 mesh, 40-70 mesh, 20-40 mesh, and 10-20 mesh.

[0015] Preferably, the copper-plated steel fiber is a wavy copper-plated steel fiber with a length of 3 mm and a diameter of 0.2 mm.

[0016] This invention also relates to a method for preparing the aforementioned ultra-high performance repair grout for underwater construction, specifically comprising the following steps:

[0017] 1) Weigh each ingredient according to its weight.

[0018] 2) Mix the fast-setting and fast-hardening high-belite sulfoaluminate cement, calcium aluminate amorphous phase, retarder, ultrafine fly ash, ultrafine mineral powder, silica fume, fine aggregate, sodium nitrite, high-performance polycarboxylate superplasticizer, defoamer, expanding agent, ethylene / vinyl laurate / vinyl chloride ternary copolymer powder, anti-dispersing agent, and copper-plated steel fiber evenly to obtain powder, package it, and the product is ready.

[0019] This invention also relates to the application of the aforementioned ultra-high performance underwater repair grout in underwater engineering repair.

[0020] Preferably, the above application includes the following steps:

[0021] a) Weigh the mixing water according to a water-to-material ratio of 0.08-0.1.

[0022] b) Add the powder to the mixer, add the mixing water and mix well to obtain a slurry.

[0023] This invention draws on the design concept of UHPC ultra-high performance concrete, using an ultra-low water-to-material ratio and high-density mix design; at the same time, it utilizes the rapid hydration of fast-hardening cementitious materials and the regulation of hydration minerals to promote the formation of AFt and improve interfacial adhesion performance; and by modifying the anti-dispersant agent, it solves the problem of the influence of the addition of traditional thickeners and flocculants on flowability and workability in the prior art, so that the repair grouting material of this invention has good workability.

[0024] This invention has the following technical advantages:

[0025] 1. Excellent volume stability: This invention uses fast-setting and fast-hardening high-belite sulfoaluminate cement as the main cementing material. Its high free gypsum content ensures that all C4A3 minerals hydrate to form AFt, ensuring excellent volume stability. The addition of an expansion agent further compensates for the volume shrinkage caused by the hydration of the cementing material. Furthermore, the addition of short copper-plated steel fibers, compared to traditional steel fibers longer than 10mm, does not affect flowability and simultaneously provides constraint on the cement paste, significantly reducing the risk of shrinkage cracking.

[0026] 2. Strong Adhesion: This invention uses ethylene / vinyl laurate / vinyl chloride ternary copolymer powder, achieving strong anti-soap properties and excellent hydrophobicity. Combined with the tenon-and-mortise structure created by the early hydration of the amorphous phase of calcium aluminate at the interface between old and new marine structures, which produces a large number of needle-like ettringite crystals, the adhesive mechanical properties can be significantly improved.

[0027] 3. Ultra-high strength: This invention employs a fast-setting and fast-hardening high-belite sulfoaluminate cement composite with amorphous calcium aluminate, combined with ultrafine admixtures. The cementitious material has a large specific surface area and high activity. Ultra-high-strength fine aggregates are used, which, compared to traditional quartz sand and basalt sand, contribute to better mechanical properties. Leveraging UHPC configuration experience, this invention uses ultra-low water consumption to reduce micro-defects within the slurry. The addition of appropriate steel fibers provides significant macro-level constraint on the matrix, greatly improving the final strength performance.

[0028] 4. High durability: This invention uses low water consumption, reduces internal defects, minimizes the diffusion of harmful components such as chloride ions, and significantly reduces the damage caused by freeze-thaw cycles. The application of ethylene / vinyl laurate / vinyl chloride terpolymer powder achieves a hydrophobic effect inside the hardened slurry, reducing the damage to the hardened slurry caused by external harmful substances.

[0029] 5. Excellent underwater repair effect: This invention prepares a specific anti-dispersion agent for cementitious materials, which has good compatibility with high-performance polycarboxylate superplasticizer. It can ensure that the repair grout does not disperse during the underwater repair construction process and has good fluidity. Detailed Implementation

[0030] To demonstrate the technical effectiveness of this invention, a repair grouting material was prepared and its performance was tested. During the experiment, the retarder was composed of sodium citrate, citric acid, tartaric acid, and boric acid in a mass ratio of 1:1:1:1. The high-performance polycarboxylate superplasticizer was a powder with a water reduction rate of 34%. The expanding agent was a mixture of plastic expanding agent and ZY-II type CaO mineral expanding agent in a mass ratio of 0.5:10. The fine aggregate was calcined corundum, composed of continuous gradation within four particle size ranges: 70-120 mesh, 40-70 mesh, 20-40 mesh, and 10-20 mesh. The copper-plated steel fiber was a wavy copper-plated steel fiber with a length of 3 mm and a diameter of 0.2 mm.

[0031] During the testing process, the water-to-material ratio was 0.085. The mortar flowability was tested in an underwater environment at a depth of 0.3m. The spread of the mortar underwater was tested, and the compressive strength specimens were cured using standard methods.

[0032] Example 1: Repair grouting material, composed of the following raw materials in parts by weight: 25 parts rapid-setting and fast-hardening high-belite sulfoaluminate cement, 4 parts amorphous calcium aluminate, 0.01 parts retarder, 5 parts ultrafine fly ash, 9 parts ultrafine mineral powder, 3 parts silica fume, 50 parts fine aggregate, 0.1 parts sodium nitrite, 0.4 parts high-performance polycarboxylate superplasticizer, 0.04 parts defoamer, 0.3 parts expanding agent, 0.8 parts ethylene / vinyl laurate / vinyl chloride terpolymer powder, 0.7 parts anti-dispersing agent, copper plating... Three parts of steel fiber; the anti-dispersant is a compound of tack modifier, disodium ethylenediaminetetraacetate, sodium sulfoaluminate, glycerol polyoxyethylene ether, sodium phosphate, and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.2:0.9:0.6:0.5:0.3. The tack modifier is prepared by dissolving 85 parts of water-soluble acrylic acid and 15 parts of ethyleneimine in an alkaline sodium hydroxide solution, stirring at 90°C until uniformly dissolved, and then adding 0.02 parts of sodium thiosulfate solution dropwise to the solution to induce a polymerization reaction.

[0033] The slurry was tested and found to have an initial flowability of 305 mm, a flowability of 265 mm after 30 minutes, good underwater cohesion, and no dispersion. Its 28-day flexural strength was 25.5 MPa, 1-day compressive strength was 80.6 MPa, 3-day compressive strength was 103.2 MPa, 28-day compressive strength was 131.3 MPa, 3-hour vertical expansion rate was 0.08%, the difference between 24-hour and 3-hour expansion values ​​was 0.06%, 28-day tensile bond strength was 2.9 MPa, 28-day static elastic modulus was 52.8 GPa, and 28-day self-drying shrinkage was 0.029%.

[0034] Example 2: Repair grouting material, composed of the following raw materials in parts by weight: 30 parts rapid-setting and fast-hardening high-belite sulfoaluminate cement, 3.5 parts amorphous calcium aluminate, 0.03 parts retarder, 8 parts ultrafine fly ash, 6 parts ultrafine mineral powder, 5 parts silica fume, 50 parts fine aggregate, 0.11 parts sodium nitrite, 0.6 parts high-performance polycarboxylate superplasticizer, 0.04 parts defoamer, 0.4 parts expanding agent, 0.7 parts ethylene / vinyl laurate / vinyl chloride terpolymer powder, and 0.9 parts anti-dispersing agent. The product contains 4 parts copper-plated steel fiber. The anti-dispersant is composed of a viscosity modifier, disodium ethylenediaminetetraacetate, sodium sulfoaluminate, glycerol polyoxyethylene ether, sodium phosphate, and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.1:1:0.6:0.4:0.3. The viscosity modifier is prepared by dissolving 85 parts water-soluble acrylic acid and 15 parts ethyleneimine in a sodium hydroxide alkaline solution and stirring at 90°C until the solution is uniformly dissolved. Then, 0.02 parts sodium thiosulfate solution is added dropwise to the solution to induce a polymerization reaction.

[0035] The slurry was tested and found to have an initial flowability of 330 mm and a flowability of 310 mm after 30 minutes. It exhibited good underwater cohesion and did not disperse. The 28-day flexural strength was 27.6 MPa, the 1-day compressive strength was 86.5 MPa, the 3-day compressive strength was 112.3 MPa, the 28-day compressive strength was 144.1 MPa, the 3-hour vertical expansion rate was 0.09%, the difference between the 24-hour and 3-hour expansion values ​​was 0.08%, the 28-day tensile bond strength was 3.1 MPa, the 28-day static elastic modulus was 52.2 GPa, and the 28-day self-drying shrinkage was 0.026%.

[0036] Comparative Example 1: Repair grouting material, composed of the following raw materials in parts by weight: 25 parts of 52.5 grade sulfoaluminate cement, C 12 The mixture consists of 4 parts A7 mineral, 0.01 parts retarder, 5 parts ultrafine fly ash, 9 parts ultrafine mineral powder, 3 parts silica fume, 50 parts fine aggregate, 0.4 parts high-performance polycarboxylate superplasticizer, 0.04 parts defoamer, 0.3 parts expanding agent, 0.8 parts ethylene / vinyl laurate / vinyl chloride terpolymer powder, 0.7 parts anti-dispersant, and 3 parts copper-plated steel fiber. The anti-dispersant is a mixture of tack modifier, disodium ethylenediaminetetraacetate, sodium sulfoaluminate, glycerol polyoxyethylene ether, sodium phosphate, and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.2:0.9:0.6:0.5:0.3. The tack modifier is prepared by dissolving 85 parts water-soluble acrylic acid and 15 parts ethyleneimine in a sodium hydroxide alkaline solution, stirring at 90°C until uniformly dissolved, and then adding 0.02 parts sodium thiosulfate solution dropwise to the solution to induce a polymerization reaction.

[0037] The slurry was tested and found to have an initial flowability of 310 mm, a flowability of 268 mm after 30 minutes, good underwater cohesion, and no dispersion. Its 28-day flexural strength was 19.3 MPa, 1-day compressive strength was 56.4 MPa, 3-day compressive strength was 87.3 MPa, 28-day compressive strength was 91.2 MPa, vertical expansion rate after 3 hours was 0.05%, the difference between expansion values ​​after 24 hours and 3 hours was 0.04%, tensile bond strength after 28 hours was 1.8 MPa, static elastic modulus after 28 hours was 41.9 GPa, and self-drying shrinkage after 28 hours was 0.038%.

[0038] Comparative Example 2: Repair grouting material, composed of the following raw materials in parts by weight: 25 parts rapid-setting and fast-hardening high-belite sulfoaluminate cement, 4 parts amorphous calcium aluminate, 0.01 parts retarder, 5 parts ultrafine fly ash, 9 parts ultrafine mineral powder, 3 parts silica fume, 50 parts fine aggregate, 0.1 parts sodium nitrite, 0.4 parts high-performance polycarboxylate superplasticizer, 0.04 parts defoamer, 0.3 parts expanding agent, 0.8 parts ethylene / vinyl acetate copolymer powder, 0.7 parts anti-dispersing agent, and anti-foaming agent. The dispersant is composed of a viscosity modifier, disodium ethylenediaminetetraacetate, sodium sulfoaluminate, glyceryl polyoxyethylene ether, sodium phosphate, and sodium dodecylbenzenesulfonate in a mass ratio of 1:0.2:0.9:0.6:0.5:0.3. The viscosity modifier is prepared by dissolving 85 parts of water-soluble acrylic acid and 15 parts of ethyleneimine in a sodium hydroxide alkaline solution, stirring at 90°C until uniformly dissolved, and then adding 0.02 parts of sodium thiosulfate solution dropwise to the solution to induce a polymerization reaction.

[0039] The slurry was tested and found to have an initial flowability of 320 mm, a flowability of 260 mm after 30 minutes, good underwater cohesion, and no dispersion. Its 28-day flexural strength was 13.4 MPa, 1-day compressive strength was 59.0 MPa, 3-day compressive strength was 87.1 MPa, 28-day compressive strength was 96.6 MPa, vertical expansion rate after 3 hours was 0.07%, the difference between expansion values ​​after 24 hours and 3 hours was 0.04%, tensile bond strength after 28 hours was 2.5 MPa, static elastic modulus after 28 hours was 43.5 GPa, and self-drying shrinkage after 28 hours was 0.042%.

[0040] Comparative Example 3: Repair grouting material, composed of the following raw materials in parts by weight: 25 parts of fast-setting and fast-hardening high-belite sulfoaluminate cement, 4 parts of calcium aluminate amorphous phase, 0.01 parts of retarder, 5 parts of ultrafine fly ash, 9 parts of ultrafine mineral powder, 3 parts of silica fume, 50 parts of fine aggregate, 0.1 parts of sodium nitrite, 0.4 parts of high-performance polycarboxylate superplasticizer, 0.04 parts of defoamer, 0.3 parts of expansion agent, 0.8 parts of ethylene / vinyl laurate / vinyl chloride terpolymer powder, 0.7 parts of hydroxypropyl methylcellulose ether, and 3 parts of copper-plated steel fiber.

[0041] The slurry was tested and found to have an initial flowability of 300 mm, a flowability of 250 mm after 30 minutes, moderate underwater cohesion, and partial dispersion. The 28-day flexural strength was 23.4 MPa, the 1-day compressive strength was 42.5 MPa, the 3-day compressive strength was 79.0 MPa, the 28-day compressive strength was 114.1 MPa, the 3-hour vertical expansion rate was 0.07%, the difference between the 24-hour and 3-hour expansion values ​​was 0.03%, the 28-day tensile bond strength was 2.5 MPa, the 28-day static elastic modulus was 38.2 GPa, and the 28-day self-drying shrinkage was 0.036%.

[0042] Comparative Example 4: Repair grouting material, composed of the following raw materials in parts by weight: 25 parts rapid-setting and fast-hardening high-belite sulfoaluminate cement, 4 parts amorphous calcium aluminate, 0.01 parts retarder, 5 parts ultrafine fly ash, 9 parts ultrafine mineral powder, 3 parts silica fume, 50 parts fine aggregate, 0.1 parts sodium nitrite, 0.4 parts high-performance polycarboxylate superplasticizer, 0.04 parts defoamer, 0.3 parts expanding agent, and 0.8 parts ethylene / vinyl laurate / vinyl chloride terpolymer powder. 0.7 parts of anti-dispersant and 3 parts of copper-plated steel fiber. The anti-dispersant is a compound of viscosity modifier, glycerol polyoxyethylene ether, sodium phosphate and sodium dodecylbenzene sulfonate in a mass ratio of 1:0.6:0.5:0.3. The viscosity modifier is prepared by dissolving 85 parts of water-soluble acrylic acid and 15 parts of ethyleneimine in sodium hydroxide alkaline solution, stirring at 90°C until uniformly dissolved, and then adding 0.02 parts of sodium thiosulfate solution dropwise to the solution to induce a polymerization reaction.

[0043] The slurry was tested and found to have an initial flowability of 322 mm, a 30-minute flowability of 280 mm, good underwater cohesion, slight dispersion, a 28-day flexural strength of 20.7 MPa, a 1-day compressive strength of 69.8 MPa, a 3-day compressive strength of 84.5 MPa, a 28-day compressive strength of 117.2 MPa, a 3-hour vertical expansion rate of 0.07%, a difference of 0.04% between the 24-hour and 3-hour expansion values, a 28-day tensile bond strength of 2.2 MPa, a 28-day static elastic modulus of 38.8 GPa, and a 28-day self-drying shrinkage of 0.038%.

[0044] Comparative Example 5: Repair grouting material, composed of the following raw materials in parts by weight: 25 parts of fast-setting and fast-hardening high-belite sulfoaluminate cement, 4 parts of calcium aluminate amorphous phase, 0.01 parts of retarder, 5 parts of ultrafine fly ash, 9 parts of ultrafine mineral powder, 3 parts of silica fume, 50 parts of fine aggregate, 0.1 parts of sodium nitrite, 0.4 parts of high-performance polycarboxylate superplasticizer, 0.04 parts of defoamer, 0.3 parts of expansion agent, 0.8 parts of ethylene / vinyl laurate / vinyl chloride terpolymer powder, 0.7 parts of anti-dispersant agent, and 3 parts of copper-plated steel fiber. The anti-dispersant agent is a compound of polyacrylamide, disodium ethylenediaminetetraacetate, and sodium sulfoaluminate in a mass ratio of 1:0.2:0.9.

[0045] The slurry was tested and found to have an initial flowability of 310 mm, a flowability of 280 mm after 30 minutes, moderate underwater cohesion, and partial dispersion. The 28-day flexural strength was 20.2 MPa, the 1-day compressive strength was 41.7 MPa, the 3-day compressive strength was 60.3 MPa, the 28-day compressive strength was 89.4 MPa, the 3-hour vertical expansion rate was 0.04%, the difference between the 24-hour and 3-hour expansion values ​​was 0.07%, the 28-day tensile bond strength was 2.3 MPa, the 28-day static elastic modulus was 36.5 GPa, and the 28-day self-drying shrinkage was 0.039%.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance underwater repair grout, characterized in that, Composed of the following raw materials in parts by weight: 23-30 parts of rapid-setting and fast-hardening high-belite sulfoaluminate cement, 0.5-4.5 parts of amorphous calcium aluminate, 0.01-0.03 parts of retarder, 3-8 parts of ultrafine fly ash, 5-10 parts of ultrafine mineral powder, 2-6 parts of silica fume, 43-55 parts of fine aggregate, 0.01-0.15 parts of sodium nitrite, 0.3-0.6 parts of high-performance polycarboxylate superplasticizer, 0.03-0.06 parts of defoamer, 0.02-0.5 parts of expanding agent, 0.6-1.1 parts of ethylene / vinyl laurate / vinyl chloride terpolymer powder, 0.5-1 part of anti-dispersing agent, and 2-6 parts of copper-plated steel fiber. The anti-dispersant is composed of a viscosity modifier, disodium ethylenediaminetetraacetate, sodium sulfoaluminate, glyceryl polyoxyethylene ether, sodium phosphate, and sodium dodecylbenzenesulfonate in a mass ratio of 1:(0.1-0.2):(0.8-1):(0.5-0.8):(0.3-0.6):(0.2-0.3). The viscosity modifier is prepared by dissolving 85 parts of water-soluble acrylic acid and 15 parts of ethyleneimine in a sodium hydroxide alkaline solution, stirring at 90°C until uniformly dissolved, and then adding 0.02 parts of sodium thiosulfate solution dropwise to the solution to induce a polymerization reaction.

2. The ultra-high performance repair grouting material for underwater construction according to claim 1, characterized in that, The fast-setting and fast-hardening high belite sulfoaluminate cement is composed of fast-setting and fast-hardening high belite sulfoaluminate clinker, anhydrite, and admixtures. The fast-setting and fast-hardening high belite sulfoaluminate cement clinker contains 0.5-4.6% f-CaO and 14-26.3% CaSO4.

3. The ultra-high performance repair grouting material for underwater construction according to claim 1, characterized in that, The retarder is composed of sodium citrate, citric acid, tartaric acid, and boric acid in a mass ratio of 1:1:1:1 or 2:1:1:

2.

4. The ultra-high performance repair grouting material for underwater construction according to claim 1, characterized in that, The high-performance polycarboxylate superplasticizer is a powder with a water reduction rate of ≥32%.

5. The ultra-high performance repair grouting material for underwater construction according to claim 1, characterized in that, The defoamer is a polyether-based defoamer, and the expanding agent is at least one of a plastic expanding agent or a CaO-C4A3 mineral expanding agent.

6. The ultra-high performance repair grouting material for underwater construction according to claim 1, characterized in that, The fine aggregate is calcined corundum, composed of continuous gradation within four particle size ranges: 70-120 mesh, 40-70 mesh, 20-40 mesh, and 10-20 mesh.

7. The ultra-high performance repair grouting material for underwater construction according to claim 1, characterized in that, The copper-plated steel fiber is a wavy copper-plated steel fiber with a length of 3 mm and a diameter of 0.2 mm.

8. The method for preparing the ultra-high performance repair grout for underwater construction according to any one of claims 1-7, characterized in that, Includes the following steps: 1) Weigh each ingredient according to its weight. 2) Mix the fast-setting and fast-hardening high-belite sulfoaluminate cement, calcium aluminate amorphous phase, retarder, ultrafine fly ash, ultrafine mineral powder, silica fume, fine aggregate, sodium nitrite, high-performance polycarboxylate superplasticizer, defoamer, expanding agent, ethylene / vinyl laurate / vinyl chloride ternary copolymer powder, anti-dispersing agent, and copper-plated steel fiber evenly to obtain powder, package it, and the product is ready.

9. The application of the ultra-high performance underwater repair grouting material according to any one of claims 1-7 in underwater engineering repair.

10. The application according to claim 9, characterized in that, Includes the following steps: a) Weigh the mixing water according to a water-to-material ratio of 0.08-0.

1. b) Add the powder to the mixer, add the mixing water and mix well to obtain a slurry.