Ultra-high performance grouting material for offshore wind power jacket and preparation method and application thereof

Abstract

The present application relates to the technical field of cement-based building materials, and particularly relates to a super-high-performance grouting material for offshore wind power guide pipe frames, a preparation method and application thereof, which adopts cement, fine aggregate, corundum micro powder, ultra-fine mineral admixture, reinforcing agent, reinforcing accelerator, expanding agent, water reducing agent, defoaming agent and steel fiber as raw materials, and uses the compatibility of the ultra-fine mineral admixture, the reinforcing agent and the reinforcing accelerator to synergistically prepare the grouting material for offshore wind power guide pipe frames with high compressive strength, good tensile strength and elastic limit tensile strength.

Description

Technical Field

[0001] This invention relates to the field of cement-based building materials technology, and in particular to an ultra-high performance grouting material for offshore wind turbine jackets, its preparation method, and its application. Background Technology

[0002] With the increasing demand for green energy, wind power has attracted much attention due to its sustainability, leading to a surge in offshore wind power construction in recent years. However, the complex offshore environment makes the construction of wind turbine foundations increasingly challenging.

[0003] Offshore wind turbines are developing towards larger sizes and deeper offshore spaces. Currently, offshore wind power mainly uses jacket foundation structures, and the reliability of the grouting connection section determines the safety and reliability of the entire wind turbine foundation. Grouting materials used for offshore wind turbine jacket foundations need to have properties such as high flowability, ultra-high strength, high elastic modulus, fatigue resistance, and high durability, with particularly outstanding performance in compressive strength and uniaxial tensile strength.

[0004] Currently, foreign products, represented by BASF's 9500, account for a large proportion of offshore wind power. Domestic companies such as CNBM Zhongyan Technology (CN116693262A, CN118307272A), CCCC Third Harbor Engineering Co., Ltd. (CN104003681A), and Subote (CN113968698A) have the development and production capabilities and have applied for patents. At present, the compressive strength of the products of the above-mentioned companies is between 120-160MPa under similar water-to-material ratio conditions. However, there is very little structural verification data, such as tensile strength and elastic limit tensile strength, which are important structural performance data for the stability of large-scale offshore wind turbines. These data play an important supporting role in the development of large-scale, deep-sea jacket foundations. Steel fiber is a commonly used toughening fiber, but it is difficult to disperse in cement-based materials and is prone to settling. The application of grouting materials in offshore wind power jacket foundations is relatively blank. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an ultra-high performance grouting material for offshore wind turbine jacket structures. Specifically, this invention uses cement, fine aggregate, corundum powder, ultrafine mineral admixtures, reinforcing agents, reinforcing accelerators, expanding agents, water-reducing agents, defoamers, and steel fibers as raw materials. By utilizing the compatibility of ultrafine mineral admixtures, reinforcing agents, and reinforcing accelerators, and in conjunction with steel fibers, a grouting material for offshore wind turbine jacket structures with high compressive strength, good tensile strength, and elastic limit tensile strength is prepared.

[0006] Specifically, the ultra-high performance grouting material for offshore wind power jackets of the present invention is composed of the following raw materials in parts by weight: 20-30 parts cement, 30-45 parts fine aggregate, 1-10 parts corundum powder, 5-15 parts ultrafine mineral admixture, 1-10 parts reinforcing agent, 0.1-2 parts reinforcing accelerator, 0.1-1 part expanding agent, 0.1-0.3 parts water reducing agent, 0.01-0.1 parts defoamer, and 0.1-5 parts steel fiber.

[0007] Preferably, the cement is P•W52.5 cement, wherein the C3S mineral content is ≥70%. To meet performance requirements, the present invention preferably uses white silicate cement, which has a higher C3S mineral content than ordinary silicate cement and has better performance.

[0008] Preferably, the fine aggregate is at least one of basalt sand and quartz sand.

[0009] Preferably, the fine aggregate is composed of a continuous gradation within four particle size ranges: 10-20 mesh, 20-40 mesh, 40-70 mesh, and 70-120 mesh.

[0010] Preferably, the corundum micro powder has a particle size of 200-300 mesh.

[0011] Preferably, the ultrafine mineral admixture is a mixture of metakaolin, rice husk ash, tuff, and mineral powder in a mass ratio of (1.0-3.2):(0.4-1.5):(1.7-3.1):(2.2-5.5), which is then ground with the addition of a grinding aid. More preferably, the grinding aid is a mixture of triisopropanolamine, polyethylene glycol, and diethanolisopropanolamine in a mass ratio of (0.1-0.2):(0.2-0.3):(0.1-0.2).

[0012] Ultrafine mineral admixtures exhibit a good pozzolanic effect and can directly impact the workability of grouting materials. This invention adds fine aggregate and corundum powder as aggregates and fillers, and steel fibers as toughening materials. To ensure the homogeneity of steel fibers and the workability of the grout, this invention uses metakaolin, rice husk ash, tuff, and mineral powder as ultrafine mineral admixtures. Metakaolin and rice husk ash have high activity, mineral powder can supplement later strength, and metakaolin and tuff can promote the dispersion of steel fibers in the grout. The combination of ultrafine admixtures with fine aggregate, corundum powder, and steel fibers can improve the construction effect and mechanical properties of the grouting material.

[0013] Preferably, the reinforcing agent preparation process involves uniformly mixing CaO, Al2O3, and SiO2 at a mass ratio of 1:(0.5-0.8):(0.1-0.2), pressing the mixture into sheets, calcining it to the liquid phase, holding it at a certain temperature, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum at a mass ratio of (6.5-7):(3-4) and subjected to ultrafine grinding to obtain the final product. More preferably, the calcination temperature is 2000-2100℃, the holding time is 10-20 min, rapid cooling is achieved using water jet quenching, anhydrite is selected as the gypsum, and ultrafine grinding is performed using an air jet mill to achieve a specific surface area of ​​900-1000 cm². 2 / g.

[0014] Preferably, the enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanofibers and triethanolamine in a mass ratio of (0.5-5):(0.01-1):1.

[0015] The reinforcing agent of this invention has high activity, and the reinforcing accelerator can further promote the hydration of the reinforcing agent. However, the accelerated hydration rate in the early stage can also easily form micropores between the hydration products ettringite, leading to a reduction in the strength of the grout in the later stage. The addition of calcium sulfate whiskers in the reinforcing accelerator can fill the pores of the hydration products, especially forming overlaps for needle-shaped ettringite. Small-sized CSH crystal nuclei can promote the dispersion of calcium sulfate nano whiskers. Triethanolamine promotes the formation of nucleation sites for CSH crystal nuclei and calcium sulfate nano whiskers, thereby increasing the degree of hydration of C3S minerals in white cement, thus promoting the early strength development and later strength supplementation of the grout.

[0016] Preferably, the expanding agent is at least one of a plastic expanding agent and a mineral expanding agent. More preferably, the expanding agent is a composite of a plastic expanding agent and a mineral expanding agent, with a mass ratio of (1-2):100. Even more preferably, the plastic expanding agent is azodicarbonamide, and the mineral expanding agent is HP-CSA expanding agent.

[0017] Preferably, the defoamer is at least one of an organosilicon defoamer and a fatty acid defoamer. More preferably, the defoamer is a mixture of an organosilicon defoamer and a fatty acid defoamer in a mass ratio of 3.5-6.5.

[0018] Preferably, the water-reducing agent is a polycarboxylate superplasticizer. More preferably, the water-reducing agent is an early-strength polycarboxylate superplasticizer.

[0019] Preferably, the steel fiber is a straight copper-plated steel fiber with a length of 3 mm and a diameter of 0.2-0.2 mm.

[0020] This invention also relates to a method for preparing the aforementioned ultra-high performance grouting material for offshore wind turbine jackets, specifically comprising the following steps:

[0021] 1) Weigh each ingredient according to its weight.

[0022] 2) Mix all the ingredients evenly to obtain the final product.

[0023] This invention also relates to the application of the above-mentioned grouting material in the construction of offshore wind turbine jacket foundations. More preferably, this invention relates to the application of the above-mentioned grouting material in the construction of large-scale offshore wind turbine units and deep-sea jacket foundations.

[0024] Preferably, the application involves directly mixing the grouting material with water until uniform. More preferably, the water-to-material ratio during application is (0.08-0.09):1.

[0025] This invention has the following technical advantages:

[0026] 1. This invention improves the activity of cementitious materials, enhances the workability of the paste, and promotes the uniform dispersion of steel fibers by combining ultrafine mineral admixtures, reinforcing agents, reinforcing accelerators, and cement.

[0027] 2. The reinforcing accelerator of this invention promotes the effect of the reinforcing agent, and works synergistically with steel fibers to improve the crack resistance of the grouting material.

[0028] 3. The grouting material of this invention has superior mechanical properties and only requires the addition of water for mixing during application, making it convenient to use. Detailed Implementation

[0029] To characterize the technical effects of this invention, grouting material was prepared and its initial fluidity, compressive strength, tensile strength, and elastic limit tensile strength were tested. During the experiment, P•W52.5 cement was selected, the fine aggregate consisted of continuously graded quartz sand with four particle sizes: 10-20 mesh, 20-40 mesh, 40-70 mesh, and 70-120 mesh, the corundum powder had a particle size of 200-300 mesh, the expanding agent was a composite of azodicarbonamide and HP-CSA expanding agent in a mass ratio of 1:100, the defoamer was an organosilicon defoamer, the water-reducing agent was an early-strength polycarboxylate water-reducing agent with a water reduction rate of 25%, the steel fiber was a straight copper-plated steel fiber with a length of 3 mm and a diameter of 0.2-0.2 mm, and the mass ratio of grouting material to mixing water was 1:0.08.

[0030] Example 1

[0031] The grouting material is composed of the following raw materials in parts by weight: 30 parts cement, 40 parts fine aggregate, 10 parts corundum powder, 12 parts ultrafine mineral admixture, 8 parts reinforcing agent, 1.5 parts reinforcing accelerator, 0.8 parts expanding agent, 0.3 parts water-reducing agent, 0.04 parts defoamer, and 2 parts steel fiber. The fine mineral admixture is a mixture of metakaolin, rice husk ash, tuff, and mineral powder in a mass ratio of 3:1:2:5. After uniform mixing and adding a grinding aid, the mixture is ground to obtain the final product.

[0032] The reinforcing agent is prepared by uniformly mixing CaO, Al2O3, and SiO2 in a mass ratio of 1:0.7:0.1, pressing the mixture into sheets, calcining it at 2100℃ until it reaches the liquid phase, holding it at that temperature for 15 minutes, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum in a mass ratio of 7:3 and subjected to ultrafine grinding to obtain the final product.

[0033] The enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanocrystals and triethanolamine in a mass ratio of 3.5:0.5:1.

[0034] The initial fluidity of the slurry was 360 mm, the 1-day compressive strength was 102.5 MPa, the 3-day compressive strength was 115.5 MPa, the 28-day compressive strength was 165.8 MPa, the 28-day tensile strength was 11.2 MPa, and the elastic limit tensile strength was 8.6 MPa.

[0035] Example 2

[0036] The grouting material is composed of the following raw materials in parts by weight: 28 parts cement, 40 parts fine aggregate, 8 parts corundum powder, 13 parts ultrafine mineral admixture, 10 parts reinforcing agent, 2 parts reinforcing accelerator, 0.7 parts expanding agent, 0.3 parts water-reducing agent, 0.05 parts defoamer, and 2.5 parts steel fiber. The fine mineral admixture is composed of metakaolin, rice husk ash, tuff, and mineral powder mixed evenly in a mass ratio of 1.5:1.2:3:4, and then ground with a grinding aid to obtain the final product.

[0037] The reinforcing agent is prepared by uniformly mixing CaO, Al2O3, and SiO2 at a mass ratio of 1:0.6:0.15, pressing the mixture into sheets, calcining it at 2050℃ until it reaches the liquid phase, holding it at that temperature for 15 minutes, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum at a mass ratio of 7:3 and subjected to ultrafine grinding to obtain the final product.

[0038] The enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanocrystals and triethanolamine in a mass ratio of 4:0.6:1.

[0039] The initial fluidity of the slurry was 360 mm, the 1-day compressive strength was 105.6 MPa, the 3-day compressive strength was 118.3 MPa, the 28-day compressive strength was 172.6 MPa, the 28-day tensile strength was 11.7 MPa, and the elastic limit tensile strength was 8.9 MPa.

[0040] Comparative Example 1

[0041] The grouting material is composed of the following raw materials in parts by weight: 30 parts cement, 40 parts fine aggregate, 10 parts corundum powder, 12 parts ultrafine mineral admixture, 8 parts reinforcing agent, 1.5 parts reinforcing accelerator, 0.8 parts expanding agent, 0.3 parts water-reducing agent, and 0.04 parts defoamer.

[0042] The fine mineral admixture is obtained by mixing fly ash, rice husk ash, silica fume, and mineral powder in a mass ratio of 3:1:2:5, adding a grinding aid, and then grinding.

[0043] The reinforcing agent is prepared by uniformly mixing CaO, Al2O3, and SiO2 in a mass ratio of 1:0.7:0.1, pressing the mixture into sheets, calcining it at 2100℃ until it reaches the liquid phase, holding it at that temperature for 15 minutes, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum in a mass ratio of 7:3 and subjected to ultrafine grinding to obtain the final product.

[0044] The enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanocrystals and triethanolamine in a mass ratio of 3.5:0.5:1.

[0045] The initial fluidity of the slurry was 350 mm, the 1-day compressive strength was 95.1 MPa, the 3-day compressive strength was 103.4 MPa, the 28-day compressive strength was 146.2 MPa, the 28-day tensile strength was 5.7 MPa, and the elastic limit tensile strength was 5.3 MPa.

[0046] Comparative Example 2

[0047] The grouting material is composed of the following raw materials in parts by weight: 30 parts cement, 40 parts fine aggregate, 10 parts corundum powder, 12 parts ultrafine mineral admixture, 8 parts reinforcing agent, 1.5 parts reinforcing accelerator, 0.8 parts expanding agent, 0.3 parts water-reducing agent, 0.04 parts defoamer, and 2 parts steel fiber.

[0048] The fine mineral admixture is obtained by mixing fly ash, rice husk ash, silica fume, and mineral powder in a mass ratio of 3:1:2:5, adding a grinding aid, and then grinding.

[0049] The reinforcing agent is prepared by uniformly mixing CaO, Al2O3, and SiO2 in a mass ratio of 1:0.7:0.1, pressing the mixture into sheets, calcining it at 2100℃ until it reaches the liquid phase, holding it at that temperature for 15 minutes, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum in a mass ratio of 7:3 and subjected to ultrafine grinding to obtain the final product.

[0050] The enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanocrystals and triethanolamine in a mass ratio of 3.5:0.5:1.

[0051] The test results showed that the initial fluidity of the slurry was 300 mm, the steel fibers settled and clumped at the bottom, the 1-day compressive strength was 92.1 MPa, the 3-day compressive strength was 103.8 MPa, the 28-day compressive strength was 137.3 MPa, the 28-day tensile strength was 9.2 MPa, and the elastic limit tensile strength was 7.1 MPa.

[0052] Comparative Example 3

[0053] The grouting material is composed of the following raw materials in parts by weight: 30 parts cement, 40 parts fine aggregate, 10 parts corundum powder, 12 parts ultrafine mineral admixture, 8 parts reinforcing agent, 1.5 parts CSH crystal nuclei, 0.8 parts expanding agent, 0.3 parts water-reducing agent, 0.04 parts defoamer, and 2 parts steel fiber.

[0054] The fine mineral admixture is a mixture of metakaolin, rice husk ash, tuff, and mineral powder in a mass ratio of 3:1:2:5. A grinding aid is then added before grinding to obtain the final product.

[0055] The reinforcing agent is prepared by uniformly mixing CaO, Al2O3 and SiO2 in a mass ratio of 1:0.7:0.1, pressing them into sheets, calcining them at 2100℃ to the liquid phase, holding them at that temperature for 15 minutes, rapidly cooling them, and grinding them into powder. The powder is then mixed with gypsum in a mass ratio of 7:3 and subjected to ultrafine grinding to obtain the final product.

[0056] The initial fluidity of the slurry was 320 mm, the 1-day compressive strength was 86.3 MPa, the 3-day compressive strength was 93.5 MPa, the 28-day compressive strength was 139.7 MPa, the 28-day tensile strength was 8.4 MPa, and the elastic limit tensile strength was 7.7 MPa.

[0057] Comparative Example 4

[0058] The grouting material is composed of the following raw materials in parts by weight: 30 parts cement, 40 parts fine aggregate, 10 parts corundum powder, 12 parts ultrafine mineral admixture, 8 parts 42.5 grade sulfoaluminate cement, 1.5 parts reinforcing accelerator, 0.8 parts expanding agent, 0.3 parts water-reducing agent, 0.04 parts defoamer, and 2 parts steel fiber.

[0059] The fine mineral admixture is a mixture of metakaolin, rice husk ash, tuff, and mineral powder in a mass ratio of 3:1:2:5. A grinding aid is then added before grinding to obtain the final product.

[0060] The enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanocrystals and triethanolamine in a mass ratio of 3.5:0.5:1.

[0061] The initial fluidity of the slurry was 300 mm, the 1-day compressive strength was 80.8 MPa, the 3-day compressive strength was 89.6 MPa, the 28-day compressive strength was 121.9 MPa, the 28-day tensile strength was 8.1 MPa, and the elastic limit tensile strength was 7.3 MPa.

[0062] Comparative Example 5

[0063] The grouting material is composed of the following raw materials in parts by weight: 30 parts cement, 40 parts fine aggregate, 10 parts corundum powder, 12 parts ultrafine mineral admixture, 8 parts reinforcing agent, 1.5 parts reinforcing accelerator, 0.8 parts expanding agent, 0.3 parts water-reducing agent, 0.04 parts defoamer, and 2 parts polyvinyl alcohol fiber.

[0064] The fine mineral admixture is a mixture of metakaolin, rice husk ash, fly ash, and mineral powder in a mass ratio of 3:1:2:5. A grinding aid is then added before grinding to obtain the final product.

[0065] The reinforcing agent is prepared by uniformly mixing CaO, Al2O3, and SiO2 in a mass ratio of 1:0.7:0.1, pressing the mixture into sheets, calcining it at 2100℃ until it reaches the liquid phase, holding it at that temperature for 15 minutes, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum in a mass ratio of 7:3 and subjected to ultrafine grinding to obtain the final product.

[0066] The enhancing accelerator is composed of CSH crystal nuclei, nanocellulose, and triethanolamine in a mass ratio of 3.5:0.5:1.

[0067] The initial fluidity of the slurry was 340 mm, the 1-day compressive strength was 78.2 MPa, the 3-day compressive strength was 85.7 MPa, the 28-day compressive strength was 126.0 MPa, the 28-day tensile strength was 7.5 MPa, and the elastic limit tensile strength was 6.9 MPa.

[0068] 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 grouting material for offshore wind turbine jacket structures, characterized in that, It is composed of the following raw materials in parts by weight: 20-30 parts cement, 30-45 parts fine aggregate, 1-10 parts corundum powder, 5-15 parts ultrafine mineral admixture, 1-10 parts reinforcing agent, 0.1-2 parts reinforcing accelerator, 0.1-1 part expanding agent, 0.1-0.3 parts water-reducing agent, 0.01-0.1 parts defoamer, and 0.1-5 parts steel fiber. The ultrafine mineral admixture is made by mixing metakaolin, rice husk ash, tuff, and mineral powder in a mass ratio of (1.0-3.2):(0.4-1.5):(1.7-3.1):(2.2-5.5), adding a grinding aid, and then grinding to obtain the final product. The reinforcing agent is prepared by uniformly mixing CaO, Al2O3, and SiO2 in a mass ratio of 1:(0.5-0.8):(0.1-0.2), pressing the mixture into sheets, calcining it to the liquid phase, holding it at that temperature, rapidly cooling it, and grinding it into powder. The powder is then mixed with gypsum in a mass ratio of (6.5-7):(3-4) and subjected to ultrafine grinding to obtain the final product. The enhancing accelerator is composed of CSH crystal nuclei, calcium sulfate nanofibers, and triethanolamine in a mass ratio of (0.5-5):(0.01-1):

1. The cement is P•W52.5 cement, wherein the C3S mineral content is ≥70%.

2. The ultra-high performance grouting material for offshore wind turbine jackets according to claim 1, characterized in that, The fine aggregate is at least one of basalt sand and quartz sand.

3. The ultra-high performance grouting material for offshore wind turbine jackets according to claim 1, characterized in that, The fine aggregate consists of a continuous gradation within four particle size ranges: 10-20 mesh, 20-40 mesh, 40-70 mesh, and 70-120 mesh.

4. The ultra-high performance grouting material for offshore wind turbine jackets according to claim 1, characterized in that, The corundum micro powder has a particle size of 200-300 mesh.

5. The method for preparing the ultra-high performance grout for offshore wind turbine jackets according to any one of claims 1-4, characterized in that, Includes the following steps: 1) Weigh each ingredient according to its weight. 2) Mix all the ingredients evenly to obtain the final product.

6. The application of the grouting material according to any one of claims 1-4 in the construction of offshore wind turbine jackets.