Repair material for release structure and preparation method of repair material

Abstract

The invention relates to the technical field of repair of release structures, and discloses a repair material for release structures and a preparation method of the repair material. The repairing material is prepared from the following components in parts by mass: 50 to 60 parts of epoxy emulsion, 28 to 35 parts of fluorocarbon emulsion, 6 to 10 parts of composite silicon powder, 5 to 8 parts of elastic polyurethane modified monomer, 4 to 8 parts of pigment, 8 to 14 parts of coalescing agent, 20 to 30 parts of composite filler, 3 to 5 parts of thickening agent, 0.3 to 0.5 part of pH (Potential of Hydrogen) regulator, 1.5 to 2.5 parts of defoaming agent, 3 to 6 parts of microcapsule coated capillary crystalline anti-permeability agent and 0.5 to 1 part of silane coupling agent. The strength and flexibility of the base material are balanced through rigid epoxy and flexible fluorocarbon / polyurethane, the cracking risk caused by temperature difference and impact is solved by combining the dispersion enhancing characteristic of the composite silicon powder and the long-acting anti-seepage function of the microcapsule anti-seepage agent, meanwhile, technological parameters are optimized, production and construction adaptability is ensured, and the application prospect is wide. The anti-scouring, anti-seepage, corrosion-resistant and durable properties of the repairing material are comprehensively improved, and the repairing material is adaptive to complex working conditions of release structures.

Description

Technical Field

[0001] This application relates to the field of coatings for building repair, and more particularly to the field of coatings for the repair of drainage structures. More specifically, it relates to a repair material for drainage structures and a method for preparing the same. Background Technology

[0002] Spillway structures serve as "safety barriers" in hydraulic engineering projects. Their core functions are to discharge excess floodwaters, regulate water levels, and ensure the stable operation of main structures such as reservoirs and dams. These structures operate in extremely harsh environments, enduring multiple deteriorating factors over extended periods: First, high-speed water flow, often reaching 20-30 m / s, carries hard particles such as silt and gravel, continuously grinding and impacting the structure's surface. Second, water vapor infiltration erosion occurs when prolonged immersion in water or water vapor condensation penetrates the structure through surface pores, leading to concrete carbonization, steel corrosion, and a decrease in structural strength. Third, acid and alkali corrosion occurs when industrial wastewater, acid rain, and dissolved salts in the water react chemically with concrete or metal components, accelerating material aging and degradation. Fourth, temperature stress occurs when temperature fluctuations (from -10℃ to 40℃) caused by day-night or seasonal changes result in differences in thermal expansion and contraction between the repair layer and the substrate, leading to cracking or peeling.

[0003] To address the aforementioned problems, existing technologies mainly employ three types of repair materials, including: (1) ordinary concrete, which is mainly composed of cement and sand, is inexpensive and widely available, but has poor erosion resistance, insufficient impermeability, and is brittle and lacks flexibility; (2) traditional polymer cement-based materials, which are often blended with cement to improve concrete, but have an imbalance between the substrate's weather resistance and erosion resistance, poor water resistance, poor dispersibility, and insufficient construction compatibility; (3) single resin-type repair materials, but such solutions are prone to cracking, have poor adhesion, are easy to fall off, and have a short-lasting anti-seepage function, making it impossible to achieve long-term anti-seepage effects.

[0004] In summary, existing repair materials for spillway structures generally suffer from four major defects: weak erosion resistance, short-lasting impermeability, poor resistance to temperature differences and cracking, and insufficient construction adaptability, making them unsuitable for the complex working conditions of spillway structures. Therefore, developing a repair material that can simultaneously solve the above problems and possesses high erosion resistance, long-lasting impermeability, resistance to temperature differences and cracking, and good construction adaptability has become an urgent need in the field of spillway structure repair. Summary of the Invention

[0005] To overcome the shortcomings of existing drainage structure repair materials, such as "weak erosion resistance, short anti-seepage time, poor temperature difference cracking resistance, and insufficient construction adaptability," this application provides a repair material for drainage structures and its preparation method. Through optimization of the substrate system, improvement of the reinforcement system, innovation of anti-seepage components, and clarification of process parameters, a breakthrough in the comprehensive performance of the repair material is achieved.

[0006] Firstly, this application provides a repair material for a drainage structure, comprising the following components in parts by weight: 4-8 parts pigment; 50-60 parts of epoxy emulsion; Fluorocarbon emulsion, 28-35 parts; 6-10 parts of composite silicon powder; the composite silicon powder includes 2-3 parts of 4000 mesh nano silicon dioxide and 4-7 parts of 2000 mesh ultrafine silicon powder; 5-8 parts of elastic polyurethane modified monomer; Film-forming aid 8-14 parts; 20-30 parts of composite filler; Thickener 3-5 parts; pH adjuster 0.3-0.5 parts; 1.5-2.5 parts of defoamer; 3-6 parts of microencapsulated penetrating crystallizing antipermeability agent; 0.5-1 part of silane coupling agent; The film-forming aid is a compound of propylene glycol methyl ether acetate and dipropylene glycol butyl ether in a mass ratio of 1:(0.5-2.0); The composite filler is a mixture of talc powder, quartz sand and bentonite in a mass ratio of 1:(0.6-0.8):(0.3-0.5); Furthermore, the microcapsule-encapsulated permeation crystallizing antipermeation agent includes a core material and a capsule wall, wherein the core material is a sodium silicate-aluminum sulfate composite permeation crystallizing agent; Preferably, the mass ratio of sodium silicate to aluminum sulfate is 2:1; Preferably, the capsule wall is made of polylactic acid; Furthermore, the microcapsule particle size is 5-10 μm.

[0007] Epoxy emulsions have high adhesion and high strength, while fluorocarbon emulsions have high weather resistance and low surface energy. When the two are compounded in a ratio of 50-60:28-35, the adhesion of water flow to the repair layer can be significantly reduced, and the abrasion of mud and sand can be reduced. At the same time, the introduction of hydroxyl-terminated polybutadiene-type elastic polyurethane modified monomers can link and branch with epoxy molecules, thereby improving the elongation at break of the repair layer and taking into account both strength and impact resistance. The composite silica powder is made of nano silica and ultrafine silica powder, which are uniformly dispersed under the action of silane coupling agent. Nano silica can improve the density by filling the gaps, while ultrafine silica powder (Mohs hardness 7) acts as a hard aggregate to enhance wear resistance. Together, they reduce the quality loss rate of the repair layer. The composite core material is made of sodium silicate and aluminum sulfate, and the polylactic acid (PLA) bladder wall is made of polylactic acid. Sodium silicate and aluminum sulfate are mixed in a specific ratio in the composite core material, which can synergistically generate calcium silicate and calcium sulfate double crystals, improving the pore-blocking efficiency compared with sodium silicate alone. The PLA bladder wall isolates moisture during storage, preventing the core material from reacting prematurely. After construction, it slowly degrades as water seeps in, releasing the core material to react with the hydration products of concrete, thus extending the impermeability period. The flexible segments of the elastic polyurethane modified monomer can alleviate the rigidity of the epoxy emulsion, thereby improving the low-temperature bending resistance of the repair layer and enhancing its resistance to temperature differences. Propylene glycol methyl ether acetate can form a film quickly, while dipropylene glycol butyl ether has low shrinkage. When the two are compounded in a certain proportion, the curing shrinkage rate of the repair layer can be reduced, and surface cracking can be avoided during high-temperature drying.

[0008] Furthermore, the elastic polyurethane modified monomer is a hydroxyl-terminated polybutadiene type polyurethane monomer.

[0009] This type of monomer has excellent compatibility with epoxy emulsions. It can be grafted through chemical reaction of hydroxyl and epoxy groups, rather than simple physical mixing, to ensure that flexibility is improved without reducing the strength and adhesion of the substrate. There is no risk of delamination failure during long-term use.

[0010] Secondly, this application provides a method for preparing a repair material for a drainage structure, comprising the following steps: Step (1): Mix pigment, composite filler, thickener, composite silica powder, microcapsule-encapsulated penetrating crystallization antipermeability agent and silane coupling agent, stir at 50-60 r / min for 10-15 min, eliminate composite silica powder agglomeration through coupling agent pretreatment, and obtain premix; Step (2): Mix the premix with 35%-40% of the total amount of fluorocarbon emulsion, stir at 120-150 r / min for 3-5 min, and then grind for 40-50 min using a horizontal sand mill (grinding media: 0.3-0.5 mm zirconium beads, speed: 1500-2000 r / min) to control the fineness of the base material color paste to ≤20 μm, and obtain the base material color paste; Step (3): Add the remaining fluorocarbon emulsion, epoxy emulsion, elastic polyurethane modified monomer, film-forming aid and pH adjuster to the base color paste, stir at 120-150 r / min for 15-20 min, and then adjust the viscosity according to the construction method: add 0.5-1 part deionized water to adjust the viscosity to 4000-5000 mPa·s when spraying, and add 0.5 parts thickener to adjust the viscosity to 8000-10000 mPa·s when scraping. After stirring evenly, the repair material for the drainage structure is obtained.

[0011] Furthermore, the microcapsule-encapsulated permeation-crystallizing antipermeation agent is prepared by an emulsification-solvent evaporation method; Furthermore, the specific preparation steps for microcapsule-encapsulated permeation crystallization include: Dissolve 6-8 parts of polylactic acid in 75-130 parts of dichloromethane to form an oil phase. Dissolve 8-12 parts of sodium silicate and 4-6 parts of aluminum sulfate composite penetrating crystallizer in 33-84 parts of deionized water to form an aqueous phase. Add the aqueous phase to the oil phase and emulsify at high speed. Then add 4-7.5 parts of polyvinyl alcohol aqueous solution (PVA aqueous solution mass concentration 2%-3%) and stir until the solvent evaporates. Centrifuge and dry to obtain microcapsules.

[0012] This application has the following beneficial effects: 1. Excellent erosion resistance, far superior to existing concrete materials; 2. Long-lasting impermeability can be achieved through slow release, which can solve the problem of short impermeability duration of existing materials; 3. Resistant to temperature difference cracking, meets low temperature bending performance standards, and is suitable for different climatic conditions; 4. It has good adaptability to construction and the viscosity can be adjusted according to the spraying / scraping requirements to avoid clogging or sagging, making it suitable for engineering applications; 5. The preparation method is simple and easy to operate, and is easy to prepare on a large scale and promote commercialization. Detailed Implementation

[0013] The present application will be further described in detail below with reference to the embodiments, focusing on verifying the improvement effect of the repair material on the defects of the prior art.

[0014] Raw materials used in the examples and comparative examples: epoxy emulsion (Tuoda (Shandong) New Material Technology Industry TD-98, viscosity 15 (mPas)), fluorocarbon emulsion (Shenzhen Yoshida Chemical Co., Ltd. F13-0801, viscosity 500-1000 (S)), hydroxyl-terminated polybutadiene polyurethane monomer (Shandong Yinuowei TDI-80), polylactic acid (Shanghai Celluloid, molecular weight 80000-100000); propylene glycol methyl ether acetate, dipropylene glycol butyl ether (Sinopharm Group), talc (1250 mesh), quartz sand (2000 mesh), bentonite (calcium-based, Shijiazhuang Zhengyu New Material Technology Co., Ltd.), hydroxypropyl methylcellulose (Shandong Heda), polyether modified silicone defoamer (Datian Chemical Co., Ltd. MWF-07); other raw materials are commercially available unless otherwise specified.

[0015] Example 1 I. Preparation of microcapsule-encapsulated permeation-crystallizing antipermeation agent: ① Oil phase preparation: Dissolve 6g of polylactic acid in 100mL of dichloromethane and stir at 500r / min for 10min until dissolved; ② Aqueous phase preparation: Dissolve 4g sodium silicate + 2g aluminum sulfate in 40mL deionized water and stir at 500r / min for 5min until dissolved; ③ Emulsification and dispersion: Add the aqueous phase obtained above to the oil phase and emulsify at 2200 r / min for 18 min to form an O / W type emulsion; ④ Solvent evaporation: Add 200 mL of 2.5% polyvinyl alcohol aqueous solution, stir at 32℃ and 550 r / min for 2.5 h until dichloromethane evaporates; ⑤ Separation and drying: Centrifuge at 8500 r / min for 18 min, vacuum dry at 42℃ for 5 h, and pass through a 2000 mesh sieve to obtain microcapsules (particle size 7-9 μm, encapsulation rate 88%).

[0016] II. Preparation of Repair Materials: Step (1), premixing: Mix 6g titanium dioxide, 25g composite filler (12.5g talc + 8.75g quartz sand + 3.75g bentonite), 4g hydroxypropyl methylcellulose, 8g composite silica powder (2.5g nano silica + 5.5g ultrafine silica powder), 4.5g microcapsule antipermeability agent, and 0.7g KH-550, and stir at 55r / min for 12min. Step (2), sand milling: the premix is ​​mixed with 11.2g of fluorocarbon emulsion (35% of the total 32g), stirred at 130r / min for 4min, and ground in a horizontal sand mill (0.4mm zirconium beads, 1800r / min) for 45min, with a fineness ≤20μm; Step (3), compounding: Add 20.8g of the remaining fluorocarbon emulsion, 55g of epoxy emulsion, 6.5g of polyurethane monomer, 11g of film-forming aid (5.5g of propylene glycol methyl ether acetate + 5.5g of dipropylene glycol butyl ether), and 0.4g of potassium dihydrogen phosphate. Stir at 130r / min for 18min, and add 0.8g of deionized water to adjust the viscosity to 4500mPa·s.

[0017] Example 2 The difference from Example 1 is that: 35g of fluorocarbon emulsion and 50g of epoxy emulsion are used, while the amount of other raw materials and the steps are the same.

[0018] Example 3 The difference from Example 1 is that the composite filler is 30g (15.8g talc powder + 12.6g quartz sand + 1.6g bentonite), while the amount of other raw materials and the steps are the same.

[0019] Example 4 The difference from Example 1 is that no elastic polyurethane modified monomer was added, while the amount of other raw materials and steps are the same.

[0020] Example 5 The difference from Example 1 is that the composite silicon powder is 8g of pure 4000 mesh nano silicon dioxide (without ultrafine silicon powder, without KH-560), while the amount of other raw materials and steps are the same.

[0021] Comparative Example 1 C30 concrete (300g cement + 1800g sand and gravel + 180g water) was mixed and molded using conventional methods and used as the repair material.

[0022] Comparative Example 2 Mix 20g acrylic emulsion, 300g cement, 1500g sand and gravel, and 150g water thoroughly to make a repair material.

[0023] Comparative Example 3 Mix 80g of pure epoxy emulsion, 10g of silica powder, 20g of talc powder, and 16g of curing agent evenly to make a repair material.

[0024] Performance testing 1. Erosion resistance: Refer to SL / T 191-2008, the repair material is coated on a concrete test block (100mm×100mm×100mm), the coating thickness is 3mm, cured for 28 days, and then flushed with 30m / s water for 24 hours. The mass loss rate (%) is measured. 2. Impermeability: Refer to GB / T 50082-2009, measure the initial impermeability pressure after 28 days of curing, and remeasure the impermeability pressure after 6 months of storage, and calculate the attenuation rate (%). 3. Temperature difference resistance: -10℃ (4h) → 40℃ (4h) cycle 20 times, observe cracking; test the bending performance at -10℃ (180° bend). 4. Construction compatibility: The smoothness of spraying is tested using a spray gun (1.5mm nozzle diameter) (no clogging is acceptable), and the scraping performance is tested using a scraper (no sagging and uniform coating are acceptable).

[0025] Table 1 Performance test results of the examples and comparative examples

[0026] The mass loss rate of Examples 1-3 was ≤0.38%, which was much lower than that of Comparative Example 1 (3.52%) and Comparative Example 2 (1.86%), proving that the "epoxy-fluorocarbon-composite silicon powder" system can significantly improve the erosion resistance. In Example 5, the mass loss rate increased to 1.25% due to the agglomeration of composite silicon powder without the addition of coupling agent, proving the importance of the dispersion process. The 6-month anti-seepage attenuation rate of Examples 1-3 was <10%, which was far better than that of Comparative Example 2 (45%), proving that the microcapsule anti-seepage agent can effectively prolong the anti-seepage time; the anti-seepage pressure of Comparative Example 1 was only 0.4 MPa, which could not meet the anti-seepage requirements of the drainage structure.

[0027] Examples 1-3 showed no cracking during temperature cycling and no cracking during low-temperature bending, while Example 4 (without polyurethane monomer) showed microcracks, and Comparative Examples 1 and 3 showed obvious cracking. This proves that the elastic polyurethane monomer is the key to improving flexibility and solving the defects of existing materials in temperature resistance.

[0028] Examples 1-3 show no spray gun clogging and no sag when spraying, while Comparative Example 1 cannot be sprayed and Comparative Example 2 shows spray gun clogging and sag, proving that the viscosity adjustment process of this application can solve the construction compatibility problem.

[0029] In summary, the building repair coating of this application comprehensively solves the defects of existing building repair materials such as "weak erosion resistance, short anti-seepage time, poor temperature difference cracking resistance, and insufficient construction adaptability", and is fully adapted to the complex working conditions of drainage structures.

[0030] This specific embodiment is only for the purpose of explaining this application and is not intended to limit it. Those skilled in the art can make minor adjustments to the raw material specifications and process parameters within the scope of the claims. As long as the core improvement logic is consistent with this application, it shall fall within the protection scope of this application.

Claims

1. A repair material for a drainage structure, characterized in that: The components include the following parts by mass: 4-8 parts pigment; 50-60 parts of epoxy emulsion; 28-35 parts of fluorocarbon emulsion; 6-10 parts of composite silicon powder; the composite silicon powder is composed of 2-3 parts of 4000 mesh nano silicon dioxide and 4-7 parts of 2000 mesh ultrafine silicon powder; 5-8 parts of elastic polyurethane modified monomer; 8-14 parts of film-forming aid; the film-forming aid is a compound of propylene glycol methyl ether acetate and dipropylene glycol butyl ether in a mass ratio of 1:(0.5-2.0); 20-30 parts of composite filler; the composite filler is a mixture of talc powder, quartz sand and bentonite in a mass ratio of 1:(0.6-0.8):(0.3-0.5); Thickener 3-5 parts; pH adjuster 0.3-0.5 parts; 1.5-2.5 parts of defoamer; 3-6 parts of microcapsule-encapsulated penetrating crystallizing antipermeability agent; 0.5-1 part of silane coupling agent.

2. The repair material for the drainage structure according to claim 1, characterized in that: The silane coupling agent is at least one of the following: KH-550, KH-560, and KH-570 silane coupling agents.

3. The repair material for the drainage structure according to claim 1, characterized in that: The capsule wall material of the microcapsule-encapsulated permeable crystallizing antipermeability agent is polylactic acid, and the microcapsule particle size is 5-10 μm.

4. The repair material for the drainage structure according to claim 1, characterized in that: The pH adjuster is either potassium dihydrogen phosphate or dipotassium hydrogen phosphate.

5. The repair material for the drainage structure according to claim 1, characterized in that: The thickener is hydroxypropyl methylcellulose.

6. The repair material for the drainage structure according to claim 1, characterized in that: The defoamer is a polyether-modified silicone defoamer.

7. The repair material for a drainage structure according to claim 1, characterized in that: The elastic polyurethane modified monomer is a hydroxyl-terminated polybutadiene type polyurethane monomer.

8. The repair material for the drainage structure according to claim 1, characterized in that: The microcapsule-encapsulated permeable crystallizing antipermeation agent includes a core material and a capsule wall, wherein the core material is a sodium silicate-aluminum sulfate composite permeable crystallizing agent.

9. The repair material for a drainage structure according to claim 8, characterized in that: The sodium silicate to aluminum sulfate mass ratio is 2:1, the capsule wall is made of polylactic acid, and the microcapsule particle size is 5-10 μm.

10. A method for preparing a repair material for a drainage structure as described in any one of claims 1-9, characterized in that: Includes the following steps: Step (1): Mix pigment, composite filler, thickener, composite silica powder, microcapsule-encapsulated penetrating crystallization antipermeability agent and silane coupling agent, stir at 50-60 r / min for 10-15 min, eliminate composite silica powder agglomeration through coupling agent pretreatment, and obtain premix; Step (2): Mix the premix with 35%-40% of the total amount of fluorocarbon emulsion, stir at 120-150 r / min for 3-5 min, and then grind for 40-50 min using a horizontal sand mill (grinding media: 0.3-0.5 mm zirconium beads, speed: 1500-2000 r / min) to control the fineness of the base material color paste to ≤20 μm, and obtain the base material color paste; Step (3): Add the remaining fluorocarbon emulsion, epoxy emulsion, elastic polyurethane modified monomer, film-forming aid and pH adjuster to the base color paste, stir at 120-150 r / min for 15-20 min, and then adjust the viscosity according to the construction method: add 0.5-1 part deionized water to adjust the viscosity to 4000-5000 mPa·s when spraying, and add 0.5 parts thickener to adjust the viscosity to 8000-10000 mPa·s when scraping. After stirring evenly, the repair material for the drainage structure is obtained.

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