Preparation process of anti-chloride-erosion solid waste-based marine concrete material

Abstract

The application discloses a preparation process of a solid waste-based marine concrete material resistant to chlorine ion erosion, and comprises the following steps: (1) mixing multi-walled carbon nanotubes with Fe 2+ and / or Fe 3+ solution, and then standing; separating the carbon nanotubes, drying the carbon nanotubes, adding NaBH4 solution, and then standing to obtain Fe@MWCNT; (2) mixing Fe@MWCNT with iron acetate solution, standing, then separating solid substances, adding the solid substances into lye, and heating and keeping warm to obtain Fe-Fe(OH)2@MWCNT; (3) adding Fe-Fe(OH)2@MWCNT into N,N,N-trimethylglycine solution, adding Fe 2+ and / or Fe 3+ , and then standing to obtain a chlorine erosion-resistant agent; and (4) using granulated blast furnace slag powder, sulfate, alkaline activator and the chlorine erosion-resistant agent as raw materials to prepare the concrete material. The application effectively improves the ability of the concrete to resist chlorine ion erosion by using the chlorine erosion-resistant agent formed based on the carbon nanotubes.

Description

Technical Field

[0001] This invention relates to the field of supersulfate cement technology, specifically to a preparation process for a chloride ion-resistant solid waste-based marine concrete material. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Solid waste-based cement (SWC) refers to cementitious materials formed primarily from industrial or municipal solid waste. Cross-sea bridges, port terminals, offshore wind power foundations, artificial islands and reefs, and deep-sea drilling platforms are crucial engineering projects for human development of the ocean. Concrete is a vital building material for these projects, consumed in enormous quantities. The production of traditional Portland cement (OPC) is highly dependent on natural resources such as limestone and requires high-temperature calcination, making it a typical energy-intensive and carbon-intensive industry. Statistics show that the cement industry contributes approximately 8% of global anthropogenic carbon dioxide emissions while consuming large amounts of minerals and energy. Therefore, the green transformation of the traditional cement industry is urgently needed. Applying SWC to marine engineering construction not only facilitates the disposal and resource utilization of large quantities of solid waste but also significantly reduces the cement industry's carbon emissions, energy consumption, and dependence on natural resources at their source.

[0004] However, concrete structures in marine environments are subjected to severe tests from complex dynamic loads such as wind, waves, and tides over long periods. A more insidious and destructive threat comes from the chemical corrosive media in seawater. Among these, chloride ion (Cl⁻) corrosion is considered one of the core factors leading to the deterioration and even premature failure of reinforced concrete structures in marine engineering. Due to its small radius, high reactivity, and excellent penetrating power, chloride ions can migrate from the surface to the interior of the concrete structure through various mechanisms such as diffusion, penetration, and capillary adsorption via the pores and microcracks within the concrete, thereby causing corrosion of the reinforcing steel. Therefore, developing concrete materials resistant to chloride ion corrosion is crucial for ensuring the lifespan of marine engineering projects and maintaining the safety and durability of critical infrastructure. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a preparation process for chloride ion-resistant solid waste-based marine concrete materials. This process effectively enhances the concrete's resistance to chloride ion erosion by employing a chloride-resistant agent based on carbon nanotubes, while also improving the mechanical properties of the concrete material. Specifically, the technical solution of this invention is as follows.

[0006] A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Adding multi-walled carbon nanotubes to Fe 2+ and / or Fe 3+ The solution was subjected to ultrasonic treatment and then allowed to stand. After completion, the carbon nanotubes were separated, dried, and then NaBH4 solution was added and allowed to stand. The solid product was then separated, washed, and vacuum dried to obtain elemental iron-modified carbon nanotubes (Fe@MWCNT).

[0007] (2) The Fe@MWCNT was added to the ferric acetate solution, stirred and allowed to stand. The solid was then separated and added to the alkaline solution. After heating and keeping warm, Fe-Fe(OH)2@MWCNT was obtained.

[0008] (3) Add the Fe-Fe(OH)2@MWCNT to the N,N,N-trimethylglycine solution, stir well, let stand, and then add Fe 2+ and / or Fe 3+ The mixture is then stirred. After completion, the solids are separated and dried to obtain the chlorine-resistant agent.

[0009] (4) Using granulated blast furnace slag powder, sulfate activator, alkaline activator, silica fume, coarse aggregate, fine aggregate, the aforementioned chlorine corrosion resistant agent, calcium stearate powder, and water-reducing agent as raw materials, mechanically mix them with mixing water to obtain the aforementioned solid waste-based marine concrete material.

[0010] Further, in step (1), the multi-walled carbon nanotubes and Fe 2+ and / or Fe 3+ The solution ratio is 1g:10~20mL. Optionally, the Fe... 2+ and / or Fe 3+ The concentration of the solution is 3~5 mol / L.

[0011] Further, in step (1), the ultrasonic treatment time is 5-10 minutes. Optionally, the settling time is not less than 20 minutes.

[0012] Further, in step (1), the ratio of carbon nanotubes to NaBH4 solution is 1g: 20~35mL. Optionally, the concentration of the NaBH4 solution is 0.4~0.7mol / L.

[0013] Further, in step (1), after adding the NaBH4 solution, let it stand for 30~45 minutes.

[0014] Furthermore, in step (1), the vacuum drying temperature is 90~110℃ and the time is 40~60min.

[0015] Further, in step (2), the ratio of Fe@MWCNT to ferric acetate solution is 1g:30~50mL. Optionally, the concentration of the ferric acetate solution is 0.2~0.45mol / L.

[0016] Furthermore, in step (2), the settling time after ultrasonic treatment is 10~15 min.

[0017] Further, in step (2), the ratio of the solid to the alkaline solution is 1g:30~50mL. Optionally, the concentration of the alkaline solution is 0.1~0.2mol / L. The alkaline solution includes at least one of sodium hydroxide solution, potassium hydroxide solution, etc.

[0018] Furthermore, in step (2), the heating temperature is 60~70℃ and the holding time is 2~4 hours.

[0019] Further, in step (3), the ratio of Fe-Fe(OH)2@MWCNT to N,N,N-trimethylglycine solution is 1g:20~30mL. Optionally, the concentration of N,N,N-trimethylglycine solution is 1~1.5mol / L.

[0020] Furthermore, in step (3), the settling time is 30~40 minutes.

[0021] Further, in step (3), the Fe 2+ and / or Fe 3+ The molar ratio of N,N,N-trimethylglycine to N,N,N-trimethylglycine is 2-2.3:1. Optionally, the stirring time is 5-15 min.

[0022] Furthermore, in steps (1) and (3), the Fe 2+ It is provided by at least one of FeCl2, FeSO4, Fe(NO3)2, etc.

[0023] Furthermore, in steps (1) and (3), the Fe 3+ It is provided by at least one of FeCl3, Fe2(SO4)3, Fe(NO3)3, etc.

[0024] Further, in step (4), the proportions of each component in the raw material are as follows: 75-85 parts by weight of granulated blast furnace slag powder, 10-17 parts by weight of sulfate activator, 2-4.8 parts by weight of alkaline activator, 10-13 parts by weight of silica fume, 205-240 parts by weight of coarse aggregate, 130-155 parts by weight of fine aggregate, 8.5-11 parts by weight of chlorine corrosion resistant agent, 6-8 parts by weight of calcium stearate powder, and 1.45-2.1 parts by weight of water reducing agent.

[0025] Furthermore, in step (4), the mass ratio of the mixing water to the total mass of granulated blast furnace slag powder and silica fume is 0.32~0.36:1.

[0026] Furthermore, in step (4), the sulfate activator includes at least one of the following: gypsum dihydrate, anhydrous gypsum, phosphogypsum, desulfurized gypsum, etc.

[0027] Furthermore, in step (4), the alkaline activator includes at least one of calcium hydroxide, quicklime, carbide slag, etc.

[0028] Further, in step (4), the water-reducing agent includes at least one of the following: polycarboxylate water-reducing agent, naphthalene water-reducing agent, lignin sulfonate water-reducing agent, etc.

[0029] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects: This invention first uses multi-walled carbon nanotubes as a carrier to load elemental iron to form Fe@MWCNTs. Then, these Fe@MWCNTs are added to a ferric acetate solution, where the provided iron ions activate the surface of the elemental iron on the Fe@MWCNTs to Fe. 2+ After adding an alkaline solution and undergoing aging, a ferrous hydroxide coating layer is formed on the surface of elemental iron. Finally, this invention uses N,N,N-trimethylglycine to treat the Fe-Fe(OH)2@MWCNT obtained after the above modification treatment, loading N,N,N-trimethylglycine onto the inner wall of the multi-walled carbon nanotubes and the surface of the ferrous hydroxide coating layer of elemental iron. Simultaneously, the carboxyl groups on the N,N,N-trimethylglycine are used to capture and store Fe. 2+ and / or Fe 3+ A chloride-resistant agent was subsequently obtained, which not only possesses good dispersibility, facilitating more uniform distribution in concrete materials, but also effectively enhances the concrete structure's resistance to chloride ion erosion and its strength. When a concrete structure prepared using this chloride-resistant agent is invaded by chloride ions, the -N⁺(CH₃)₃ group on the N,N,N-trimethylglycine adsorbs and aggregates the chloride ions into the interlayer gaps of multi-walled carbon nanotubes and on the surface of the iron coating layer, thus delaying further diffusion. As the chloride ion concentration on the surface of the coating layer increases, the coating layer is damaged, exposing the iron core particles, which are converted into expansive products such as iron oxide under the influence of air and moisture. Simultaneously, Fe₂O₃ stored on the N,N,N-trimethylglycine is captured... 2+ and / or Fe 3+The above reaction can also form expansive products. Due to the constraint of the concrete structure, the expansion mainly extends towards the inner cavity and interlayer of the multi-walled carbon nanotubes, thereby sealing chloride ions within the multi-walled carbon nanotubes and better preventing chloride ion diffusion. Furthermore, the anti-chloride erosion agent located at the crack can utilize the formed expansive products to fill and seal the crack, helping to reduce chloride ion intrusion. This invention utilizes the chloride ion enrichment effect of N,N,N-trimethylglycine to not only inhibit chloride ion diffusion but also to activate the chloride ion sealing and retention mechanism at the appropriate time, maximizing the ability of the concrete structure to resist chloride ion erosion and making the concrete structure better adaptable to the marine environment. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention and do not constitute an undue limitation of the invention.

[0031] Figure 1 The image shows a sample of the chlorine-resistant erosion agent prepared in Example 1 below.

[0032] Figure 2 The following is a diagram showing the compressive strength test results for Example 1.

[0033] Figure 3 The image shows a sample of the chlorine-resistant erosion agent prepared in Example 2 below.

[0034] Figure 4 The following is a diagram showing the compressive strength test results for Example 2.

[0035] Figure 5 The image shows a sample of the chlorine-resistant erosion agent prepared in Example 3 below.

[0036] Figure 6 The following is a diagram showing the compressive strength test results for Example 3.

[0037] Figure 7 The image shows a sample of the chlorine-resistant erosion agent prepared in Example 4 below.

[0038] Figure 8 The image shows a sample of the chlorine-resistant erosion agent prepared in Example 5 below.

[0039] Figure 9 The image shows a sample of the chlorine-resistant erosion agent prepared in Example 6 below. Detailed Implementation

[0040] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. The preferred embodiments and materials described in this invention are for illustrative purposes only. The technical solutions of the present invention will now be further described with reference to specific embodiments.

[0041] Example 1: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with a 4.5 mol / L Fe(NO3)3 solution at a ratio of 1 g: 15 mL and ultrasonicated for 10 min, then allowed to stand for 25 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.6 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 30 mL. After standing for 40 min, the solid product was separated by centrifugation, washed with deionized water, and dried under vacuum at 100 °C for 50 min to obtain Fe@MWCNT.

[0042] (2) The Fe@MWCNT was mixed with a 0.35 mol / L ferric acetate solution at a ratio of 1 g: 40 mL and stirred until homogeneous. After standing for 10 min, the mixture was centrifuged to separate the solid. A 0.2 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 30 mL: 1 g to the solid. The resulting mixture was then heated to 60 °C and kept at that temperature for 4 hours for aging. After aging, the solid product was centrifuged to obtain Fe-Fe(OH)2@MWCNT.

[0043] (3) Add the Fe-Fe(OH)2@MWCNT to a 1.2 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g:25 mL, stir well, and let stand for 30 min. Then, according to Fe... 3+ Fe(NO3)3 was added to the system at a molar ratio of 2.2:1 to N,N,N-trimethylglycine, and the mixture was stirred for 10 min. Afterward, the solid was separated and dried to obtain the chlorine-resistant agent (e.g., ...). Figure 1 (As shown).

[0044] (4) Take the following raw materials in the following proportions: 80 parts by weight of granulated blast furnace slag powder, 13 parts by weight of dihydrate gypsum powder, 3.5 parts by weight of calcium carbide slag powder, 11 parts by weight of silica fume, 215 parts by weight of coarse aggregate, 142 parts by weight of fine aggregate, 10 parts by weight of the chlorine erosion resistant agent of this embodiment, 7 parts by weight of calcium stearate powder, and 1.6 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 31 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0045] Performance Testing: 1. The chloride ion migration coefficient (DL) of the solid waste-based marine concrete material prepared in this embodiment was tested according to the "Standard for Test Methods of Long-Term Performance and Durability of Concrete" (GBT 50082-2024). RCM 2. Test the 28-day compressive strength of the solid waste-based marine concrete material according to the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" (GBT 50081-2019). Figure 2 As shown), the result is: D RCM =0.39×10 -12 m / s, 28d compressive strength = 51.73MPa.

[0046] Example 2: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with a 3 mol / L FeSO4 solution at a ratio of 1 g: 20 mL and ultrasonicated for 10 min, then allowed to stand for 25 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.4 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 35 mL. After standing for 30 min, the solid product was separated by centrifugation, washed with deionized water, and dried under vacuum at 90 °C for 60 min to obtain Fe@MWCNT.

[0047] (2) The Fe@MWCNT was mixed with a 0.2 mol / L ferric acetate solution at a ratio of 1 g: 50 mL and stirred until homogeneous. After standing for 10 min, the mixture was centrifuged to separate the solid. A 0.15 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 40 mL: 1 g to the solid. The resulting mixture was then heated to 70 °C and kept at that temperature for 2 hours for aging. After aging, the solid product was centrifuged to obtain Fe-Fe(OH)2@MWCNT.

[0048] (3) Add the Fe-Fe(OH)2@MWCNT to a 1.0 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g:30 mL, stir well, and let stand for 40 min. Then, according to Fe... 2+ FeSO4 was added to the system at a molar ratio of 2:1 to N,N,N-trimethylglycine, and the mixture was stirred for 5 minutes. Afterward, the solid was separated and dried to obtain the chlorine-resistant agent (e.g., Figure 3 (As shown).

[0049] (4) Take the following proportions of raw materials: 75 parts by weight of granulated blast furnace slag powder, 10 parts by weight of desulfurized gypsum powder, 2 parts by weight of calcium hydroxide powder, 10 parts by weight of silica fume, 205 parts by weight of coarse aggregate, 130 parts by weight of fine aggregate, 8.5 parts by weight of the chlorine erosion resistant agent of this embodiment, 6 parts by weight of calcium stearate powder, and 1.45 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 27.2 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0050] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM ) and 28-day compressive strength (e.g. Figure 4 As shown), the result is: D RCM =0.27×10 - 12 m / s, 28d compressive strength = 53.08MPa.

[0051] Example 3: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with a 5 mol / L Fe(NO3)2 solution at a ratio of 1 g: 10 mL and ultrasonicated for 5 min, then allowed to stand for 20 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.7 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 20 mL. After standing for 45 min, the solid product was separated by centrifugation, washed with deionized water, and dried under vacuum at 110 °C for 40 min to obtain Fe@MWCNT.

[0052] (2) The Fe@MWCNT was mixed with a 0.45 mol / L ferric acetate solution at a ratio of 1 g: 30 mL and stirred until homogeneous. After standing for 15 min, the mixture was centrifuged to separate the solid. A 0.1 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 50 mL: 1 g to the solid. The resulting mixture was then heated to 60 °C and kept at that temperature for 3 hours for aging. After aging, the solid product was centrifuged to obtain Fe-Fe(OH)2@MWCNT.

[0053] (3) Add the Fe-Fe(OH)2@MWCNT to a 1.5 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g:20 mL, stir well, and let stand for 35 min. Then, according to Fe... 3+ Fe2(SO4)3 was added to the system at a molar ratio of 2.3:1 to N,N,N-trimethylglycine, and the mixture was stirred for 15 min. Afterward, the solid was separated and dried to obtain the chlorine-resistant agent (e.g., ...). Figure 5 (As shown).

[0054] (4) Take the following raw materials in the following proportions: 85 parts by weight of granulated blast furnace slag powder, 17 parts by weight of phosphogypsum powder, 4.8 parts by weight of calcium hydroxide powder, 13 parts by weight of silica fume, 240 parts by weight of coarse aggregate, 155 parts by weight of fine aggregate, 11 parts by weight of the chlorine erosion resistant agent of this embodiment, 8 parts by weight of calcium stearate powder, and 2.1 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 35.3 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0055] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM ) and 28-day compressive strength (e.g. Figure 6 As shown), the result is: D RCM =0.46×10 - 12 m / s, 28d compressive strength = 50.14MPa.

[0056] Example 4: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with a 4.5 mol / L Fe(NO3)3 solution at a ratio of 1 g: 15 mL and ultrasonicated for 10 min, then allowed to stand for 25 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.6 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 30 mL. After standing for 40 min, the solid product was separated by centrifugation, washed with deionized water, and dried under vacuum at 100 °C for 50 min to obtain Fe@MWCNT.

[0057] (2) The Fe@MWCNT was mixed with a 0.35 mol / L ferric acetate solution at a ratio of 1 g: 40 mL and stirred until homogeneous. The mixture was then allowed to stand for 10 min before centrifugation to separate the solid. A 0.2 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 30 mL: 1 g to the solid. The resulting mixture was then heated to 60°C and kept at that temperature for 4 hours for aging. After aging, the solid product was separated by centrifugation to obtain Fe-Fe(OH)2@MWCNT (e.g., ...). Figure 7 As shown in the figure, it is used as the chlorine erosion resistant agent in this embodiment.

[0058] (3) Take the following raw materials in the following proportions: 80 parts by weight of granulated blast furnace slag powder, 13 parts by weight of dihydrate gypsum powder, 3.5 parts by weight of calcium carbide slag powder, 11 parts by weight of silica fume, 215 parts by weight of coarse aggregate, 142 parts by weight of fine aggregate, 10 parts by weight of the chlorine erosion resistant agent of this embodiment, 7 parts by weight of calcium stearate powder, and 1.6 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 31 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0059] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM The results for the 28-day compressive strength are: D RCM =1.68×10 -12 m / s, 28d compressive strength = 50.89MPa.

[0060] Example 5: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with 0.2 mol / L ferric acetate solution at a ratio of 1 g: 50 mL and stirred until homogeneous. The mixture was then allowed to stand for 10 min and centrifuged to separate the solid. A 0.15 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 40 mL: 1 g to the solid. The resulting mixture was then heated to 70 °C and kept at that temperature for 2 hours for aging. After aging, the solid product was separated by centrifugation to obtain Fe(OH)3@MWCNT.

[0061] (2) Add the Fe(OH)3@MWCNT to a 1.0 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g:30 mL, stir well, and let stand for 40 min. Then, according to Fe... 2+ FeSO4 was added to the system at a molar ratio of 2:1 to N,N,N-trimethylglycine, and the mixture was stirred for 5 minutes. Afterward, the solid was separated and dried to obtain the chlorine-resistant agent (e.g., Figure 8 (As shown).

[0062] (3) Take the following raw materials in the following proportions: 75 parts by weight of granulated blast furnace slag powder, 10 parts by weight of desulfurized gypsum powder, 2 parts by weight of calcium hydroxide powder, 10 parts by weight of silica fume, 205 parts by weight of coarse aggregate, 130 parts by weight of fine aggregate, 8.5 parts by weight of the chlorine erosion resistant agent of this embodiment, 6 parts by weight of calcium stearate powder, and 1.45 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 27.2 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0063] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM The results for the 28-day compressive strength are: D RCM =1.94×10 -12 m / s, 28d compressive strength = 51.26MPa.

[0064] Example 6: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with a 4.5 mol / L Fe(NO3)3 solution at a ratio of 1 g: 15 mL and ultrasonicated for 10 min, then allowed to stand for 25 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.6 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 30 mL. After standing for 40 min, the solid product was separated by centrifugation, washed with deionized water, and dried under vacuum at 100 °C for 50 min to obtain Fe@MWCNT.

[0065] (2) Add the Fe@MWCNT to a 1.2 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g:25 mL, stir well, and let stand for 30 min. Then, proceed according to Fe... 3+ Fe(NO3)3 was added to the system at a molar ratio of 2.2:1 to N,N,N-trimethylglycine, and the mixture was stirred for 10 min. Afterward, the solid was separated and dried to obtain the chlorine-resistant agent (e.g., ...). Figure 9 (As shown).

[0066] (3) Take the following raw materials in the following proportions: 80 parts by weight of granulated blast furnace slag powder, 13 parts by weight of dihydrate gypsum powder, 3.5 parts by weight of calcium carbide slag powder, 11 parts by weight of silica fume, 215 parts by weight of coarse aggregate, 142 parts by weight of fine aggregate, 10 parts by weight of the chlorine erosion resistant agent of this embodiment, 7 parts by weight of calcium stearate powder, and 1.6 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 31 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0067] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM The results for the 28-day compressive strength are: D RCM =1.31×10 -12 m / s, 28d compressive strength = 49.57MPa.

[0068] Example 7: A preparation process for a chloride ion-resistant solid waste-based marine concrete material includes the following steps: (1) Multi-walled carbon nanotubes were mixed with a 5 mol / L Fe(NO3)2 solution at a ratio of 1 g: 10 mL and ultrasonicated for 5 min, then allowed to stand for 20 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.7 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 20 mL. After standing for 45 min, the solid product was separated by centrifugation, washed with deionized water, and dried under vacuum at 110 °C for 40 min to obtain Fe@MWCNT.

[0069] (2) The Fe@MWCNT was mixed with a 0.45 mol / L ferric acetate solution at a ratio of 1 g: 30 mL and stirred until homogeneous. After standing for 15 min, the mixture was centrifuged to separate the solid. A 0.1 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 50 mL: 1 g to the solid. The resulting mixture was then heated to 60 °C and kept at that temperature for 3 hours for aging. After aging, the solid product was centrifuged to obtain Fe-Fe(OH)2@MWCNT.

[0070] (3) Add the Fe-Fe(OH)2@MWCNT to a 1.5 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g: 20 mL, stir well, and let stand for 35 min. After completion, separate the solid and dry it to obtain the chlorine erosion resistant agent.

[0071] (4) Take the following raw materials in the following proportions: 85 parts by weight of granulated blast furnace slag powder, 17 parts by weight of phosphogypsum powder, 4.8 parts by weight of calcium hydroxide powder, 13 parts by weight of silica fume, 240 parts by weight of coarse aggregate, 155 parts by weight of fine aggregate, 11 parts by weight of the chlorine erosion resistant agent of this embodiment, 8 parts by weight of calcium stearate powder, and 2.1 parts by weight of polycarboxylate superplasticizer, wherein: the coarse aggregate is crushed stone with a particle size distribution between 10 and 15 mm, and the fine aggregate is river sand with a particle size distribution between 1 and 3 mm. Add the above raw materials to a mixer and mechanically stir for 3 minutes, then add 35.3 parts by weight of mixing water and mechanically stir for 2 minutes to obtain solid waste-based marine concrete material.

[0072] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM The results for the 28-day compressive strength are: D RCM =0.83×10 -12 m / s, 28d compressive strength = 49.91MPa.

[0073] Example 8:A preparation process for a chloride-resistant solid waste-based marine concrete material is the same as in Example 3 above, except that the chloride-resistant agent in this example is prepared using the following method: (1) Single-walled carbon nanotubes were mixed with a 5 mol / L Fe(NO3)2 solution at a ratio of 1 g: 10 mL, and then sonicated for 5 min, followed by standing for 20 min. After completion, the carbon nanotubes were separated by centrifugation and dried under vacuum at 80 °C. Then, a 0.7 mol / L NaBH4 solution was added dropwise to the dried product at a ratio of 1 g: 20 mL. After standing for 45 min, the solid product was separated by centrifugation, washed with deionized water, and then dried under vacuum at 110 °C for 40 min to obtain Fe@SWCNT.

[0074] (2) The Fe@SWCNT was mixed with a 0.45 mol / L ferric acetate solution at a ratio of 1 g: 30 mL and stirred until homogeneous. After standing for 15 min, the mixture was centrifuged to separate the solid. A 0.1 mol / L sodium hydroxide solution was added dropwise to the mixture at a ratio of 50 mL: 1 g to the solid. The resulting mixture was then heated to 60 °C and kept at that temperature for 3 hours for aging. After aging, the solid product was centrifuged to obtain Fe-Fe(OH)2@SWCNT.

[0075] (3) Add the Fe-Fe(OH)2@SWCNT to a 1.5 mol / L N,N,N-trimethylglycine solution in a ratio of 1 g:20 mL, stir well, and let stand for 35 min. Then, according to Fe... 3+ Fe2(SO4)3 was added to the system at a molar ratio of 2.3:1 to N,N,N-trimethylglycine, and the mixture was stirred for 15 min. After the reaction was completed, the solid was separated and dried to obtain the chlorine-resistant agent.

[0076] Performance testing: The chloride ion migration coefficient (Di) of the solid waste-based marine concrete material prepared in this embodiment was tested using the same method as in Example 1 above. RCM The results for the 28-day compressive strength are: D RCM =1.02×10 -12 m / s, 28d compressive strength = 47.61MPa.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A preparation process for a chloride ion-resistant solid waste-based marine concrete material, characterized in that, Includes the following steps: (1) Adding multi-walled carbon nanotubes to Fe 2+ and / or Fe 3+ The solution was subjected to ultrasonic treatment and then allowed to stand. After completion, the carbon nanotubes were separated, dried, and then NaBH4 solution was added to the solution and allowed to stand. The solid product was then separated, washed, and vacuum dried to obtain Fe@MWCNT. (2) The Fe@MWCNT was added to ferric acetate solution, stirred and allowed to stand. The solid was then separated and added to alkaline solution. After heating and keeping warm, Fe-Fe(OH)2@MWCNT was obtained. (3) Add the Fe-Fe(OH)2@MWCNT to the N,N,N-trimethylglycine solution, stir until homogeneous, let stand, and then add Fe to the solid-liquid system. 2+ and / or Fe 3+ The mixture is then stirred; after completion, the solids are separated and dried to obtain the chlorine-resistant agent. (4) Take the following raw materials in the following proportions: 75-85 parts by weight of granulated blast furnace slag powder, 10-17 parts by weight of sulfate activator, 2-4.8 parts by weight of alkaline activator, 10-13 parts by weight of silica fume, 205-240 parts by weight of coarse aggregate, 130-155 parts by weight of fine aggregate, 8.5-11 parts by weight of the anti-chlorine corrosion agent, 6-8 parts by weight of calcium stearate powder, and 1.45-2.1 parts by weight of water-reducing agent; mix the above raw materials with mixing water mechanically until uniform to obtain the solid waste-based marine concrete material.

2. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the multi-walled carbon nanotubes and Fe 2+ and / or Fe 3+ The solution ratio is 1g: 10~20mL.

3. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the Fe 2+ and / or Fe 3+ The concentration of the solution is 3~5 mol / L.

4. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the ultrasonic treatment time is 5 to 10 minutes.

5. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the settling time after ultrasonic treatment is not less than 20 minutes.

6. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the ratio of carbon nanotubes to NaBH4 solution is 1g: 20~35mL.

7. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the concentration of the NaBH4 solution is 0.4~0.7 mol / L.

8. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), after adding the NaBH4 solution, let it stand for 30~45 minutes.

9. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (1), the vacuum drying temperature is 90~110℃ and the time is 40~60min.

10. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the ratio of Fe@MWCNT to ferric acetate solution is 1g: 30~50mL.

11. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the concentration of the ferric acetate solution is 0.2~0.45 mol / L.

12. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the settling time is 10-15 minutes.

13. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the ratio of the solid to the alkaline solution is 1g: 30~50mL.

14. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the concentration of the alkaline solution is 0.1~0.2 mol / L.

15. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the alkaline solution includes at least one of sodium hydroxide solution and potassium hydroxide solution.

16. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (2), the heating temperature is 60~70℃ and the holding time is 2~4 hours.

17. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (3), the ratio of Fe-Fe(OH)2@MWCNT to N,N,N-trimethylglycine solution is 1g:20~30mL.

18. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (3), the concentration of the N,N,N-trimethylglycine solution is 1~1.5 mol / L.

19. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (3), the settling time is 30-40 minutes.

20. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (3), the Fe 2+ and / or Fe 3+ The molar ratio of N,N,N-trimethylglycine to N is 2~2.3:

1.

21. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In step (3), the stirring time is 5 to 15 minutes.

22. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In steps (1) and (3), the Fe 2+ It is provided by at least one of FeCl2, FeSO4, and Fe(NO3)2.

23. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to claim 1, characterized in that, In steps (1) and (3), the Fe 3+ It is provided by at least one of FeCl3, Fe2(SO4)3, and Fe(NO3)3.

24. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to any one of claims 1-23, characterized in that, In step (4), the mass ratio of the mixing water to the total mass of granulated blast furnace slag powder and silica fume is 0.32~0.36:

1.

25. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to any one of claims 1-23, characterized in that, In step (4), the sulfate activator includes at least one of the following: gypsum dihydrate, anhydrous gypsum, phosphogypsum, and desulfurized gypsum.

26. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to any one of claims 1-23, characterized in that, In step (4), the alkaline activator includes at least one of calcium hydroxide, quicklime, and carbide slag.

27. The preparation process of the chloride ion erosion resistant solid waste-based marine concrete material according to any one of claims 1-23, characterized in that, In step (4), the water-reducing agent includes at least one of polycarboxylate water-reducing agent, naphthalene-based water-reducing agent, and lignin sulfonate water-reducing agent.

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