Marine environment steel pipe pile anti-corrosion method based on basalt fibers and composite anti-corrosion layer

Abstract

The invention discloses a marine environment steel pipe pile anti-corrosion method based on basalt fibers and a composite anti-corrosion layer. The anti-corrosion method comprises the steps that the outer wall of a steel pipe pile is polished for smooth finish treatment; the surface of the steel pipe pile is coated with a modified epoxy resin bottom layer; the basalt fiber cloth impregnated with the modified epoxy resin is pasted in the circumferential direction; carrying out rolling treatment; pasting the basalt fiber cloth impregnated with the modified epoxy resin again in a peak staggering manner; and standing to form the composite anti-corrosion layer. The composite anti-corrosion layer is manufactured on the basis of the marine environment steel pipe pile anti-corrosion method based on the basalt fibers. The basalt fiber cloth and the modified epoxy resin are coated to form a compact anti-corrosion layer, the durability is remarkably improved to 50 years or above, and the whole life cycle cost is reduced by 28%.

Description

Technical Field

[0001] This application belongs to the field of marine engineering corrosion protection technology, and relates to a corrosion protection method for steel pipe piles using a composite coating of basalt fiber and modified epoxy resin. Specifically, it relates to a corrosion protection method for marine steel pipe piles based on basalt fiber and a composite anti-corrosion layer, which is suitable for long-term corrosion protection of steel pipe piles in marine environments. Background Technology

[0002] With the rapid growth of the global marine economy, numerous marine structures have emerged in the marine environment; however, they all suffer from the severe test of seawater corrosion. The marine environment leads to severe corrosion of structures, especially steel. The main causes of corrosion are threefold: first, chloride ions in seawater compete with oxygen atoms on the steel surface to form soluble chlorides, accelerating corrosion; second, the potential difference caused by the difference in chloride ion content between the splash zone and the underwater zone triggers current corrosion. Furthermore, defects in steel structures during manufacturing, transportation, and installation may occur due to welding slag, collisions, etc. These defects act like microscopic corrosion cells, promoting the intensification and spread of localized corrosion. Therefore, scholars both domestically and internationally have conducted in-depth research on steel corrosion prevention technologies in marine environments, covering advancements in coating protection technology, marine biofouling prevention technology, sacrificial anode cathodic protection technology, impressed current cathodic protection technology, and seawater-resistant steel. According to relevant research, the average corrosion rate of unprotected steel pipe piles in the splash zone can reach 0.4–0.5 mm / a, while in inland freshwater environments, the corrosion rate is significantly reduced to 0.047 mm / a. To address this issue, scholars have proposed several anti-corrosion technologies, including epoxy resin coating, sacrificial anodes, pre-applying thickness for corroded steel, self-dispersing polyurea nanofiber coating, and carbon fiber coating. These technologies effectively reduce the corrosion rate and extent of steel structures in marine environments, thereby extending the service life of the structures. While epoxy resin is a mature technology with low initial cost, it is prone to aging, cracking, and peeling, exhibiting weak durability and typically failing within 5-10 years, requiring recoating during operation and maintenance. Sacrificial anodes are particularly suitable for corrosion protection in underwater areas, but their protection efficiency in splash zones is less than 50%. Glass fiber has good resin wettability, but it is prone to brittleness at low temperatures. Carbon fiber cloth, due to its high density, can effectively block chloride ion penetration, but this also increases the difficulty of resin impregnation, affecting its adhesion to the structure. Furthermore, carbon fiber has a certain degree of conductivity, posing a challenge to its anti-corrosion effect. On the other hand, with the continued development of marine transportation, transport ships are becoming larger, placing increasingly higher demands on structures such as docks, and similarly raising the technical requirements for corrosion protection of steel structures in marine environments. Therefore, there is an urgent need to propose new methods for corrosion protection of steel pile structures in marine environments in response to these current conditions. Summary of the Invention

[0003] In view of the shortcomings or deficiencies of the prior art, the technical problem to be solved by this application is to provide a method for corrosion protection of marine steel pipe piles based on basalt fiber and a composite anti-corrosion layer, which forms a dense anti-corrosion layer by coating basalt fiber cloth with modified epoxy resin, significantly improving durability to more than 50 years and reducing the total life cycle cost by 28%.

[0004] To solve the above-mentioned technical problems, this application provides the following technical solution: This application proposes a corrosion protection method for marine steel pipe piles based on basalt fiber, including: The outer wall of the steel pipe pile is ground to achieve a smooth finish; A modified epoxy resin undercoat is applied to the surface of the steel pipe pile; Basalt fiber cloth impregnated with the modified epoxy resin is pasted circumferentially; Roll forming process; The basalt fiber cloth impregnated with the modified epoxy resin was then pasted again in staggered shifts. After standing, a composite anti-corrosion layer is formed; The modified epoxy resin is TYFO-S modified epoxy resin, and the modified epoxy resin is mixed with epoxy resin at a weight ratio of component A: component B = 100: 34.5, where component A is the epoxy resin matrix and component B is the curing agent.

[0005] Further optionally, the above-mentioned surface finishing treatment of the outer wall of the steel pipe pile includes: grinding the outer wall of the steel pipe pile to a surface finish of Sa2.5 and a roughness of 50-85μm.

[0006] Further optionally, the ion permeability of the basalt fiber cloth is <0.01 g / m³. 2 • Year, thickness 0.18mm, tensile strength ≥2000MPa.

[0007] Alternatively, the basalt fiber cloth may be made of bidirectional woven fiber material with a fabric density of 260–400 g / m³. 2 Porosity <1%.

[0008] Further optionally, the modified epoxy resin has a tensile strength ≥60MPa.

[0009] Further optionally, the modified epoxy resin is applied at a temperature of 10–35°C and a humidity of <70% when mixed with component A and component B.

[0010] Further optionally, the basalt fiber cloth impregnated with the modified epoxy resin in the above-mentioned circumferential bonding includes: longitudinal overlap ≥150mm and circumferential overlap ≥100mm.

[0011] Alternatively, the above-mentioned rolling process may include: performing bidirectional rolling several times with rubber rollers to completely eliminate air bubbles.

[0012] Alternatively, the steel pipe pile may be made of Q355B low-alloy high-strength structural steel.

[0013] This application also proposes a composite anti-corrosion layer, which is made based on the aforementioned basalt fiber-based marine environment steel pipe pile anti-corrosion method.

[0014] Compared with the prior art, this application has the following technical effects: This application combines basalt fiber cloth with modified epoxy resin, which can mutually enhance the anti-corrosion performance. The basalt fiber cloth can improve the tensile strength and wear resistance of epoxy resin, reduce its tendency to crack under stress, and effectively prevent chloride ions from penetrating the surface of steel pipe piles through cracks. The basalt fiber cloth impregnated with modified epoxy resin can better block chloride ion penetration and can be widely used for anti-corrosion of steel pipe piles in marine environments. It avoids the disadvantages of low strength of glass fiber and conductivity of carbon fiber, and can more effectively play the role of anti-corrosion of marine engineering steel structures. Attached Figure Description

[0015] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This application includes a flowchart of a corrosion protection method for marine steel pipe piles based on basalt fiber, according to one embodiment. Figure 2 This application presents an embodiment of a steel pipe pile anti-corrosion zoning diagram (splash zone, water level fluctuation zone, underwater section). Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] like Figure 1 and Figure 2 As shown, in one embodiment of this application, the corrosion protection method for marine steel pipe piles based on basalt fiber includes: The outer wall of the steel pipe pile is ground to achieve a smooth finish; A modified epoxy resin undercoat is applied to the surface of the steel pipe pile; Basalt fiber cloth impregnated with the modified epoxy resin is pasted circumferentially; Roll forming process; The basalt fiber cloth impregnated with the modified epoxy resin was then pasted again in staggered shifts. After standing, a composite anti-corrosion layer is formed. Further, it is left to stand and cure in a dry environment for 24 hours to form a composite anti-corrosion layer. The modified epoxy resin is TYFO-S modified epoxy resin, and the modified epoxy resin is mixed with epoxy resin at a weight ratio of component A: component B = 100: 34.5, where component A is the epoxy resin matrix and component B is the curing agent.

[0018] In this embodiment, basalt fiber cloth is preferably combined with modified epoxy resin, which can enhance each other's anti-corrosion performance. Basalt fiber cloth can improve the tensile strength and wear resistance of epoxy resin, reduce its tendency to crack under stress, and effectively prevent chloride ions from penetrating the surface of steel pipe piles through cracks. Basalt fiber cloth impregnated with modified epoxy resin can better block chloride ion penetration and can be widely used for anti-corrosion of steel pipe piles in marine environments.

[0019] Preferably, the anti-corrosion zones of the steel pipe pile include: a splash zone, a water level fluctuation zone, and an underwater section.

[0020] In this embodiment, the steel pipe pile is made of Q355B low-alloy high-strength structural steel. Compared with conventional Q345 steel, it has better structural strength and atmospheric corrosion resistance. After being encapsulated with epoxy resin, the Q355B low-alloy high-strength structural steel can significantly improve its corrosion resistance in seawater environments. In specific applications, it is preferable to leave a 4mm corrosion allowance in the steel pipe pile to enhance its service life reliability.

[0021] The above-mentioned surface finishing treatment of the outer wall of the steel pipe pile includes: grinding the outer wall of the steel pipe pile to Sa2.5 level surface finish, roughness 50-85μm, free of oil stains, oxide scale and rust, which can enhance the bonding strength with modified epoxy resin and reduce the hollow rate.

[0022] In one embodiment of this application, the specific material preparation involves: the ion permeability of the basalt fiber cloth is <0.01 g / m³. 2 • Annual thickness, 0.18 mm, tensile strength ≥ 2000 MPa. More preferably, the basalt fiber cloth is made of bidirectional woven fiber material with a fabric density of 260–400 g / m². 2 Its porosity is less than 1%, which is lower than that of glass fiber cloth (3% to 5%).

[0023] More preferably, the silicon-oxygen tetrahedral molecular structure of basalt fiber can block chloride ion diffusion, thus exhibiting better resistance to chloride ion erosion, with a chloride ion diffusion coefficient of 1×10⁻⁶. -14 m 2The basalt fiber cloth exhibits excellent chemical corrosion resistance, maintaining stable material properties within a pH range of 3-11. In contrast, carbon fiber cloth is easily oxidized in alkaline environments, and the SiO2 in glass fiber cloth dissolves in alkaline conditions. Basalt fiber cloth demonstrates better penetration of modified epoxy resin during construction, exhibiting strong affinity and requiring no additional measures. Carbon fiber cloth, due to its high density, requires specific conductive resins for wetting, while glass fiber requires pretreatment with coupling agents to achieve resin wetting. Basalt fiber exhibits good field adaptability, allowing for cutting and bending within a temperature range of -20 to +60 degrees Celsius, while the bonding strength of carbon fiber cloth decreases at humidity levels above 70%. Glass fiber exhibits low-temperature brittleness, resulting in poor adaptability. Basalt fiber can be bonded in environments with humidity not exceeding 80%, while the bonding strength of carbon fiber cloth decreases at humidity levels above 70%. Basalt fiber is easier to control in terms of quality, typically achieving a hollow rate of less than 5%, which can be resolved by direct repair measures. However, when repairing carbon fiber cloth, special care must be taken to prevent conductive short circuits, and due to the anisotropic nature of glass fiber, the fiber arrangement direction must be strictly controlled.

[0024] It should also be noted that the material cost of basalt fiber is approximately 80-120 yuan / m. 2 Carbon fiber cloth costs as much as 300-500 yuan / m 2 Fiberglass is relatively inexpensive, costing 40-80 yuan / m. 2 Basalt fiber cloth has low operating costs; a single layer is sufficient, while double-layer wrapping improves corrosion resistance and weather resistance. Carbon fiber cloth is more expensive due to the need for a conductive insulating layer; glass fiber is moderately priced because it requires multiple layers to delay the rapid decline in strength after aging. Basalt fiber cloth has a long-term effectiveness of over 50 years, while carbon fiber cloth can achieve a service life of 30-50 years with galvanic corrosion protection measures. Glass fiber, due to its rapid strength decline after aging, only maintains a service life of 15-25 years. Because of its non-conductive properties, basalt fiber cloth offers better protection and can be used in humid environments, alkaline soils, and environments with alternating strong acids and alkalis, but it cannot be used in cathodic protection auxiliary layers that require conductivity.

[0025] In this embodiment, the modified epoxy resin is TYFO-S modified epoxy resin, which can form a tight cross-linked network after curing, and the chloride ion diffusion rate is less than 3×10. -10 m 2 / s, which is only about 1 / 10 of that of ordinary epoxy resin, and the tensile strength is ≥60MPa.

[0026] More preferably, the modified epoxy resin is mixed with epoxy resin at a weight ratio of component A: component B = 100: 34.5, with an application temperature of 10–35°C and humidity <70%; wherein component A is the epoxy resin matrix and component B is the curing agent. After mixing, components A and B will form chemical bonds that "colloidalize" the resin. Therefore, during use, the two components must be mixed evenly and strictly according to the ratio, and the operation must be completed within the specified time to form a high-performance mixed epoxy resin.

[0027] The modified epoxy resin used in this embodiment can adapt to a wider range of pH levels (pH 3-pH 11). Especially when combined with basalt fiber, the modified epoxy resin can have a service life of over 50 years, compared to 10-15 years for ordinary resin. Furthermore, the modified epoxy resin exhibits superior mechanical properties, with a tensile strength exceeding 60 MPa, a significant improvement over the 40-50 MPa of ordinary epoxy resin. It also possesses better ductility, accommodating greater surface strain in the steel pipe pile substrate. The elongation at break reaches 7.08%, compared to 3%-5% for ordinary epoxy resin. In terms of construction performance, the modified epoxy resin also performs excellently, adapting to a wide temperature range of 5-35 degrees Celsius, while the construction temperature range for ordinary epoxy resin is limited to 10-30 degrees Celsius.

[0028] In this embodiment, preferably, the bond strength between the modified epoxy resin and the steel pipe pile is greater than 5 MPa.

[0029] This embodiment uses basalt fiber cloth and modified epoxy resin, which can effectively improve the interfacial and mechanical properties of the composite material.

[0030] Furthermore, in this embodiment, a modified epoxy resin undercoat is applied to the clean and smooth surface of the steel pipe pile.

[0031] The basalt fiber cloth impregnated with the modified epoxy resin in the above-mentioned circumferential bonding includes: longitudinal overlap ≥150mm and circumferential overlap ≥100mm.

[0032] The above-mentioned roller pressing process includes: using rubber rollers to perform bidirectional roller pressing several times to completely eliminate air bubbles; specifically, using rubber rollers to perform bidirectional roller pressing, such as five times, to completely eliminate air bubbles, effectively reduce the void rate, and ensure that the first layer of basalt fiber cloth and epoxy resin layer are tightly bonded to the surface of the steel pipe pile foundation.

[0033] This embodiment also proposes a composite anti-corrosion layer, which is manufactured based on the aforementioned basalt fiber-based marine environment steel pipe pile anti-corrosion method. The manufacturing method involved is described above and will not be repeated here.

[0034] The composite anti-corrosion layer in this embodiment can be widely used in anti-corrosion scenarios for steel pipe piles in marine environments.

[0035] Taking the anti-corrosion construction of Φ1200mm steel pipe piles in a wharf project in Shanghai's Yangshan district as an example, the pile height using basalt fiber cloth + modified epoxy resin protection is 8.18m, the pile slope is 3.5:1, and the protection area of ​​a single pile is 9.6m². 2 The wharf structure is designed for a service life of 100 years. To ensure the bonding quality of the basalt fiber cloth and the corrosion resistance of the steel pipe piles, the corrosion protection of the steel pipe piles in this embodiment is implemented in the factory workshop. First, preparatory work is carried out by grinding the surface of the steel pipe piles to Sa2.5 grade and preparing epoxy resin at a ratio of 100:34.5. Then, modified epoxy resin is applied to the surface of the steel pipe piles. After confirming that the epoxy resin layer is free of bubbles, the impregnated basalt fiber cloth is evenly coated and the air bubbles in the fiber cloth are completely eliminated through a roller pressing process. A second layer of impregnated basalt fiber cloth is then cross-laid to ensure the elimination of air bubbles. The epoxy resin coverage of the anti-corrosion layer surface is checked, and exposed areas are re-applied epoxy resin and ground smooth. The presence of voids is checked, and for void areas less than 50 cm², the voids are addressed accordingly. 2 In areas with hollow areas, adhesive injection should be used for repair; the hollow area is 50-100 cm². 2 Perform local replacement between them; for those exceeding 100cm 2 For any hollow areas, cut them off and re-attach them, ensuring that the overlap width is increased to 120% of the original width.

[0036] Over the 100-year lifespan of the wharf structure, the use of basalt fiber reinforced concrete technology requires only two maintenance sessions (recoating with epoxy resin), achieving a cumulative comprehensive unit cost control of 1270 yuan / m². 2 The conventional epoxy resin anti-corrosion method requires six coats of epoxy resin, with a total unit price of 1760 yuan / m². 2 The combined cost of epoxy resin and a 2mm allowance for steel plate corrosion thickness is 1830 yuan / m. 2 Therefore, the overall cost of basalt fiber cloth is 27.8% lower than that of the epoxy resin method, and 44% lower than that of the epoxy resin + reserved steel plate corrosion thickness method. In summary, this application has broad market application prospects.

[0037] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] In the description of this embodiment, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0040] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. The preferred embodiments have been described in detail. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the claims of this application.

Claims

1. A corrosion protection method for marine steel pipe piles based on basalt fiber, characterized in that, include: The outer wall of the steel pipe pile is ground to achieve a smooth finish; A modified epoxy resin undercoat is applied to the surface of the steel pipe pile; Basalt fiber cloth impregnated with the modified epoxy resin is pasted circumferentially; Roll forming process; The basalt fiber cloth impregnated with the modified epoxy resin was then pasted again in staggered shifts. After standing, a composite anti-corrosion layer is formed; The modified epoxy resin is TYFO-S modified epoxy resin, and the modified epoxy resin is mixed with epoxy resin at a weight ratio of component A: component B = 100: 34.5, where component A is the epoxy resin matrix and component B is the curing agent.

2. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The above-mentioned surface finishing treatment of the outer wall of the steel pipe pile includes grinding the outer wall of the steel pipe pile to a surface finish of Sa 2.5, with a roughness of 50-85μm.

3. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The ion permeability of the basalt fiber cloth is <0.01 g / m. 2 • Year, thickness 0.18mm, tensile strength ≥2000MPa.

4. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The basalt fiber cloth is made of bidirectional woven fiber material with a fabric density of 260–400 g / m². 2 Porosity <1%.

5. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The modified epoxy resin has a tensile strength ≥60MPa.

6. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The modified epoxy resin is applied at a temperature of 10–35°C and a humidity of <70% when it is mixed with component A and component B.

7. The corrosion protection method for marine steel pipe piles based on basalt fiber according to claim 1, characterized in that, The basalt fiber cloth impregnated with the modified epoxy resin in the above-mentioned circumferential bonding includes: longitudinal overlap ≥150mm and circumferential overlap ≥100mm.

8. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The above-mentioned rolling process includes: using rubber rollers to perform bidirectional rolling several times to completely eliminate air bubbles.

9. The corrosion protection method for marine environment steel pipe piles based on basalt fiber according to claim 1, characterized in that, The steel pipe piles are made of Q355B low-alloy high-strength structural steel.

10. A composite anti-corrosion layer, characterized in that, It is manufactured based on the corrosion protection method for marine environment steel pipe piles based on basalt fiber as described in any one of claims 1 to 9.

Images