Comprehensive treatment method for corrosion of reinforcing steel bars on surface layer of building concrete

Abstract

The invention discloses a comprehensive treatment method for corrosion of reinforcing steel bars on a concrete surface layer of a building, which comprises the following steps: step 1, confirming a corrosion position of a reinforcing steel bar structure on the concrete surface layer, and stripping loose concrete on the surface layer to expose the corroded reinforcing steel bars; 2, the rusted surface of the steel bar is coated with an iron rust converting agent, and iron rust is converted into a conversion film with corrosion resistance; step 3, brushing a water-based epoxy sealing agent or an oily epoxy coating on the generated conversion film and the surface of the concrete without the loose surface layer for moisture-proof and water-proof sealing; and step 4, carrying out recovery reinforcement treatment on the surface of the water-based epoxy sealing agent by adopting water-based epoxy mortar. According to the comprehensive treatment method for corrosion of the steel bars on the building concrete surface layer, rusting of the rusted steel bars on the building concrete surface layer is stopped, moisture and moisture in air do not permeate any more, the structural strength of the concrete is recovered and reinforced, and the structural safety of a building is effectively guaranteed.

Description

Technical Field

[0001] The present application relates to the field of insulation or other protection technology for buildings, and specifically to a comprehensive treatment method for steel bar corrosion on the surface of concrete in buildings. Background Art

[0002] There are a lot of concrete and steel structures in buildings, such as concrete and steel structures in the underground space of buildings, including beams, columns, and roofs. The surface steel bars of concrete and steel structures will rust when exposed to moisture and water in the air. When the rust is serious, the surface concrete will collapse, and the surface steel bars will continue to rust after being exposed until they break, which seriously endangers the structural safety of the building.

[0003] At present, the treatment method for dealing with the above-mentioned corrosion phenomenon is usually to apply anti-rust paint on the surface of the concrete structure's render layer or the exposed steel bar surface. Although the current corrosion status is covered, the corrosion of the steel bar is not stopped, water and moisture will still penetrate, and the corrosion situation is still developing. Over time, the surface concrete will still collapse, the surface steel bars will be exposed or even rusted and broken, the damaged concrete strength will not be reinforced, and the structural safety of the building will still be affected. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a comprehensive treatment method for the corrosion of the steel bars on the surface of the concrete of a building, which can effectively treat the steel bar structure of the concrete of the building. The technical solution adopted includes:

[0005] A comprehensive treatment method for steel bar corrosion on the surface of concrete in a building, comprising:

[0006] Step 1: Confirm the corrosion position of the steel bars on the concrete surface, and peel off the loose surface concrete to expose the corroded steel bars;

[0007] Step 2: coating the rusted surface of the steel bar with a rust conversion agent that is non-corrosive to concrete, so that the rust is converted into a corrosion-resistant conversion film;

[0008] Step 3: Apply water-based epoxy sealant or oil-based epoxy paint to the steel bars with conversion film and the concrete surface with loose surface peeled off for moisture-proof and waterproof sealing;

[0009] Step 4: Use water-based epoxy mortar to restore and reinforce the steel bars and concrete surfaces painted with epoxy paint to restore the damaged concrete strength. Alternatively, glass fiber cloth, carbon fiber cloth or steel mesh can be implanted when reinforcing with water-based epoxy mortar to further improve the strength of the repaired concrete.

[0010] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the amount of the rust conversion agent in step 2 is 50 to 300 g / m2.

[0011] The technical solution adopted by an embodiment of the present invention to solve its technical problem is: the raw materials of the rust conversion agent include, by weight percentage, 10-40% ethylhexyl acrylate, 1-20% methacrylic acid, 0-20% acrylic acid, 0.25-0.5% peroxide initiator, 1-3% anionic emulsifier, 0.5-1.5% nonionic emulsifier, 1-3% film-forming aid, and the balance is water.

[0012] A technical solution adopted by an embodiment of the present invention to solve the technical problem is: the anionic emulsifier is polyoxyethylene ether ammonium sulfate.

[0013] A technical solution adopted by an embodiment of the present invention to solve the technical problem is: the non-ionic emulsifier is fatty alcohol polyoxyethylene ether.

[0014] A technical solution adopted by an embodiment of the present invention to solve the technical problem is: the peroxide initiator is ammonium persulfate or potassium persulfate.

[0015] An embodiment of the present invention adopts a technical solution to solve the technical problem as follows: the preparation method of the rust conversion agent comprises:

[0016] Step 1, weigh the raw materials according to the formula;

[0017] Step 2, dissolving the peroxide initiator in water to prepare a 10wt% initiator solution; Step 3, dissolving the anionic emulsifier and the nonionic emulsifier in water to prepare a 5wt% emulsifier solution, wherein the mass ratio of the anionic emulsifier to the nonionic emulsifier in the emulsifier solution is 2:1, retaining a small amount of the emulsifier solution, adding ethylhexyl acrylate, methacrylic acid, and acrylic acid monomers into the remaining emulsifier solution and dispersing them to obtain a monomer emulsion;

[0018] Step 4: Add the retained emulsifier solution into the reaction container, heat it to 80-85°C, add part of the monomer emulsion and initiator solvent and stir evenly, then gradually drop the remaining monomer emulsion and initiator solution into the reaction container, stir and react at about 80°C for about 4-5h, heat it to 90-95°C, continue to react for 1-2h under vacuum conditions and then cool it down to 40-50°C, add the film-forming aid, stir evenly, and obtain a water-based acrylate copolymer type rust converter.

[0019] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the amount of water-based epoxy sealant or oil-based epoxy coating used in step 3 is 50 to 300 g / m2.

[0020] A technical solution adopted by an embodiment of the present invention to solve its technical problem is: the amount of water-based epoxy mortar used in step 4 is 1kg to 5kg / ㎡.

[0021] Beneficial effects of the present invention:

[0022] The polymer film generated by the reaction between the rust converter and the rust used in the comprehensive treatment method for steel bar corrosion on the surface of the building concrete described in the present application is non-corrosive to the concrete, has good waterproof performance, can prevent water and moisture from continuing to react with the steel bars, and itself is non-corrosive to the concrete. Then, a water-based epoxy sealant or oil-based epoxy coating with good permeability, impermeability to water vapor, good sealing, and resistance to salt spray is used for sealing, and finally, a water-based epoxy mortar with good sealing and high strength is used for surface restoration and reinforcement, so that the rusted steel bars on the surface of the building concrete stop rusting, water and moisture in the air no longer penetrate, the structural strength of the concrete is restored and reinforced, and the structural safety of the building is effectively guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 This is a schematic diagram of the building before treatment;

[0025] Figure 2 Schematic diagram of the loose surface concrete of the building after stripping;

[0026] Figure 3 A schematic diagram of coating a rust conversion agent on the surface steel bars;

[0027] Figure 4 This is a schematic diagram of applying water-based epoxy sealant to the surface steel bars;

[0028] Figure 5 This is a schematic diagram of applying water-based epoxy mortar to the peeling areas of the surface concrete for restoration and reinforcement. DETAILED DESCRIPTION

[0029] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art.

[0030] The present invention is further described in detail below in conjunction with specific examples and with reference to data. It should be understood that this embodiment is only for illustrating the present invention and is not intended to limit the scope of the present invention in any way.

[0031] In the following examples, various processes and methods not described in detail are conventional methods known in the art. The materials, reagents, devices, instruments, equipment, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0032] The comprehensive treatment method for steel bar corrosion on the concrete surface of a building disclosed in this embodiment includes:

[0033] Step 1: Figure 1 As shown, confirm the corrosion position of the surface steel bars of the concrete structure; peel off the loose surface concrete to expose the corroded steel bars, such as Figure 2 As shown;

[0034] Step 2: Coat the rusted surface of the steel bar with a rust conversion agent that is non-corrosive to concrete, so that the rust is converted into a corrosion-resistant conversion film, such as Figure 3 As shown;

[0035] Step 3: Apply water-based epoxy sealant to the concrete surface where the conversion film is formed and the loose surface layer is peeled off for moisture-proof and waterproof sealing. Figure 4 As shown;

[0036] Step 4: Use water-based epoxy mortar to restore and reinforce the steel bars and concrete surfaces coated with epoxy paint to restore the damaged concrete strength. Figure 5 shown.

[0037] The polymer film generated by the reaction of the rust converter and the rust in the comprehensive treatment method for steel bar corrosion on the concrete surface of the building described in the present application is non-corrosive to the concrete and has good waterproof performance, and can prevent water and moisture from continuing to react with the steel bars. The polymer film itself is non-corrosive to the concrete and is then sealed with a water-based epoxy sealer or oily epoxy coating with good permeability, impermeability to water vapor, good sealing and resistance to salt spray, and then the surface is restored and reinforced with a water-based epoxy mortar with good sealing and high strength, so that the rusted steel bars in the surface concrete of the underground space stop rusting, water and moisture in the air no longer penetrate, the structural strength of the concrete is restored and reinforced, and the structural safety of the underground space is effectively guaranteed.

[0038] In this embodiment, the raw materials of the rust conversion agent which is non-corrosive to concrete, has good waterproof performance, and can prevent water and moisture from continuing to react with steel bars include, by weight percentage, 10-40% of ethylhexyl acrylate, 1-20% of methacrylic acid, 1-20% of acrylic acid, 0.25-0.5% of peroxide initiator, 1-3% of anionic emulsifier, 0.5-1.5% of nonionic emulsifier, 1-3% of film-forming aid, and the balance is water.

[0039] The carboxyl groups in the methacrylic acid and acrylic acid units in the water-based acrylic ester copolymer react with rust to form a dense polymer film that can firmly adhere to the metal surface. At the same time, the polymer film formed after the application of the water-based acrylic ester copolymer type rust conversion agent has excellent waterproof properties and can prevent water and moisture from continuing to contact the rusted iron substrate, thereby preventing the iron substrate from continuing to rust.

[0040] Methacrylic acid is used to replace part of the acrylic acid monomer to generate a copolymer. The introduced methacrylic acid unit has weaker acidity than acrylic acid due to the electron-donating property of the methyl group. After partially replacing the acrylic acid unit, the acidity of the rust converter can be reduced, which can not only solve the rust problem on the steel bars, but also avoid the corrosion of the rust converter to the concrete matrix.

[0041] Ethylhexyl acrylate monomer is introduced into the water-based acrylate copolymer type rust conversion agent. The ethylhexyl acrylate monomer has a relatively long hydrophobic side group, which can provide better hydrophobic properties for the copolymer, improve the salt spray resistance of the rust conversion film, and make the neutral salt spray resistance test result of the polymer film generated after the application of the water-based acrylate copolymer type rust conversion agent reach 144h.

[0042] In this embodiment, the amount of the rust conversion agent in step 2 is 50-300 g / ㎡. Examples of the raw material component content of the rust conversion agent are shown in Table 1.

[0043] Table 1

[0044]

[0045]

[0046] The water-based acrylate copolymer rust conversion agent prepared in composition 1-3 is applied to the iron sheet with yellow rust at a dosage of 100 g / ㎡. After a period of time, a black polymer film layer is formed on the rusty iron sheet.

[0047] The pH value of the water-based acrylate copolymer rust conversion agent prepared in composition 1 was tested according to GB / T 14518-1993. The test results are shown in Table 2.

[0048] In this embodiment, the rusted iron sheet producing a polymer film layer of composition 1 was subjected to a neutral salt spray test according to the method of GB / T1771-2007, and the test results are shown in Table 2; the coating adhesion test was performed according to the standard of GB / T9286-2021, and the test results are shown in Table 2.

[0049] Table 2

[0050]

[0051]

[0052] According to the test results in Table 2, the polymer film produced by coating the rusty iron sheet with the water-based acrylate copolymer rust converter can withstand neutral salt spray for 144 hours, and has excellent neutral salt spray resistance.

[0053] According to the standard of JTS / T 209-2020 "Specifications for Construction of Anti-corrosion of Water Transport Engineering Structures 5 Silane Impregnation of Concrete", water-based epoxy sealer was used as the impregnating agent to test the water absorption of blank concrete and concrete after impregnation. The test results are shown in Table 3.

[0054] Table 3

[0055]

[0056]

[0057] According to the test results in Table 3, the water-based epoxy sealant used in this embodiment has excellent waterproof performance.

[0058] The amount of water-based epoxy sealant used in step 3 is 50-300 g / m2, and the amount of water-based epoxy mortar used in step 4 is 1 kg-5 kg / m2.

[0059] In this embodiment, the rust conversion agent prepared in composition 1 is applied to the surface of the corroded steel bar in an amount of 100 g / ㎡; the water-based epoxy sealant is used Water-based epoxy sealer, dosage is 200g / ㎡; water-based epoxy mortar is used Water-based epoxy mortar, dosage is 4kg / ㎡.

[0060] According to the test results in Table 2 and Table 3, the concrete reinforced structure treated by the above-mentioned comprehensive treatment method can be safely and effectively protected.

[0061] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A comprehensive treatment method for steel bar corrosion on the surface of building concrete, characterized in that: include: Step 1: Confirm the corrosion position of the steel bars on the concrete surface, and peel off the loose surface concrete to expose the corroded steel bars; Step 2: coating the rusted surface of the steel bar with a rust conversion agent that is non-corrosive to concrete, so that the rust is converted into a corrosion-resistant conversion film; Step 3: Apply water-based epoxy sealant or oil-based epoxy paint to the steel bars with conversion film and the concrete surface with loose surface peeled off for moisture-proof and waterproof sealing; Step 4: Use water-based epoxy mortar to restore and reinforce the steel bars and concrete surfaces coated with epoxy paint to restore the damaged concrete strength, or implant glass fiber cloth, carbon fiber cloth or steel mesh when reinforcing with water-based epoxy mortar to further improve the strength of the repaired concrete.

2. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 1, characterized in that: The amount of rust conversion agent used in step 2 is 50 to 300 g / m2.

3. The comprehensive treatment method for steel bar corrosion on the surface of concrete in a building according to claim 1, characterized in that: The raw materials of the rust conversion agent include, by weight percentage, 10-40% ethylhexyl acrylate, 1-20% methacrylic acid, 0-20% acrylic acid, 0.25-0.5% peroxide initiator, 1-3% anionic emulsifier, 0.5-1.5% nonionic emulsifier, 1-3% film-forming aid, and the balance is water.

4. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 3 is characterized in that: The anionic emulsifier is polyoxyethylene ether ammonium sulfate.

5. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 3, characterized in that: The nonionic emulsifier is fatty alcohol polyoxyethylene ether.

6. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 3, characterized in that: The peroxide initiator is ammonium persulfate or potassium persulfate.

7. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 1, characterized in that: The preparation method of the rust conversion agent comprises: Step 1, weigh the raw materials according to the formula; Step 2, dissolving the peroxide initiator in water to prepare a 10 wt % initiator solution; Step 3, dissolving anionic emulsifier and nonionic emulsifier in water to prepare a 5wt% emulsifier solution, wherein the mass ratio of anionic emulsifier to nonionic emulsifier in the emulsifier solution is 2:1, retaining a small amount of emulsifier solution, adding ethylhexyl acrylate, methacrylic acid, and acrylic acid monomers into the remaining emulsifier solution and dispersing to obtain a monomer emulsion; Step 4: Add the retained emulsifier solution into the reaction container, heat it to 80-85°C, add part of the monomer emulsion and initiator solvent and stir evenly, then gradually drop the remaining monomer emulsion and initiator solution into the reaction container, stir and react at about 80°C for about 4-5h, heat it to 90-95°C, continue to react for 1-2h under vacuum conditions and then cool it down to 40-50°C, add the film-forming aid, stir evenly, and obtain a water-based acrylate copolymer type rust converter.

8. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 1, characterized in that: The amount of water-based epoxy sealant used in step 3 is 50-300g / ㎡.

9. The comprehensive treatment method for steel bar corrosion on the surface of building concrete according to claim 1, characterized in that: The amount of water-based epoxy mortar used in step 4 is 1kg to 5kg / ㎡.

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