Anti-crack grouting material for connecting floating bodies of floating offshore wind power tower drum and preparation method of anti-crack grouting material

Abstract

The invention belongs to the technical field of special engineering materials, and particularly relates to an anti-crack grouting material for floating offshore wind power tower tube floating body connection and a preparation method, the anti-crack grouting material comprises the following raw materials by weight: 25-40 parts of cement, 1-12 parts of a superfine active filler, 40-55 parts of quartz sand, 1-5 parts of nano modified powder, 0.1-1.2 parts of a composite chemical admixture, and 0.1-0.8 part of an expanding agent, and 0.005 to 0.1 part of hybrid fiber. According to the invention, the porosity of a matrix is reduced and the growth of a hydration product is promoted by optimizing the grain composition of the raw materials and introducing nano-particle crystal nucleuses and hybrid fibers, and the anti-cracking and high-toughness cement-based grouting material is prepared by physically resisting cracks and consuming crack propagation energy; the grouting material has the characteristics of large flow state, high retention, ultrahigh strength, high toughness, crack resistance, high durability and the like, the crack resistance and long-term durability of the grouting material for connecting the floating offshore wind power tower tube floating body are ensured, and the high-fluidity construction requirement of the grouting material is met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of special engineering materials, and particularly relates to a crack-resistant grouting material for connecting a floating body of a floating offshore wind power tower and a preparation method. BACKGROUND

[0002] Energy security is the core pillar of national economic security and strategic security. For a long time, China's traditional energy system has been highly dependent on external oil and gas resources - oil dependence on external resources is over 70%, and natural gas dependence on external resources is close to 40%. Under the background of the profound evolution of the global geopolitical pattern, the frequent occurrence of local conflicts, and the continuous pressure on the stability of the supply chain, oil and gas import channels are facing increasingly severe "supply interruption" risks. Under this situation, accelerating the construction of a modern energy system with local renewable energy as the main body, which is independent, safe, efficient and green, has become the only way to ensure national energy security and achieve the "double carbon" strategic goal.

[0003] As a key growth pole of high-quality development of renewable energy in China, offshore wind power has multiple advantages such as superior resource endowment, great development potential, and significant environmental synergy benefits. According to authoritative assessment, the developable amount of offshore wind energy technology in China is about 2254 GW, of which the deep sea area accounts for 67%, which is more than twice the nearshore resources, providing the basic conditions to support the development of million-kilowatt scale and cluster. With the saturation of onshore and nearshore wind power resource development, promoting offshore wind power from nearshore to deep sea has become an inevitable trend of industry development and an important direction of national strategy.

[0004] Floating wind power technology, which can break through the water depth limit (usually applicable to waters with a water depth of more than 50 m), is the only feasible path to unlock high-quality wind energy resources in deep sea, and is accelerating from the demonstration stage to commercial-scale deployment, and is widely regarded as the core technology of the next generation of offshore wind power. However, unlike fixed foundations, floating wind power platforms are in a six-degree-of-freedom dynamic response state in complex marine environments for a long time, and the connection structure between the tower and the floating body not only needs to bear the huge static gravity load of the wind turbine body, but also needs to continuously resist high-frequency dynamic bending moments, shear forces and fatigue cycle loads caused by wind-wave-flow coupling. The structural integrity and service reliability of this connection section are directly related to the safe and stable operation of the whole machine system and even the economy of the whole life cycle.

[0005] As the current mainstream rigid connection method of tower drum-floater, the performance of the core material of grouting connection, high-performance grouting material, is crucial. The ideal grouting material for floating wind power must meet the multi-dimensional and strict requirements of high flow state retention (ensuring sufficient filling of narrow annular joints), ultra-high strength (≥150 MPa compressive strength to match high-strength steel structure), high toughness and crack resistance (effectively inhibiting micro-crack initiation and propagation), excellent durability (resisting seawater erosion, dry-wet cycle and chloride ion permeation), and good construction adaptability.

[0006] However, the existing offshore wind power grouting material technology mainly faces the fixed jacket foundation design, and it is difficult to adapt to the extreme mechanical environment under the floating condition. For example, CN 104003681A has good fluidity and basic mechanical properties, but the elastic modulus is not controlled, which has the risk of long-term stiffness mismatch; CN 113968698A and CN 116693262A respectively introduce static / dynamic elastic modulus regulation, but still do not pay attention to the crack resistance and toughness behavior of the material under alternating load; CN 118307272A is optimized for low-temperature construction, but uses a modified C-S-H phase with poor stability, which significantly increases the complexity of on-site construction. Most importantly, all the above-mentioned solutions do not take "high toughness and crack resistance" as the core design index, lack effective solutions for the crack control ability of the floating connection section under complex dynamic load, and are difficult to meet the extreme requirements of grouting connection reliability for large-scale, deep-sea floating wind power engineering in the future.

[0007] Therefore, it is urgent to develop a new type of high-performance grouting material specially used for floating offshore wind tower drum-floater connection, which can significantly improve the toughness and crack resistance while ensuring ultra-high strength and high flow state retention, thereby laying a solid material technology foundation for large-scale development of deep-sea wind power in China, and effectively supporting national energy security and "double carbon" strategy. SUMMARY

[0008] The present application provides a kind of anti-crack grouting material for floating offshore wind tower drum-floater connection and preparation method to solve the technical problems existing in the prior art.

[0009] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0010] A kind of anti-crack grouting material for floating offshore wind tower drum-floater connection, consisting of the following weight parts of raw materials: cement 25-40 parts, ultra-fine active filler 1-12 parts, quartz sand 40-55 parts, nano-modified powder 1-5 parts, composite chemical admixture 0.1-1.2 parts, expanding agent 0.1-0.8 parts, hybrid fiber 0.005-0.1 parts;

[0011] The superfine active filler includes silica ash and fly ash beads, and the superfine active filler is a mixture of silica ash and fly ash beads in a volume ratio of (5-10):(0-5); the composite chemical admixture includes water reducing agent, retarder and defoaming agent, and the composite chemical admixture is a mixture of water reducing agent, retarder and defoaming agent in a mass ratio of (75-95):(1-5):(0.5-3).

[0012] The hybrid fiber is selected from any one of the following:

[0013] (a) polyvinyl alcohol composite fiber, the amount of which is 0.005-0.02 parts, which is a mixture of polyvinyl alcohol long fibers with a length of 12 mm and a diameter of 20 μm and polyvinyl alcohol short fibers with a length of 6 mm and a diameter of 20 μm in a volume ratio of (0-5):(5-10);

[0014] (b) polypropylene composite fiber, the amount of which is 0.05-0.1 parts, which is a mixture of polypropylene long fibers with a length of 12 mm and an aspect ratio of 345 and polypropylene short fibers with a length of 6 mm and an aspect ratio of 345 in a volume ratio of (0-5):(5-10);

[0015] (c) polyacrylonitrile composite fiber, the amount of which is 0.005-0.03 parts, which is a mixture of polyacrylonitrile long fibers with a length of 12 mm and a diameter of 25 μm and polyacrylonitrile short fibers with a length of 6 mm and a diameter of 25 μm in a volume ratio of (0-5):(5-10).

[0016] The cement is P·O 52.5 grade ordinary Portland cement, the particle size distribution of which is D50 5-10 μm, D90 25-35 μm, and the content of calcium silicate mineral phase (C3S, C2S) is not less than 70%.

[0017] The quartz sand is compounded by four different particle sizes of quartz sand, and the mass percentage of each component is as follows: 0.1-0.3 mm quartz sand: 20-60%; 0.3-0.5 mm quartz sand: 10-50%; 0.5-1.0 mm quartz sand: 0-35%; 1.0-1.5 mm quartz sand: 0-20%.

[0018] The nano-modified powder is nano calcium carbonate powder with an average particle size of 80-100 nm and a calcium carbonate content of more than 90%.

[0019] The water reducing agent is polycarboxylic acid superplasticizer; the retarder is at least one of trisodium citrate and sodium gluconate; and the defoaming agent is at least one of polyether and mineral oil.

[0020] The expansive agent is at least one of plastic expansive agent and mineral expansive agent.

[0021] A preparation method of a crack-resistant grouting material for connecting a floating offshore wind power tower body, comprising the following steps:

[0022] S1. Each raw material is weighed according to the mass proportion, and mixed uniformly;

[0023] S2. 80% of water is added for wet mixing for 120s;

[0024] S3. The remaining 20% of water and composite admixture are added for mixing;

[0025] S4. Hybrid fibers are added for mixing;

[0026] S5. After mixing, air is discharged, and the mixture is transported to a grouting machine for pumping construction.

[0027] The premixing time of the solid powder in the step S1 is 120s of low-speed stirring; the wet mixing time in the step S2 is 120s of low-speed stirring; the mixing time in the step S3 is 180s of low-speed mixing; the specific steps of the step S4 are that after adding the hybrid fibers, low-speed mixing is first carried out for 90s, and then high-speed mixing is carried out for 120s; and the standing time in the step S5 is 2-5min.

[0028] The grouting material and water are mixed at a water-material ratio of 0.072:1-0.085:1.

[0029] The application has the following beneficial effects:

[0030] (1) The application realizes the synergistic optimization of mechanical properties and working performance: by accurately controlling the ultra-fine active fillers of cement, silica fume and fly ash microbeads, and the particle size distribution of four-grade continuous gradation quartz sand, a dense packing skeleton is constructed; combined with the high dispersibility polycarboxylic acid water reducer and the retardation-foam control synergistic system, excellent construction performance of initial fluidity ≥320 mm and 2h fluidity retention rate >80% can still be obtained under very low water consumption, effectively guaranteeing the self-compacting filling quality of narrow annular joints.

[0031] (2) Significantly improve the crack resistance and fatigue durability: innovatively introduce a long-short compound system of three kinds of high-performance hybrid fibers (PVA, PP or PAN), use the bridging, pulling out and crack deflection mechanisms of different scale fibers in the matrix to greatly improve the fracture energy and impact resistance of the material; experiments show that the 28d flexural strength of the grouting material of the application can reach more than 15 MPa, and the flexural pressure ratio is significantly better than that of conventional ultra-high performance concrete (UHPC), effectively inhibiting the initiation and expansion of microcracks under dynamic load, meeting the million-level fatigue service requirements of the floating platform under the wind-wave-current coupling effect.

[0032] (3) Constructed high stability microstructure: nano calcium carbonate (80-100 nm, purity > 90%) not only promotes the directional growth of early hydration products as a crystal nucleus, but also fills the nano-scale pores, significantly reduces the porosity and refines the pore size distribution; Combined with the double compensation of the expansion agent for plastic shrinkage and drying shrinkage, the volume stability of the material is greatly improved, which fundamentally improves its long-term durability in marine chloride salt, dry-wet cycle and freeze-thaw alternating environment.

[0033] (4) Strong process adaptability, conducive to engineering scale application: The proposed staged low-speed-high-speed stirring process ensures uniform dispersion of nano powder and distribution of mixed fibers without clumps, avoiding the problem of difficult mixing of traditional high-viscosity UHPC; At the same time, all raw materials are stable products on the market, without special storage conditions (such as avoiding the use of modified C-S-H which is prone to deterioration), which significantly reduces the complexity and cost of on-site construction;

[0034] In summary, the present application reduces the porosity of the matrix, promotes the growth of hydration products, and physically blocks cracks and consumes crack propagation energy by optimizing the particle size distribution of raw materials, introducing nano-particle crystal nucleus and polypropylene fiber, to prepare a crack-resistant high-toughness cement-based grouting material. The grouting material has the characteristics of large flow state and high retention, ultra-high strength, high toughness, crack resistance and high durability, etc. The initial fluidity is ≥320 mm, the 2h fluidity is ≥260 mm, the compressive strength after 28d water curing at 20℃ is not less than 150MPa, and the flexural strength is not less than 15MPa. The crack resistance and long-term durability of the grouting material for connecting the floating body of the floating offshore wind tower are ensured, and the high flowability construction requirement of the grouting material is met. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The preparation steps flow chart of the crack-resistant grouting material for connecting the floating body of the floating offshore wind tower according to the present application;

[0036] Figure 2 The optimal theoretical grading of raw material particles in the present application (red curve-calculated grading; blue curve-designed grading). DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application is described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0038] The crack-resistant grouting material for connecting the floating body of the floating offshore wind power tower is composed of the following raw materials by weight: cement 25-40 parts, ultra-fine active filler 1-12 parts, quartz sand 40-55 parts, nano-modified powder 1-5 parts, composite chemical admixture 0.1-1.2 parts, expanding agent 0.1-0.8 parts, and hybrid fiber 0.005-0.1 parts.

[0039] The cement is P·O 52.5 ordinary portland cement, the particle size distribution is D50 5-10 μm, D90 25-35 μm, and the content of calcium silicate mineral phase (C3S, C2S) is not less than 70%. The quartz sand is compounded by four different particle sizes of quartz sand, and the mass percentage of each component is: 0.1-0.3 mm quartz sand: 20-60%; 0.3-0.5 mm quartz sand: 10-50%; 0.5-1.0 mm quartz sand: 0-35%; 1.0-1.5 mm quartz sand: 0-20%. The nano-modified powder is nano calcium carbonate powder with an average particle size of 80-100 nm and a calcium carbonate content of more than 90%.

[0040] The ultra-fine active filler includes silica fume and fly ash beads, and the ultra-fine active filler is a mixture of silica fume and fly ash beads in a volume ratio of (5-10):(0-5); the composite chemical admixture includes water reducing agent, retarder and defoaming agent, and the composite chemical admixture is a mixture of water reducing agent, retarder and defoaming agent in a mass ratio of (75-95):(1-5):(0.5-3). The water reducing agent is a polycarboxylic acid superplasticizer; the retarder is at least one of trisodium citrate and sodium gluconate; the defoaming agent is at least one of polyether and mineral oil; and the expanding agent is at least one of plastic expanding agent and mineral expanding agent.

[0041] The hybrid fiber is selected from any one of the following:

[0042] (a) polyvinyl alcohol composite fiber, the amount of which is 0.005-0.02 parts, which is a mixture of polyvinyl alcohol long fibers with a length of 12 mm and a diameter of 20 μm and polyvinyl alcohol short fibers with a length of 6 mm and a diameter of 20 μm in a volume ratio of (0-5):(5-10); wherein the density of the polyvinyl alcohol long fiber is 1.30 g / cm 3 , the breaking strength is 1633 MPa, and the elastic modulus is 10.4 GPa; the density of the polyvinyl alcohol short fiber is 1.30 g / cm 3 , the breaking strength is 1633 MPa, and the elastic modulus is 10.4 GPa;

[0043] (b) polypropylene composite fibers, in an amount of 0.05-0.1 parts, which are obtained by mixing polypropylene long fibers with a length of 12 mm and an aspect ratio of 345 and polypropylene short fibers with a length of 6 mm and an aspect ratio of 345 at a volume ratio of (0-5):(5-10); wherein the polypropylene long fibers have a density of 0.91 g / cm 3 , a breaking strength of 480 MPa, and an elastic modulus of 5.1 Gpa; and the polypropylene short fibers have a density of 0.91 g / cm 3 , a breaking strength of 480 MPa, and an initial modulus of 5.1 Gpa;

[0044] (c) polyacrylonitrile composite fibers, in an amount of 0.005-0.03 parts, which are obtained by mixing polyacrylonitrile long fibers with a length of 12 mm and a diameter of 25 μm and polyacrylonitrile short fibers with a length of 6 mm and a diameter of 25 μm at a volume ratio of (0-5):(5-10); wherein the polyacrylonitrile long fibers have a density of 1.18 g / cm 3 , a breaking strength of 550 MPa, and an elastic modulus of 8.5 GPa; and the polyacrylonitrile short fibers have a density of 1.18 g / cm 3 , a breaking strength of 550 MPa, and an elastic modulus of 8.5 GPa.

[0045] A preparation method of a crack-resistant grouting material for floating offshore wind power tower cylinder floating body connection, comprising the following steps: S1. weighing each raw material according to the mass ratio and mixing uniformly; S2. wet mixing for 120 s by adding 80% of water; S3. adding the remaining 20% of water and a composite additive and mixing; S4. adding hybrid fibers and mixing; S5. after the mixing is completed, standing and exhausting, and then conveying to a grouting machine for pumping construction.

[0046] As shown in Figure 1 , the premixing time of the solid powder in step S1 is 120 s of low-speed stirring; the wet mixing time in step S2 is 120 s of low-speed stirring; the mixing time in step S3 is 180 s of low-speed mixing; the specific steps of step S4 are first low-speed mixing for 90 s after adding the hybrid fibers, and then high-speed mixing for 120 s; the standing time in step S5 is 2-5 min; and the grouting material is mixed with water at a water-material ratio of 0.072:1-0.085:1.

[0047] In view of the defect that the general cement-based grouting material in the prior art cannot simultaneously ensure high fluidity, ultrahigh strength and high toughness and crack resistance, the cement-based grouting material with large flow state, high mechanical properties, high toughness, crack resistance and durability is prepared through the synergistic effect of material optimization, hydration product regulation and fiber toughening, and the grouting material is particularly suitable for floating offshore wind power tower cylinder floating body connection.

[0048] Referring to Table 1 below, which lists the components of the anti-cracking grouting material for connecting the floating offshore wind tower body of the application and the content thereof.

[0049] Table 1: Components and content (wt%) of the cement-based anti-cracking grouting material

[0050]

[0051] The hybrid fiber is one of polyvinyl alcohol composite fiber, polypropylene composite fiber or polyacrylonitrile composite fiber, and the content of the polyvinyl alcohol composite fiber is 0.005-0.02 parts, which is mixed by polyvinyl alcohol long fiber with a length of 12 mm and a diameter of 20 μm and polyvinyl alcohol short fiber with a length of 6 mm and a diameter of 20 μm at a volume ratio of (0-5):(5-10); the content of the polypropylene composite fiber is 0.05-0.1 parts, which is mixed by polypropylene long fiber with a length of 12 mm and an aspect ratio of 345 and polypropylene short fiber with a length of 6 mm and an aspect ratio of 345 at a volume ratio of (0-5):(5-10); and the content of the polyacrylonitrile composite fiber is 0.005-0.03 parts, which is mixed by polyacrylonitrile long fiber with a length of 12 mm and a diameter of 25 μm and polyacrylonitrile short fiber with a length of 6 mm and a diameter of 25 μm at a volume ratio of (0-5):(5-10).

[0052] Example 1: Preferred component raw materials in the grouting material

[0053] 1. Cement

[0054] The performance indicators of the cement need to meet the quality requirements of ordinary Portland cement with a strength grade of 52.5 specified in the standard GB 175-2023 "General Portland Cement". The mortar strength, stability, setting time and other performance indicators of the cement were tested, and the performance indicator test results are shown in Table 2. The particle size distribution of the cement is shown in Table 3.

[0055] Table 2: Test results of the physical and mechanical performance indicators of the cement

[0056]

[0057] Table 3: Particle size distribution values of the cement

[0058]

[0059] 2. Ultra-fine active filler

[0060] The ultra-fine active filler used in the application is composed of silica fume and fly ash microbeads. The ball bearing effect of the fly ash microbeads can improve the flow performance of the grouting material slurry. The fly ash microbeads and silica fume optimize the particle close packing and composite cementing effect, optimize the microstructure of the cement hydration products, reduce the porosity of the matrix, and improve the mechanical properties and long-term durability of the grouting material.

[0061] 2.1 Silica fume

[0062] The silica fume used in the present application should meet the requirements of the standard GB / T 18736-2017 Mineral Admixtures for High Strength and High Performance Concrete. The main performance indicators of the silica fume are: SiO2 content of 85-97%, average particle size of 0.15-0.20 μm, and specific surface area of 18000-20000 m 2 / kg. The main chemical composition and particle size distribution are shown in Table 4 and Table 5, respectively:

[0063] Table 4: Main chemical composition of silica fume

[0064]

[0065] Table 5: Particle size distribution value of silica fume

[0066]

[0067] 2.2 Fly ash microbeads

[0068] The fly ash microbeads used in the present application should meet the requirements of the standard GB / T 18736-2017 Mineral Admixtures for High Strength and High Performance Concrete. The specific surface area, activity index, water content, loss on ignition and other performance indicators were tested, and the results are shown in Table 6. The main chemical composition and particle size distribution are shown in Table 7 and Table 8, respectively.

[0069] Table 6: Test results of technical indicators of fly ash microbeads

[0070]

[0071] Table 7: Main chemical composition of fly ash microbeads

[0072]

[0073] Table 8: Particle size distribution value of fly ash microbeads

[0074]

[0075] 3. Quartz sand

[0076] The quartz sand shall meet the requirements of standards GB / T 14684-2022 "Sand for construction" and JGJ 52-2006 "Standard for quality and test method of sand and stone for ordinary concrete". Specifically, four different fineness quartz sands are compounded to form a continuous gradation quartz sand fine aggregate. Among them, the quartz sand has an average particle size of 0.1-0.3 mm, 0.3-0.5 mm, 0.5-1.0 mm and 1.0-1.5 mm, and the mass percentage of 0.1-0.3 mm quartz sand is 20-60%; the mass percentage of 0.3-0.5 mm quartz sand is 10-50%; the mass percentage of 0.5-1.0 mm quartz sand is 0-35%; and the mass percentage of 1.0-1.5 mm quartz sand is 0-20%.

[0077] 4. Nano-modified material

[0078] The nano-modified material used in the present application is calcium carbonate powder with a particle size of nanometer scale, and its performance shall meet the requirements of standard GB / T 19590-2023 "Nano calcium carbonate". The average particle size, specific surface area, calcium carbonate content, water content and other performance indicators are tested, and the results are shown in Table 9.

[0079] Table 9: Test results of technical indicators of nano calcium carbonate

[0080]

[0081] 5. Composite chemical admixture

[0082] The composite chemical admixture used in the present application is composed of polycarboxylate superplasticizer, retarder and defoamer. The polycarboxylate superplasticizer disperses the cement particles efficiently by the synergistic effect of "steric hindrance effect" as the main, "electrostatic repulsion" and "hydration film lubrication" as the auxiliary, releases the free water wrapped, and thus realizes the high fluidity and workability of the grouting material at a very low water-cement ratio. The retarder can be adsorbed on the surface of the cement particles to delay the dissolution of the mineral phase, and can also complex Ca 2+ , reduce the concentration of free Ca 2+ in the liquid phase, and delay the crystallization process of the hydration products (such as calcium hydroxide CH and C-S-H gel). The retarder mainly intervenes in the hydration process of cement through these two ways to maintain the fluidity of the grouting material. The defoamer makes the bubbles coalesce and break by reducing the surface tension of the bubble liquid film and destroying its self-repairing ability, so as to achieve the purpose of eliminating the bubbles in the grouting material slurry.

[0083] 5.1 Polycarboxylate superplasticizer

[0084] The polycarboxylate superplasticizer used in the present application shall meet the requirements of standard GB 8076-2008 "Concrete admixtures". The solid content, density, total alkali content and other performance indicators are tested, and the results are shown in Table 10.

[0085] Table 10: Technical index test results of polycarboxylic acid superplasticizer

[0086] 5.2 Retarder

[0087] The retarder used in the present application meets the requirements of the standard GB 8076-2008 "Concrete Admixtures". The retarder used in the present application is sodium gluconate. The molecular formula of sodium gluconate is C6H 11 NaO7, and the molecular weight is 218.14 g / mol.

[0088] 5.3 Defoamer

[0089] The defoamer used in the present application is polyether type, and the performance index meets the requirements of the standard GB 8076-2008 "Concrete Admixtures". The solid content, density, total alkali content and other performance indexes are tested, and the results are shown in Table 11.

[0090] Table 11: Technical index test results of defoamer

[0091]

[0092] 6. Expansive agent

[0093] The expansive agent used in the present application is a mineral type expansive agent, and the performance index meets the requirements of the standard GB 23439-2017 "Concrete Expansive Agent". The specific performance index of the expansive agent is shown in Table 12.

[0094] Table 12: Technical index test results of expansive agent

[0095]

[0096] 7. Hybrid fiber

[0097] The hybrid fiber in the present application uses polyvinyl alcohol composite fiber, polypropylene composite fiber or polyacrylonitrile composite fiber, which all contain short fibers and long fibers. The short fibers are distributed in three dimensions in the grouting material matrix, forming a dense support network that can effectively inhibit the plastic shrinkage of the grouting material and the generation and expansion of microcracks in the early stage of hardening. The long fibers cross between the cracks and significantly improve the toughness and crack resistance of the grouting material by consuming energy when pulled out. The long and short fiber composite forms a multi-scale and multi-level fiber system from the micro to the macro, achieving a full-process cooperative inhibition of crack generation, development and penetration, thereby comprehensively improving the toughness and crack resistance of the grouting material.

[0098] The performance indicators of the polyvinyl alcohol long fibers, polyvinyl alcohol short fibers, polypropylene long fibers, polypropylene short fibers, polyacrylonitrile long fibers and polyacrylonitrile short fibers used in the present application meet the requirements of the composite standard GB / T 21120-2018 "Synthetic fibers for cement concrete and mortar". The performance indicators such as length, diameter, breaking strength and elastic modulus are tested, and the results are shown in Tables 13-18.

[0099] Table 13: Test results of technical indicators of polyvinyl alcohol long fibers

[0100]

[0101] Table 14: Test results of technical indicators of polyvinyl alcohol short fibers

[0102]

[0103] Table 15: Test results of technical indicators of polypropylene long fibers

[0104]

[0105] Table 16: Test results of technical indicators of polypropylene short fibers

[0106]

[0107] Table 17: Test results of technical indicators of polyacrylonitrile long fibers

[0108]

[0109] Table 18: Test results of technical indicators of polyacrylonitrile short fibers

[0110]

[0111] 8. Water

[0112] The water used in the present application is mixing water that meets the standard JGJ63-2006 "Water standard for concrete".

[0113] Example 2: Optimization design and test verification of raw material particle size distribution

[0114] The present application uses cement, silica fume, fly ash microbeads, quartz sand and other 7 kinds of powders with different particle sizes. Based on the test results of the particle size distribution of solid raw materials, the particle size distribution "closest packing" theoretical curve of the raw material mixture is calculated by the Modified Andreasen and Andersen (MAA) model formula, so as to minimize the porosity and ensure the optimal mechanical properties of the grouting material. Figure 2The optimal grading result is based on the particle size calculation of the above-mentioned preferred solid raw material. Table 19 lists the composition of the grouting material based on the optimal grading calculation and the composition of three groups of grouting materials based on the conventional design grading, and Table 20 is the comparison of the working performance and mechanical properties of four different compositions of grouting materials. The fluidity is tested according to GB / T 50448-2015 “Technical Specification for Application of Cement-based Grouting Materials”; the compressive strength test refers to JTJ 270 “Concrete Test Specification for Water Transport Engineering”, and the cube test block with a side length of 100mm is not multiplied by the conversion coefficient; the chloride ion diffusion coefficient test refers to GB / T50082-2009 “Standard Test Methods for Long-term Performance and Durability of Ordinary Concrete”.

[0115] Table 19: Raw material composition of grouting material based on optimal grading and three conventional design gradings (wt%)

[0116]

[0117] Table 20: Comparison of working performance and mechanical properties of four different compositions of grouting materials (wt%)

[0118]

[0119] According to the test results in Table 20, grouting material 4 simultaneously optimizes the particle grading of cementitious materials (nano and micron scale particles) and fine aggregates (millimeter scale particles), and its working performance, mechanical properties and durability performance are significantly better than the other three groups of grouting materials with conventional design gradings.

[0120] Example 3: Toughening and crack resistance design and test verification of grouting material

[0121] The application uses nano calcium carbonate particles as crystal nuclei to induce the growth of hydration products, and inhibits the internal crack propagation of grouting material by physical crack resistance and consumption of crack propagation energy, thereby realizing direct toughening and crack resistance function. The application uses polyvinyl alcohol composite fibers, polypropylene composite fibers or polyacrylonitrile composite fibers. The long and short fiber composite realizes toughening and crack resistance through fine division and cooperation: the short fibers are densely distributed in the matrix, which can effectively inhibit the initiation and early expansion of microcracks and improve the uniformity of the matrix; and the long fibers span the potential macroscopic cracks and provide strong bridging and load transfer capacity in the late stage of crack propagation. This combination builds a continuous reinforcement network from micro to macro in the material, so that the material can effectively dissipate energy in all stages of crack development. Finally, the two complement each other, significantly improve the overall toughness, post-cracking load capacity and crack resistance of the material, avoid the adverse effects of single long fiber on workability or the limited toughening effect of single short fiber, and realize the optimization of comprehensive performance.

[0122] To verify the effect of nano calcium carbonate and composite fiber on the toughening and crack resistance of grouting material, three kinds of grouting materials (see Table 21) are designed on the basis of the four components of the above grouting material, respectively adding nano calcium carbonate, hybrid fiber and both of them. Tables 22-24 are the comparison of working performance and mechanical properties of the three kinds of grouting materials with different toughening and crack resistance materials under the use of three kinds of hybrid fibers.

[0123] Table 21: Composition of grouting material with single and complex toughening and crack resistance materials (wt%)

[0124]

[0125] It should be noted that in grouting material 4 and grouting material 5, no matter which one of polyvinyl alcohol composite fiber, polypropylene composite fiber or polyacrylonitrile composite fiber is used, the composition of 6mm and 12mm is 0wt%. In grouting material 6 and grouting material 7, if polyvinyl alcohol composite fiber is used, the composition of short fiber (6mm) and long fiber (12mm) is 0.01wt%; if polypropylene composite fiber is used, the composition of short fiber (6mm) and long fiber (12mm) is 0.05wt%; if polyacrylonitrile composite fiber is used, the composition of short fiber (6mm) and long fiber (12mm) is 0.015wt%.

[0126] Table 22: Comparison of working performance and mechanical properties of four different compositions of grouting material when polyvinyl alcohol composite fiber is used (wt%)

[0127]

[0128] Table 23: Comparison of working performance and mechanical properties of four different compositions of grouting material when polypropylene composite fiber is used (wt%)

[0129]

[0130] Table 24: Comparison of working performance and mechanical properties of four different compositions of grouting material when polyacrylonitrile composite fiber is used (wt%)

[0131]

[0132] According to the test results in Tables 22-24, adding nano calcium carbonate (grouting material 5) or fiber (grouting material 6) will reduce the fluidity of the grouting material, but will significantly improve the bending strength of the grouting material. By adding nano calcium carbonate and hybrid fiber (grouting material 7) at the same time, the compressive and bending strength of the grouting material can be greatly improved on the basis of maintaining the fluidity of the grouting material.

[0133] It can be seen from the test results of examples 2 and 3 that, according to the application, through optimization of particle gradation, regulation of hydration products and fiber toughening, the performance of grouting material can be improved, such as high fluidity, super high strength, high durability and high toughness and crack resistance, and the comprehensive performance of grouting material can be greatly improved.

[0134] Example 4: Preparation of grouting material 8

[0135] A polyvinyl alcohol fiber-based anti-cracking grouting material 8 for floating offshore wind power tower floating body connection was prepared, which was composed of the following mass parts of dry materials:

[0136] P·O 52.5 Portland cement 39 parts,

[0137] Superfine active filler 8 parts (containing silica fume 58%, fly ash microbeads 42%),

[0138] Quartz sand 52 parts (containing 0.1-0.3 mm quartz sand 40%, 0.3-0.5 mm quartz sand 30%, 0.5-1.0 mm quartz sand 20% and 1.0-1.5 mm quartz sand 10%),

[0139] Nano calcium carbonate 0.8 parts,

[0140] Composite chemical admixture 1.4 parts (containing polycarboxylic acid superplasticizer 97.7%, retarder 2.0% and defoamer 0.3%),

[0141] Expanding agent 0.8 parts,

[0142] Polyvinyl alcohol composite fiber 0.02 parts (containing polyvinyl alcohol short fiber 50% and polyvinyl alcohol long fiber 50%),

[0143] Water material ratio 0.075.

[0144] It was detected that the grouting material had good working performance, 0% bleeding rate, 300 mm initial fluidity, 280 mm fluidity at 120 min, 7d flexural strength 15.8 MPa, 28d flexural strength 25.9 MPa, 7d compressive strength 135 MPa and 28d compressive strength 161 MPa.

[0145] Alternatively, a polypropylene fiber-based anti-cracking grout 8 for floating offshore wind power tower floating body connection is prepared, which is the same as the above except that polypropylene composite fibers are used instead of polyvinyl alcohol composite fibers, and 0.1 parts of polypropylene composite fibers (containing 50% polypropylene staple fibers and 50% polypropylene long fibers) are used. The test shows that the grout has good working performance, a bleeding rate of 0%, an initial fluidity of 300 mm, a 120 min fluidity of 280 mm, a 7d flexural strength of 15.5 MPa, a 28d flexural strength of 24.9 MPa, a 7d compressive strength of 137 MPa, and a 28d compressive strength of 165 MPa.

[0146] Alternatively, a polyacrylonitrile fiber-based anti-cracking grout 8 for floating offshore wind power tower floating body connection is prepared, which is the same as the above except that polyacrylonitrile composite fibers are used instead of polyvinyl alcohol composite fibers, and 0.03 parts of polyacrylonitrile composite fibers (containing 50% polyacrylonitrile staple fibers and 50% polyacrylonitrile long fibers) are used. The test shows that the grout has good working performance, a bleeding rate of 0%, an initial fluidity of 300 mm, a 120 min fluidity of 285 mm, a 7d flexural strength of 15.5 MPa, a 28d flexural strength of 25.1 MPa, a 7d compressive strength of 134 MPa, and a 28d compressive strength of 159 MPa.

[0147] Example 5: Preparation of grout 9

[0148] A polyvinyl alcohol fiber-based anti-cracking grout 9 for floating offshore wind power tower floating body connection is prepared, which is composed of the following dry materials in mass parts:

[0149] P·O 52.5 Portland cement 35 parts,

[0150] Superfine active filler 12 parts (containing silica fume 58%, fly ash microbeads 42%),

[0151] Quartz sand 52 parts (containing 0.1-0.3 mm quartz sand 40%, 0.3-0.5 mm quartz sand 30%, 0.5-1.0 mm quartz sand 20%, 1.0-1.5 mm quartz sand 10%),

[0152] Nano calcium carbonate 1 part,

[0153] Composite chemical admixture 1.2 parts (containing polycarboxylic acid superplasticizer 96.7%, retarder 3.0%, defoamer 0.3%),

[0154] Expanding agent 0.8 parts,

[0155] Polyvinyl alcohol composite fibers 0.02 parts (containing 50% polyvinyl alcohol staple fibers and 50% polyvinyl alcohol long fibers),

[0156] Water material ratio 0.08.

[0157] The grouting material has good working performance, a bleeding rate of 0%, an initial fluidity of 340 mm, a 120 min fluidity of 310 mm, a 7d flexural strength of 10.6 MPa, a 28d flexural strength of 18.2 MPa, a 7d compressive strength of 119 MPa, and a 28d compressive strength of 150 MPa.

[0158] Alternatively, a polypropylene fiber-based anti-cracking grouting material 9 for connecting a floating body of a floating offshore wind power tower is prepared, which has the same conditions as above, wherein polypropylene composite fibers are used to replace polyvinyl alcohol composite fibers, and 0.1 parts of polypropylene composite fibers (containing 50% of polypropylene staple fibers and 50% of polypropylene long fibers) are used. The grouting material has good working performance, a bleeding rate of 0%, an initial fluidity of 340 mm, a 120 min fluidity of 310 mm, a 7d flexural strength of 10.5 MPa, a 28d flexural strength of 18.9 MPa, a 7d compressive strength of 121 MPa, and a 28d compressive strength of 154 MPa.

[0159] Further alternatively, a polyacrylonitrile fiber-based anti-cracking grouting material 9 for connecting a floating body of a floating offshore wind power tower is prepared, which has the same conditions as above, wherein polyacrylonitrile composite fibers are used to replace polyvinyl alcohol composite fibers, and 0.03 parts of polyacrylonitrile composite fibers (containing 50% of polyacrylonitrile staple fibers and 50% of polyacrylonitrile long fibers) are used. The grouting material has good working performance, a bleeding rate of 0%, an initial fluidity of 330 mm, a 120 min fluidity of 300 mm, a 7d flexural strength of 10.2 MPa, a 28d flexural strength of 17.8 MPa, a 7d compressive strength of 119 MPa, and a 28d compressive strength of 148 MPa.

[0160] Example 6: Preparation of grouting material 10

[0161] A polyvinyl alcohol fiber-based anti-cracking grouting material 10 for connecting a floating body of a floating offshore wind power tower is prepared, which is composed of dry materials in the following mass parts:

[0162] P·O 52.5 Portland cement 35 parts,

[0163] Superfine active filler 12 parts (containing silica fume 42% and fly ash microbeads 58%),

[0164] Quartz sand 52 parts (containing 0.1-0.3 mm quartz sand 40%, 0.3-0.5 mm quartz sand 30%, 0.5-1.0 mm quartz sand 20%, and 1.0-1.5 mm quartz sand 10%),

[0165] Nano calcium carbonate 1 part,

[0166] Composite chemical admixture 1.2 parts (containing polycarboxylic acid superplasticizer 96.7%, retarder 3.0%, defoaming agent 0.3%),

[0167] Expanding agent 0.8 parts,

[0168] Polyvinyl alcohol composite fiber 0.02 parts (containing polyvinyl alcohol short fiber 30%, polyvinyl alcohol long fiber 70%),

[0169] Water material ratio 0.081.

[0170] It is detected that the grouting material has good working performance, water bleeding rate 0%, initial fluidity 300 mm, 120 min fluidity 290 mm, 7d flexural strength 12.1 MPa, 28d flexural strength 18.6 MPa, 7d compressive strength 115 MPa, 28d compressive strength 138 MPa.

[0171] Alternatively, a polypropylene fiber-based anti-cracking grouting material 10 for connecting floating bodies of floating offshore wind power tower is prepared, and other conditions are the same as above, wherein polypropylene composite fiber is used to replace polyvinyl alcohol composite fiber, and polypropylene composite fiber 0.1 parts (containing polypropylene short fiber 30%, polypropylene long fiber 70%) is used. It is detected that the grouting material has good working performance, water bleeding rate 0%, initial fluidity 300 mm, 120 min fluidity 290 mm, 7d flexural strength 12.5 MPa, 28d flexural strength 19.6 MPa, 7d compressive strength 116 MPa, 28d compressive strength 152 MPa.

[0172] Further alternatively, a polyacrylonitrile fiber-based anti-cracking grouting material 10 for connecting floating bodies of floating offshore wind power tower is prepared, and other conditions are the same as above, wherein polyacrylonitrile composite fiber is used to replace polyvinyl alcohol composite fiber, and polyacrylonitrile composite fiber 0.03 parts (containing polyacrylonitrile short fiber 30%, polyacrylonitrile long fiber 70%) is used. It is detected that the grouting material has good working performance, water bleeding rate 0%, initial fluidity 305 mm, 120 min fluidity 295 mm, 7d flexural strength 12.0 MPa, 28d flexural strength 18.1 MPa, 7d compressive strength 117 MPa, 28d compressive strength 135 MPa.

[0173] Example 7: Preparation of grouting material 11

[0174] A polyvinyl alcohol fiber-based anti-cracking grouting material 11 for connecting floating bodies of floating offshore wind power tower is prepared, which is composed of dry materials in the following mass parts:

[0175] P·O 52.5 Portland cement 37 parts,

[0176] Superfine active filler 12 parts (containing silica fume 42%, fly ash microbead 58%),

[0177] Quartz sand 50 parts (including 0.1-0.3 mm quartz sand 40%, 0.3-0.5 mm quartz sand 30%, 0.5-1.0 mm quartz sand 20 parts, 1.0-1.5 mm quartz sand 10%),

[0178] Nano calcium carbonate 1.1 parts,

[0179] Composite chemical admixture 1.3 parts (including polycarboxylic acid superplasticizer 96.7%, retarder 3.0%, defoaming agent 0.3%),

[0180] Expanding agent 0.8 parts,

[0181] Polyvinyl alcohol composite fiber 0.02 parts (including polyvinyl alcohol short fiber 70%, polyvinyl alcohol long fiber 30%),

[0182] Water material ratio 0.080.

[0183] It is detected that the grouting material has good working performance, the bleeding rate is 0%, the initial fluidity is 330 mm, the 120 min fluidity is 300 mm, the 7d flexural strength is 11.1 MPa, the 28d flexural strength is 17.6 MPa, the 7d compressive strength is 122 MPa, and the 28d compressive strength is 143 MPa.

[0184] Alternatively, a polypropylene fiber-based anti-cracking grouting material 11 for connecting floating bodies of a floating offshore wind power tower is prepared, and other conditions are the same as above, wherein polypropylene composite fiber is used to replace polyvinyl alcohol composite fiber, and polypropylene composite fiber 0.1 parts (including polypropylene short fiber 70%, polypropylene long fiber 30%) is used. It is detected that the grouting material has good working performance, the bleeding rate is 0%, the initial fluidity is 330 mm, the 120 min fluidity is 300 mm, the 7d flexural strength is 11.5 MPa, the 28d flexural strength is 18.6 MPa, the 7d compressive strength is 125 MPa, and the 28d compressive strength is 147 MPa.

[0185] Further alternatively, a polyacrylonitrile fiber-based anti-cracking grouting material 11 for connecting floating bodies of a floating offshore wind power tower is prepared, and other conditions are the same as above, wherein polyacrylonitrile composite fiber is used to replace polyvinyl alcohol composite fiber, and polyacrylonitrile composite fiber 0.03 parts (including polyacrylonitrile short fiber 70%, polyacrylonitrile long fiber 30%) is used. It is detected that the grouting material has good working performance, the bleeding rate is 0%, the initial fluidity is 330 mm, the 120 min fluidity is 305 mm, the 7d flexural strength is 10.9 MPa, the 28d flexural strength is 17.1 MPa, the 7d compressive strength is 120 MPa, and the 28d compressive strength is 141 MPa.

[0186] Example 8: Preparation of grouting material 12

[0187] A polyvinyl alcohol fiber-based anti-cracking grout 12 for floating offshore wind turbine tower floating body connection is prepared, which is composed of the following dry materials in mass parts:

[0188] P·O 52.5 Portland cement 39 parts,

[0189] Superfine active filler 10 parts (containing silica fume 42%, fly ash microbead 58%),

[0190] Quartz sand 50 parts (containing 0.1-0.3 mm quartz sand 40%, 0.3-0.5 mm quartz sand 30%, 0.5-1.0 mm quartz sand 20% parts, 1.0-1.5 mm quartz sand 10%),

[0191] Nano calcium carbonate 1.2 parts,

[0192] Composite chemical admixture 1.4 parts (containing polycarboxylic acid superplasticizer 96.7%, retarder 3.0%, defoaming agent 0.3%),

[0193] Expanding agent 0.8 parts,

[0194] Polyvinyl alcohol composite fiber 0.02 parts (containing polyvinyl alcohol short fiber 70%, polyvinyl alcohol long fiber 30%),

[0195] Water material ratio 0.075.

[0196] It is detected that the grout has good workability, water bleeding rate 0%, initial fluidity 320 mm, 120 min fluidity 290 mm, 7d flexural strength 14.9 MPa, 28d flexural strength 23.9 MPa, 7d compressive strength 136 MPa, 28d compressive strength 165 MPa.

[0197] Alternatively, a polypropylene fiber-based anti-cracking grout 12 for floating offshore wind turbine tower floating body connection is prepared, which is the same as the above except that polypropylene composite fiber is used instead of polyvinyl alcohol composite fiber, and polypropylene composite fiber 0.1 parts (containing polypropylene short fiber 70%, polypropylene long fiber 30%) is used. It is detected that the grout has good workability, water bleeding rate 0%, initial fluidity 320 mm, 120 min fluidity 290 mm, 7d flexural strength 14.5 MPa, 28d flexural strength 22.9 MPa, 7d compressive strength 132 MPa, 28d compressive strength 160 MPa.

[0198] Alternatively, a polyacrylonitrile fiber-based anti-cracking grouting material 12 for floating offshore wind power tower floating body connection is prepared, and other conditions are the same as above, wherein polyacrylonitrile composite fibers are used to replace polyvinyl alcohol composite fibers, and 0.03 parts of polyacrylonitrile composite fibers (including 70% of polyacrylonitrile staple fibers and 30% of polyacrylonitrile long fibers) are used. It is detected that the grouting material has good working performance, the bleeding rate is 0%, the initial fluidity is 315 mm, the 120 min fluidity is 295 mm, the 7d flexural strength is 14.2 MPa, the 28d flexural strength is 23.5 MPa, the 7d compressive strength is 138 MPa, and the 28d compressive strength is 162 MPa.

[0199] In summary, the anti-cracking grouting material for floating offshore wind power tower floating body connection and the preparation method thereof provided by the present application can meet the index requirements of deep sea offshore wind power tower floating body connection grouting (grouting material initial fluidity > 290 mm, 28d compressive strength > 80-140 MPa, etc.) through working performance, mechanical properties and durability tests, and has the characteristics of large flow state and high retention, ultra-high strength, high toughness, anti-cracking and high durability. Therefore, the present application effectively overcomes the shortcomings of the prior art that strength and toughness cannot be simultaneously improved, and has high industrial utilization value.

[0200] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A crack-resistant grouting material for connecting the floating body of a floating offshore wind turbine tower, characterized in that, Composed of the following raw materials in parts by weight: 25-40 parts cement 1-12 parts of ultrafine active filler 40-55 parts of quartz sand 1-5 parts of nano-modified powder 0.1-1.2 parts of compound chemical admixture, 0.1-0.8 parts of expanding agent, Mixed fibers: 0.005-0.1 parts; The ultrafine active filler includes silica fume and fly ash microspheres, and the ultrafine active filler is a mixture of silica fume and fly ash microspheres in a volume ratio of (5-10):(0-5). The composite chemical admixture includes a water-reducing agent, a retarder, and a defoamer, wherein the composite chemical admixture is a mixture of the water-reducing agent, the retarder, and the defoamer in a mass ratio of (75-95):(1-5):(0.5-3); The hybrid fibers are selected from any of the following: (a) Polyvinyl alcohol composite fiber, which is used in an amount of 0.005-0.02 parts, is made by mixing polyvinyl alcohol long fibers with a length of 12 mm and a diameter of 20 μm with polyvinyl alcohol short fibers with a length of 6 mm and a diameter of 20 μm in a volume ratio of (0-5):(5-10); (b) Polypropylene composite fiber, which is used in an amount of 0.05-0.1 parts, is made by mixing polypropylene long fibers with a length of 12 mm and an aspect ratio of 345 with polypropylene short fibers with a length of 6 mm and an aspect ratio of 345 in a volume ratio of (0-5):(5-10). (c) Polyacrylonitrile composite fiber, which is used in an amount of 0.005-0.03 parts, is made by mixing polyacrylonitrile long fibers with a length of 12 mm and a diameter of 25 μm with polyacrylonitrile short fibers with a length of 6 mm and a diameter of 25 μm in a volume ratio of (0-5):(5-10).

2. The anti-crack grouting material for connecting the floating body of a floating offshore wind turbine tower as described in claim 1, characterized in that: The cement is P·O 52.5 grade ordinary Portland cement, with a particle size distribution of D50 5-10μm, D90 25-35μm, and the content of calcium silicate mineral phase (C3S, C2S) is not less than 70%.

3. The anti-crack grouting material for connecting the floating body of a floating offshore wind turbine tower as described in claim 1, characterized in that: The quartz sand is a blend of four different particle sizes of quartz sand, with the following mass percentages: 0.1-0.3mm quartz sand: 20-60%; 0.3-0.5mm quartz sand: 10-50%; 0.5-1.0mm quartz sand: 0-35%; 1.0-1.5mm quartz sand: 0-20%.

4. The anti-crack grouting material for connecting the floating body of a floating offshore wind turbine tower as described in claim 1, characterized in that: The nano-modified powder is a nano-calcium carbonate powder with an average particle size of 80-100 nm and a calcium carbonate content of more than 90%.

5. The anti-crack grouting material for connecting the floating body of a floating offshore wind turbine tower as described in claim 1, characterized in that: The water-reducing agent is a polycarboxylate superplasticizer; the retarder is at least one of trisodium citrate and sodium gluconate; and the defoamer is at least one of polyether and mineral oil.

6. The anti-crack grouting material for connecting the floating body of a floating offshore wind turbine tower as described in claim 1, characterized in that: The expanding agent is at least one of plastic expanding agents and mineral expanding agents.

7. A method for preparing a crack-resistant grouting material for connecting the floating body of a floating offshore wind turbine tower as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Weigh each raw material according to the mass ratio and mix them evenly; S2. Add 80% water and wet mix for 120 seconds; S3. Add the remaining 20% ​​of water and compound additives and mix. S4. Add mixed fibers and mix; S5. After mixing, allow the mixture to stand and release air, then transport it to the grouting machine for pumping construction.

8. The method for preparing a crack-resistant grout for connecting the floating body of a floating offshore wind turbine tower as described in claim 7, characterized in that: The premixing time of the solid powder in step S1 is 120s at low speed; the wet mixing time in step S2 is 120s at low speed; the mixing time in step S3 is 180s at low speed; the specific steps of step S4 are to add mixed fibers, mix at low speed for 90s, and then mix at high speed for 120s; the standing time in step S5 is 2-5min.

9. The method for preparing a crack-resistant grouting material for connecting the floating body of a floating offshore wind turbine tower as described in claim 7, characterized in that: The grouting material and water are mixed at a water-material ratio of 0.072:1 to 0.085:1.

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