A basalt fiber-reinforced photocured trenchless repair composite material and a method for preparing the same

Abstract

The application discloses a basalt fiber reinforced photocuring trenchless repair composite material and a preparation method and application thereof, and belongs to the technical field of trenchless pipeline repair. The composite material is composed of surface modified basalt fiber, low viscosity photocuring resin, photoinitiator and functional additives, and is rapidly formed through a vacuum assisted impregnation process and a multi-waveband UV-LED dynamic curing technology. The preparation method comprises fiber pretreatment (silane coupling agent impregnation and plasma activation), resin preparation, fiber-resin compounding and intelligent photocuring. The material has a tensile strength of greater than or equal to 150 MPa, a curing time of less than or equal to 2 hours / 100 meters, VOC emission of less than or equal to 10 g / L, can be adapted to DN200-DN2400 pipe diameters and special-shaped pipeline repair, and significantly improves construction efficiency and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of trenchless pipeline repair materials, specifically to a basalt fiber-reinforced ultraviolet-cured composite material, which is suitable for the rapid repair and reinforcement of underground pipelines such as municipal pipelines and oil and gas pipelines, especially for trenchless repair scenarios of complex diameter (DN200-DN2400) and irregularly shaped pipelines. Background Technology

[0002] Traditional trenchless repair materials (such as glass fiber reinforced resin) have the following problems: Insufficient mechanical properties: The tensile strength is generally below 120 MPa, which is insufficient to meet the needs of high-pressure pipeline repair; Low curing efficiency: Traditional thermosetting processes take 5-8 hours, resulting in a long construction cycle; Poor environmental performance: The resin system has high VOC emissions (>50 g / L), which does not meet the standards for green building materials; It has poor corrosion resistance: it is prone to aging in acidic or high-salt environments, and its service life is less than 20 years.

[0003] Basalt fiber is an ideal reinforcing material due to its high specific strength (≥150 MPa), acid and alkali resistance (stable in environments with pH=1-12), high temperature resistance (operating temperature -260~700℃), and environmentally friendly biodegradability. However, existing basalt fiber composites suffer from problems such as poor interfacial bonding and insufficient curing uniformity, which limit their application in trenchless repair. Summary of the Invention

[0004] This invention provides a basalt fiber-reinforced photocurable trenchless repair composite material, comprising the following components and preparation method: Reinforcing phase: Surface-modified basalt fibers (8-15 μm in diameter, 30-50 mm in length), treated with silane coupling agent (KH550 / KH560) and plasma activation; The light-curable resin matrix is ​​composed of acrylate monomers (50-70%), epoxy resin modified prepolymer (20-30%), and diluent (5-10%), with a viscosity of 200-500 mPa·s. Functional additives: photoinitiator (TPO / HCPK, 2-5%), nano silica (5-10%), bio-based plasticizer (3-5%), VOC emissions ≤10 g / L.

[0005] Step 1: Fiber pretreatment. After cleaning with acetone, basalt fibers are impregnated with 1-3% silane coupling agent ethanol solution for 15-30 minutes, dried at 60℃, and then plasma activated in a vacuum environment (50-100 W, 5-10 minutes). Step 2: Resin preparation. Mix the acrylate monomer, epoxy resin prepolymer, photoinitiator and additives, and stir until homogeneous; Step 3: The fiber-resin composite is applied using a vacuum-assisted impregnation process (vacuum degree -0.08~-0.1 MPa, pressure 0.3-0.5 MPa), with the fiber volume ratio being 30-50%. Step 4: Photocuring is achieved by dynamic irradiation with a multi-band UV-LED light source (365 nm + 395 nm), with a curing energy density ≤300 J / m² and a curing degree ≥95%.

[0006] Municipal pipeline repair: Suitable for pipe diameters from DN200 to DN2400; after repair, the compressive strength is ≥150 MPa and the service life against sewage corrosion is ≥30 years. Intelligent construction system: integrates robot positioning and real-time curing degree monitoring modules (spectral analysis accuracy ±2%) to achieve a fitting rate of ≥98% for repairing bent (45°) and collapsed pipes. Beneficial effects

[0007] Improved mechanical properties: tensile strength ≥150 MPa, chemical corrosion resistance increased by 40% compared to traditional materials; Optimized construction efficiency: UV curing time ≤ 2 hours / 100 meters, 60% shorter than thermosetting process; Outstanding environmental friendliness: Bio-based plasticizers and recyclable design (recycling rate ≥85%), meeting the "Green Building Materials Evaluation Standard"; Adaptable to complex working conditions: By intelligent light source control and fiber arrangement optimization, the problem of fitting and repairing irregular tubes is solved. Attached Figure Description

[0008] Figure 1 Flowchart of basalt fiber surface treatment process; Figure 2 Schematic diagram of the vacuum-assisted impregnation device; Figure 3 Schematic diagram of a multi-band UV-LED intelligent curing system; Figure 4 Comparison of the performance of the pipe cross section after repair (compressive strength, corrosion resistance). Detailed Implementation

[0009] Example 1: Repair of DN1200 sewage pipeline 1. Pretreatment: After the pipeline to be repaired is dredged, the inner wall is cleaned using a high-pressure water jet-laser composite equipment; 2. Material preparation: (1) Basalt fiber is treated with KH550 and activated by plasma; (2) Resin formulation: 60% bisphenol A type epoxy acrylate, 25% polyurethane acrylate, 10% 1,6-hexanediol diacrylate, 3% TPO, 5% nano SiO2; 3. Construction: Pull the hose into the pipe, turn on the UV-LED light source (395 nm main band), cure time 2.5 hours, repair layer thickness 3 mm; 4. Performance verification: The compressive strength reaches 180 MPa, the flow capacity is improved by 12%, and the VOC emission is 8.5 g / L.

[0010] Material improvement: Adding 15% carbon nanotubes enhances wear resistance; Curing process: 365 nm wavelength penetrates deep into the resin, curing energy density 250 J / m²; Performance testing: No corrosion after 2000 hours of salt spray test (ASTM B117), tensile strength retention rate ≥90%.

[0011] index Traditional glass fiber composite materials This invention relates to basalt fiber composite materials. tensile strength 80-120 MPa ≥150 MPa Curing time 5-8 hours / 100 meters ≤2 hours / 100 meters VOC emissions >50 g / L ≤10 g / L Acid resistance (pH=1) Valid for 6 months No significant corrosion after 12 months Innovation points: Interface strengthening technology: Plasma activation and silane coupling agent synergistically enhance fiber-resin interfacial bonding; Intelligent curing system: Dynamic control of multi-band light source solves the problem of curing uniformity in large-diameter pipes; Environmentally friendly and recyclable design: materials are recycled through dynamic ester bonds.

[0012] This material can be widely used in municipal pipelines, oil and gas transportation, and new energy facilities (such as offshore wind power pile foundations), and is expected to form a market scale of tens of billions of yuan, promoting the green and intelligent upgrading of trenchless repair technology.

Claims

1. Claim 1 A basalt fiber-reinforced photocurable trenchless repair composite material, characterized in that, Includes the following components: (1) Basalt fiber: surface treated with silane coupling agent, fiber diameter is 8-15 μm and length is 30-50 mm; (2) Photocurable resin: containing acrylate monomers and epoxy resin modified prepolymer, with a viscosity of 200-500 mPa·s; (3) Photoinitiator: A UV-LED light source with a wavelength of 365-395 nm, selected from TPO (2,4,6-trimethylbenzoyl diphenylphosphine oxide) or HCPK (1-hydroxycyclohexylphenyl ketone). (4) Coupling agent: silane coupling agent KH550 or KH560, accounting for 1-3% of the total fiber weight; (5) Functional additives: nano silica (to enhance wear resistance) and flame retardant (aluminum hydroxide or phosphorus compounds), accounting for 5-10% of the total weight of the resin.

2. Claim 2 The composite material according to claim 1, characterized in that, The basalt fiber surface treatment includes the following steps: (1) Immerse the fiber in a 1-3% (w / w) silane coupling agent ethanol solution for 15-30 minutes; After drying at 60℃, plasma activation treatment is carried out under vacuum conditions with a power of 50-100 W and a treatment time of 5-10 minutes.

3. Claim 3 The composite material according to claim 1, characterized in that, The photocurable resin is composed of the following components in the following mass ratio: (1) Acrylic ester monomer (bisphenol A type epoxy acrylate) 50-70%; Epoxy resin modified prepolymer (polyurethane acrylate) 20-30%; Diluent (1,6-hexanediol diacrylate) 5-10%; Polymerization inhibitor (hydroquinone) 0.1-0.5%.

4. Claim 4 The composite material according to claim 1, characterized in that, The amount of photoinitiator added is 2-5% of the total weight of the resin, and it is compatible with multi-band UV-LED light sources (365 nm + 395 nm combination), with a curing energy density ≤300 J / m² and a degree of curing ≥95%.

5. Claim 5 The composite material according to claim 1, characterized in that, The functional additives further include a bio-based plasticizer (polylactic acid derivative), added at 3-5% of the total weight of the resin, and the VOC emission of the composite material is ≤10 g / L.

6. Claim 6 (Independent Claim) A method for preparing the composite material as described in any one of claims 1-5, characterized in that, Includes the following steps: (1) Fiber pretreatment: After being cleaned with acetone, basalt fibers are impregnated with silane coupling agent and then subjected to plasma activation treatment in sequence; (2) Resin preparation: Mix acrylate monomer, epoxy resin modified prepolymer, photoinitiator and functional additives, and stir until homogeneous; Fiber-resin composite: Vacuum-assisted impregnation process is adopted, controlling the fiber volume ratio to 30-50% and the impregnation temperature to 40-60℃; Photocuring molding: Through dynamic irradiation with multi-band UV-LED light source, the curing time is 2-4 minutes / mm thickness, forming a dense repair layer.

7. Claim 7 The preparation method according to claim 6 is characterized in that, The vacuum degree of the vacuum-assisted impregnation process is -0.08 to -0.1 MPa, and the impregnation pressure is 0.3 to 0.5 MPa.

8. Claim 8 An application of the composite material as described in any one of claims 1-5, characterized in that it is applied in the following scenarios: (1) Trenchless repair of municipal pipelines: suitable for DN200-DN2400 pipe diameter, compressive strength after repair ≥150 MPa, and service life against sewage corrosion ≥30 years; (2) Oil and gas pipeline reinforcement: In corrosive environments with pH=1-12, the chemical corrosion resistance of the material is improved by 40%; (3) Repair of irregular pipes: including elliptical pipes and horseshoe-shaped pipes, with a repair fit rate of ≥98% and a flow capacity improvement of 15%.

9. Claim 9 The application according to claim 8 is characterized in that, The repair work is carried out in conjunction with an intelligent curing system, which includes: Multi-band UV-LED light source array; Real-time curing degree monitoring module (based on near-infrared spectroscopy analysis); Robot positioning and traction device, adapted for repairing 45° bends and collapsed pipes.

10. Claim 10 The application according to claim 8 is characterized in that, The repaired materials are recyclable, and the recycling rate of waste materials can be ≥85% through dynamic ester bond decrosslinking technology.

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