Electrodeposition repairing auxiliary agent and electrodeposition repairing method for concrete cracks

Abstract

The invention relates to the technical field of concrete crack repair, in particular to an electro-deposition repair assistant and an electro-deposition repair method for concrete cracks, and the electro-deposition repair assistant is composed of a solid component A and a solid component B which are independently packaged; the solid component A is prepared from the following raw materials: beta-cyclodextrin and boric acid; the solid component B is prepared from the following raw materials: lauryl sodium sulfate and sulphobetaine; the mass ratio of the solid component A to the solid component B is 1: 1. According to the invention, the deposition uniformity of zinc ions in concrete cracks is remarkably improved through the electro-deposition repairing auxiliary agent, so that a uniform and compact deposition layer is formed at the repaired cracks, the integrity and stability of a concrete structure are effectively enhanced, meanwhile, the formation of zinc dendrites is inhibited, the defects of the repairing layer and the structural damage caused by the growth of the zinc dendrites are reduced, and the service life of the concrete is prolonged. And the repairing quality and durability are improved.

Description

Technical Field

[0001] This invention relates to the field of concrete crack repair technology, specifically to an electrodeposition repair additive and an electrodeposition repair method for concrete cracks. Background Technology

[0002] During long-term use, concrete structures inevitably develop cracks due to factors such as load and environment. The presence of cracks not only affects the appearance of the concrete structure but also reduces its durability and safety, allowing moisture and corrosive media to penetrate, accelerating steel corrosion, and further weakening the structural performance.

[0003] Electrodeposition repair technology, as an effective method for repairing concrete cracks, involves applying an electric field to the cracks, causing metal ions in the electrolyte to deposit and fill the cracks, thus restoring the structural integrity of the concrete. However, in traditional electrodeposition repair processes, the deposition of zinc ions in the cracks suffers from problems such as uneven deposition, dendrite growth, and low efficiency, which seriously affect the repair effect. Summary of the Invention

[0004] The purpose of this invention is to provide an electrodeposition repair additive and an electrodeposition repair method for concrete cracks, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an electrodeposition repair aid, wherein the electrodeposition repair aid is composed of separately packaged solid component A and solid component B; solid component A is composed of the following raw materials in mass percentage: β-cyclodextrin 62.5%–76.9%, boric acid 23.1%–37.5%; solid component B is composed of the following raw materials in mass percentage: sodium dodecyl sulfate 75%–80%, sulfobetaine 20%–25%; the mass ratio of solid component A to solid component B is 1:1.

[0006] Optionally, the solid component A and solid component B are packaged in an aluminum-plastic composite bag, and the aluminum-plastic composite bag has a PET / AL / PE combination structure.

[0007] Optionally, the particle sizes of solid component A and solid component B are each independently 80 to 200 mesh, and the difference in D50 particle size is ≤20 mesh.

[0008] On the other hand, the present invention also provides the following technical solution: an electrodeposition repair method for concrete cracks, using an electrodeposition repair solution and an electrodeposition repair additive, wherein the electrodeposition repair solution is a 5 g / L ZnSO4 aqueous solution or an 8 g / L Zn(NO3)2 aqueous solution, and the method steps are as follows: S1. First, calculate the required mass of β-cyclodextrin, then calculate the required mass of solid component A and solid component B. Add the calculated solid component A and solid component B to the electrodeposition repair solution and stir thoroughly to obtain the repair solution. The concentration of β-cyclodextrin in the repair solution is 10-100 g / L. S2. Place the concrete specimen to be repaired in a container, and insert the anode and cathode on both sides of the concrete specimen respectively; S3. Pour the repair fluid into the container until the repair fluid completely submerges the concrete specimen; S4. Power the anode and cathode with a 10-30V DC regulated power supply, controlling the current density to be 1-10mA / cm². 2 It lasts for 5 to 15 days.

[0009] Optionally, the anode is a graphite electrode or a platinum electrode, and the cathode is a stainless steel electrode or a copper electrode.

[0010] Optionally, in S4, the current density is 3-5 mA / cm². 2 .

[0011] Compared with the prior art, the present invention has the following beneficial effects: The present invention significantly improves the uniformity of zinc ion deposition in concrete cracks through electrodeposition repair additives, so that a uniform and dense deposition layer is formed at the repaired crack, which effectively enhances the integrity and stability of the concrete structure, while inhibiting the formation of zinc dendrites, reducing repair layer defects and structural damage caused by zinc dendrite growth, and improving repair quality and durability. Attached Figure Description

[0012] Figure 1 This is the deposition result of Experimental Example 1 in this invention. Detailed Implementation

[0013] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Example 1 This invention provides an electrodeposition repair aid, which consists of separately packaged solid component A and solid component B. Solid component A is composed of the following raw materials in mass percentage: β-cyclodextrin 76.9% and boric acid 23.1%; solid component B is composed of the following raw materials in mass percentage: sodium dodecyl sulfate 75.0% and sulfobetaine 25.0%; the mass ratio of solid component A to solid component B is 1:1.

[0015] This invention also provides a method for electrodeposition repair of concrete cracks, using an electrodeposition repair solution and the aforementioned electrodeposition repair additive. The electrodeposition repair solution is a 5 g / L ZnSO4 aqueous solution. The method steps are as follows: S1. Prepare 2L of repair solution. Set the target concentration of β-cyclodextrin in the repair solution to 100g / L. Calculate the required mass of β-cyclodextrin to be 200g. The mass of solid component A and solid component B is 260g. Add 260g of solid component A and solid component B to 2L of 5g / L ZnSO4 aqueous solution and stir thoroughly to obtain the repair solution. S2. Place the concrete specimen to be repaired in a plastic container, and insert a graphite anode and a stainless steel cathode on both sides of the concrete specimen respectively. The crack width of the concrete specimen is 0.5 mm. S3. Pour the repair solution into the container until the repair solution completely submerges the concrete specimen; S4. Power the anode and cathode with a 30V DC regulated power supply, controlling the current density to 1mA / cm². 2 Electrodeposition continued for 15 days.

[0016] Example 2 This invention provides an electrodeposition repair aid, which consists of separately packaged solid component A and solid component B. Solid component A is composed of the following raw materials in mass percentage: β-cyclodextrin 62.5% and boric acid 37.5%. Solid component B is composed of the following raw materials in mass percentage: sodium dodecyl sulfate 80.0% and sulfobetaine 20.0%. The mass ratio of solid component A to solid component B is 1:1.

[0017] This invention also provides a method for electrodeposition repair of concrete cracks, using an electrodeposition repair solution and the aforementioned electrodeposition repair additive. The electrodeposition repair solution is an 8 g / L Zn(NO3)2 aqueous solution. The method steps are as follows: S1. Prepare 1L of repair solution. Set the target concentration of β-cyclodextrin in the repair solution to 10g / L. Calculate the required mass of β-cyclodextrin to be 10g. The mass of solid component A and solid component B is 16g. Add 16g of solid component A and solid component B to 1L of 8g / L Zn(NO3)2 aqueous solution and stir thoroughly to obtain the repair solution. S2. Place the concrete specimen to be repaired in a plastic container, and insert a platinum anode and a copper cathode on both sides of the concrete specimen respectively. The crack width of the concrete specimen is 0.5 mm. S3. Pour the repair solution into the container until the repair solution completely submerges the concrete specimen; S4. Power the anode and cathode with a 10V DC regulated power supply, controlling the current density to 10mA / cm².2 Electrodeposition continued for 5 days.

[0018] Example 3 This invention provides an electrodeposition repair aid, which consists of separately packaged solid component A and solid component B. Solid component A is composed of the following raw materials in mass percentage: β-cyclodextrin 70.0% and boric acid 30.0%. Solid component B is composed of the following raw materials in mass percentage: sodium dodecyl sulfate 77.5% and sulfobetaine 22.5%. The mass ratio of solid component A to solid component B is 1:1.

[0019] This invention also provides a method for electrodeposition repair of concrete cracks, using an electrodeposition repair solution and the aforementioned electrodeposition repair additive. The electrodeposition repair solution is a 5 g / L ZnSO4 aqueous solution. The method steps are as follows: S1. Prepare 5L of repair solution. Set the target concentration of β-cyclodextrin in the repair solution to 50g / L. Calculate the required mass of β-cyclodextrin to be 250g. The mass of solid component A and solid component B is 357.14g. Add 357.14g of solid component A and solid component B to 5L of 5g / L ZnSO4 aqueous solution and stir thoroughly to obtain the repair solution. S2. Place the concrete specimen to be repaired in a plastic container, and insert a graphite anode and a stainless steel cathode on both sides of the concrete specimen respectively. The crack width of the concrete specimen is 0.8 mm. S3. Pour the repair solution into the container until the repair solution completely submerges the concrete specimen; S4. Power the anode and cathode with a 15V DC regulated power supply, controlling the current density to 5mA / cm². 2 Electrodeposition continued for 10 days.

[0020] Example 4 This invention provides an electrodeposition repair aid, which consists of separately packaged solid component A and solid component B. Solid component A is composed of the following raw materials in mass percentage: β-cyclodextrin 65.0% and boric acid 35.0%. Solid component B is composed of the following raw materials in mass percentage: sodium dodecyl sulfate 78.0% and sulfobetaine 22.0%. The mass ratio of solid component A to solid component B is 1:1.

[0021] This invention also provides a method for electrodeposition repair of concrete cracks, using an electrodeposition repair solution and the aforementioned electrodeposition repair additive. The electrodeposition repair solution is an 8 g / L Zn(NO3)2 aqueous solution. The method steps are as follows: S1. Prepare 3L of repair solution. Set the target concentration of β-cyclodextrin in the repair solution to 80g / L. Calculate the required mass of β-cyclodextrin to be 240g. The mass of solid component A and solid component B is 369.23g. Add 369.23g of solid component A and solid component B to 3L of 8g / L Zn(NO3)2 aqueous solution and stir thoroughly to obtain the repair solution. S2. Place the concrete specimen to be repaired in a plastic container, and insert a platinum anode and a copper cathode on both sides of the concrete specimen respectively. The crack width of the concrete specimen is 0.8 mm. S3. Pour the repair solution into the container until the repair solution completely submerges the concrete specimen; S4. Power the anode and cathode with a 25V DC regulated power supply, controlling the current density to 3mA / cm². 2 Electrodeposition continued for 12 days.

[0022] In Examples 1-4, solid component A and solid component B are packaged in aluminum-plastic composite bags. The aluminum-plastic composite bags have a PET / AL / PE combination structure. The particle sizes of solid component A and solid component B are independently 80-200 mesh, and the D50 particle size difference is ≤20 mesh. β-cyclodextrin and boric acid are pre-treated by vacuum drying at 42°C for 2 hours, and sodium dodecyl sulfate and sulfobetaine are pre-treated by vacuum drying at 45°C for 2 hours.

[0023] The concrete specimens were cast from C30 cement and measured 150mm × 150mm × 150mm. After standard curing for 28 days, the sides of the concrete specimens were fixed using the upper and lower pressure plates of a fully automatic pressure testing machine. A loading rate of 500 N / s was set until cracks appeared in the concrete specimens. Loading was immediately stopped, and the specimens were removed. The cathode, compared to the anode, is closer to the cracks in the concrete specimens.

[0024] In the electrodeposition repair solution for concrete cracks, β-cyclodextrin molecules preferentially adsorb onto the surface of concrete cracks and around zinc ions, increasing ionic conductivity while having negligible impact on the pH of the electrolyte. On one hand, the unique structure of β-cyclodextrin molecules allows them to form an ordered molecular arrangement on the crack surface, providing specific channels for zinc ion diffusion and guiding zinc ions to diffuse uniformly into the crack interior, preventing excessive deposition in localized areas and achieving a uniform distribution of zinc ions within the crack. On the other hand, the interaction between β-cyclodextrin and zinc ions promotes the desolvation process of zinc ions, making it easier for them to deposit from the solution onto the crack surface. Simultaneously, the presence of β-cyclodextrin can regulate the deposition sites of zinc ions, inhibiting the formation of zinc dendrites, allowing zinc ions to deposit more densely and uniformly in the crack, improving the density and stability of the deposition layer, and thus enhancing the repair effect.

[0025] Sodium dodecyl sulfate (SLS), as an anionic surfactant, preferentially adsorbs its hydrophilic end onto the positively charged cathode region. Its hydrophobic tail chain extends outward, thickening the electrical double layer (EDL) structure between the electrolyte and the zinc metal anode, improving the thickness and uniformity of the EDL, and slowing down the transport kinetics of zinc ions. The abundant and strongly electronegative hydroxyl groups of β-cyclodextrin combine with the anions of SLS, causing a greater accumulation of electron density at the zinc interface, thereby generating strong spontaneous interfacial interactions that facilitate selective vertical adsorption on specific crystal planes.

[0026] Sulfobetaine, as an amphoteric surfactant, can intercalate between sodium dodecyl sulfate (DSL) molecules. Its zwitterionic structure, through electrostatic and steric hindrance effects, makes the DDL adsorption layer more uniform and dispersed, preventing localized over-density adsorption or micelle formation, thus further improving the uniformity of the EDL. The carbon chain of sulfobetaine is hydrophobic, and its hydrophobic chain can incorporate with the cavity of β-cyclodextrin, forming a more complex ternary inclusion complex of β-cyclodextrin / DSL / sulfobetaine. This ternary inclusion complex is more stable and larger in volume than the simple binary inclusion complex composed of β-cyclodextrin / DSL. After adsorption on the electrode surface, its steric hindrance effect is stronger, resulting in better suppression of dendrite formation at zinc ion deposition sites.

[0027] Boric acid, as a pH buffer, can effectively stabilize the pH of the solution within the weakly acidic range of 5.5 to 6.5, inhibiting the hydrolysis of sodium dodecyl sulfate. In addition, as a weak acid, boric acid can react with calcium hydroxide on the crack surface to form calcium metaborate, which changes the surface tension of the crack surface, allowing the electrolyte to better wet the concrete surface and providing a cleaner and stronger interface for subsequent zinc deposition.

[0028] Experimental Example 1 Experimental procedure: 100 mL of the repair solution from Examples 1-4 was taken as the experimental group, and 100 mL of 8 g / L Zn(NO3)2 was taken as the control group. The experimental and control groups were placed in five electrolytic cells respectively. Graphite was used as the anode in the electrolytic cells, and a 1 cm... 2 Stainless steel was used as the cathode. Both the experimental and control groups were immersed in the anode and cathode. A 25V DC regulated power supply was used to energize the anode and cathode, and the current density was controlled at 3mA / cm². 2 Electrodeposition was performed continuously for 1 day, and the deposition results on stainless steel were observed. The results are shown in [Figure number missing]. Figure 1 .

[0029] Depend on Figure 1 As can be seen, the addition of electrodeposition repair agent resulted in more uniform and denser deposits, and a greater amount of deposits were formed. This indicates that the electrodeposition repair agent can promote the deposition rate, improve the deposition quality, and facilitate uniform deposition.

[0030] Experimental Example 2 Experimental content: The compressive strength of concrete specimens in Examples 1 to 4 was tested using a universal mechanical testing machine, and the crack repair was observed. The results are recorded in Table 1.

[0031] Table 1

[0032] As shown in Table 1, the compressive strength of the concrete specimens after repair increased by 26% to 36% compared with that before repair. The electrodeposition repair additive disclosed in this invention can improve the electrodeposition repair effect of concrete cracks.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An electrodeposition repair aid characterized in that, The electrodeposition repair aid is composed of independently packaged solid component A and solid component B; the solid component A is composed of raw materials with the following mass percentages: 62.5%-76.9% of β-cyclodextrin and 23.1%-37.5% of boric acid; the solid component B is composed of raw materials with the following mass percentages: 75%-80% of sodium dodecyl sulfate and 20%-25% of sulfobetaine; the mass ratio of the solid component A to the solid component B is 1:

1.

2. The electrodeposition repair aid of claim 1, wherein, The packaging form of the solid component A and the solid component B is an aluminum-plastic composite bag, and the structure of the aluminum-plastic composite bag is PET / AL / PE combination.

3. The electrodeposition repair aid of claim 1, wherein, The particle size of the solid component A and the solid component B is independently 80-200 mesh, and the D50 particle size difference is ≤20 mesh.

4. A method for electrodepositing repair of concrete cracks using an electrodepositing repair solution, which is an aqueous solution of 5 g / L ZnSO4 or 8 g / L Zn(NO3)2, and the electrodepositing repair aid according to any one of claims 1 to 3, characterized in that, The method steps are as follows: S1, first, the mass of the required β-cyclodextrin is calculated, then the mass of the required solid component A and the solid component B is calculated, the calculated solid component A and the solid component B are added to the electrodeposition repair solution, and fully stirred to obtain a repair solution, wherein the concentration of β-cyclodextrin in the repair solution is 10-100 g / L; S2, the concrete test piece to be repaired is placed in a container, and an anode and a cathode are respectively inserted on both sides of the concrete test piece; S3, the repair solution is poured into the container until the repair solution immerses the concrete test piece; S4, the anode and cathode are powered by 10-30V DC regulated power supply, the current density is controlled to be 1-10 mA / cm 2 , for 5-15 days.

5. A method of electrodepositively repairing a concrete crack according to claim 4, wherein The anode is a graphite electrode or a platinum electrode, and the cathode is a stainless steel electrode or a copper electrode.

6. A method of electrodepositively repairing a concrete crack according to claim 4, wherein In S4, the current density is 3-5 mA / cm 2 .

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