Concrete surface strengthening method and system based on cooperation of electric field assisted permeation and electric curing

Abstract

The invention relates to a concrete surface strengthening method and system based on cooperation of electric field assisted permeation and electric curing, and the concrete surface strengthening method mainly comprises the following steps: through an electrified functional coating, electroosmosis migration and electric curing curing are integrated, the capillary permeation limit is broken through the low-voltage assisted permeation in the initial stage, and the electric field assisted permeation is carried out; and later-stage high-voltage maintenance realizes heat-electricity-chemical synergy. The invention also comprises a device system for implementing the method. According to the invention, a permeation-curing-hole sealing integrated reinforcing layer is formed through electric field time sequence regulation and control and coupling of an electroosmosis migration-thermocuring-electrochemical deposition triple mechanism, so that efficient surface protection and performance improvement of a concrete structure in a harsh environment are realized, the chloride ion diffusion coefficient is reduced, the adhesive force reaches 4.1-5.0 MPa, the 28-day compressive strength is improved by 9.2%, and the service life of the concrete structure is prolonged. And the method has engineering applicability.

Description

Technical Field

[0001] The present invention relates to a method and equipment for strengthening the surface layer of concrete, and in particular to a modification method for improving the durability of surface concrete by synergistically driving coating penetration through electric field and electrochemical curing, and an equipment system for implementing the method. Background Art

[0002] As the world's most widely used building material, concrete's durability directly determines the service life and safety of engineering structures. However, concrete's inherent porous structure makes it susceptible to intrusion by external corrosive media (such as chloride ions, carbon dioxide, and sulfates), leading to problems such as steel corrosion, freeze-thaw damage, and chemical corrosion. To improve concrete's durability, surface protection technologies (such as coating, infiltration crystallization, and electrochemical protection) are widely used.

[0003] Existing concrete protective coatings mainly rely on physical coverage or shallow penetration (usually less than 2mm) to block the corrosive medium, but the deep pores of concrete still provide diffusion channels for the corrosive medium. Studies have shown that the penetration depth needs to reach more than 5mm to significantly slow the diffusion of chloride ions. The electroosmosis method attempts to enhance the impermeability by driving the migration of charged particles through an electric field. However, due to its reliance on natural ions in the pore fluid, the migration efficiency is low, and a single electric field can easily cause local current overload and damage the concrete microstructure. Existing electroosmosis technology focuses more on the migration of inorganic salt solutions and is not combined with organic coatings, resulting in a lack of chemical bonding between the penetrating substance and the matrix, and insufficient long-term stability.

[0004] Electrical curing can accelerate cement hydration through electric fields and is often used to improve early strength. However, although direct current curing can induce the directional migration of calcium and silicon ions to reconstruct pores, it is difficult to form an interfacial interlock with the surface coating; and although alternating current curing can promote the formation of hydration products, it cannot synergize with protective technology. In addition, there have been many studies on optimizing pore structure by introducing functional ions such as calcium, silicon, and aluminum. However, these methods usually rely on the internal humidity conditions of concrete or use simple premixing and soaking processes, resulting in uneven ion distribution and low reaction efficiency. Moreover, they are not combined with electric field drive and polymer curing, making it difficult to achieve spatially matched synergistic reactions. The modification effect is limited to the surface layer and the effect is poor.

[0005] In summary, concrete surface modification faces three core challenges: First, it is difficult to coordinate penetration depth and interface strength. Shallow penetration cannot seal deep pores, and increasing penetration depth often comes at the expense of strength at the expense of increasing the water-cement ratio; second, the electric field energy efficiency and action dimension are insufficient. Single electro-osmosis or electrical curing technology has high energy consumption and single function, and lacks a staged coordinated regulation mechanism; third, the functional ion delivery and reaction pathway are mismatched. The simple introduction method leads to low ion utilization and the inability to form an ordered reaction network. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a concrete surface strengthening method based on the synergy of electric field assisted penetration and electrical curing, thereby increasing the penetration depth of the coating and improving the interface bonding ability between the coating and the concrete, so as to effectively extend the service life of concrete in harsh environments.

[0007] The second technical problem to be solved by the present invention is to provide a system for implementing the concrete surface strengthening method based on the coordination of electric field assisted penetration and electrical curing.

[0008] The technical solution adopted by the present invention to solve the first technical problem is a method for strengthening the concrete surface based on the synergy of electric field assisted migration and electrical curing, comprising the following steps:

[0009] S1. Preparation of charged functional coatings

[0010] The coating comprises at least a coating base liquid, a charge modifier, a soluble calcium source, a silicon source and an aluminum source;

[0011] S2. Electric field assisted penetration

[0012] Electrodes are embedded in the concrete and external electrodes are placed on the coating layer. After the concrete has initially set, a low voltage of 1 to 3 V / cm is applied to perform electric field-driven penetration.

[0013] S3. Electrical maintenance enhancement

[0014] After the infiltration is completed, the voltage is increased to 12-24V, and saturated Ca(OH)2 solution is used as the electrolyte, the pre-buried electrode inside the concrete is used as the cathode, and the external electrode is used as the anode for electrical curing enhancement.

[0015] Furthermore, step S1 further includes: a carbon nano-conductive substrate; the carbon nano-conductive substrate is any one of graphene or carbon nanotubes, and the addition amount thereof is 0 to 2 parts.

[0016] Furthermore, in step S1, the coating base liquid includes a water-based acrylic emulsion or a water-based epoxy resin emulsion.

[0017] Preferably, the present invention also provides a water-based acrylic functional coating, the raw material components of which include, by mass: 80 to 90 parts of acrylic ester emulsion, 0.5 to 5 parts of charged modifier, 0 to 2 parts of carbon nano conductive substrate, 2 to 10 parts of soluble calcium source, silicon source and aluminum source.

[0018] Preferably, the aqueous acrylic emulsion is an acrylic ester monomer copolymer emulsion with a solid content of 49-51%. At 25° C., the viscosity range is controlled at 50-500 mPa·s, and the pH value is 8-9, which is weakly alkaline.

[0019] In the present invention, charged modifiers and functional ions are uniformly mixed in the coating matrix to make the emulsion electronegative; the charged particles can undergo directionally migration under the action of the electric field, react with the hydrated cement paste to fill the surface pores; the heat generated by electrical curing promotes the in-situ polymerization of the coating to form an interlocking mechanism with the concrete matrix.

[0020] Furthermore, the charge modifier includes a cationic charge modifier or an anionic charge modifier.

[0021] Preferably, the cationic charge modifier is a cationic monomer methacryloyloxyethyltrimethylammonium chloride (DMC).

[0022] Preferably, the anionic charged modifier is one or more of acrylic acid monomer (AA) and sodium styrene sulfonate (SSS).

[0023] Furthermore, in step S1, the soluble calcium source is calcium nitrate or calcium acetate, the silicon source is silica sol or nano-silica particles, the aluminum source is sodium metaaluminate or aluminum sulfate, and the total addition amount of the soluble calcium source, silicon source and aluminum source is 2 to 10 parts.

[0024] Furthermore, in step S2, the electrodes inside the concrete are 304 stainless steel mesh electrodes or carbon fiber mesh electrodes; the embedded depth is 1 / 3 to 1 / 2 of the concrete thickness, and the electrode spacing is 100 to 200 mm.

[0025] Furthermore, in step S2, the external electrode is a titanium / platinum coated electrode.

[0026] Furthermore, in step S2, the external electrode of the coating layer is tightly bonded to the coating layer via a conductive gel; preferably, the conductive gel is a carboxymethyl cellulose solution containing 5 to 10 parts of NaCl.

[0027] Specifically, the external electrode can be selected as a positive electrode or a negative electrode according to the charge properties of the coating.

[0028] Furthermore, in step S2, the parameters of the electric field are: DC voltage gradient 1-3 V / cm, duration 1-2 hours, current density controlled at 0.5-2 A / m 2 .

[0029] Furthermore, in step S3, the electrolyte temperature is controlled at 40-60°C.

[0030] Furthermore, in step S3, the electrode spacing is adjusted to 50-100 mm; the electrical curing time is 4-8 hours, and the current density is maintained at 1-3 A / m 2 .

[0031] The technical solution adopted by the present invention to solve the second technical problem is a system for implementing the concrete surface strengthening method based on the synergy of electric field assisted migration and electrical curing, which comprises:

[0032] Functional coating module: used to prepare functional coatings and apply functional layers to the concrete surface;

[0033] Dual-mode power supply: with low voltage mode and high voltage mode, which can automatically switch output;

[0034] Electrode assembly: includes external electrodes in contact with the coating layer and internal electrodes embedded in the concrete;

[0035] Electrolyte supply unit: used to deliver saturated Ca(OH)2 solution to the concrete surface during the electrical curing stage;

[0036] The dual-mode power supply device has a built-in current monitoring module, which automatically switches to a high-voltage maintenance mode when the current drops to 30% of the initial value during the infiltration phase.

[0037] The method of the present invention first applies a low voltage gradient of 1 to 3 V / cm after the initial setting of the concrete, driving the directional migration of the charged coating containing functional ions, achieving deep penetration while avoiding damage to the concrete structure. Subsequently, the curing process is switched to 12 to 24 V DC, using Joule heat to promote in-situ crosslinking of the coating. The calcium, silicon, and aluminum ions in the electrolyte react with cement hydration products to seal the pores, creating a synergistic "penetration-curing-sealing" effect. Driven by the electric field, the functional ions are concentrated at the pore interface, reacting with cement components to form a nanoscale dense layer, breaking through the concentration gradient limitations of traditional processes. The charged modifier significantly enhances the coating interface stability through the dual mechanisms of electrostatic adsorption and chemical bonding.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) Through a phased electric field synergy mechanism, the initial low voltage (1-3 V / cm) avoids damage to the initial setting concrete structure and drives the coating to a depth of more than 8 mm. The later high voltage (12-24 V) combines Joule heating and ion migration to achieve rapid coating curing and pore reconstruction. This invention achieves breakthroughs in optimizing electric field energy efficiency, multi-component synergistic reaction, and improving interface durability, providing a new approach for long-term concrete protection in harsh environments.

[0040] (2) Functional ions are driven by the electric field to be enriched at the pore interface, and the local concentration increases by 3 to 5 times, reacting with the CSH gel to fill the pores; cationic DMC electrostatically adsorbs silicate through quaternary ammonium groups and participates in acrylate polymerization, thereby improving the interfacial bonding strength.

[0041] (3) It is compatible with conventional concrete and recycled aggregate concrete, and is suitable for harsh environmental protection such as bridges and marine engineering. The process is simple and controllable, and it is feasible for on-site construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a bar chart of the strength test results of Examples 1 to 3 of the present invention and Comparative Examples 1 to 3.

[0043] Figure 2 The Cl of Comparative Examples 1 to 3 and Example 2 - Flux test result graph.

[0044] Figure 3 A schematic diagram of the system structure for implementing the concrete surface strengthening method based on the coordination of electric field assisted migration and electrical curing of the present invention. DETAILED DESCRIPTION

[0045] In the following description, numerous specific details are set forth to provide those skilled in the art with a thorough understanding of the present invention.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0047] In the following examples and comparative examples, the aqueous acrylate emulsion used is A123GD acrylate emulsion. At 25°C, the viscosity range is controlled at 50 to 500 mPa·s, the solid content is 49% to 51%, and the pH value is 8 to 9, which is weakly alkaline. The DMC and calcium nitrate used are analytically pure. The SiO2 content of the silica sol used is 30%. The thickness of the graphene layer is 1 to 3 nm. The prepared concrete test blocks are C30 standard concrete test blocks (size 100×100×100 mm). The concrete matrix materials prepared include: P·O 42.5 silicate cement; Elkem 940 grade microsilica fume; S95 grade blast furnace slag powder; CF-710 comprehensive polycarboxylic acid mother liquor as a water reducer with a solid content of 50.0±1, a pH value of 5.0-8.0, and a water reduction rate greater than 35%; CQ-406 high-performance defoamer as a defoamer; quartz sand as fine aggregate with a particle size of 0.60-2.00 mm; and coarse aggregate with a particle size of 10.00-20.00 mm; and a water-cement ratio of 0.5; a saturated Ca(OH)2 solution (pH value of 12.5-13.0) as the electro-curing electrolyte; carbon fiber mesh electrodes with an electrode spacing of 100-200 mm; and testing instruments including a chloride ion diffusion coefficient tester (ASTM C1202 standard) and a universal testing machine.

[0048] Example 1

[0049] A method for strengthening the concrete surface based on the synergy of electric field-assisted migration and electrical curing, comprising the following steps:

[0050] S1. Preparation of functional coatings:

[0051] Weigh 3g of acrylic acid monomer and add it to 100g of aqueous acrylic ester emulsion. Then add 0.3g of calcium nitrate, 1g of silica sol and 0.2g of sodium metaaluminate to 5g of deionized water. Stir thoroughly until the solids are completely dissolved. Then mix with the acrylic ester solution and stir at a rate of 300rad / min for 5min.

[0052] S2. Electric field assisted penetration

[0053] When pouring concrete test blocks (standard size 100mm×100mm×100mm), an electrode system is embedded inside. The electrodes are carbon fiber mesh electrodes with a single filament diameter of 7 to 10μm and a weave density of 80 to 100 mesh. A positioning bracket is used to ensure that the electrode plane is parallel to the test block surface. The embedded depth is 30mm (accounting for 1 / 3 of the test block thickness). The electrode edge is 20mm away from the side of the test block and is led to the external terminal via a copper wire. After the concrete has initially set for 5 hours, the functional coating is evenly applied to the surface of the test block to a coating thickness of 1.5 to 2.0mm. After coating, the external electrode (titanium / platinum coating plate, size 100mm×100mm) was tightly attached to the coating layer through a carboxymethyl cellulose conductive gel containing 5% NaCl. The internal embedded electrode served as the cathode and the external electrode as the anode to form a closed loop. A DC regulated power supply (output range 0-100V, accuracy ±0.5%) was used to apply a 2V / cm voltage gradient (test block thickness 100mm corresponds to 20V voltage), and the initial current density was 0.8-1.2A / m 2 During the power-on process, temperature changes are monitored in real time, and the surface temperature of the test block is maintained at ≤35°C through a circulating water cooling system (water temperature 20±1°C) to avoid premature curing. During this stage, charged coating particles (such as DMC cationic monomers and calcium nitrate ions) migrate into the concrete under the drive of the electric field.

[0054] S3. Electrical maintenance

[0055] After the infiltration is completed, the power supply is switched to 18V DC output, and the saturated Ca(OH)2 solution (pH = 12.8-13.0) in the electrolyte supply unit is sprayed to cover the surface of the test block, and the flow rate is controlled at 0.5L / min·m 2 At this time, the internal embedded electrode is still the cathode, and the external one is replaced with a corrosion-resistant titanium mesh anode (the same size as before). The electrode spacing is adjusted to 80mm to enhance the electric field strength (electric field strength 22.5V / cm). After power is turned on, the Ca in the electrolyte 2+ 、SiO3 2-、AlO 2- Driven by the electric field, it migrates into the interior of the concrete; at the same time, the Joule heating effect increases the temperature of the concrete surface; it induces free radical polymerization of the latex particles under thermal activation to form a continuous film layer; Ca 2+ and SiO3 2- React at the pore interface to generate CSH gel, filling the pores; AlO 2- With SO4 2- In alkaline environment, needle-shaped ettringite is generated to enhance the mechanical bite of the interface;

[0056] After the electrical curing is completed, the power supply is disconnected and the external electrodes are removed. The residual electrolyte on the surface is rinsed with deionized water, and then the sample is placed in a curing room (temperature 20±1°C, relative humidity 60%) for air curing for 28 days.

[0057] Example 2

[0058] Pre-add 1g of nano-silica to 5g of water and ultrasonically disperse for 10 minutes to obtain a nano-silica suspension. Then, add 0.3g of calcium nitrate and 0.2g of sodium aluminate and stir to dissolve for later use. Add 1g of the cationic monomer methacryloyloxyethyltrimethylammonium chloride to 100g of aqueous acrylate emulsion and stir evenly. Add the above-mentioned nano-silica suspension and stir at a rate of 300rad / min for 5 minutes to complete the process.

[0059] The rest is the same as in Example 1.

[0060] Example 3

[0061] 0.5 parts of graphene was added to the coating of Example 2 (dispersed simultaneously with nano-silicon dioxide for 10 minutes), and the rest was the same as in Example 1.

[0062] Comparative Example 1:

[0063] The coating of Example 1 was applied to a concrete test block using a conventional coating process, and then naturally dried without electric field treatment and directly air-cured for 28 days.

[0064] Comparative Example 2

[0065] On the basis of Example 1, only electric field-assisted infiltration was used and air curing was carried out for 28 days.

[0066] Comparative Example 3

[0067] On the basis of Example 1, the coating was applied to the concrete test block and then dried naturally, and then air-cured for 28 days after electrical curing.

[0068] Performance Testing

[0069] Referring to the test standard of GB / T 17671-2021 cement mortar strength test method (IS method), the mechanical properties of the cement-based materials obtained in Examples 1-3 and Comparative Example 1 were tested. The compressive strength of the tested specimens was as follows: Figure 1 The results of the coating penetration depth are shown in Table 1; the chloride ion flux of Examples 1 to 3 and Comparative Example 1 was measured with reference to GB / T50082-2024 "Standard for Test Methods of Long-term Performance and Durability of Concrete", and the results are shown in Figure 2 As shown; the adhesion of the coating was tested using a portable adhesion tester according to ASTM D4541-09, the standard test method for measuring the pull-off strength of the coating, and the test results are shown in Table 2.

[0070] Table 1 Penetration depth results of comparative examples 1 to 3 and examples 1 to 3

[0071]

[0072] The present invention achieves a deep penetration effect of the coating through electric field assisted migration technology. The coating penetration depth of Examples 1 to 3 reaches 7.8 to 8.5 mm, which is 358% to 400% higher than that of Comparative Example 1 (1.7 mm). This is due to the optimization of the staged electric field synergistic process: after the initial setting of the concrete (4 to 6 hours), a 3 to 10 V / cm DC voltage gradient is applied for 1 to 2 hours, and the cationic coating (containing DMC) or the anionic coating (containing AA / SSS) is driven by the electric field force to migrate rapidly and directionally, far exceeding the migration rate of traditional capillary penetration; the depth of Example 3 with 0.5% graphene is increased to 8.5 mm, and the graphene sheets are arranged in a direction along the electric field direction to form a conductive network, which further improves the migration rate. Simply performing electric field assisted penetration can also increase the penetration depth of the coating, but the effect is still not as good as the effect of the synergistic effect of electric field assisted migration and electrical curing. This is because during the electrical curing stage, the charged particles in the coating still have a tendency to migrate inward.

[0073] Table 2 Adhesion test results of Comparative Examples 1 to 3 and Examples 1 to 3

[0074]

[0075] In Comparative Example 1, because no electric field treatment was performed, the coating was only combined with shallow penetration (1.7 mm) by physical adsorption, and the interface porosity was high and lacked chemical bonding, resulting in a relatively low adhesion (2.1 MPa). In Comparative Example 2, only electric field assisted migration was performed, which can improve the adhesion of the coating to a certain extent. However, due to the lack of electrical curing, the early density of the concrete was insufficient, and the interlocking force between the coating and the concrete was insufficient. In Comparative Example 3, electric field assisted penetration was not performed, and electrical curing was performed directly, which resulted in insufficient diffusion depth of the coating, thereby limiting the improvement of the coating adhesion to a certain extent. Examples 1 to 2 achieved a coating penetration depth of 8.2 mm through the synergistic effect of electric field assisted penetration (2 V / cm) and electrical curing (18 V), reduced porosity, and at the same time, cationic DMC electrostatically combined with silicate in the concrete pore fluid, which increased the adhesion to 4.1 MPa. Example 3 adds 0.5% graphene to Example 1. Its layered structure forms a three-dimensional network at the interface, enhancing the anchoring effect through van der Waals forces and mechanical interlocking. Optimizing the electric field distribution promotes the formation of a dense CSH / graphene composite layer, further increasing adhesion to 5.0 MPa. Overall data demonstrate that the electric field synergistic process can systematically improve coating adhesion through deep penetration, pore filling, and nanomaterial modification.

[0076] Compared with the comparative example, the strength of the test pieces of the embodiment of the present invention also showed different degrees of improvement. At the 3-day hydration age, the compressive strength of Example 1 reached 23.56MPa, an increase of 16.8% over the comparative example 1 (20.17MPa); at 7 days, the strength of Example 1 increased to 29.92MPa (compared to 25.83MPa), an increase of 15.8%; after 28 days of curing, the compressive strength of Example 1 reached 43.74MPa, an increase of 14.9% over the comparative example 1 (38.06MPa). The compressive strength of the other two groups of embodiments has the same improvement effect. The comprehensive improvement of compressive strength comes from the synergistic effect of the electric field - calcium ions (Ca 2+ ), nano-silicon dioxide (SiO2) and aluminum ions (AlO2 - ) is driven by the electric field and directionally migrates to the aggregate-paste interface, reacting with cement hydration products (C3S, C2S) to form high-density CSH gel and needle-shaped calcium aluminoferrite (AFt), effectively filling the pores in the interface transition zone. At the same time, the Joule heat (40-60°C) during the electrical curing stage significantly accelerates the early hydration process and increases the rate of microstructure densification. The results show that the present invention achieves stable long-term strength growth while accelerating the formation of early strength through the coupling mechanism of ion migration-thermal activation-chemical reaction, breaking through the limitations of traditional electroosmosis technology for single-age performance optimization.

[0077] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A concrete surface strengthening method based on the synergy of electric field assisted migration and electrical curing, characterized in that: The following steps are involved: S1. Preparation of charged functional coatings The coating comprises at least a coating base liquid, a charge modifier, a soluble calcium source, a silicon source and an aluminum source; S2. Electric field assisted penetration Electrodes are embedded in the concrete and external electrodes are placed on the coating layer. After the concrete has initially set, a low voltage of 1 to 3 V / cm is applied to perform electric field-driven penetration. S3. Electrical maintenance enhancement After the infiltration is completed, the voltage is increased to 12-24V, and saturated Ca(OH)2 solution is used as the electrolyte, the pre-buried electrode inside the concrete is used as the cathode, and the external titanium / platinum coated electrode is used as the anode for electrical curing and strengthening.

2. The method for strengthening the concrete surface according to claim 1, characterized in that: Step S1 further includes: a carbon nano-conductive substrate; the carbon nano-conductive substrate includes any one of graphene or carbon nanotubes, and the addition amount thereof is 0 to 2 parts.

3. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S1, the coating base liquid includes water-based acrylic emulsion or water-based epoxy resin emulsion.

4. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S1, the charge modifier is at least one of a cationic monomer methacryloyloxyethyl trimethyl ammonium chloride or an anionic monomer acrylic acid and sodium styrene sulfonate, and the amount of the charge modifier added to the coating is 0.5 to 5 parts.

5. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S1, the soluble calcium source is calcium nitrate or calcium acetate, the silicon source is silica sol or nano-silica particles, and the aluminum source is sodium metaaluminate or aluminum sulfate. The total amount of the soluble calcium source, silicon source and aluminum source added is 2 to 10 parts.

6. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S2, the electrodes inside the concrete are 304 stainless steel mesh electrodes or carbon fiber mesh electrodes; the embedded depth is 1 / 3 to 1 / 2 of the concrete thickness, and the electrode spacing is 100 to 200 mm.

7. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S2, the electrodes of the coating layer are tightly bonded to the coating layer via a conductive gel; preferably, the conductive gel is a carboxymethyl cellulose solution containing 5 to 10 parts of NaCl.

8. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S2, the parameters of the electric field are: DC voltage gradient 1-3 V / cm, duration 1-2 hours, current density controlled at 0.5-2 A / m 2 .

9. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S3, the electrolyte temperature is controlled at 40-60°C.

10. The method for strengthening the concrete surface according to claim 1, characterized in that: In step S3, the electrode spacing is adjusted to 50-100 mm; the electrical curing time is 4-8 hours, and the current density is maintained at 1-3 A / m 2 .

11. A system for implementing the concrete surface strengthening method based on the synergy of electric field assisted migration and electrical curing as described in any one of claims 1 to 10, characterized in that: include: Functional coating module: used to prepare functional coatings and apply functional coatings to concrete surfaces; Dual-mode power supply: with low voltage mode and high voltage mode, which can automatically switch output; Electrode assembly: includes external electrodes in contact with the coating layer and internal electrodes embedded in the concrete; Electrolyte supply unit: used to deliver saturated Ca(OH)2 solution to the concrete surface during the electrical curing stage; The dual-mode power supply device has a built-in current monitoring module, which automatically switches to a high-voltage maintenance mode when the current drops to 30% of the initial value during the infiltration phase.

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