Application of composite material with humidity responsiveness in ion erosion resistance

Abstract

The invention relates to an application of a composite material with humidity responsiveness in ion erosion resistance, in particular to an application of the composite material with humidity responsiveness, which is prepared from modified nano zeolite particles carried by polysiloxane, in sulfate erosion resistance and chloride ion erosion resistance of concrete. The used composite material with humidity response has a unique humidity response mechanism, after the composite material absorbs moisture and swells, the modified nano zeolite particles encapsulated in the composite material can be gradually released outwards, and when the concrete is exposed to a humid corrosive environment, the modified nano zeolite particles can release the humidity response of the concrete. And sulfate ions and chloride ions in an erosion environment can be adsorbed and fixed, and further destructive effects of erosion ions, especially destructive effects of concrete, can be hindered. The method can be used for concrete structures exposed in severe environments, such as ocean engineering, underground facilities and industrial buildings, and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to application of a composite material with humidity responsiveness in resisting ion corrosion, belonging to the technical field of material application. Background Art

[0002] When exposed to moisture and corrosive media (such as sulfate ions, chloride ions, etc.) for a long time, concrete materials are prone to cracks, resulting in reduced structural performance and durability. Such cracks not only provide a channel for corrosive media to enter the interior of the concrete, accelerating the deterioration of the concrete, but also significantly reducing the service life of the concrete structure.

[0003] Traditional crack repair methods, such as physical plugging and chemical repair, usually repair cracks by coating a protective layer, grouting, etc. However, these methods are often limited in their effectiveness in repairing microcracks and deep cracks, and the repair materials are prone to failure in harsh environments. In addition, when concrete structures are corroded by sulfates and chloride ions, they are generally accompanied by solutions, and traditional materials lack adaptive functions, making it difficult to effectively repair corroded concrete in a humid environment and provide continuous and effective protection.

[0004] In response to the problem of concrete being corroded by sulfate and chloride ions, a variety of solutions have been proposed to improve the durability of concrete structures, including increasing the thickness of the concrete cover to delay the time for chloride ions to penetrate into the steel bars; adding mineral admixtures such as fly ash, slag or silica fume to the concrete to improve the microstructure and corrosion resistance; adding self-healing agents such as microcapsules, fibers and chemicals to automatically release concrete into cracks when damaged to promote self-repair; using mortar to repair cracks caused by corrosion, etc. However, these materials are not sufficiently responsive to humidity and durable in humidity-corroding media, making it difficult to perform their repair functions and provide good corrosion resistance, which will also lead to continuous expansion of concrete cracks and concrete deterioration.

[0005] At present, although the application of humidity-responsive materials in many fields is worthy of attention and research hotspots, their application in the field of concrete resistance to ion corrosion is still relatively rare and there are some technical difficulties, such as slow response, uneven material release, and difficulty in effectively preventing the penetration of corrosive media. However, by using a composite material with a unique humidity response mechanism, it can absorb moisture and solidify to fill concrete cracks, and after swelling after moisture absorption, it can gradually release nanoparticles to adsorb sulfate ions and chloride ions in the corrosive medium to prevent them from further damaging the concrete structure, and after swelling after moisture absorption, it forms a hydrophobic barrier to prevent further erosion by corrosive solutions, thereby providing long-term effective protection. The composite materials mentioned in the above method have not yet been used in concrete resistance to ion corrosion. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In order to solve the above problems in the prior art, the present invention provides an application of a humidity-responsive composite material in resisting ion corrosion, which is particularly suitable for the application of concrete in resisting ion corrosion in harsh service environments.

[0008] (II) Technical solution

[0009] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0010] The invention discloses an application of a composite material with humidity responsiveness in resisting ion corrosion, wherein the composite material is a mixture of modified nano zeolite particles and polysiloxane organic solution.

[0011] In the application as described above, preferably, the mass ratio of the modified nano zeolite particles to the polysiloxane organic solution is 1:10 to 1:15.

[0012] In the above application, preferably, the modified nano zeolite particles are nano zeolite particles modified with a silane coupling agent, wherein the silane coupling agent is a 3-aminopropyltriethoxysilane solution (KH-550), and the mass fraction of the silane coupling agent is 1.5-3%.

[0013] Furthermore, the modification treatment is firstly ultrasonic treatment, the ultrasonic time is 10 to 30 minutes, then constant temperature stirring, and finally drying treatment.

[0014] Furthermore, the conditions for the constant temperature stirring are a temperature of 80° C., a stirring speed of 300 to 500 rpm, and a stirring time of 20 to 30 min.

[0015] Furthermore, the drying temperature is 80° C. and the drying time is 2 to 4 hours.

[0016] In the application as described above, preferably, the polysiloxane organic solution is a deoxime type RTV silica gel solution or a dealcohol type RTV silica gel solution with a mass concentration of 10 to 30%.

[0017] In the application as described above, preferably, the mixture of the modified nano-zeolite particles and the polysiloxane organic solution is subjected to ultrasonic dispersion or stirring during mixing, and the ultrasonic time is 10 to 20 minutes.

[0018] As described above, preferably, the application is to apply the composite material to concrete crack repair and concrete anti-ion corrosion engineering by filling, spraying and coating.

[0019] When repairing concrete cracks, the composite material can be filled or sprayed and applied to the concrete cracks; when applying concrete to resist ion corrosion, the composite material can be coated or sprayed on the outside of the concrete.

[0020] As mentioned above, preferably, the composite material is used for resisting sulfate corrosion and chloride ion corrosion in concrete engineering of marine engineering, underground facilities and industrial buildings exposed to harsh environments.

[0021] The humidity-responsive composite material provided by the present invention will absorb moisture and solidify when encountering moisture invasion, and form an encapsulation structure with uniformly distributed modified nano zeolite particles, fill concrete cracks, and start the response mechanism of water absorption and swelling when continuously subjected to moisture invasion, release the nano zeolite particles encapsulated inside through bursting behavior, and form a hydrophobic barrier after water absorption and swelling to prevent further erosion of the corrosive solution. Its humidity response mechanism is a multiple cycle response, and the composite material will start the humidity response when encountering moisture-corrosive medium invasion, and gradually release nanoparticles through moisture absorption and swelling; when the erosion load stops, the humidity response stops, and when encountering moisture-corrosive medium invasion again, the humidity response mechanism will restart until the nanoparticles are completely released.

[0022] (III) Beneficial effects

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides an application of a humidity-responsive composite material in resistance to ion corrosion. The humidity-responsive composite material prepared by polysiloxane-carried modified nanoparticles is applied to the resistance of concrete to ion corrosion, which can effectively avoid the problem of repeated cracking of concrete, solve the problem of insufficient humidity responsiveness of traditional materials under humidity corrosion media, and solve the problems of slow response, uneven material release, and difficulty in effectively preventing the penetration of corrosion media in most materials in concrete repair and protection.

[0025] The application of a humidity-responsive composite material in resisting ion corrosion provided by the present invention is simple in use and can be used for repairing concrete projects exposed to harsh environments such as marine projects, underground facilities and industrial buildings. It can effectively resist sulfate corrosion and chloride ion corrosion and has broad application prospects. The present invention has created a new way for concrete to resist ion corrosion in harsh service environments and solved the problem of the need for repeated repair of defects in traditional mortar repairs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The diagram is a schematic diagram of the application mode of the humidity-responsive composite material of the present invention in the resistance of concrete to ion corrosion and the humidity response mechanism. DETAILED DESCRIPTION

[0027] The application mode and humidity response mechanism of the humidity responsive composite material of the present invention in the concrete anti-ion corrosion are as follows: Figure 1 As shown, an organic solvent mixed with polysiloxane and nano-zeolite particles, i.e., a humidity-responsive composite material, is poured or sprayed into concrete cracks and solidified after 24 hours to form an encapsulation structure; after the encapsulation structure absorbs moisture and bursts, the nanoparticles are gradually released on the eroded surface to adsorb and fix SO4 2- , Cl - Plasma can effectively resist the invasion of harmful ions and form a hydrophobic layer to further resist erosion.

[0028] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods, but the scope of use of the present invention is not limited to the following examples, and the raw materials used can be commercially available products.

[0029] Example 1

[0030] (1) Take a polysiloxane organic solution (specifically, a deoxime RTV silica gel solution with a mass concentration of 10%), which contains hydroxyl groups and hydrophobic groups and has excellent humidity responsiveness. Then weigh 10% of the mass of the hydroxyl-containing polysiloxane solution, wherein the modified nano zeolite particles are nano zeolite particles modified by a 1.5% mass fraction of 3-aminopropyltriethoxysilane solution (KH-550), and the modification treatment is first ultrasonic treatment for 30 minutes, followed by stirring at 80°C for 30 minutes, and finally drying at 80°C for 3 hours to obtain a specific surface area of ​​300m 2 / g, modified nano zeolite particles with a particle size of 100nm.

[0031] The modified nano-zeolite particles are uniformly dispersed in the above-mentioned polysiloxane organic solution. The nano-zeolite particles can be uniformly distributed in the solution by stirring or ultrasonic dispersion technology, thereby obtaining a humidity-responsive composite material (suspension). During ultrasonic dispersion, ultrasonication can be performed for 20 minutes.

[0032] (2) A batch of C30 ordinary concrete test blocks with a size of 100 mm × 100 mm × 100 mm were prepared. After curing for 28 days, artificial cracks with a width of 0.1-1 mm and a length and depth of no more than 60 mm were made by the embedding method. The prepared humidity-responsive composite material (suspension) was injected into the concrete cracks by filling or spraying.

[0033] (3) Ultrasonic testing is used to determine whether the concrete test blocks are repaired to determine their repair period. The concrete test blocks in (2) are subjected to standard curing for 3 days and then their compressive strength is measured. The compressive strength is also tested after immersion in a 5% sodium sulfate solution for 30 days and the erosion damage at the cracks is observed.

[0034] Example 2

[0035] (1) A polysiloxane organic solution (specifically, a dealcoholized RTV silica gel solution with a mass concentration of 15%) was selected. The solution contained hydroxyl groups and hydrophobic groups and had excellent humidity responsiveness. Then, 15% of the mass of the solution was weighed to obtain modified nano-zeolite particles (with a specific surface area of ​​300 m 2 / g, particle size is 100nm), which is evenly dispersed in the above-mentioned polysiloxane solution, and the nano zeolite particles are evenly distributed in the solution by stirring or ultrasonic dispersion technology, thus obtaining a humidity-responsive composite material (suspension), and ultrasonication for 15min can be selected.

[0036] The modified nano-zeolite particles are obtained by mixing a silane coupling agent KH-550 solution with a mass fraction of 1.5% and nano-zeolite particles in a mass ratio of 10:1, followed by ultrasonic dispersion for 20 minutes, constant temperature stirring at 80°C (350 rpm) for 30 minutes, and drying at 80°C for 2.5 hours.

[0037] (2) A batch of C30 ordinary concrete test blocks with a size of 100 mm × 100 mm × 100 mm were prepared. After curing for 28 days, artificial cracks with a width of 0.1-1 mm and a length and depth of no more than 60 mm were made by the embedding method. The prepared humidity-responsive composite material (suspension) was injected into the concrete cracks by filling or spraying.

[0038] (3) Ultrasonic testing is used to determine whether the concrete test blocks are repaired to determine their repair period. The concrete test blocks in (2) are subjected to standard curing for 3 days and then their compressive strength is measured. The compressive strength is also tested after immersion in a 5% sodium sulfate solution for 30 days and the erosion damage at the cracks is observed.

[0039] Example 3

[0040] (1) A polysiloxane organic solution (20% deoxime RTV silica gel solution) containing hydroxyl groups and hydrophobic groups with excellent humidity responsiveness was selected. Then, 15% of the mass of the solution was weighed to obtain modified nano-zeolite particles (with a specific surface area of ​​300 m 2 / g, particle size of 150nm), uniformly disperse it in the above polysiloxane solution, and use stirring or ultrasonic dispersion technology to make the nano zeolite particles uniformly distributed in the solution to obtain a humidity-responsive composite material (suspension), and ultrasonication for 15min is optional.

[0041] The modified nano zeolite particles are obtained by mixing a 2% mass fraction of 3-aminopropyltriethoxysilane solution (KH-550) with nano zeolite particles in a mass ratio of 15:1, ultrasonically dispersing for 25 minutes, stirring at 80°C (400 rpm) for 25 minutes, and drying at 80°C for 3 hours.

[0042] (2) A batch of ordinary concrete cylindrical specimens with a diameter of 100 mm ± 1 mm and a height of 50 mm ± 2 mm were prepared. After curing for 28 days, artificial cracks with a width of 0.1-1 mm and a length and depth of no more than 60 mm were made by the embedding method. The prepared humidity-responsive composite material (suspension) was injected into the cracks of the above cylindrical specimens by filling or spraying.

[0043] (3) After the cylinder in (2) is cured for 7 days, its resistance to chloride ion penetration is tested in accordance with standard T0580-2020 "Test method for chloride ion penetration resistance of cement concrete (electric flux method)".

[0044] Example 4

[0045] (1) A moisture-curable hydroxyl-containing polysiloxane solution (a 25% dealcoholized RTV silica gel solution) was selected. The solution contained hydroxyl groups and hydrophobic groups and had excellent humidity responsiveness. Then, 15% of the mass of the solution was weighed and modified nano-zeolite particles (with a specific surface area of ​​300 m 2 / g, particle size of 100nm), uniformly disperse it in the above polysiloxane solution, and use stirring or ultrasonic dispersion technology to make the nano zeolite particles uniformly distributed in the solution to obtain a humidity-responsive composite material (suspension), and stirring for 30 minutes is optional.

[0046] The modified nano zeolite particles are obtained by mixing a 3% mass fraction of 3-aminopropyltriethoxysilane solution (KH-550) with nano zeolite particles in a mass ratio of 15:1, ultrasonically dispersing for 25 minutes, stirring at a constant temperature of 80°C (300 rpm) for 30 minutes, and drying at 80°C for 2 hours.

[0047] (2) A batch of ordinary concrete cylindrical specimens with a diameter of 100 mm ± 1 mm and a height of 50 mm ± 2 mm were prepared. After curing for 28 days, artificial cracks with a width of 0.1-1 mm and a length and depth of no more than 60 mm were made by the embedding method. The prepared humidity-responsive composite material (suspension) was injected into the cracks of the above cylindrical specimens by filling or spraying.

[0048] (3) After the cylinder in (2) is cured for 7 days, its resistance to chloride ion penetration is tested in accordance with standard T0580-2020 "Test method for chloride ion penetration resistance of cement concrete (electric flux method)".

[0049] Comparative Example 1

[0050] (1) A batch of C30 ordinary concrete test blocks with a size of 100 mm × 100 mm × 100 mm were prepared. After curing for 28 days, artificial cracks with a width of 0.1-0.1 mm and a length and depth of no more than 60 mm were made by the embedding method;

[0051] (2) Prepare a slurry repair material with the same water-cement ratio as the concrete test block in (1), and inject it into the above concrete cracks by filling or spraying.

[0052] (3) Ultrasonic testing is used to determine whether the concrete test blocks are repaired to determine their repair period. The concrete test blocks in (2) are subjected to standard curing for 3 days and then their compressive strength is measured. The compressive strength is also tested after immersion in a 5% sodium sulfate solution for 30 days and the erosion damage at the cracks is observed.

[0053] Comparative Example 2

[0054] (1) A batch of ordinary concrete cylindrical specimens with a diameter of 100 mm ± 1 mm and a height of 50 mm ± 2 mm were prepared. After curing for 28 days, artificial cracks with a width of 0.1-1 mm and a length and depth of no more than 60 mm were produced using the embedding method.

[0055] (2) Prepare a slurry repair material with the same water-cement ratio as the concrete specimen in (1), and inject it into the cracks of the cylindrical specimen by filling or spraying.

[0056] (3) After the cylinder in (2) is cured for 7 days, its resistance to chloride ion penetration is tested in accordance with standard T0580-2020 "Test method for chloride ion penetration resistance of cement concrete (electric flux method)".

[0057] The test results of the above embodiments and comparative examples are shown in Tables 1 and 2, where the compressive strength is obtained by testing with reference to the "Standard for Test Methods for Physical and Mechanical Properties of Concrete" GB / T 50081-2019.

[0058] Table 1 Test results

[0059]

[0060] Table 2 Test results

[0061]

[0062] Through the above experiments, it is verified that the humidity-responsive composite material prepared by polysiloxane-carried modified nanoparticles is applied in the resistance to ion corrosion, especially in the concrete resistance to ion corrosion to repair concrete cracks, and improve the concrete structure's resistance to sulfate corrosion and chloride ion corrosion. The humidity-responsive composite material of the present invention can effectively repair concrete cracks exposed to corrosive environments, and prevent further penetration of corrosive media, significantly improving the service life of concrete structures. Compared with the existing traditional repair technology, the nano zeolite of the present invention absorbs corrosive ions through its porous structure to prevent them from further corroding the concrete structure. At the same time, polysiloxane is transformed into a hydrophobic barrier after absorbing water, preventing the penetration of moisture and other corrosive media, and providing long-term protection. The present invention has created a new way for concrete to resist ion corrosion in harsh service environments, solving the problem of one-time repair defects of traditional mortar repairs.

[0063] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any person skilled in the art can use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. Application of a humidity-responsive composite material in resisting ion corrosion, characterized in that: The composite material is a mixture of modified nano zeolite particles and polysiloxane organic solution.

2. The use according to claim 1, characterized in that The mass ratio of the modified nano zeolite particles to the polysiloxane organic solution is 1:10 to 1:

15.

3. The use according to claim 1, characterized in that The modified nano zeolite particles are nano zeolite particles modified with a silane coupling agent, wherein the silane coupling agent is a 3-aminopropyltriethoxysilane solution, and the mass fraction of the silane coupling agent is 1.5-3%.

4. The use according to claim 3, characterized in that The modification treatment is firstly ultrasonic treatment, the ultrasonic time is 10 to 30 minutes, then constant temperature stirring, and finally drying treatment.

5. The use according to claim 4, characterized in that The conditions for the constant temperature stirring are: a temperature of 80° C., a stirring speed of 300 to 500 rpm, and a stirring time of 20 to 30 min.

6. The use according to claim 4, characterized in that The temperature of the drying treatment is 80° C., and the drying time is 2 to 4 hours.

7. The use according to claim 1, characterized in that The polysiloxane organic solvent is a deoxime type RTV silica gel solution or a dealcohol type RTV silica gel solution with a mass concentration of 10-30%.

8. The use according to claim 1, characterized in that The mixture of the modified nano-zeolite particles and the polysiloxane organic solvent is subjected to ultrasonic dispersion or stirring during mixing, and the ultrasonic time is 10 to 20 minutes.

9. The use according to claim 1, characterized in that The application is to apply the composite material to concrete crack repair and concrete anti-ion corrosion engineering by filling, spraying and coating.

10. The use according to claim 1, characterized in that The application is to use the composite material in marine engineering, underground facilities and industrial buildings to resist sulfate corrosion and chloride ion corrosion in concrete engineering exposed to harsh environments.

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