An alternating current impedance-based method for evaluating repair effect of concrete crack electro-deposition
By using an AC impedance-based detection method, with the internal steel reinforcement of concrete as the working electrode, and an auxiliary electrode and a reference electrode, the intuitiveness and sensitivity issues of evaluating the effect of electrodeposition method on concrete crack repair in existing technologies are solved. This achieves non-destructive testing and in-situ monitoring, and simplifies construction operations.
Patent Information
- Application Number
- CN202310170518.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-27
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2043-02-27
AI Technical Summary
Existing methods for evaluating the effectiveness of electrodeposition in repairing concrete cracks lack intuitiveness and sensitivity, making it difficult to conduct in-situ monitoring at the construction site and potentially causing secondary damage to the structure.
An AC impedance-based detection method was adopted, using the internal steel reinforcement of the concrete as the working electrode, with an auxiliary electrode and a reference electrode added. The impedance values of the concrete before and after cracking were tested using an electrochemical workstation, and the repair rate was calculated to evaluate the electrodeposition repair effect.
It achieves highly sensitive and accurate evaluation of the electrodeposition repair process, enabling real-time monitoring of crack repair progress without damaging the structure, simplifying construction operations and avoiding secondary damage.
Smart Images
Figure CN116068028B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of concrete crack electrodeposition repair effect evaluation, and relates to a concrete crack electrodeposition repair effect evaluation method based on alternating current impedance. BACKGROUND
[0002] As a new concrete structure crack repair method, the electrodeposition method for repairing concrete cracks can better meet the service conditions of concrete structures in water environment, and has been more and more studied and gradually applied to the repair of underground structure concrete cracks in recent years.
[0003] The electrodeposition method is to induce cations to migrate into concrete cracks to form deposits to block the cracks and achieve the repair effect under the water environment through the electric field. Compared with the existing grouting method, the electrodeposition method does not need to drill holes and has less damage to the structure itself. At present, the evaluation of the repair effect of the concrete structure cracks repaired by the electrodeposition method mainly includes the mass increase rate, the surface coverage rate, the crack healing rate, the crack filling depth, the permeability, the ultrasonic detection and the steel bar half-cell potential. The above methods have limitations such as the inability to directly reflect the repair degree, the low damage detection and the low sensitivity, and have great limitations in the electrodeposition repair construction site. SUMMARY
[0004] The purpose of the application is to provide a concrete crack electrodeposition repair effect evaluation method based on alternating current impedance to overcome the defects of the prior art such as the inability to directly reflect the repair degree, the need for damage detection or the low sensitivity. In the application, the steel bars inside the concrete are used as working electrodes, auxiliary electrodes are additionally provided, and a reference electrode is arranged. The above electrodes are immersed in an electrolyte, and an electrochemical workstation is used for impedance-frequency test to detect the impedance values of the concrete before cracking, after cracking and at the repair time t. Further, the repair rate after electrodeposition repair is calculated. When the repair rate is less than 70%, it indicates that the electrodeposition repair is not completed, and the electrodeposition repair needs to be continued at the concrete crack. When the repair rate is greater than or equal to 70%, it indicates that the electrodeposition repair is completed. Compared with the prior art, the concrete crack electrodeposition repair effect evaluation method based on alternating current impedance is convenient to operate and can realize in-situ monitoring during crack repair.
[0005] The purpose of the application can be achieved by the following technical solutions:
[0006] The application provides a concrete crack electrodeposition repair effect evaluation method based on alternating current impedance, which comprises the following steps:
[0007] The steel bars inside the concrete are used as working electrodes, an auxiliary electrode is additionally provided, and a reference electrode is arranged, the above electrodes are immersed in an electrolyte, and an impedance-frequency test is performed by using an electrochemical workstation to detect the impedance values of the concrete before cracking, after cracking, and at the repairing time t;
[0008] The repairing rate at the repairing time t is calculated as follows:
[0009]
[0010] γ represents the repairing rate at the repairing time t, Z t represents the impedance value at the repairing time t, Z 开裂 represents the impedance value after the concrete cracks, Z 未裂 represents the impedance value before the concrete cracks;
[0011] The repairing effect evaluation: when γ < the preset value, it is indicated that the electrodeposition repairing is not completed, and the electrodeposition repairing needs to be continuously performed on the concrete crack;
[0012] When γ ≥ the preset value, it is indicated that the electrodeposition repairing is completed.
[0013] In an embodiment of the present application, the preset value is 70%.
[0014] In an embodiment of the present application, the auxiliary electrode is a ruthenium iridium titanium anode.
[0015] In an embodiment of the present application, the reference electrode is selected from one of a calomel electrode, a mercurous sulfate electrode or a mercuric oxide electrode.
[0016] In an embodiment of the present application, the electrolyte is selected from one or more of zinc sulfate, magnesium sulfate, aluminum sulfate, zinc chloride, magnesium chloride, calcium acetate or zinc acetate.
[0017] In an embodiment of the present application, the detection method of the impedance value before the concrete cracks is specifically as follows:
[0018] The concrete is wetted by using the electrolyte, the steel bars inside the concrete are ensured to be in the electrolyte, the steel bars inside the concrete are connected with an external electrochemical workstation through a wire, an auxiliary electrode and a reference electrode arranged in the electrolyte are additionally provided, the auxiliary electrode and the reference electrode are connected with the external electrochemical workstation, and the impedance value is detected.
[0019] In an embodiment of the present application, the detection method of the impedance value after the concrete cracks is specifically as follows:
[0020] After the concrete crack position is treated, the electrolyte is applied to immerse the steel bars inside the concrete crack position, wires are applied to connect the steel bars inside the concrete with an external electrochemical workstation, auxiliary electrodes and reference electrodes arranged in the electrolyte are applied, and the auxiliary electrodes and the reference electrodes are connected with the external electrochemical workstation to detect the impedance value.
[0021] In one embodiment of the present application, the detection method of the impedance value at the time t of electrodepositing repair after the concrete cracks is as follows:
[0022] After the time t of electrodepositing repair, the electrodepositing repair is stopped, wires are applied to connect the steel bars inside the concrete with an external electrochemical workstation, auxiliary electrodes and reference electrodes arranged in the electrolyte are applied, and the auxiliary electrodes and the reference electrodes are connected with the external electrochemical workstation to detect the impedance value.
[0023] In one embodiment of the present application, in the impedance-frequency test, the test frequency is 10 -5 Hz-10 6 Hz.
[0024] In one embodiment of the present application, in the impedance-frequency test, the alternating current amplitude is lower than 100 mV.
[0025] Based on the current status of the evaluation of the effect of electrodepositing repair and the principle of electrodepositing repair, the present application proposes an evaluation method of the effect of electrodepositing repair based on the alternating current impedance test, which uses the repair circuit of electrodepositing repair as a test circuit to test the impedance response in the process of electrodepositing repair, establishes a corresponding model, and reflects the crack change through a part of the model to evaluate the repair effect.
[0026] In view of the problem that there is no suitable evaluation method of the repair effect of electrodepositing repair of concrete cracks, the present application proposes an evaluation method of the effect of electrodepositing repair based on the alternating current impedance test in combination with the current research status of electrodepositing repair. The method directly uses the electrodepositing repair circuit as a test circuit, uses the steel bars inside the concrete as a working electrode, uses an anode as an auxiliary electrode, arranges a reference electrode between the working electrode and the auxiliary electrode, uses a three-electrode method to test the system impedance change, and reflects the crack change in the repair process through the impedance change. The method has high sensitivity and high accuracy, and compared with the traditional evaluation method of the effect of electrodepositing repair, the method is simple and convenient to construct, does not need to damage the concrete structure, directly uses the circuit after electrodepositing repair, and tests during the interval of electrodepositing repair to realize in-situ monitoring in the crack repair process.
[0027] The application coats the areas other than the cracks with paraffin after treating the surface cracks of the concrete structure to be repaired, uses a salt solution containing zinc, magnesium, aluminum, calcium and other ions as an electrolyte, uses the steel bars in the concrete as a repair cathode, and applies a direct current to the concrete structure with cracks to repair the cracks by electrification.
[0028] Compared with the prior art, the application has the following advantages:
[0029] (1) The effect evaluation method of the electro-deposition repair is based on the alternating current impedance technology, has high testing precision, is sensitive to the crack changes in the electro-deposition repair process, and can directly reflect the crack changes in the electro-deposition repair process.
[0030] (2) The effect evaluation method of the electro-deposition repair of the concrete cracks based on the alternating current impedance is a non-destructive testing method, does not need to sample the underground structure by damaging the underground structure, does not cause secondary damage to the underground structure, and realizes in-situ detection in the electro-deposition repair process of the concrete, and is simple and convenient to operate.
[0031] (3) The effect evaluation method of the electro-deposition repair of the concrete cracks based on the alternating current impedance can collect other information such as the steel bar polarization curve and the crack resistance by the electrochemical workstation in addition to the impedance in the repair process, can be used to reflect the steel bar information in the repair process, and guide the adjustment of the subsequent construction parameters. BRIEF DESCRIPTION OF DRAWINGS
[0032] Figure 1 It is a side structure schematic diagram of the repair circuit of the embodiment 1.
[0033] Figure 2 It is a front structure schematic diagram of the repair circuit of the embodiment 1.
[0034] Figure 3 It is a side structure schematic diagram of the test circuit of the embodiment 2.
[0035] Figure 4 It is a front structure schematic diagram of the test circuit of the embodiment 2.
[0036] Mark in the figure:
[0037] 1-adjustable DC power supply; 2-wire; 3-steel bar; 4-ruthenium iridium titanium anode plate; 5-concrete; 6-electrolyte; 7-electrolyte bearing device; 8-electrochemical workstation; 9-computer; 10-calomel electrode; 11, concrete crack position. DETAILED DESCRIPTION
[0038] The present application provides a kind of concrete crack electrodeposition repair effect evaluation method based on alternating current impedance, comprising the following steps:
[0039] With the steel bar in the interior of concrete as working electrode, additional electrode is added, and reference electrode is set, the above-mentioned electrode is immersed in electrolyte, impedance-frequency test is carried out with electrochemical workstation to detect the impedance value of concrete before cracking, after cracking and at t time point of repair;
[0040] Repair rate at t time point of repair is calculated:
[0041]
[0042] γ represents the repair rate at t time point of repair, Z t represents the impedance value at t time point of repair, Z 开裂 represents the impedance value after cracking of concrete, Z 未裂 represents the impedance value before cracking of concrete;
[0043] Repair effect evaluation: when γ < preset value, it indicates that electrodeposition repair is not completed, and electrodeposition repair needs to be continued at concrete crack;
[0044] When γ ≥ preset value, it indicates that electrodeposition repair is completed.
[0045] In an embodiment of the present application, the preset value is 70%.
[0046] In an embodiment of the present application, the additional electrode is ruthenium iridium titanium anode.
[0047] In an embodiment of the present application, the reference electrode is selected from one of calomel electrode, mercurous sulfate electrode or mercuric oxide electrode.
[0048] In an embodiment of the present application, the electrolyte is selected from one or more of zinc sulfate, magnesium sulfate, aluminum sulfate, zinc chloride, magnesium chloride, calcium acetate or zinc acetate.
[0049] In an embodiment of the present application, the detection method of impedance value before cracking of concrete is specifically as follows:
[0050] The steel bars inside the concrete are immersed in the electrolyte, the steel bars inside the concrete are connected with the external electrochemical workstation through the wire, the auxiliary electrode and the reference electrode in the electrolyte are additionally arranged, the auxiliary electrode and the reference electrode are connected with the external electrochemical workstation, and the impedance value is detected.
[0051] In one embodiment of the present application, the method for detecting the impedance value after the concrete cracks is as follows:
[0052] The steel bars inside the concrete are immersed in the electrolyte, the steel bars inside the concrete are connected with the external electrochemical workstation through the wire, the auxiliary electrode and the reference electrode in the electrolyte are additionally arranged, the auxiliary electrode and the reference electrode are connected with the external electrochemical workstation, and the impedance value is detected.
[0053] In one embodiment of the present application, the method for detecting the impedance value at the time of electrodepositing repair after the concrete cracks is as follows:
[0054] After the electrodepositing repair at the time t, the electrodepositing repair is stopped, the steel bars inside the concrete are connected with the external electrochemical workstation through the wire, the auxiliary electrode and the reference electrode in the electrolyte are additionally arranged, the auxiliary electrode and the reference electrode are connected with the external electrochemical workstation, and the impedance value is detected.
[0055] In one embodiment of the present application, in the impedance-frequency test, the test frequency is 10 -5 Hz-10 6 Hz.
[0056] In one embodiment of the present application, in the impedance-frequency test, the alternating current amplitude is lower than 100 mV.
[0057] The present application will be described in detail below in combination with the drawings and specific embodiments. The embodiments are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following embodiments.
[0058] In the following embodiments or examples, if there is no special description of the function components or structures, it is indicated that the conventional components or conventional structures are adopted in the field to realize the corresponding functions.
[0059] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0060] In the following examples, if specially stated, the reagents used are commercially available reagents, and the detection means and methods used are conventional detection means and methods in the art.
[0061] Example 1
[0062] This embodiment provides a method for repairing concrete crack position by electrodeposition, and the repair circuit is as shown in Figure 1 and Figure 2 The repair circuit includes an adjustable DC power supply 1, a wire 2, a steel bar 3, a ruthenium iridium titanium anode plate 4, an electrolyte 6 (in this embodiment, a 0.1 mol / L zinc sulfate aqueous solution, which can also be magnesium sulfate, aluminum sulfate, zinc chloride, magnesium chloride, calcium acetate or zinc acetate) and an electrolyte carrying device 7.
[0063] The steel bar 3 is located inside the concrete 5 and is connected to the adjustable DC power supply 1 through the wire 2 as an electrodeposition repair cathode; the electrolyte carrying device 7 has good sealing property and is arranged on the side of the concrete crack position 11, and contains the electrolyte 6 inside, the electrolyte 6 seeps into the concrete 3 from the side and ensures that the steel bar of the concrete crack position 11 is immersed in the electrolyte 6, and the ruthenium iridium titanium anode plate 4 is additionally provided as an electrodeposition repair anode, which is immersed in the electrolyte 6 and connected to the adjustable DC power supply 1 through the wire 2.
[0064] Among them, the adjustable DC power supply 1 is used to generate a repair current, the current size is adjusted according to the needs, and the voltage and current can be displayed; the ruthenium iridium titanium anode plate 4 is used as an electrodeposition repair anode; the electrolyte 6 is used to provide the required cations in the repair process.
[0065] The specific repair process includes the following steps (the following is a simple description, which can be repaired by using existing conventional electrodeposition) :
[0066] (1) Repair area selection and pretreatment
[0067] Examine the water seepage condition of the concrete 3 structure, record the crack length, width position and other parameters, polish the concrete crack position 11, wipe off the surface moisture, coat the area to be repaired except the crack with paraffin, and check the sealing property of the electrolyte carrying device 7.
[0068] (2) Steel bar communication test and power repair
[0069] After the electrolyte 6 (zinc sulfate aqueous solution) is added into the electrolyte bearing device 7, the electrolyte 6 is immersed in the crack, and then the ruthenium iridium titanium anode plate 4 is placed in the electrolyte 6. The positive and negative poles of the adjustable direct current power supply 1 are connected with the ruthenium iridium titanium anode plate 4 and the steel bar 3 respectively through the wires 2, and then power is supplied for repair. The adjustable direct current power supply 1, the ruthenium iridium titanium anode plate 4, the steel bar 3 and the electrolyte 6 constitute a closed loop of the repair circuit.
[0070] First, a weak current is applied to test whether the circuit is connected (i.e. a closed loop of the repair circuit is formed). If not, the steel bar 3 needs to be reconnected. If yes, power repair is carried out. During the repair process, the voltage is always kept below 36V.
[0071] Example 2
[0072] This example provides a repair effect evaluation method based on the electrodeposition repair method of Example 1. The test circuit is as shown in Figure 3 Figure 4 The adjustable direct current power supply 1 of the repair circuit of Example 1 is removed, and an electrochemical workstation 8, a computer 9 and a mercury-mercury electrode 10 are added.
[0073] In addition to the ruthenium iridium titanium anode plate 4 and the steel bar 3 being connected with the electrochemical workstation 8 through the wires 2, the mercury-mercury electrode 10 immersed in the electrolyte 6 is also connected with the electrochemical workstation 8 through the wires 2. The electrochemical workstation 8 is connected with the computer 9 through the wires 2. The rest is the same as the repair circuit of Example 1.
[0074] In the test circuit, the steel bar 3 serves as the working electrode, the ruthenium iridium titanium anode plate 4 serves as the auxiliary electrode, and the mercury-mercury electrode 10 serves as the reference electrode to assist in testing the impedance.
[0075] The electrochemical workstation 8 is used to measure the impedance change during the repair process, and the computer 9 is used to control the electrochemical workstation 8 and record and analyze the data obtained by the electrochemical workstation 8.
[0076] The repair effect evaluation method is as follows:
[0077] At the t moment (such as 1 day, 3 days, 7 days, 14 days, 28 days) of the repair of Example 1, the concrete crack position 11 is temporarily powered off. The steel bar 3 serves as the impedance test working electrode, the ruthenium iridium titanium anode plate 4 serves as the impedance test auxiliary electrode (counter electrode), and the reference electrode is set between the working electrode and the auxiliary electrode. The impedance-frequency test is selected, and the test frequency is selected to be 10 -5 Hz-10 6 Hz, AC amplitude is 100 mV or less, after the open circuit potential stable after the start of the test and record the measured data. After the test, if the repair rate is less than 70%, reconnection repair circuit repair.
[0078] (4) Repair effect evaluation
[0079] The impedance data obtained to establish the corresponding equivalent circuit model, through the element change in the model reflects the change of the crack, at the same time, observe the crack surface healing and water seepage, combined with the AC impedance test results to calculate the repair rate. The calculation method is as follows:
[0080]
[0081] γ represents the repair rate at time t, Z t represents the impedance value at time t, Z 开裂 represents the impedance value of the concrete after cracking, Z 未裂 represents the impedance value of the concrete before cracking;
[0082] The impedance value of the uncracked, cracked concrete 3 and the repaired impedance value is measured by using ruthenium iridium titanium anode plate 4, steel bar 3 and mercury electrode 10 as auxiliary electrode, working electrode and reference electrode respectively.
[0083] The detection method of the impedance value of the concrete 5 before cracking is as follows:
[0084] The concrete 5 is soaked with electrolyte 6 to ensure that the steel bar 3 inside the concrete 5 is in the electrolyte 6, and the steel bar 3 inside the concrete 5 is connected with the external electrochemical workstation 8 through the wire 2, and the auxiliary electrode and the reference electrode are additionally set in the electrolyte 6, and the auxiliary electrode and the reference electrode are connected with the external electrochemical workstation, and the impedance value is detected;
[0085] The detection method of the impedance value of the concrete 5 after cracking is as follows:
[0086] The steel bar 3 inside the concrete crack position 11 is immersed with electrolyte 6 after the concrete crack position 11 is treated, and the steel bar 3 inside the concrete 5 is connected with the external electrochemical workstation 8 through the wire, and the auxiliary electrode and the reference electrode are additionally set in the electrolyte 6, and the auxiliary electrode and the reference electrode are connected with the external electrochemical workstation 8, and the impedance value is detected;
[0087] The detection method of the impedance value of the concrete 5 after cracking is as follows:
[0088] After the electro-deposition repair time (1st day, 3rd day, 7th day and 14th day), the electro-deposition repair is stopped, the wires are applied to connect the steel bars 3 inside the concrete 5 with the external electrochemical workstation 8, the auxiliary electrode and the reference electrode set in the electrolyte 6 are applied and connected with the external electrochemical workstation, and the impedance value detection is carried out.
[0089] The impedance value of the concrete 3 is measured on the 1st day, 3rd day, 7th day and 14th day of the repair respectively, and the repair rate is calculated, and the results are 22.78%, 24.50%, 46.55% and 79.23% respectively.
[0090] It is shown that the electro-deposition repair of the concrete crack position 11 on the 1st day, 3rd day and 7th day of the repair is not completed, and there is still a certain repair space; on the 14th day, the electro-deposition repair of the concrete crack position 11 has been basically completed, and has a good repair effect at this time.
[0091] The above description of the embodiments is for the convenience of the ordinary skilled in the art to understand and use the invention. Those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the present application is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art according to the disclosure of the present application without departing from the scope of the present application should be within the scope of protection of the present application.
Claims
1. An alternating current impedance-based method for evaluating the repair effect of electro-deposition of concrete cracks, characterized in that, The method comprises the following steps: The steel bars inside the concrete are used as working electrodes, auxiliary electrodes are additionally provided, and reference electrodes are provided, the above electrodes are immersed in an electrolyte, and an impedance-frequency test is performed by using an electrochemical workstation to detect the impedance values of the concrete before cracking, after cracking, and at a repair time t; The repair rate at the repair time t is calculated: ； γ represents a repair rate at a repair time t, Z t γ represents a repair rate at a repair time t, Z 开裂 γ represents a repair rate at a repair time t, Z 未裂 γ represents a repair rate at a repair time t, The repair effect is evaluated: when γ < a preset value, it is indicated that the electrodeposition repair is not completed, and the electrodeposition repair needs to be continuously performed on the concrete cracks; When γ ≥ the preset value, it is indicated that the electrodeposition repair is completed. The detection method of the impedance value before the concrete cracking is as follows: The concrete is soaked with the electrolyte, the steel bars inside the concrete are connected to the external electrochemical workstation through wires, auxiliary electrodes and reference electrodes provided in the electrolyte are additionally provided, and the auxiliary electrodes and the reference electrodes are connected to the external electrochemical workstation to detect the impedance value; The detection method of the impedance value after the concrete cracking is as follows: After the concrete crack position is treated, the steel bars inside the concrete crack position are soaked with the electrolyte, the steel bars inside the concrete are connected to the external electrochemical workstation through wires, auxiliary electrodes and reference electrodes provided in the electrolyte are additionally provided, and the auxiliary electrodes and the reference electrodes are connected to the external electrochemical workstation to detect the impedance value; The detection method of the impedance value at the electrodeposition repair time t after the concrete cracking is as follows: After the electrodeposition repair at the time t, the electrodeposition repair is stopped, the steel bars inside the concrete are connected to the external electrochemical workstation through wires, auxiliary electrodes and reference electrodes provided in the electrolyte are additionally provided, and the auxiliary electrodes and the reference electrodes are connected to the external electrochemical workstation to detect the impedance value; In impedance-frequency tests, the test frequency is 10 -5 Hz-10 6 Hz; In the impedance-frequency test, the alternating current amplitude is lower than 100 mV.
2. The method for evaluating the repair effect of electro-deposition of concrete cracks based on AC impedance according to claim 1, characterized in that, The preset value is 70%.
3. The AC impedance-based method for evaluating the repair effect of electro-deposition of concrete cracks according to claim 1, characterized in that, The auxiliary electrode is a ruthenium iridium titanium anode.
4. The AC impedance-based method for evaluating the repair effect of electro-deposition of concrete cracks according to claim 1, characterized in that, The reference electrode is selected from one of a calomel electrode, a mercurous sulfate electrode, or a mercuric oxide electrode.
5. The AC impedance-based method for evaluating the repair effect of electro-deposition of concrete cracks according to claim 1, characterized in that, The electrolyte is selected from one or more of zinc sulfate, magnesium sulfate, aluminum sulfate, zinc chloride, magnesium chloride, calcium acetate, or zinc acetate.