Deep-sea self-adaptive ultra-high performance concrete and preparation method thereof

Abstract

The invention discloses deep-sea self-adaptive ultra-high performance concrete and a preparation method thereof, and the deep-sea self-adaptive ultra-high performance concrete comprises the following components in parts by weight: 50-60 parts of a base material, 10-20 parts of a reinforcing material, 10-20 parts of a functional material and 10-20 parts of a special additive. 5-10 parts of a reinforcing material; 0-5 parts of a functional material; the matrix material is prepared from the following components in parts by weight: 30-40 parts of anti-erosion cement, 30-40 parts of nano silica fume and 30-40 parts of fused quartz powder; 5 to 15 parts of nano silica fume; and 10-20 parts of fused quartz powder. The deep-sea self-adaptive ultra-high-performance concrete prepared by the invention has ultrahigh compression resistance and durability, has a concrete material crack self-repairing capability in a deep-sea environment, can effectively improve the corrosion capability of seawater in a deep-sea low-temperature environment, has obviously improved strength, corrosion resistance, microbial adhesion resistance and wear resistance, has improved durability, and is suitable for large-scale production. And the cable is long in service life and can be used in ocean engineering construction.

Description

Technical Field

[0001] The present invention relates to the technical field of ocean engineering materials, and specifically to a deep-sea adaptive ultra-high performance concrete and a preparation method thereof. Background Art

[0002] In a marine environment, the main factors causing damage to building structures include steel bar corrosion, carbonation, dissolution, salt erosion, freeze-thaw cycle, alkali-aggregate reaction, acid-base erosion, impact wear, and mechanical damage. The characteristics of the deep-sea environment are high hydrostatic pressure, low temperature, and the presence of various corrosive ions. The requirements for protective materials are reflected in high-pressure penetration resistance, resistance to low-temperature effects, and excellent corrosion resistance.

[0003] In the prior art, for example, Patent No. 202211629283.7 discloses an ultra-high performance concrete for deep-sea environment and a preparation method thereof. The main components of this ultra-high performance concrete are: 573 - 596 parts of ordinary Portland cement, 286 - 298 parts of fine cenospheres, 95 - 100 parts of silica fume, 1050 - 1093 parts of river sand, 28 - 30 parts of expansive agent, 190 - 200 parts of steel fiber, 18 - 20 parts of water reducer, and 155 - 195 parts of water. However, the mixing ratio preparation method proposed in the above-mentioned invention patent has no obvious difference from that of ordinary ultra-high performance concrete, and its anti-brittle failure performance under deep water pressure is questionable. In addition, the structural deterioration caused by the erosion of marine organisms is not considered, resulting in the need for regular cleaning and high maintenance costs. Patent No. 202111445614.7 discloses a grouting material for repairing deep-sea concrete defects and a preparation method thereof. The grouting material includes the following raw materials in parts by weight: 50 parts of anti-erosion cement, 86 - 116 parts of sea sand, 0 - 30 parts of coral sand, 15 parts of silica fume, 5 parts of gypsum, 20 - 25 parts of steel fiber, 5 - 15 parts of polyvinyl alcohol microfiber, 1 part of flocculant, 1 part of expansive agent, and 2 parts of water reducer. Although the grouting material disclosed in the above-mentioned invention patent has significantly improved strength, anti-erosion, anti-impact, and wear resistance, it overly relies on one-way protection by additives and lacks dynamic response ability. In addition, the structural deterioration caused by the erosion of deep-sea organisms such as barnacles and bacteria is not considered, and its durability performance is questionable.

[0004] Therefore, in the harsh deep-sea environment, higher performance requirements are imposed on ultra-high performance concrete materials, including high strength, high durability, and high volume stability. However, traditional technologies can no longer meet the requirements of modern ocean engineering, and there is an urgent need to research and develop new ultra-high performance deep-sea engineering concrete with excellent anti-high-pressure brittle failure and excellent anti-biological erosion performance. Summary of the Invention

[0005] The purpose of the present invention is to provide a deep-sea adaptive ultra-high performance concrete and a preparation method thereof to solve the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solution: a deep-sea adaptive ultra-high performance concrete, which is composed of a matrix material, a reinforcing material, a functional material and a special additive. The components in parts by weight are: 50-60 parts of the matrix material; 5-10 parts of the reinforcing material; 0-5 parts of the functional material; 30-40 parts of the special additive.

[0007] Preferably, the matrix material is composed of erosion-resistant cement, nano-silica fume and fused quartz powder. The components in parts by weight are: 30-40 parts of erosion-resistant cement; 5-15 parts of nano-silica fume; 10-20 parts of fused quartz powder. The erosion-resistant cement is composed of 72.5-grade sulfoaluminate cement and piezoelectric TiO 2 -BaTiO 3 core-shell particles. The average particle size D50 of the nano-silica fume is 0.1μm, the SiO 2 content is ≥95%, the pozzolanic activity index is ≥95%, and the piezoelectric constant d33 of the piezoelectric TiO 2 -BaTiO 3 particles is 150 pC / N.

[0008] Preferably, the reinforcing material is composed of copper-plated microfilaments and carbon nanotubes. The components in parts by weight are: 5-15 parts of copper-plated microfilaments; 0-1 part of carbon nanotubes. The length of the copper-plated microfilaments is 12 mm and the diameter is 0.15 mm, which can achieve the dual functions of conductivity and corrosion prevention and form an electromagnetic shielding layer. The length of the carbon nanotubes is 10μm and the diameter is 8nm, which can construct a three-dimensional conductive network and improve the toughness of the material.

[0009] Preferably, the functional material is composed of piezoelectric ceramic fibers, microbial capsules and a biomimetic hydrophobic coating. The components in parts by weight are: 1-5 parts of piezoelectric ceramic fibers; 1-5 parts of microbial capsules; 0-2 parts of the biomimetic hydrophobic coating. The piezoelectric ceramic fibers are lead zirconate titanate fibers with a diameter of 0.1 mm, which can convert deep-sea pressure fluctuations into electrical energy. The microbial capsules are chitosan-embedded piezophilic bacteria and calcium lactate with a particle size of 50μm, which can trigger the self-healing function under high-pressure environments. The biomimetic hydrophobic coating is a graphene-fluorosilane composite coating with a contact angle of not less than 160°, which can inhibit the adhesion of marine organisms.

[0010] Preferably, the special additive is composed of a water reducer, water and a titanium alloy honeycomb skeleton. The components in parts by weight are: 0-2 parts of the water reducer; 0-10 parts of water; 25-40 parts of the titanium alloy honeycomb skeleton. The water reducer is a polycarboxylate-based (including slow-release nano-bubbles) with a water reduction rate of not less than 30%. The titanium alloy honeycomb skeleton is a 3D-printed honeycomb structure with a porosity of not less than 70%, which can effectively disperse stress and improve the compressive performance of the matrix material.

[0011] A preparation method of deep - sea adaptive ultra - high - performance concrete, comprising the following steps: A. Matrix mixing: Put anti - erosion cement, nano - silica fume, quartz powder, and carbon nanotubes into a high - speed mixer according to the specified ratio, stir for 3 min to ensure full mixing, add the specified ratio of water and water - reducing agent, and disperse through an ultrasonic disperser for 10 min to prepare a uniform UHPC ultra - high - performance concrete slurry. Add lead zirconate titanate piezoelectric fibers, titanium alloy honeycomb skeleton, and microbial capsules to the slurry, stir at a low speed for 2 min (to prevent structure damage), and induce the fibers to arrange at a certain angle through a magnetic - field - assisted orientation device to improve the piezoelectric output efficiency; B. Surface treatment: Spray a graphene - fluorosilane coating after initial setting, and perform steam treatment at 80 °C for 2 h to form a super - hydrophobic surface; C. Curing and activation: After steam curing for 72 h, obtain deep - sea adaptive ultra - high - performance concrete with a graphene - microorganism symbiotic system.

[0012] Preferably, in step A, the rotation speed of the high - speed mixer is 2000 rpm / min, the frequency of the ultrasonic disperser is 20 kHz, the rotation speed during low - speed stirring is 60 rpm / min, and the magnetic field intensity of the magnetic - field assistance is 0.5 T.

[0013] Preferably, the curing temperature in step C is 85 °C and the humidity is 95%.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The deep - sea adaptive ultra - high - performance concrete prepared by the present invention has ultra - high compressive performance and durability, has the ability of self - repair of cracks in concrete materials under deep - sea environments, can effectively improve the erosion resistance of seawater under deep - sea low - temperature environments, and its strength, erosion resistance, anti - microbial adhesion, and wear resistance are all significantly improved, with enhanced durability and long service life, and can be used in ocean engineering construction. Description of the drawings

[0015] Figure 1 Schematic diagram of the titanium alloy honeycomb skeleton of the present invention; Figure 2 Schematic diagram of the microbial capsule of the present invention; Figure 3 Flow chart of the compressive and self - repair mechanism of the present invention; Figure 4 Schematic diagram of the piezoelectric and bactericidal synergistic mechanism of the present invention. Detailed implementation manners

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0017] Example 1: Matrix material formula (parts by mass): 72.5-grade sulfoaluminate cement: 30 Piezoelectric TiO 2 -BaTiO 3 Core-shell particles: 2 Nano-silica fume: 8 Fused quartz powder (D50 = 0.1 μm): 12 Copper-plated microfilaments: 6 Carbon nanotubes: 0.4 Lead zirconate titanate piezoelectric fibers: 2 Microbial capsules: 1.5 Graphene-fluorosilane biomimetic hydrophobic coating: 0.5 Water reducer: 0.5 Water: 5 Titanium alloy honeycomb skeleton: 32 Example effect: Mechanical properties: Compressive strength 182.5 MPa, flexural strength 35.8 MPa, crack self-healing rate 92.5% under deep-sea high pressure (simulating 100 MPa); Piezoelectric output: Generate 0.5 W / m² of electric energy under 10 Hz pressure fluctuation, driving the release of ClO⁻ (concentration 0.1 ppm); Biofouling inhibition: Exposed to barnacle larva suspension for 6 months, the attachment area is reduced by 85%.

[0018] Example 2: Matrix material formula (parts by mass): 72.5-grade sulfoaluminate cement: 25 Piezoelectric TiO 2 -BaTiO 3 Core-shell particles: 7 Nano-silica fume: 8 Fused quartz powder (D50 = 0.1 μm): 15 Copper-plated microfilaments: 7 Carbon nanotubes: 0.5 Lead zirconate titanate piezoelectric fibers: 3 Microbial capsules: 1.0 Graphene-fluorosilane biomimetic hydrophobic coating: 0.5 Water reducing agent: 0.5 Water: 5 Titanium alloy honeycomb skeleton: 28 Effect of the example: Mechanical properties: Compressive strength 168.5 MPa, flexural strength 32.7 MPa, crack self-healing rate 88.6% under deep-sea high pressure (simulating 100 MPa); Piezoelectric output: Generate 0.4 W / m² of electric energy under 10 Hz pressure fluctuation to drive the release of ClO⁻ (concentration 0.2 ppm); Biofouling inhibition: Exposed to barnacle larva suspension for 6 months, the attachment area is reduced by 80%.

[0019] Example three: Matrix material formula (parts by mass): 72.5-grade sulphoaluminate cement: 30 Piezoelectric TiO 2 -BaTiO 3 Core-shell particles: 3 Nano-silica fume: 6 Fused quartz powder (D50 = 0.1 μm): 20 Copper-plated micro wire: 5 Carbon nanotubes: 0.5 Lead zirconate titanate piezoelectric fiber: 4 Microbial capsule: 2.0 Graphene-fluorosilane biomimetic hydrophobic coating: 0.5 Water reducing agent: 0.5 Water: 5 Titanium alloy honeycomb skeleton: 24 Effect of the example: Mechanical properties: Compressive strength 175.6 MPa, flexural strength 34.8 MPa, crack self-healing rate 85.5% under deep-sea high pressure (simulating 100 MPa); Piezoelectric output: Generate 0.2 W / m² of electric energy under 10 Hz pressure fluctuation to drive the release of ClO⁻ (concentration 0.1 ppm); Biofouling inhibition: Exposed to barnacle larva suspension for 6 months, the attachment area is reduced by 77%.

[0020] Ultra-high performance concrete material structure design: including biomimetic microstructure design and self-healing-piezoelectric synergistic system; Bionic Microstructure Design: It includes a titanium alloy honeycomb skeleton. A 3D-printed titanium alloy honeycomb skeleton (with a porosity of 60%) is embedded in the ultra-high performance concrete matrix. The titanium alloy honeycomb skeleton is a hexagonal honeycomb structure (with a wall thickness of 0.1 mm and a pore diameter of 5 mm), which is embedded inside the matrix to disperse stress and prevent cracks from penetrating. The inside of the titanium alloy honeycomb skeleton is filled with carbon nanotube (CNT)-graphene aerogel to form a lightweight (density < 2.5 g / cm³) and highly compressive bionic compressive structure; Self-healing - Piezoelectric Synergy System: The microbial capsule is coated with a chitosan-silica double layer (with a particle size of 50 - 100 μm), containing piezophilic bacteria and calcium lactate. When a crack occurs, the capsule ruptures, and the bacterial population is released after the crack ruptures. The deep-sea high-pressure environment is used to activate the bacterial metabolism, and calcium lactate is decomposed to generate calcium carbonate to repair the crack. The reaction formula is as follows: Ca(C 3 H 5 O 3 ) 2 + CO 3 2- → CaCO 3 ↓+2C 3 H 5 O 3 - Piezoelectric Ceramic Fiber Mesh: Lead zirconate titanate piezoelectric fibers (with a diameter of 0.1 mm and a volume ratio of 5%) are embedded in the ultra-high performance concrete matrix, converting deep-sea pressure fluctuations into electrical energy to supply the built-in micro electrolysis device, continuously releasing hypochlorite ions (ClO ⁻ ) to inhibit biofouling; Detailed Description of the Mechanism of Action: It includes the mechanism of anti-erosion action, the mechanism of compressive and self-healing, and the mechanism of piezoelectric and bactericidal synergy; Mechanism of Anti-erosion Action: Sulfoaluminate cement has excellent anti-erosion performance. Composite TiO 2 -BaTiO 3 core-shell piezoelectric particles generate an electric field under the deformation caused by seawater pressure in the dark, electrolyzing NaCl to generate ClO⁻ (concentration 0.1 ppm), continuously inhibiting the formation of biofilms. The reaction formula is as follows: 2Cl − →Cl 2 ↑+2e − →Cl 2 +H 2 O→HClO+HCl (in the dark) Refer to the compressive and self-healing mechanism Figure 3 , and refer to the piezoelectric and bactericidal synergy mechanism Figure 4 .

[0021] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A deep-sea adaptive ultra-high performance concrete, characterized by: Deep-sea adaptive ultra-high performance concrete is composed of matrix material, reinforcing material, functional material and special additives, and its components in weight parts are: 50-60 parts of matrix material; 5-10 parts of reinforcing material; 0-5 parts of functional material; 30-40 parts of special additives.

2. The deep-sea adaptive ultra-high performance concrete according to claim 1, characterized in that: The matrix material is composed of erosion-resistant cement, nano-silica fume and fused quartz powder, and the weight proportions thereof are: 30-40 parts of erosion-resistant cement; 5-15 parts of nano-silica fume; 10-20 parts of fused quartz powder. The erosion-resistant cement is composed of 72.5-grade sulphoaluminate cement and piezoelectric TiO2-BaTiO3 core-shell particles added in an amount of 5-10%. The nano-silica fume has an average particle size D50 of 0.1 μm, a SiO2 content of ≥95%, a volcanic ash activity index of ≥95%, and a piezoelectric constant d33 of the piezoelectric TiO2-BaTiO3 particles of 150 pC / N.

3. The deep-sea adaptive ultra-high performance concrete according to claim 1, characterized in that: The reinforcing material is composed of copper-plated microwires and carbon nanotubes, and the weight proportions thereof are: 5-15 parts of copper-plated microwires; 0-1 part of carbon nanotubes. The copper-plated microwires are 12 mm long and 0.15 mm in diameter, and the carbon nanotubes are 10 μm long and 8 nm in diameter.

4. The deep-sea adaptive ultra-high performance concrete according to claim 1, characterized in that: The functional material is composed of piezoelectric ceramic fibers, microbial capsules and bionic hydrophobic coatings, and the weight proportions of the components are: 1-5 parts of piezoelectric ceramic fibers; 1-5 parts of microbial capsules; 0-2 parts of bionic hydrophobic coatings, the piezoelectric ceramic fiber is lead zirconate titanate fiber with a diameter of 0.1 mm, the microbial capsule is chitosan-embedded piezophilic bacteria and calcium lactate with a particle size of 50 μm, and the bionic hydrophobic coating is a graphene-fluorosilane composite coating with a contact angle of not less than 160°.

5. The deep-sea adaptive ultra-high performance concrete according to claim 1, characterized in that: The special additive is composed of a water reducing agent, water and a titanium alloy honeycomb framework, and the weight proportions thereof are: 0-2 parts of the water reducing agent; 0-10 parts of water; 25-40 parts of titanium alloy honeycomb skeleton, the water reducing agent is polycarboxylic acid series (including slow-release nanobubbles), the water reduction rate is not less than 30%, the titanium alloy honeycomb skeleton is a 3D printed honeycomb structure, and the porosity is not less than 70%.

6. A method for preparing deep-sea adaptive ultra-high performance concrete, characterized in that: The following steps are involved: A. Matrix mixing: Anti-corrosion cement, nano-silica fume, quartz powder, and carbon nanotubes are placed in a high-speed mixer according to the specified proportion and stirred for 3 minutes. Water and water reducer are added in the specified proportion and dispersed by ultrasonic disperser for 10 minutes to prepare a uniform UHPC ultra-high performance concrete slurry. Lead zirconate titanate piezoelectric fibers, titanium alloy honeycomb skeletons, and microbial capsules are added to the slurry and stirred at a low speed for 2 minutes. The fibers are induced to align at a certain angle by a magnetic field-assisted orientation device. B. Surface treatment: spraying graphene-fluorosilane coating after initial coagulation, and then treating with 80°C steam for 2h to form a super-hydrophobic surface; C. Curing and activation: After 72 hours of steam curing, the deep-sea adaptive ultra-high performance concrete with graphene-microorganism symbiotic system was obtained.

7. The method for preparing deep-sea adaptive ultra-high performance concrete according to claim 6, characterized in that: In the step A, the rotation speed of the high-speed stirrer is 2000 rpm / min, the frequency of the ultrasonic disperser is 20 kHz, the rotation speed during low-speed stirring is 60 rpm / min, and the magnetic field strength of the magnetic field auxiliary is 0.5 T.

8. The method for preparing deep-sea adaptive ultra-high performance concrete according to claim 6, characterized in that: The curing temperature in step C is 85° C. and the humidity is 95%.

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