Method and system for testing critical chloride ion concentration of port reinforced concrete

Abstract

The invention relates to the technical field of chloride ion concentration testing, in particular to a port reinforced concrete critical chloride ion concentration testing method and system. In the passivation stage, an alkaline solution is adopted to replace a concrete passivation environment, so that the passivation time of the steel bar sample is shortened; the steel bar sample is manufactured into a reinforced concrete sample in the depassivation link, so that the real port reinforced concrete environment is simulated, and the test accuracy of the critical chloride ion concentration of the reinforced concrete is improved; meanwhile, the invention provides a method for determining power-on voltage in the chloride ion electromigration acceleration test and a method for determining a data set by taking test parameters and change rate parameters of the test as data sources in the data set, and meanwhile, after a model prediction result is obtained, a formula is adopted to further correct the model prediction result according to the change rate; the determination result of the power-on voltage is more accurate; therefore, the accuracy of determining the electrical parameters of the blunt removal test is improved, and an accurate data basis is provided for determining the blunt removal opportunity.

Description

Technical Field

[0001] The invention relates to the technical field of chloride ion concentration testing, and in particular to a method and system for testing critical chloride ion concentration of reinforced concrete in a port. Background Art

[0002] Reinforced concrete structure is one of the most widely used structural forms in the world's port construction process. The combination of high compressive strength of concrete and high tensile strength of steel bars makes reinforced concrete structure have many advantages. Reinforced concrete structures in port environments have been subjected to chloride erosion for a long time. If the durability design, detection and protection of the structure are not taken seriously, its service life will be difficult to meet the design requirements, which will bring economic losses and safety hazards to national infrastructure. Therefore, the durability research of reinforced concrete structures in marine environments has become one of the important topics, and an important parameter in durability life prediction, detection and protection is the critical chloride ion concentration of steel corrosion. In the reinforced concrete in the splash zone and tidal zone of the port, the chloride ion transmission mode includes capillary absorption and penetration in addition to diffusion, resulting in a large intrusion rate. At the same time, it is also subject to the effects of dry-wet alternation, wind and wave loads, and microbial corrosion. Therefore, the steel corrosion in the concrete in these areas is the most serious. Therefore, it is necessary to test the critical chloride ion concentration of the port reinforced concrete to explore the corrosion of the steel bars in the concrete and its mechanism.

[0003] In the prior art, there are schemes for testing the critical concentration of chloride ions. For example, a Chinese invention patent (CN108254302A) discloses a test device and method for studying the critical concentration of chloride ions in the tidal zone and splash zone of a bridge pier, which includes the following steps: 1) Preparation of a test specimen, wherein the test specimen includes a specimen body and a test steel bar, wherein the specimen body is cast with cement, fly ash, water, and standard sand according to a certain mix ratio, and the test steel bar includes a test embedded section and a test connecting section, wherein the test embedded section is embedded in the specimen body, and the test connecting section is exposed outside the specimen body; 2) After the test specimen is prepared, the test specimen is then placed in a first water tank in the test device, and the other end of the connecting resistor is connected to the test connecting section, wherein the test specimen is connected to the polarized steel bar through the connecting resistor, and after the test specimen is placed and connected, seawater or sodium chloride is added to the first water tank. solution; 3) simulation of tidal zone and splash zone, the simulated tidal device controls the elevation of the solution contained in the first water tank to perform periodic changes in the tidal zone, and the tidal zone period is 6h or 12h; the simulated splash device performs periodic spraying of the test specimen in the splash zone, and the splash zone period is 6-12h; 4) during the simulation of tidal zone and splash zone, the test specimen is monitored for corrosion; 5) after the corrosion monitoring detects that the test specimen is corroded, the simulation of tidal zone and splash zone is stopped, the connection resistor set on the test steel bar is removed, and the test specimen is taken out of the first water tank; 6) after the test specimen is taken out, the surface of the specimen body is wiped dry, and the specimen body is destroyed to expose the test inner embedded section; 7) observing the test inner embedded section, sampling the test body above the test inner embedded section where no corrosion occurs and close to corrosion, and measuring the chloride ion content, which is the chloride ion critical concentration value.

[0004] However, the above scheme has technical problems in the test process of critical concentration of chloride ions, such as long test time, rough test process and low test accuracy. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method and system for testing the critical chloride ion concentration of reinforced concrete in a port, which are used to solve the problems existing in the prior art.

[0006] The present invention provides a method for testing the critical chloride ion concentration of reinforced concrete in a port, comprising the following steps: S1: Prepare several steel bar specimens; S2: performing a passivation operation on the steel bar sample; S3: placing the steel bar sample in concrete to obtain a reinforced concrete sample; S4: performing a depassivation test on the reinforced concrete specimen; The S4 is specifically: S4.1: Prepare solutions for depassivation testing; S4.2: placing the reinforced concrete sample in the solution for depassivation test, and performing accelerated chloride ion electromigration treatment according to the energization parameters for depassivation; The power-on parameters include the power-on voltage; determining the power-on voltage V for accelerating the chloride ion electromigration process f The process is: Sa: Set the initial power-on voltage V0 to accelerate the chloride ion electromigration treatment for 6h; Sb: The reinforced concrete sample is left to stand for 24 hours, and then the open circuit voltage of the reinforced concrete sample at different times is collected; Sc: Calculate the change rate of the open circuit voltage between two adjacent sampling moments; Sd: Established to predict the power-on voltage V f Datasets; Se: Input the data set into the artificial neural network model to obtain the power-on voltage V predicted by the model f1 ; Sf: The power-on voltage V predicted by the model f1 It is used to accelerate the electromigration of chloride ions for 6 hours, and then the reinforced concrete sample is left to stand for 24 hours, and then the open circuit voltage V of the reinforced concrete sample after standing is collected. 13 and the open circuit voltage V of the reinforced concrete sample after standing for 0.5 h 14 ; Sg: Calculate the open circuit voltage V of the reinforced concrete sample after standing 13 and the open circuit voltage V of the reinforced concrete sample after standing for 0.5 h 14 The rate of change n 12 ; Sh: The current-carrying voltage V predicted by the model f1 And the rate of change n 12 , and the power-on voltage V for accelerating chloride ion electromigration treatment is obtained f ; S5: monitoring the electrochemical parameters of the reinforced concrete sample in real time, and after monitoring that the reinforced concrete sample is depassivated, testing the critical chloride ion concentration of the reinforced concrete sample.

[0007] Preferably, in the Sd, the chloride ion concentration in the solution for the depassivation test, the initial power-on voltage, the open circuit voltage of the reinforced concrete sample at different times, and the change rate of the open circuit voltage at two adjacent sampling times are used as the parameters for predicting the power-on voltage V f of the dataset.

[0008] Preferably, in the Se, the artificial neural network model further includes a model training step before prediction; The steps of model training are specifically as follows: setting different chloride ion concentrations and different initial power-on voltages, obtaining multiple data sets according to the Sa-Sd steps, and then annotating the data sets by experts to obtain training sets and verification sets for training and verification of the artificial neural network model, and then constraining the training process of the artificial neural network model through a loss function to obtain the final artificial neural network model.

[0009] Preferably, in the Sh, the power-on voltage V predicted by the model is f1 And the rate of change n 12 , and the power-on voltage V for accelerating chloride ion electromigration treatment is obtained f The specific formula is:

[0010] Where n i is the i-th rate of change, and a is a constant.

[0011] Preferably, in S2, the passivation operation is specifically: S2.1: placing the steel bar sample into a saturated calcium hydroxide solution; S2.2: collecting the open circuit voltage on the surface of the steel bar sample in real time; S2.3: When the open circuit voltage is stable, the passivation operation is terminated.

[0012] Preferably, S1 specifically comprises: cutting steel bars with a diameter of 10 mm into steel bars with a length of 4 cm in segments, and then grinding the steel bars with 60-mesh, 80-mesh, and 120-mesh sandpapers to remove the oxide layer on the surface of the steel bars; then placing them in deionized water for ultrasonic cleaning; then welding copper wires in the cleaned steel bars, and placing them in epoxy resin to form the steel bar sample.

[0013] Preferably, the epoxy resin is a second-generation bisphenol A epoxy resin.

[0014] Preferably, in S2.2, a silver-silver chloride electrode is used as a reference electrode of the steel bar sample, and the steel bar sample and the reference electrode are connected to an electrochemical workstation to achieve real-time collection of the open circuit voltage on the surface of the steel bar sample.

[0015] Preferably, in S2.3, the stable open circuit voltage of the steel bar sample is -254 mV.

[0016] According to another aspect of the present invention, a system for testing the critical chloride ion concentration of reinforced concrete in a port is provided. The system adopts the above-mentioned method for testing the critical chloride ion concentration of reinforced concrete in a port, and the system comprises: A steel bar sample preparation unit, used to prepare a number of steel bar samples; A passivation operation unit, used for performing a passivation operation on the steel bar sample; A reinforced concrete sample preparation unit, used for placing the reinforced concrete sample in concrete to obtain a reinforced concrete sample; A depassivation unit, used for performing a depassivation test on the reinforced concrete sample; The critical chloride ion concentration determination unit is used to perform real-time electrochemical parameter monitoring on the reinforced concrete sample, and after monitoring that the reinforced concrete sample is depassivated, test the critical chloride ion concentration of the reinforced concrete sample.

[0017] The embodiments of the present invention have the following technical effects: The invention adopts alkaline solution to replace the concrete passivation environment in the passivation stage, thereby reducing the passivation time of the steel bar sample; and in the depassivation stage, the steel bar sample is made into a reinforced concrete sample, in order to simulate the environment of real port reinforced concrete, so as to improve the accuracy of the critical chloride ion concentration test of reinforced concrete; The present invention proposes a method for determining a power-on voltage in a chloride ion electromigration acceleration test. In the method, an initial power-on voltage is first set to perform an electromigration acceleration test, and then parameters for predicting the power-on voltage are obtained. Moreover, compared with the prior art, this embodiment proposes a method of using test parameters and experimental change rate parameters as data sources in a data set, so that the prediction effect of the model is more accurate; at the same time, after obtaining the model prediction result, the model prediction result is used as the power-on voltage, and the change rate of the open circuit voltage is further obtained, and then the model prediction result is further corrected according to the change rate using a formula; so that the determination result of the power-on voltage is more accurate; thereby improving the accuracy of determining the electrical parameters of the depassivation test, thereby providing an accurate data basis for determining the timing of depassivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the electrochemical reaction of reinforced concrete corrosion in the prior art; Figure 2It is a flow chart of a method for testing critical chloride ion concentration of reinforced concrete in a port provided by an embodiment of the present invention; Figure 3 It is a flow chart of performing a passivation operation on a steel bar sample provided by an embodiment of the present invention; Figure 4 It is a flow chart of a depassivation test on a reinforced concrete specimen provided by an embodiment of the present invention; Figure 5 It is a flow chart of determining the power-on voltage for accelerating chloride ion electromigration treatment provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0021] Concrete has a porous structure, so there is often oxygen in the pores of the reinforced concrete structure. Figure 1 The schematic diagram of the electrochemical reaction of reinforced concrete corrosion is shown in the attached figure. Figure 1 As shown in the figure, the corrosion reaction of steel bars in reinforced concrete structures is mainly oxygen absorption corrosion, and the reaction process is as follows: Anode reaction: ; Cathode reaction: ; When the hydroxide ions at the cathode are transferred to the anode, they continue to react with the divalent iron ions at the anode. The reaction equation is as follows: ; However, for the port environment, the pH value of the internal pore fluid on the concrete is very high, up to about 13. Under high alkaline conditions, the Fe(OH)2 generated by steel corrosion is relatively stable and continues to undergo oxidation reactions in the presence of sufficient oxygen: ; The generated corrosion products Fe(OH)2 and Fe(OH)3 undergo a series of reactions and eventually generate FeO, Fe203, Fe304 and other compounds attached to the surface of the steel bar. These products are the passivation film formed on the surface of the steel bar. Regardless of the passivation process or the depassivation process of the steel bar, the above-mentioned anodic reaction will occur. The metal matrix of the steel bar loses electrons and becomes the raw material for the formation of the steel bar passivation film. During the passivation process, as the passivation film is gradually formed, the corrosion rate of the steel bar becomes slower and slower, while the growth rate of the passivation film continues to decrease, and eventually stops growing, reaching a relatively stable state.

[0022] The passivation film formed on the surface of the steel bars in the concrete structure can protect the steel bars from corrosion. However, for the concrete structure in a chloride environment such as a port, chloride ions will enter the pore liquid of the concrete through capillary action, diffusion and penetration, and then gradually migrate to the steel bar / concrete interface and contact the passivation film on the surface of the steel bars. When the chloride ions on the surface of the steel bars accumulate to the threshold value that causes the steel bars to depassivate, that is, the critical chloride ion concentration is reached, even if the steel bars are still under high alkaline conditions, the passivation film on their surface will be destroyed, resulting in steel corrosion. This embodiment tests the critical chloride ion concentration of reinforced concrete in ports.

[0023] Embodiment 1, Figure 2 This is a flow chart of a method for testing the critical chloride ion concentration of reinforced concrete in a port provided in Example 1 of the present invention. Figure 2 , a method for testing the critical chloride ion concentration of reinforced concrete in a port, specifically comprising the following steps: S1: Prepare several steel bar specimens; A steel bar with a diameter of 10 mm is cut into steel bars with a length of 4 cm, and then the steel bars are polished with 60-mesh, 80-mesh, and 120-mesh sandpaper to remove the oxide layer on the surface of the steel bar and make the surface of the steel bar present the original color of the steel bar, and then the steel bar is placed in deionized water for ultrasonic cleaning; then a copper wire is welded in the cleaned steel bar, and the steel bar is placed in epoxy resin to form the steel bar sample; Specifically, the epoxy resin is a second-generation bisphenol A epoxy resin, which has the advantages of good stability, fast curing speed, small shrinkage, etc., and has little impact on the subsequent testing process; It is worth emphasizing that the steel bar sample includes a copper wire, a steel bar, and epoxy resin, wherein the upper section of the steel bar is welded to the copper wire, the epoxy resin surrounds the side of the steel bar, and the lower section of the steel bar sample is a working surface for testing the critical chloride ion concentration of reinforced concrete.

[0024] S2: performing a passivation operation on the steel bar sample; From the above introduction, we can know that the steel bars in the concrete structure will form a passivation film on the surface. As time goes by, the passivation film is gradually destroyed before the steel bars will corrode. Therefore, in order to explore the critical chloride ion concentration for steel bar corrosion in concrete, it is necessary to first passivate the steel bar samples. Specifically, attached Figure 3 The flow chart of the passivation operation of steel bar specimens is shown in the attached Figure 3 As shown, the passivation operation is specifically as follows: S2.1: placing the steel bar sample into a saturated calcium hydroxide solution; Since the main component of the pore fluid of concrete before carbonization is calcium hydroxide solution, in order to achieve a better simulation effect, in this embodiment, a saturated calcium hydroxide solution is used as the carbonization solution of the steel bar sample; S2.2: collecting the open circuit voltage on the surface of the steel bar sample in real time; In the steps, since the silver-silver chloride electrode has good stability and reproducibility and does not contain toxic mercury elements, the silver-silver chloride electrode is used as the reference electrode of the steel bar sample; after the reference electrode is determined, the steel bar sample and the reference electrode are connected to an electrochemical workstation, so as to realize real-time collection of the open circuit voltage on the surface of the steel bar sample; S2.3: When the open circuit voltage is stable, the passivation operation is terminated; When the steel bar sample is passivated, the open circuit voltage of the steel bar sample rises rapidly in the initial period, and then gradually stabilizes as time goes by, indicating that a passivation film has been formed on the surface of the steel bar sample. Specifically, the stable open circuit voltage of the steel bar sample is -254mV.

[0025] S3: placing the steel bar sample in concrete to obtain a reinforced concrete sample; In the prior art, a reinforced concrete sample is generally prepared before passivation, and then a passivation test and a depassivation test are carried out. However, the above process requires a long time to achieve passivation and depassivation, resulting in a long test time for the critical chloride ion concentration of reinforced concrete. According to the above defects, this embodiment adopts an alkaline solution to replace the concrete passivation environment in the passivation stage, thereby reducing the passivation time of the steel sample; and in the depassivation stage, the steel sample is made into a reinforced concrete sample, in order to simulate the environment of real port reinforced concrete, so as to improve the accuracy of the critical chloride ion concentration test of reinforced concrete.

[0026] Specifically, S3 is as follows: placing the steel bar sample into a mold so that the working surface of the steel bar sample contacts the mold, then selecting concrete of the same specification as the facilities in the port and pouring it into the mold, placing it in a vibrating mixing table for uniform vibration and stirring, and after uniform vibration and stirring, standing for 24 hours and demolding, thereby obtaining the reinforced concrete sample.

[0027] S4: performing a depassivation test on the reinforced concrete specimen; In this step, a chloride ion electromigration system is used to accelerate the transmission of chloride ions in the reinforced concrete sample by electromigration, thereby achieving the effect of reducing the test time; Specifically, attached Figure 4 The flowchart of the depassivation test on reinforced concrete specimens is shown in the attached Figure 4As shown, the S4 is specifically: S4.1: Prepare solutions for depassivation testing; In this step, S4.1 is specifically as follows: injecting 500 ml of a sodium hydroxide solution having a concentration of 0.5 mol / L into a water tank, and then injecting 10 L of a 5% sodium chloride solution into the water tank, and stirring evenly, thereby obtaining a solution for a depassivation test; S4.2: placing the reinforced concrete sample in the solution for depassivation test, and performing accelerated chloride ion electromigration treatment according to the energization parameters for depassivation; Wherein, the power-on parameters include power-on voltage and power-on time; Among them, the power-on time is 48h, and for the setting of the power-on voltage, in the prior art, the power-on voltage is generally determined based on experiments or experience to ensure the accuracy and stability of the test results of reinforced concrete specimens; generally, the greater the power-on voltage, the shorter the time required for depassivation, but it also brings about the problem of poor stability of depassivation detection data; therefore, according to the above problem, this embodiment proposes a method for determining electromigration parameters that takes into account both the depassivation test time and the stability of depassivation detection data; Specifically, as attached Figure 5 As shown, the power-on voltage V for accelerating the chloride ion electromigration treatment is determined f The process is: Sa: Set the initial power-on voltage V0 to accelerate the chloride ion electromigration treatment for 6h; In this embodiment, the initial power-on voltage V0 is 4V; Sb: The reinforced concrete sample is left to stand for 24 hours, and then the open circuit voltage of the reinforced concrete sample at different times is collected; The open circuit voltage of the reinforced concrete sample at different times is collected from the end of the static state, and one open circuit voltage is collected every 0.5 h, and a total of 12 open circuit voltages are collected, namely V1, V2, ... V 12 ; Sc: Calculate the change rate of the open circuit voltage between two adjacent sampling moments; Among them, through this step, 11 open circuit voltage change rates n1, n2...n are obtained from the 12 open circuit voltages. 11 ; Sd: Established to predict the power-on voltage V f Datasets; The chloride ion concentration in the solution for the depassivation test, the initial power-on voltage, the open circuit voltage of the reinforced concrete sample at different times, and the change rate of the open circuit voltage at two adjacent sampling times are used as the parameters for predicting the power-on voltage V f Datasets; In this step, the chloride ion concentration in the solution used for the depassivation test, the initial power-on voltage, the open circuit voltage of the reinforced concrete sample at different times, and the change rate of the open circuit voltage at two adjacent sampling times are used as a data set; Se: Input the data set into the artificial neural network model to obtain the power-on voltage V predicted by the model f1 ; Wherein, the artificial neural network model further includes a model training step before prediction; The model training process is as follows: setting different chloride ion concentrations and different initial power-on voltages, obtaining multiple data sets according to the Sa-Sd process, then annotating the data sets by experts to obtain training sets and verification sets for training and verification of the artificial neural network model, and then constraining the training process of the artificial neural network model through a loss function, thereby obtaining a final artificial neural network model; Sf: The power-on voltage V predicted by the model f1 It is used to accelerate the electromigration of chloride ions for 6 hours, and then the reinforced concrete sample is left to stand for 24 hours, and then the open circuit voltage V of the reinforced concrete sample after standing is collected. 13 and the open circuit voltage V of the reinforced concrete sample after standing for 0.5 h 14 ; Sg: Calculate the open circuit voltage V of the reinforced concrete sample after standing 13 and the open circuit voltage V of the reinforced concrete sample after standing for 0.5 h 14 The rate of change n 12 ; Sh: The current-carrying voltage V predicted by the model f1 And the rate of change n 12 , and the power-on voltage V for accelerating chloride ion electromigration treatment is obtained f ; The power-on voltage V predicted by the model is f1 And the rate of change n 12 , and the power-on voltage V for accelerating chloride ion electromigration treatment is obtained f The specific formula is: ; Where n i is the i-th rate of change, a is a constant; In this embodiment, compared with the prior art, a method for determining the on-voltage in a chloride ion electromigration acceleration test is proposed. In this method, an initial on-voltage is first set to perform an electromigration acceleration test, and then parameters for predicting the on-voltage are obtained. Moreover, compared with the prior art, this embodiment proposes a method of using test parameters and experimental rate of change parameters as data sources in a data set, so that the prediction effect of the model is more accurate; at the same time, after obtaining the model prediction result, the model prediction result is used as the on-voltage, and the rate of change of the open-circuit voltage is further obtained, and then the model prediction result is further corrected according to the rate of change using a formula; so that the determination result of the on-voltage is more accurate; thereby improving the accuracy of determining the electrical parameters of the depassivation test.

[0028] S5: monitoring the electrochemical parameters of the reinforced concrete sample in real time, and after monitoring that the reinforced concrete sample is depassivated, testing the critical chloride ion concentration of the reinforced concrete sample.

[0029] Wherein, the electrochemical parameters include the planned resistance and current density of the reinforced concrete sample.

[0030] In this step, thanks to the above-determined power-on voltage, the depassivation timing can be determined more accurately in the chloride ion electromigration acceleration test.

[0031] Embodiment 2, the present invention also provides a port reinforced concrete critical chloride ion concentration testing system, the system adopts the port reinforced concrete critical chloride ion concentration testing method of embodiment 1, the system comprises: A steel bar sample preparation unit, used to prepare a number of steel bar samples; A passivation operation unit, used for performing a passivation operation on the steel bar sample; A reinforced concrete sample preparation unit, used for placing the reinforced concrete sample in concrete to obtain a reinforced concrete sample; A depassivation unit, used for performing a depassivation test on the reinforced concrete sample; The critical chloride ion concentration determination unit is used to perform real-time electrochemical parameter monitoring on the reinforced concrete sample, and after monitoring that the reinforced concrete sample is depassivated, test the critical chloride ion concentration of the reinforced concrete sample.

[0032] Embodiment 3, the present invention also provides an electronic device, including one or more processors and a memory.

[0033] The processor may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0034] The memory may include one or more computer program products, and the computer program product may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor may run the program instructions to implement the critical chloride ion concentration test method for reinforced concrete in the port of any embodiment of the present application described above and / or other desired functions. Various contents such as initial external parameters, threshold values, etc. may also be stored in the computer-readable storage medium.

[0035] In one example, the electronic device may further include: an input device and an output device, and these components are interconnected through a bus system and / or other forms of connection mechanisms. The input device may include, for example, a keyboard, a mouse, etc. The output device may output various information to the outside, including early warning information, braking force, etc. The output device may include, for example, a display, a speaker, a printer, and a communication network and a remote output device connected thereto, etc.

[0036] Of course, for the sake of simplicity, components such as buses, input / output interfaces, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application conditions.

[0037] In addition to the above-mentioned methods and devices, the embodiments of the present application may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to implement the functions of the critical chloride ion concentration test method for port reinforced concrete provided in any embodiment of the present application.

[0038] The computer program product may be written in any combination of one or more programming languages ​​to write program codes for performing the operations of the embodiments of the present application, including object-oriented programming languages, such as Java, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0039] In addition, an embodiment of the present application may also be a computer-readable storage medium on which computer program instructions are stored. When the computer program instructions are executed by a processor, the processor implements a method for testing the critical chloride ion concentration of reinforced concrete in a port provided in any embodiment of the present application.

[0040] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0041] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0042] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing critical chloride ion concentration of reinforced concrete in a port, characterized in that: The following steps are involved: S1: Prepare several steel bar specimens; S2: performing a passivation operation on the steel bar sample; S3: placing the passivated steel bar sample in concrete to obtain a reinforced concrete sample; S4: performing a depassivation test on the reinforced concrete specimen; The S4 is specifically: S4.1: Prepare the solution for the depassivation test; S4.2: placing the reinforced concrete sample in the solution for the depassivation test, and performing accelerated chloride ion electromigration treatment according to the power-on parameters for depassivation, wherein the power-on parameters include a power-on voltage, and determining a power-on voltage V for accelerating chloride ion electromigration treatment. f The process is: Sa: setting an initial power-on voltage V0, accelerating the chloride ion electromigration treatment at the initial power-on voltage V0, and the treatment time is 6 hours; Sb: The treated reinforced concrete sample is left to stand for 24 hours, and then the open circuit voltage of the reinforced concrete sample is collected at different times; Sc: Calculate the change rate of the open circuit voltage between two adjacent sampling moments; Sd: Established to predict the power-on voltage V f Datasets; Se: Input the data set into the first artificial neural network model to obtain the model predicted power-on voltage V f1 ; Sf: The model predicts the power-on voltage V f1 It is used to accelerate the electromigration of chloride ions for 6 hours, and then the reinforced concrete sample is left to stand for 24 hours, and then the open circuit voltage V of the reinforced concrete sample after standing is collected. 13 and the open circuit voltage V of the reinforced concrete sample after standing for 0.5 h 14 ; Sg: Calculate the open circuit voltage V of the reinforced concrete sample after standing 13 and the open circuit voltage V of the reinforced concrete sample after standing for 0.5 h 14 The rate of change n 12 ; Sh: The power-on voltage V predicted according to the model f1 And the rate of change n 12 , and the power-on voltage V for accelerating chloride ion electromigration treatment is obtained f ; S5: monitoring the electrochemical parameters of the reinforced concrete sample in real time, and after monitoring that the reinforced concrete sample is depassivated, testing the critical chloride ion concentration of the reinforced concrete sample.

2. A method for testing critical chloride ion concentration of reinforced concrete in a port according to claim 1, characterized in that: In the Sd, the chloride ion concentration in the solution for the depassivation test, the initial power-on voltage, the open circuit voltage of the reinforced concrete sample at different times, and the change rate of the open circuit voltage at two adjacent sampling times are used as the parameters for predicting the power-on voltage V f of the dataset.

3. A method for testing critical chloride ion concentration of port reinforced concrete according to claim 1, characterized in that: In the Se, the artificial neural network model further includes a model training step before prediction; The steps of model training are specifically as follows: setting different chloride ion concentrations and different initial power-on voltages, obtaining multiple data sets according to the Sa-Sd steps, and then annotating the data sets to obtain training sets and verification sets for training and verification of the artificial neural network model, and then constraining the training process of the artificial neural network model through a loss function to obtain the final artificial neural network model.

4. A method for testing critical chloride ion concentration of reinforced concrete in a port according to claim 1, characterized in that: In the Sh, the power-on voltage V predicted by the model f1 And the rate of change n 12 , and the power-on voltage V for accelerating chloride ion electromigration treatment is obtained f The specific formula is: ； Where n i is the i-th rate of change, and a is a constant.

5. A method for testing critical chloride ion concentration of port reinforced concrete according to claim 1, characterized in that: In S2, the passivation operation is specifically as follows: S2.1: placing the steel bar sample into a saturated calcium hydroxide solution; S2.2: collecting the open circuit voltage on the surface of the steel bar sample in real time; S2.3: When the open circuit is stable, the passivation operation is terminated.

6. A method for testing critical chloride ion concentration of port reinforced concrete according to claim 1, characterized in that: In S1, the preparation of several steel bar samples is specifically as follows: a steel bar with a diameter of 10 mm is cut into steel bar bars with a length of 4 cm, and then the steel bar bars are polished by sandpaper of 60 mesh, 80 mesh, and 120 mesh respectively to remove the oxide layer on the surface of the steel bar bars; then the steel bar bars are placed in deionized water for ultrasonic cleaning; then copper wires are welded in the cleaned steel bar bars, and placed in epoxy resin to form the steel bar samples.

7. A method for testing critical chloride ion concentration of port reinforced concrete according to claim 6, characterized in that: The epoxy resin is a second-generation bisphenol A epoxy resin.

8. A method for testing critical chloride ion concentration of port reinforced concrete according to claim 5, characterized in that: In S2.2, a silver-silver chloride electrode is used as a reference electrode of the steel bar sample, and the steel bar sample and the reference electrode are connected to an electrochemical workstation to achieve real-time collection of the open circuit voltage on the surface of the steel bar sample.

9. A method for testing critical chloride ion concentration of reinforced concrete in a port according to claim 5, characterized in that: In S2.3, the stable open circuit voltage of the steel bar sample is -254mV.

10. A critical chloride ion concentration test system for reinforced concrete in a port, characterized in that: The system adopts the critical chloride ion concentration test method for reinforced concrete in a port according to any one of claims 1 to 9, and the system comprises: A steel bar sample preparation unit, used to prepare a number of steel bar samples; A passivation operation unit, connected to the steel bar sample preparation unit, and used to perform a passivation operation on the steel bar sample; A reinforced concrete sample preparation unit is connected to the passivation operation unit and is used to place the steel sample after the passivation operation in concrete to obtain a reinforced concrete sample; a depassivation unit, connected to the reinforced concrete sample preparation unit, and used for performing a depassivation test on the reinforced concrete sample; The critical chloride ion concentration determination unit is connected to the depassivation unit and is used to monitor the electrochemical parameters of the reinforced concrete sample in real time, and after monitoring the depassivation of the reinforced concrete sample, test the critical chloride ion concentration of the reinforced concrete sample.

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