Anti-permeation corrosion self-repairing hydraulic engineering pipeline

Abstract

The utility model relates to a kind of anti-permeation corrosion self-repairing hydraulic engineering pipeline, belongs to hydraulic engineering pipeline design technical field.The anti-permeation corrosion self-repairing hydraulic engineering pipeline, pipeline main body base material selects high-strength material, anti-permeation adhesive layer is arranged on the inner wall and outer wall surface of pipeline main body base material, aspartic polyurea corrosion self-repairing dense coating, aliphatic polyaspartic ester polyurea reinforcing layer and aromatic polyurea interface enhancement layer are sequentially arranged on the inner wall and outer wall adhesive layer top, hydrophobic aliphatic finish is arranged on the inner wall and outer wall aromatic polyurea interface enhancement layer top, and flexible structure layer is arranged on the outer wall hydrophobic aliphatic finish top.By combining anti-permeation finish and aspartic polyurea corrosion self-repairing material with pipeline structure design, the water erosion resistance of pipeline is significantly improved, and self-repairing function is realized, with light weight, durability and environmental protection.

Description

Technical Field

[0001] This utility model relates to the field of water conservancy engineering pipeline design technology, and in particular to a seepage-resistant, corrosion-resistant, and self-healing water conservancy engineering pipeline. It focuses on improving the resistance to water seepage, chemical corrosion, and self-healing capabilities under water conservancy scenarios. It is primarily suitable for water conservancy engineering scenarios such as municipal water supply, agricultural irrigation, long-distance water transfer, and urban sewage pipe networks, clearly distinguishing it from the application areas of general-purpose coating resins. Background Technology

[0002] In water conservancy projects, pipeline systems, as the core carriers for water resource allocation and transportation, are exposed to complex environments such as high temperature, humidity, and acid and alkali corrosion for extended periods, posing severe challenges to their durability and safety. Traditional metal pipe materials, such as steel pipes, cast iron pipes, and galvanized pipes, are relatively unstable in chemical properties and are susceptible to corrosion, aging, and fatigue failure, leading to decreased pipe structural strength, shortened service life, and even safety hazards such as pipe rupture and leakage. Plastic pipes can serve as the core material for water transmission systems and are widely used in current water transmission projects. With their advantages of strong chemical corrosion resistance, light weight, convenient installation, and low flow resistance, they have become an important alternative to metal pipes and are widely used in municipal water supply, agricultural irrigation, industrial water transmission, urban sewage networks, and long-distance water transfer. However, plastic pipes can also undergo physical or chemical structural changes due to environmental influences, such as thermal aging, photo-oxidative aging, and biodegradation.

[0003] In practical engineering, pipeline corrosion not only affects its service life but can also lead to serious economic losses and social risks. For example, leaks caused by pipeline corrosion not only waste water resources but may also trigger secondary disasters such as ground subsidence and building damage. This utility model addresses the specific pain points of water conservancy pipelines by solving the problem of insufficient protection in traditional pipelines through the synergistic design of structure and coating. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a seepage-resistant, corrosion-resistant, and self-healing water conservancy pipeline. By combining corrosion-resistant and self-healing materials with the pipeline structure design, it significantly improves the pipeline's corrosion resistance, seepage resistance, and self-healing capabilities, while also taking into account lightweight design and durability.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A seepage-resistant, corrosion-resistant, and self-healing water conservancy pipeline includes a pipeline body. An anti-seepage adhesive layer is provided on the inner and outer surfaces of the pipeline body. Above the anti-seepage adhesive layer on the inner and outer walls, an aspartic polyurea anti-corrosion and self-healing dense coating, an aliphatic polyaspartic ester polyurea reinforcing layer, and an aromatic polyurea interface reinforcement layer are sequentially provided. Above the aromatic polyurea interface reinforcement layer on the inner and outer walls, a hydrophobic aliphatic topcoat is provided. Above the hydrophobic aliphatic topcoat on the outer wall, a flexible structural layer is provided.

[0006] The main body of the pipeline is made of high-strength material, preferably steel pipe or high-density polyethylene (HDPE) pipe. Among them, carbon steel is commonly used for steel pipe, and more specifically, Q235B carbon steel or Q355B carbon steel is preferred.

[0007] The surface of the main body of the pipe should be flat, without sharp protrusions, burrs, or pits. The depth of pits must be within the allowable range or repaired by welding or grinding.

[0008] The main body of the pipeline is made of steel pipe, which needs to be sandblasted to remove rust to Sa 2.5 grade and the roughness reaches Ra 40-80μm, in order to achieve the bonding between the main body of the pipeline and the aspartic polyurea anti-corrosion self-healing dense coating.

[0009] When HDPE pipe is selected as the main body of the pipeline, sandblasting is cancelled and low-temperature plasma treatment (power 400W, time 4min) is used instead. The surface is activated by plasma to form polar groups, thus avoiding physical damage.

[0010] The impermeable adhesive layer material uses a sulfurized carbon nanotube-reinforced epoxy primer that is compatible with aspartic polyurea, which enhances adhesion (especially for welds and corners), seals residual trace corrosion or anchor pattern peaks, and provides an additional impermeable barrier. The thickness of the impermeable adhesive layer is 80-100μm.

[0011] The aforementioned aspartic polyurea anti-corrosion self-healing dense coating has a thickness of 0.8-1.5mm, which can meet most water conservancy requirements.

[0012] The aliphatic polyaspartic ester polyurea reinforced layer (APU) has a thickness of 0.5-1.0 mm and can be adapted to more demanding water conservancy engineering scenarios.

[0013] The aromatic polyurea interface reinforcement layer (ARPU) has a thickness of 0.3-0.5 mm and enhances the impact resistance of the outer structure of the pipe.

[0014] The hydrophobic aliphatic topcoat has a thickness of 80-100 μm.

[0015] Furthermore, the flexible structural layer is a polypropylene layer, specifically, the polypropylene tape is spirally wrapped by mechanical winding, and a tension of ≥5N / mm is applied to ensure close adhesion with the hydrophobic topcoat.

[0016] The aforementioned seepage-resistant, corrosion-resistant, and self-healing water conservancy engineering pipeline has a density ≥1.05 g / cm³. 3 According to national standards, after long-term immersion in corrosive media such as acids, alkalis, and salts for 240 hours, the coating shows no corrosion, blistering, or peeling; after long-term use in high-temperature environments (≤80℃), the coating shows no cracking or peeling; after bending tests in low-temperature environments (-40℃), the coating shows no cracks or peeling; in a 1200-hour accelerated aging test, the coating maintains good performance, showing no powdering or cracking. When cracks appear on the material surface, it achieves a 99.06% self-repair efficiency and reaches an elongation at break of 1010.88% in just 12 hours at room temperature. Furthermore, even under extreme temperature changes (such as rising to 50℃ or falling to -18℃), the material can still self-repair damage.

[0017] Compared with existing technologies, the beneficial effects of this utility model's anti-seepage, anti-corrosion, and self-repairing water conservancy engineering pipeline are as follows: This utility model, through a redesign of the pipe structure, has the following advantages: (1) Corrosion Protection and Self-Healing: Aspartic polyurea material has excellent waterproof performance, with a hydrostatic pressure resistance of >1.0MPa. Its excellent chemical corrosion resistance can effectively resist the penetration of corrosive media such as acids, alkalis, and salts, preventing cracks in the pipe substrate due to chemical erosion and extending the service life of the pipe. Even if minor damage occurs during construction, its waterproof and corrosion protection properties can be restored through the material's self-healing ability.

[0018] (2) Lightweight: Aspartic polyurea material has a low density, and its overall weight can be reduced by about 40% compared with traditional metal pipes. At the same time, its excellent chemical corrosion resistance can effectively resist the penetration of corrosive media such as acids, alkalis and salts, and prevent the pipe substrate from cracking due to chemical erosion, thereby extending the service life of the pipe.

[0019] (3) Interlayer synergy: Aspartic polyurea provides efficient self-healing ability, while APU utilizes excellent erosion resistance and ultra-low temperature resistance to cover the performance shortcomings of aspartic polyurea in high flow rate and cold environment. Both are aliphatic structures with good compatibility and no risk of interface peeling. The flexibility of APU and the high strength of ARPU form a "flexible-rigid" transition, avoiding cracking caused by interlayer hardness differences. The rapid curing characteristics of ARPU can shorten the construction cycle, and its high bonding strength ensures tight adhesion with the polypropylene flexible structure layer, blocking the penetration of soil moisture and acidic substances.

[0020] (4) By implementing a multi-layer design for the main body of the pipeline, the pipeline can be designed for water conservancy projects. The functions of seepage prevention, corrosion prevention, self-repair, mechanical protection, and resistance to extreme environments can be decomposed into different levels. Through synergistic effects, the protection effect of "1+1>2" can be achieved, and the goal of "reducing maintenance costs, extending lifespan, and adapting to water conservancy-specific needs" can be achieved. This avoids the defect of a single coating that is "fully functional but poorly adaptable to different scenarios". Attached Figure Description

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] Figure 1 This is a schematic cross-sectional view of a self-healing, anti-seepage, corrosion-resistant water conservancy pipeline according to the present invention. In the above diagram: 1 is the main body of the pipe, 2 is the impermeable adhesive layer, 3 is the aspartic polyurea anti-corrosion self-healing dense coating, 4 is the aliphatic polyaspartic ester polyurea reinforcing layer, 5 is the aromatic polyurea interface reinforcing layer, 6 is the hydrophobic aliphatic topcoat, and 7 is the flexible structural layer. Detailed Implementation

[0023] The technical solutions in the embodiments of this utility model will be described in detail with reference to the accompanying drawings to ensure their clarity and completeness. Obviously, the described embodiments are only a part of this utility model, and not all of it. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort should fall within the protection scope of this utility model.

[0024] Example 1

[0025] A seepage-resistant, corrosion-resistant, and self-healing water conservancy pipeline, its structural schematic diagram is shown below. Figure 1 The system includes a pipeline body 1. To improve the adhesion and impermeability of the aspartic polyurea anti-corrosion self-healing dense coating to the pipeline body, an impermeable adhesive layer 2 is required on the inner and outer walls of the pipeline. The introduction of this impermeable adhesive layer 2 aims to enhance the interfacial bonding force between the material and the substrate, thereby improving the overall durability and impermeability of the structure. An aspartic polyurea anti-corrosion self-healing dense coating 3 is applied on the inner and outer walls. An aliphatic polyaspartic ester polyurea reinforcing layer 4 is applied on the aspartic polyurea anti-corrosion self-healing dense coating 3. An aromatic polyurea interface reinforcing layer 5 is applied on the aliphatic polyaspartic ester polyurea reinforcing layer 4. A hydrophobic aliphatic topcoat 6 is applied on the inner and outer walls and the aromatic polyurea interface reinforcing layer 5. During pipeline construction, due to the action of external forces, a flexible structural layer 7 is required as a protective layer to prevent the aspartic polyurea waterproof and anti-corrosion dense coating on the outer wall surface from being damaged by mechanical stress or environmental factors, and to enhance its overall strength and crack resistance.

[0026] The impermeable adhesive layer 2 is made of epoxy primer reinforced with carbon sulfide nanotubes, which has good compatibility with aspartic polyurea and has a thickness of 80-100μm, which is 96μm in this embodiment.

[0027] The aspartic polyurea anti-corrosion self-healing dense coating has a thickness of 0.8-1.5mm, and in this embodiment, the thickness is 1.2mm.

[0028] The aliphatic polyaspartic ester polyurea reinforcing layer has a thickness of 0.5-1.0 mm, and in this embodiment, the thickness is 0.8 mm.

[0029] The aromatic polyurea interface reinforcement layer has a thickness of 0.3-0.5 mm, and in this embodiment, the thickness is 0.4 mm.

[0030] The hydrophobic aliphatic topcoat has a thickness of 80-100 μm, and in this embodiment, the thickness is 90 μm.

[0031] Among them, the seepage-resistant, corrosion-resistant, and self-healing water conservancy engineering pipelines have a density ≥1.05 g / cm³. 3 According to national standards, after long-term immersion in corrosive media such as acids, alkalis, and salts for 240 hours, the coating shows no corrosion, blistering, or peeling; after long-term use in high-temperature environments (≤80℃), the coating shows no cracking or peeling; after bending tests in low-temperature environments (-40℃), the coating shows no cracks or peeling; in a 1200-hour accelerated aging test, the coating maintains good performance, showing no powdering or cracking. When cracks appear on the material surface, it achieves a 99.06% self-repair efficiency and reaches an elongation at break of 1010.88% in just 12 hours at room temperature. Furthermore, even under extreme temperature changes (such as rising to 50℃ or falling to -18℃), the material can still self-repair damage.

[0032] This utility model adopts a multi-layer coating design to create interlayer synergy, which enables the anti-seepage, anti-corrosion and self-healing water conservancy pipeline to have excellent water resistance, corrosion resistance and good mechanical properties, and is suitable for the long-term protection needs of water conservancy pipelines.

[0033] The aspartic polyurea anti-corrosion self-healing dense coating material uses existing known bio-based prepolymer materials (see CN120209691A for preparation). A composite of zinc phosphate and calcium molybdate is added as a corrosion-resistant filler. Then, the viscosity of the polyurethane prepolymer is adjusted, 3% microencapsulated epoxy resin is added to improve the self-healing performance, and 15%-20% polydimethylsiloxane is added (refer to Examples 2-3 of CN120209691A). The aspartic polyurea anti-corrosion self-healing material is obtained by interpenetrating network polymerization (IPN). The slurry is directly sprayed onto the inner and outer wall substrates of the pipeline body using a two-component high-pressure airless spraying equipment to form a dense coating of aspartic polyurea waterproof and anti-corrosion material.

[0034] Among them, aliphatic polyaspartic acid ester polyurea uses aliphatic isocyanate as raw material, and its molecular structure does not contain benzene rings. Its weather resistance and UV aging resistance are far superior to traditional aromatic polyurea, and it has excellent low-temperature elasticity.

[0035] Among them, aromatic polyurea uses aromatic isocyanates (such as MDI) as raw materials, has high mechanical strength, fast curing speed (gel time <10s), and excellent compatibility with flexible materials such as polypropylene and HDPE, which can enhance the impact resistance of the outer structure of pipes.

[0036] The manufacturing process of a seepage-resistant, corrosion-resistant, and self-healing water conservancy project pipeline is as follows: S1: Surface treatment: Remove sharp protrusions and burrs from the surface of the main pipe, repair and grind the pits, and sandblast the surface of the main pipe to remove rust and oil stains, thus obtaining the main pipe 1.

[0037] S2: Coated impermeable adhesive layer material An epoxy primer reinforced with carbon nanotubes that is compatible with aspartic polyurea is applied to the surface of the main pipe to obtain an impermeable adhesive layer 2.

[0038] S3: Spray-applied aspartic polyurea anti-corrosion and self-healing dense material A two-component high-pressure airless spraying device was used to directly spray aspartic polyurea anti-corrosion self-healing dense material onto the surface of the inner and outer impermeable adhesive layer 2. The layered spraying controlled the thickness of the single wet film at 200-300μm, and the cumulative dry film thickness reached 1.5-3.0mm. The interlayer construction interval was 5-15min, resulting in an aspartic polyurea anti-corrosion self-healing dense coating 3.

[0039] S4: Spray APU material while the aspartic polyurea layer is not fully cured, with a single wet film thickness of 150-200μm and a cumulative dry film thickness of 0.5-1.0mm. Cure for 2 hours to obtain aliphatic polyaspartic ester polyurea reinforced layer 4.

[0040] S5: After the APU layer has cured for 1 hour (surface is completely dry), spray ARPU material with a single wet film thickness of 100-150μm and a cumulative dry film thickness of 0.3-0.5mm. After curing for 1 hour, the aromatic polyurea interface reinforcement layer 5 is obtained.

[0041] S6: Apply hydrophobic aliphatic topcoat A hydrophobic aliphatic topcoat is applied to the surface of the aromatic polyurea interface reinforcement layer 5 to obtain the hydrophobic aliphatic topcoat 6.

[0042] S7: Installation of the outer flexible structural layer Before the hydrophobic aliphatic topcoat 6 on the outer wall is fully cured, the polypropylene tape is spirally wrapped by mechanical winding, and a tension of ≥5N / mm is applied to ensure close contact with the hydrophobic aliphatic topcoat. The overlap width is ≥55% to obtain the flexible structural layer 7, and finally the anti-seepage, anti-corrosion and self-healing water conservancy pipeline is obtained.

[0043] Example 2

[0044] In this embodiment, when HDPE pipe is used as the main pipe body, sandblasting is omitted. Instead of modifying the substrate surface according to CN120209691A, low-temperature plasma treatment (power 400W, time 4min) is used to activate the surface and form polar groups, thus avoiding physical damage. Other aspects are the same as in Embodiment 1.

[0045] It should be understood that this embodiment is only used to illustrate the technical solution of this utility model and does not constitute a limitation on the protection scope of this utility model. After reading this specification, those skilled in the art can make various modifications, substitutions or improvements to the technical features of this utility model, and as long as such modifications, substitutions or improvements are within the scope defined by the claims, they should be considered to fall within the protection scope of this utility model.

[0046] Comparative Example 1 Similar to Example 1, but with the difference that aspartic polyurea anti-corrosion self-healing dense material, aliphatic polyaspartic ester polyurea, and aromatic polyurea are directly sprayed onto the pipe body. Due to the lack of an impermeable adhesive layer, the bonding force between these materials and the pipe substrate is insufficient, causing the coating to easily detach or peel off under high temperature, high pressure, or mechanical stress, affecting the overall protective effect. Furthermore, the lack of an impermeable adhesive layer results in a loose interface bond between the material and the substrate, thus reducing the coating's durability and anti-aging ability. Especially during long-term use, the coating may experience cracking and blistering due to thermal expansion and contraction, chemical corrosion, and other factors. Although aspartic polyurea itself has excellent waterproof performance, if there is no good adhesion between it and the substrate, moisture may still penetrate through the interface, thereby reducing the overall waterproof effect.

[0047] Comparative Example 2 Similar to Example 1, but with the difference that no flexible structural layer is installed on the outer wall of the pipe. Due to the lack of a flexible buffer layer, during construction, the hydrophobic topcoat on the outer wall is directly rubbed or impacted by hoisting ropes, backfilled gravel, etc., resulting in three scratches with a depth >0.5mm on the hydrophobic topcoat. This exposes the aspartic polyurea layer, which corrodes and blisters after immersion in acidic or alkaline media for 120 hours, leading to mechanical damage such as scratches and perforations. Furthermore, the rigid coating is prone to micro-cracks (crack width >0.3mm) under uneven soil pressure, disrupting the continuity and integrity of the anti-corrosion layer and thus affecting its anti-corrosion performance.

[0048] Comparative Example 3 Similar to Example 1, but with the difference that without a hydrophobic aliphatic topcoat on the inner and outer walls of the pipe, the water stays on the coating surface for a longer time when flowing through the inner wall of the pipe. Minerals are easily precipitated and deposited to form scale, and silt also accumulates due to increased surface adhesion, resulting in a decrease in water delivery capacity. Without a hydrophobic aliphatic topcoat, although the aspartic polyurea layer has a self-healing function, long-term water flow (simulated flow velocity 3m / s) will cause micro-scratches (width ≤0.2mm) to appear on its surface. Without a topcoat to seal it, water can easily seep into the interior of the aspartic polyurea layer through the scratches. After a 1.0MPa hydrostatic pressure test, the pipe without a topcoat showed interface seepage after 72 hours (the pipe with a topcoat could withstand more than 240 hours), and its impermeability decreased by more than 60% compared to the intact structure. The outer aspartic polyurea layer is in direct contact with the flexible structural layer (polypropylene tape) and is exposed to the moisture and microbial environment in the soil. Without the isolation of the topcoat, acidic substances in the soil (such as humic acid) can easily penetrate through the gaps in the polypropylene tape to the surface of the aspartic polyurea layer, which in turn leads to a decline in the outer wall's resistance to environmental erosion.

[0049] Comparative Example 4 Similar to Example 1, but with the difference that: without the aliphatic polyaspartic ester polyurea reinforcing layer and aromatic polyurea interface reinforcing layer on the inner and outer walls of the pipe, the functionally complementary system of "aspartic polyurea layer-APU layer-ARPU layer" cannot be formed, and the interlayer synergistic effect is not achieved. This results in significant shortcomings in the protective performance of the pipe in various scenarios, specifically as follows: Lack of resistance to extreme environments: Without the excellent low-temperature resistance and erosion resistance of the APU layer, the aspartic polyurea layer is prone to cracking in the -40℃ low-temperature bending test (the intact structure has no cracks). Furthermore, in high-flow-rate hydraulic scenarios (such as long-distance water diversion, simulating a flow velocity of 3m / s), long-term water flow erosion will cause scratches with a depth >0.3mm on the surface of the aspartic polyurea layer, reducing the self-healing efficiency from 99.06% to below 75%, making it impossible to fully restore the protective performance. Interlayer bonding failure: Without the "flexible-rigid" transition effect of the ARPU layer, the aspartic polyurea layer (flexible) and the outer flexible structural layer (polypropylene layer, flexible) lack a rigid bonding layer. Under uneven compression of the soil, interlayer delamination is prone to occur due to deformation differences. After 240 hours of immersion in corrosive media, obvious corrosion spots appear at the delamination points (the intact structure is not corroded).

Claims

1. A seepage-resistant, corrosion-resistant, and self-healing water conservancy engineering pipeline, comprising a pipeline body, characterized in that: The main body of the pipeline is made of high-strength material. An impermeable adhesive layer is provided on the inner and outer surfaces of the main body of the pipeline. Above the inner and outer adhesive layers, an aspartic polyurea anti-corrosion self-healing dense coating, an aliphatic polyaspartic ester polyurea reinforcing layer, and an aromatic polyurea interface reinforcement layer are sequentially provided. Above the aromatic polyurea interface reinforcement layer on the inner and outer walls, a hydrophobic aliphatic topcoat is provided. Above the hydrophobic aliphatic topcoat on the outer wall, a flexible structural layer is provided.

2. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 1, characterized in that: The main body of the pipeline is made of steel pipe or HDPE pipe.

3. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 1, characterized in that: The surface of the main body of the pipe should be flat, without sharp protrusions, burrs, or pits.

4. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 1, characterized in that: The impermeable adhesive layer material uses a sulfurized carbon nanotube-reinforced epoxy primer that is highly compatible with aspartic polyurea.

5. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 4, characterized in that: The thickness of the impermeable adhesive layer material is 80-100μm.

6. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 1, characterized in that: The aspartic polyurea anti-corrosion self-healing dense coating has a thickness of 0.8-1.5 mm; the aliphatic polyaspartic ester polyurea reinforcing layer has a thickness of 0.5-1.0 mm; and the aromatic polyurea interface reinforcing layer has a thickness of 0.3-0.5 mm.

7. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 1, characterized in that: The hydrophobic aliphatic topcoat has a thickness of 80-100 μm.

8. The anti-seepage, corrosion-resistant, and self-healing water conservancy pipeline according to claim 1, characterized in that: The flexible structural layer is a polypropylene layer.

Images