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

Abstract

The present invention relates to the technical field of chloride ion concentration testing, and in particular to a method and system for testing a critical chloride ion concentration of reinforced concrete in ports. In the present invention, an alkaline solution is used to replace a concrete passivation environment in a passivation phase, thereby shortening the passivation time of steel bar specimens; and in a depassivation process, the steel bar specimens are then fabricated into reinforced concrete specimens, so as to simulate a real environment of reinforced concrete in ports, thereby improving the accuracy of testing a critical chloride ion concentration of the reinforced concrete. Further provided are a method for determining an applied voltage in an accelerated chloride ion electromigration test, and a data set determination method using test parameters and experimental change rate parameters as data sources of a data set. Moreover, after being obtained, a model prediction result is further corrected by means of a formula and on the basis of a change rate, such that a determination result of the applied voltage is more accurate, and the accuracy of determining electrical parameters of a depassivation test is thus improved, thereby providing an accurate data basis for determining the depassivation timing.

Description

A method and system for testing the critical chloride ion concentration in reinforced concrete in ports. Technical Field

[0001] This invention relates to the field of chloride ion concentration testing technology, and in particular to a method and system for testing the critical chloride ion concentration in reinforced concrete in ports. Background Technology

[0002] Reinforced concrete structures are one of the most widely used structural forms in port construction worldwide. The combination of high compressive strength of concrete and high tensile strength of steel reinforcement gives reinforced concrete structures numerous advantages. However, reinforced concrete structures in port environments are subject to long-term chloride ion corrosion. If durability design, testing, and protection are not prioritized, their service life may fail to meet design requirements, leading to economic losses and safety hazards for national infrastructure. Therefore, the durability research of reinforced concrete structures in marine environments has become a crucial issue, and a key parameter in durability life prediction, testing, and protection is the critical chloride ion concentration for steel corrosion. In the splash zones and tidal zones of ports, the chloride ion transport mechanisms include diffusion, capillary absorption, and infiltration, resulting in a high intrusion rate. Furthermore, these areas are subjected to alternating wet and dry conditions, wind and wave loads, and microbial corrosion. Consequently, steel corrosion is most severe in these areas, necessitating critical chloride ion concentration testing to investigate the corrosion status and mechanisms of steel reinforcement in port reinforced concrete.

[0003] In the prior art, there are schemes for testing the critical concentration of chloride ions. For example, 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 bridge piers, including the following steps: 1) Preparation of test specimens, wherein the test specimens include a specimen body and test reinforcing bars. The specimen body is cast from cement, fly ash, water and standard sand in a certain mix ratio. The test reinforcing bars include an embedded test section and a connecting test section. The embedded test section is embedded in the specimen body, and the connecting test section is exposed outside the specimen body. 2) After the test specimen is prepared, it is placed in the first water tank of the test device, and the other end of the connecting resistor is connected to the test connection section. The test specimen and the polarized steel bar are connected through the connecting resistor. After the test specimen is placed and connected, seawater or sodium chloride solution is added to the first water tank; 3) Simulation of tidal zone and splash zone: The tidal simulation device controls the elevation of the solution in the first water tank to change the tidal zone periodically. The tidal zone period is 6h or 12h; the splash simulation device sprays the test specimen periodically in the splash zone. The splash zone period is 6-1h. 2h; 4) During the simulation of the tidal zone and splash zone, corrosion monitoring is performed on the test specimen; 5) After corrosion monitoring detects corrosion on the test specimen, the simulation of the tidal zone and splash zone is stopped, the connecting 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 damaged to expose the test embedded section; 7) The test embedded section is observed, and a sample is taken from the test body above the test embedded section that has not been corroded and is close to the corroded section, and the chloride ion content is measured. This chloride ion content is the chloride ion critical concentration value.

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

[0005] To address the aforementioned technical problems, this invention provides a method and system for testing the critical chloride ion concentration in reinforced concrete in ports, thereby resolving the issues existing in the prior art.

[0006] This invention provides a method for testing the critical chloride ion concentration in reinforced concrete in ports, comprising the following steps:

[0007] S1: Prepare several steel reinforcement samples;

[0008] S2: Passivate the steel bar sample;

[0009] S3: Place the steel bar sample in concrete to obtain a reinforced concrete sample;

[0010] S4: Perform a depassivation test on the reinforced concrete sample;

[0011] Specifically, S4 is:

[0012] S4.1: Prepare the solution for the depassivation test;

[0013] S4.2: Place the reinforced concrete sample into the solution used for the depassivation test, and proceed according to the energizing parameters.

[0014] Depassivation was achieved by accelerating chloride ion electromigration.

[0015] The energizing parameters include the energizing voltage; the process for determining the energizing voltage Vf for accelerating chloride ion electromigration is as follows:

[0016] Sa: Set the initial energizing voltage V0 to accelerate chloride ion electromigration treatment for 6 hours;

[0017] Sb: The reinforced concrete sample was left to stand for 24 hours, and then the open circuit voltage of the reinforced concrete sample was collected at different times.

[0018] Sc: Calculate the rate of change of open-circuit voltage between two adjacent sampling times;

[0019] Sd: Establish a method for predicting the applied voltage V f The dataset;

[0020] Se: Input the dataset into the artificial neural network model to obtain the predicted voltage V. f1 ;

[0021] Sf: The voltage V predicted by the model. f1 To accelerate chloride ion electromigration treatment for 6 hours, and then the steel bars

[0022] The concrete sample was left to stand for 24 hours, and then the open-circuit voltage V of the reinforced concrete sample after standing was collected. 13 and after standing for 0.5 hours

[0023] The open-circuit voltage V of the reinforced concrete specimen 14 ;

[0024] Sg: Calculate the open-circuit voltage V of the reinforced concrete sample after it has been left to stand. 13 The open-circuit voltage V of the reinforced concrete sample after standing for 0.5 hours. 14 rate of change n 12 ;

[0025] Sh: The voltage V predicted by the model f1 and the rate of change n 12The energizing voltage V for accelerating chloride ion electromigration treatment was obtained. f ;

[0026] S5: Real-time electrochemical parameter monitoring is performed on the reinforced concrete sample. After the depassivation of the reinforced concrete sample is detected, the critical chloride ion concentration of the reinforced concrete sample is tested.

[0027] Preferably, in Sd, the chloride ion concentration in the solution used for the depassivation test, the initial energized voltage, the open-circuit voltage of the reinforced concrete sample at different times, and the rate of change of the open-circuit voltage between two adjacent sampling times are used as parameters for predicting the energized voltage V. f The dataset.

[0028] Preferably, in the Se, the artificial neural network model further includes a model training step before prediction;

[0029] The specific steps for model training are as follows: setting different chloride ion concentrations and different initial energizing voltages, obtaining multiple datasets according to the Sa-Sd steps, then having the datasets labeled by experts to obtain training and validation sets for training and validating 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.

[0030] Preferably, in Sh, the energizing voltage V predicted according to the model f1 and the rate of change n 12 The energizing voltage V for accelerating chloride ion electromigration treatment was obtained. f The specific formula is:

[0031]

[0032] In the formula, n i Let be the i-th rate of change, and a be a constant.

[0033] Preferably, in step S2, the passivation operation specifically includes:

[0034] S2.1: Immerse the steel bar sample in a saturated calcium hydroxide solution;

[0035] S2.2: Real-time acquisition of the open-circuit voltage on the surface of the steel bar sample;

[0036] S2.3: When the open-circuit voltage is stable, the passivation operation ends.

[0037] Preferably, step S1 specifically involves: cutting a 10mm diameter steel bar into 4cm long steel bars, then grinding the steel bars with 60, 80, and 120 grit sandpaper to remove the oxide layer on the surface of the steel bars; then immersing them in deionized water for ultrasonic cleaning; then welding copper wires into the cleaned steel bars and placing them in epoxy resin to form the steel bar sample.

[0038] Preferably, the epoxy resin is a second-generation bisphenol A type epoxy resin.

[0039] Preferably, in step S2.2, a silver-silver chloride electrode is used as a reference electrode for the steel bar sample, and the steel bar sample and the reference electrode are connected to an electrochemical workstation to realize real-time acquisition of the open-circuit voltage on the surface of the steel bar sample.

[0040] Preferably, in step S2.3, the stable open-circuit voltage of the steel bar sample is -254mV.

[0041] According to another aspect of the present invention, a critical chloride ion concentration testing system for reinforced concrete in ports is provided. The system employs the aforementioned method for testing the critical chloride ion concentration of reinforced concrete in ports, and the system comprises:

[0042] A steel bar specimen preparation unit is used to prepare several steel bar specimens.

[0043] A passivation operation unit is used to perform a passivation operation on the steel bar sample.

[0044] A reinforced concrete specimen preparation unit is used to place the steel reinforcement specimen in concrete to obtain a reinforced concrete specimen.

[0045] A depassivation unit is used to perform a depassivation test on the reinforced concrete sample.

[0046] The critical chloride ion concentration determination unit is used to monitor the electrochemical parameters of the reinforced concrete sample in real time, and to test the critical chloride ion concentration of the reinforced concrete sample after the depassivation of the sample is detected.

[0047] Compared with the prior art, the present invention has the following advantages and technical effects:

[0048] In the passivation stage, the present invention uses an alkaline solution to replace the concrete passivation environment, 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 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.

[0049] This invention proposes a method for determining the energizing voltage in an accelerated chloride ion electromigration test. The method first sets an initial energizing voltage for the accelerated electromigration test, then obtains parameters for predicting the energizing voltage. Compared to existing technologies, this embodiment proposes using experimental parameters and the rate of change of the experimental parameters as centralized data sources, resulting in more accurate model predictions. Furthermore, after obtaining the model prediction results, these results are used as the energizing voltage, and the rate of change of the open-circuit voltage is further obtained. The model prediction results are then further corrected using a formula based on the rate of change, making the determination of the energizing voltage more accurate. This improves the accuracy of determining the electrical parameters in the depassivation test, thus providing an accurate data basis for determining the depassivation timing. Attached Figure Description

[0050] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0051] Figure 1 is a schematic diagram of the electrochemical reaction of reinforced concrete corrosion in the prior art;

[0052] Figure 2 is a flowchart of a method for testing the critical chloride ion concentration in reinforced concrete in a port according to an embodiment of the present invention.

[0053] Figure 3 is a flowchart of the passivation operation of the steel bar sample provided in an embodiment of the present invention;

[0054] Figure 4 is a flowchart of the depassivation test of reinforced concrete samples provided in an embodiment of the present invention;

[0055] Figure 5 is a flowchart of determining the energizing voltage for accelerating chloride ion electromigration treatment provided in an embodiment of the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0057] Concrete has a porous structure, so oxygen often exists in the pores of actual reinforced concrete structures. Figure 1 shows a schematic diagram of the electrochemical reaction of reinforced concrete corrosion. As shown in Figure 1, the corrosion of steel bars in reinforced concrete structures is mainly manifested as oxygen absorption corrosion, and the reaction process is as follows:

[0058] Anode reaction: ;

[0059] Cathode reaction: ;

[0060] When hydroxide ions from the cathode are transferred to the anode, they continue to react with ferrous ions from the anode, as shown in the following reaction equation:

[0061] ;

[0062] However, in port environments, the pH value of the pore fluid inside the concrete is very high, reaching up to about 13. Under highly 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.

[0063] ;

[0064] The generated corrosion products Fe(OH)2 and Fe(OH)3 undergo a series of reactions to eventually form compounds such as FeO, Fe2O3, and Fe3O4, which adhere to the surface of the steel reinforcement. These products constitute the passivation film formed on the surface of the steel reinforcement. Whether it is the passivation process or the depassivation process of the steel reinforcement, the above-mentioned anodic reaction will occur. The metal matrix of the steel reinforcement loses electrons and becomes the raw material for the formation of the steel reinforcement passivation film. During the passivation process, as the passivation film gradually forms, the corrosion rate of the steel reinforcement slows down, while the growth rate of the passivation film continuously decreases and eventually stops growing, reaching a relatively stable state.

[0065] The passivation film formed on the surface of steel bars in concrete structures can protect the steel bars from corrosion. However, in concrete structures in chloride-rich environments such as ports, chloride ions will enter the pore fluid of the concrete through capillary action, diffusion, and penetration, and then gradually migrate to the steel bar / concrete interface, contacting the passivation film on the steel bar surface. When the chloride ions on the steel bar surface accumulate to the threshold that causes depassivation, i.e., the critical chloride ion concentration is reached, even if the steel bar is still under highly alkaline conditions, its surface passivation film will be damaged, leading to steel bar corrosion. This embodiment tests the critical chloride ion concentration of reinforced concrete in ports.

[0066] Example 1, Figure 2 is a method for testing the critical chloride ion concentration in reinforced concrete in ports provided by Example 1 of the present invention.

[0067] The flowchart is shown in Figure 2. Referring to Figure 2, a method for testing the critical chloride ion concentration in reinforced concrete at a port specifically includes the following steps:

[0068] S1: Prepare several steel reinforcement samples;

[0069] The 10mm diameter steel bar was cut into 4cm long steel bars. The steel bars were then polished with 60, 80, and 120 grit sandpaper to remove the oxide layer and reveal the natural color of the steel bar. Next, the steel bars were ultrasonically cleaned in deionized water. After cleaning, copper wires were welded into the steel bars, and the bars were placed in epoxy resin to form the steel bar sample.

[0070] Specifically, the epoxy resin is a second-generation bisphenol A type epoxy resin, which has advantages such as good stability, fast curing speed, and low shrinkage, and has little impact on the subsequent testing process.

[0071] It is worth emphasizing that the steel bar sample includes a copper wire, a steel bar, and epoxy resin. The upper section of the steel bar is welded to the copper wire, and the epoxy resin surrounds the side of the steel bar. The lower section of the steel bar sample is the working surface, used for testing the critical chloride ion concentration of reinforced concrete.

[0072] S2: Passivate the steel bar sample;

[0073] As can be seen from the above introduction, a passivation film will form on the surface of the steel bars in the concrete structure. Corrosion of the steel bars will only occur after the passivation film is gradually destroyed over time. Therefore, in order to investigate the critical chloride ion concentration for steel bar corrosion in concrete, it is necessary to first passivate the steel bar samples.

[0074] Specifically, Figure 3 shows a flowchart of the passivation operation for the steel bar sample. As shown in Figure 3, the passivation operation is as follows:

[0075] S2.1: Immerse the steel bar sample in a saturated calcium hydroxide solution;

[0076] Since the pore fluid of concrete before carbonation is mainly composed of calcium hydroxide solution, in order to achieve better simulation results, this embodiment uses saturated calcium hydroxide solution as the carbonation solution for the steel reinforcement sample.

[0077] S2.2: Real-time acquisition of the open-circuit voltage on the surface of the steel bar sample;

[0078] In this step, since the silver-silver chloride electrode has good stability and reproducibility and does not contain toxic mercury, it is used as the reference electrode for the steel bar sample. After the reference electrode is determined, the steel bar sample and the reference electrode are connected to an electrochemical workstation to realize the real-time acquisition of the open-circuit voltage on the surface of the steel bar sample.

[0079] S2.3: When the open-circuit voltage stabilizes, the passivation operation ends;

[0080] During the passivation of the steel bar sample, the open circuit voltage of the steel bar sample rose rapidly in the initial period. Then, as time went on, the open circuit voltage of the steel bar sample gradually stabilized, indicating that a passivation film had been formed on the surface of the steel bar sample at this time.

[0081] Specifically, the stable open-circuit voltage of the steel bar sample is -254mV.

[0082] S3: Place the steel bar sample in concrete to obtain a reinforced concrete sample;

[0083] In existing technologies, reinforced concrete samples are typically prepared before passivation, followed by passivation and depassivation tests. However, these processes require a considerable amount of time to achieve passivation and depassivation, resulting in a prolonged testing time for the critical chloride ion concentration of reinforced concrete. To address these shortcomings, this embodiment employs an alkaline solution to replace the concrete passivation environment during the passivation stage, thereby reducing the passivation time of the reinforcing steel samples. Furthermore, during the depassivation stage, the reinforcing steel samples are prepared into reinforced concrete samples to simulate the environment of real port reinforced concrete, thereby improving the accuracy of the critical chloride ion concentration test for reinforced concrete.

[0084] Specifically, S3 involves: placing the reinforcing bar sample into a mold, ensuring the working surface of the sample contacts the mold; then pouring concrete of the same specifications as the port facility into the mold and placing it on a vibrating mixing table for uniform mixing; after uniform mixing, allowing it to stand for 24 hours before demolding to obtain the reinforced concrete sample. S4 involves performing a depassivation test on the reinforced concrete sample.

[0085] In this step, a chloride ion electromigration system is used to accelerate the deposition of chloride ions in the reinforced concrete through electromigration.

[0086] The transfer of concrete samples reduces the testing time.

[0087] Specifically, Figure 4 is a flowchart illustrating the depassivation test of reinforced concrete specimens. As shown in Figure 4, step S4 specifically involves:

[0088] S4.1: Prepare the solution for the depassivation test;

[0089] In this step, S4.1 specifically involves: injecting 500 ml of sodium hydroxide solution into a water tank, wherein the concentration of the sodium hydroxide solution is 0.5 mol / L, and then injecting 10 L of 5% sodium chloride solution into the water tank and stirring evenly to obtain a solution for the depassivation test;

[0090] S4.2: The reinforced concrete sample is placed in the solution used for the depassivation test, and depassivation is carried out by accelerating chloride ion electromigration according to the energizing parameters;

[0091] The energizing parameters include energizing voltage and energizing time;

[0092] The energizing time is 48 hours. In the prior art, the energizing voltage is generally determined based on experiments or experience to ensure the accuracy and stability of the test results of reinforced concrete samples. Generally, the larger the energizing voltage, the less time is required for depassivation. However, this also leads to poor stability of the depassivation test data. Therefore, this embodiment proposes a method for determining electromigration parameters that takes into account both the depassivation test time and the stability of the depassivation test data.

[0093] Specifically, as shown in Figure 5, the process of determining the energizing voltage Vf for accelerating chloride ion electromigration is as follows:

[0094] Sa: Set the initial energizing voltage V0 to accelerate chloride ion electromigration treatment for 6 hours;

[0095] In this embodiment, the initial energizing voltage V0 is 4V;

[0096] Sb: The reinforced concrete sample was left to stand for 24 hours, and then the open circuit voltage of the reinforced concrete sample was collected at different times.

[0097] The open-circuit voltages of the reinforced concrete samples at different times were collected starting from the end of the static settling period, with one open-circuit voltage collected every 0.5 hours, for a total of 12 open-circuit voltages, namely V1, V2, ... V 12 ;

[0098] Sc: Calculate the rate of change of open-circuit voltage between two adjacent sampling times;

[0099] In this step, a total of 11 open-circuit voltage change rates n1, n2...n are obtained from the 12 open-circuit voltages. 11 ;

[0100] Sd: Establish a method for predicting the applied voltage V f The dataset;

[0101] Specifically, the chloride ion concentration in the solution used for the depassivation test, the initial energized voltage, the open-circuit voltage of the reinforced concrete sample at different times, and the rate of change of the open-circuit voltage between two adjacent sampling times are used to predict the energized voltage V. f The dataset;

[0102] In this step, the chloride ion concentration in the solution used for the depassivation test, the initial energizing voltage, and the concentrations at different times will be measured.

[0103] The open-circuit voltage of the reinforced concrete specimen and the rate of change of the open-circuit voltage at two adjacent sampling times are used as the dataset.

[0104] Se: Input the dataset into the artificial neural network model to obtain the predicted voltage V. f1 ;

[0105] The artificial neural network model includes a model training step before prediction.

[0106] The model training process is as follows: different chloride ion concentrations and different initial voltages are set, multiple datasets are obtained according to the Sa-Sd process, and then the datasets are labeled by experts to obtain training and validation sets for training and validation of the artificial neural network model. Then, the training process of the artificial neural network model is constrained by a loss function to obtain the final artificial neural network model.

[0107] Sf: The voltage V predicted by the model. f1 The reinforced concrete sample was subjected to an accelerated chloride ion electromigration treatment for 6 hours, and then left to stand for 24 hours. The open-circuit voltage V of the standing reinforced concrete sample was then measured. 13 The open-circuit voltage V of the reinforced concrete sample after standing for 0.5 hours. 14 ;

[0108] Sg: Calculate the open-circuit voltage V of the reinforced concrete sample after it has been left to stand. 13 The open-circuit voltage V of the reinforced concrete sample after standing for 0.5 hours. 14 rate of change n 12 ;

[0109] Sh: The voltage V predicted by the model f1 and the rate of change n 12 The energizing voltage V for accelerating chloride ion electromigration treatment was obtained. f ;

[0110] Wherein, the energizing voltage V predicted according to the model f1 and the rate of change n 12 The energizing voltage V for accelerating chloride ion electromigration treatment was obtained. f The specific formula is:

[0111]

[0112] In the formula, n i Let be the i-th rate of change, and 'a' be a constant.

[0113] In this embodiment, compared with the prior art, a method for determining the energizing voltage in an accelerated chloride ion electromigration test is proposed. This method first sets an initial energizing voltage for the accelerated electromigration test, then obtains parameters for predicting the energizing voltage. Furthermore, compared with the prior art, this embodiment proposes using experimental parameters and the rate of change of the experiment as the central data source, making the model's prediction more accurate. Simultaneously, after obtaining the model prediction result, the model prediction result is used as the energizing voltage, and the rate of change of the open-circuit voltage is further obtained. Then, the model prediction result is further corrected using a formula based on the rate of change, making the determination of the energizing voltage more accurate, thereby improving the accuracy of determining the electrical parameters in the depassivation test.

[0114] S5: Real-time electrochemical parameter monitoring is performed on the reinforced concrete sample. After the depassivation of the reinforced concrete sample is detected, the critical chloride ion concentration of the reinforced concrete sample is tested.

[0115] The electrochemical parameters include the planned resistance and current density of the reinforced concrete sample.

[0116] In this step, thanks to the determined energizing voltage mentioned above, the timing of depassivation can be determined more accurately in the chloride ion electromigration acceleration test.

[0117] Example 2: The present invention also provides a critical chloride ion concentration testing system for reinforced concrete in ports. The system employs the critical chloride ion concentration testing method for reinforced concrete in ports described in Example 1. The system includes:

[0118] A steel bar specimen preparation unit is used to prepare several steel bar specimens.

[0119] A passivation operation unit is used to perform a passivation operation on the steel bar sample.

[0120] A reinforced concrete specimen preparation unit is used to place the steel reinforcement specimen in concrete to obtain a reinforced concrete specimen.

[0121] A depassivation unit is used to perform a depassivation test on the reinforced concrete sample.

[0122] The critical chloride ion concentration determination unit is used to monitor the electrochemical parameters of the reinforced concrete sample in real time, and to test the critical chloride ion concentration of the reinforced concrete sample after the depassivation of the sample is detected.

[0123] Example 3: The present invention also provides an electronic device, including one or more processors and a memory.

[0124] A processor can be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and can control other components in an electronic device to perform desired functions.

[0125] The memory may include one or more computer program products, which 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. 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 a processor may execute the program instructions to implement the critical chloride ion concentration testing method for reinforced concrete in ports described above in any embodiment of this application, and / or other desired functions. Various contents such as initial external parameters and thresholds may also be stored in the computer-readable storage medium.

[0126] In one example, the electronic device may also include input and output devices, which are interconnected via a bus system and / or other forms of connection. The input device may include, for example, a keyboard, a mouse, etc. The output device may output various information to the outside, including warning messages, braking force, etc. The output device may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0127] Of course, for simplicity, components such as buses and input / output interfaces have been omitted. In addition, depending on the specific application, the electronic device may include any other appropriate components.

[0128] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the function of the port reinforced concrete critical chloride ion concentration testing method provided in any embodiment of this application.

[0129] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0130] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to implement a method for testing the critical chloride ion concentration in reinforced concrete in ports provided in any embodiment of this application.

[0131] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0132] It should be noted that the terminology used in this invention is for describing specific embodiments only and is not intended to limit the scope of this application. As shown in this specification, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0133] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the critical chloride ion concentration in reinforced concrete of ports, characterized in that, Includes the following steps: S1: Prepare several steel reinforcement samples; S2: Passivate the steel bar sample; S3: Place the passivated steel bar sample in concrete to obtain a reinforced concrete sample; S4: Perform a depassivation test on the reinforced concrete sample; Specifically, S4 is: S4.1: Prepare the solution for the depassivation test; S4.2: The reinforced concrete sample is placed in the solution used for the depassivation test, and depassivation is performed by accelerating chloride ion electromigration according to the energizing parameters, wherein the energizing parameters include the energizing voltage, and the energizing voltage V for accelerating chloride ion electromigration is determined. f The process is as follows: Sa: Set the initial energizing voltage V0, and accelerate the chloride ion electromigration treatment under the initial energizing voltage V0 for a treatment time of 6 hours; Sb: The treated reinforced concrete sample was left to stand for 24 hours, and then the open circuit voltage of the reinforced concrete sample was collected at different times. Sc: Calculate the rate of change of open-circuit voltage between two adjacent sampling times; Sd: Establish a dataset for predicting the applied voltage Vf; Se: Input the dataset into the first artificial neural network model to obtain the model-predicted energized voltage V. f1 ; Sf: The model predicts the on-state voltage V. f1 The reinforced concrete sample was subjected to an accelerated chloride ion electromigration treatment for 6 hours, and then left to stand for 24 hours. The open-circuit voltage V of the standing reinforced concrete sample was then measured. 13 The open-circuit voltage V of the reinforced concrete sample after standing for 0.5 hours. 14 ; Sg: Calculate the open-circuit voltage V of the reinforced concrete specimen after it has been left to stand. 13 The open-circuit voltage V of the reinforced concrete sample after standing for 0.5 hours. 14 rate of change n 12 ; Sh: Predict the energizing voltage V based on the model. f1 and the rate of change n 12 The energizing voltage V for accelerating chloride ion electromigration treatment was obtained. f ; S5: Real-time electrochemical parameter monitoring is performed on the reinforced concrete sample. After the depassivation of the reinforced concrete sample is detected, the critical chloride ion concentration of the reinforced concrete sample is tested.

2. The method for testing the critical chloride ion concentration in reinforced concrete in ports according to claim 1, characterized in that: In the Sd, the chloride ion concentration in the solution used for the depassivation test, the initial energized voltage, the open-circuit voltage of the reinforced concrete sample at different times, and the rate of change of the open-circuit voltage between two adjacent sampling times are used as the dataset for predicting the energized voltage Vf.

3. The method for testing the critical chloride ion concentration in reinforced concrete in ports according to claim 1, characterized in that: In the Se, the artificial neural network model includes a model training step before prediction; The specific steps for model training are as follows: setting different chloride ion concentrations and different initial energizing voltages, obtaining multiple datasets according to the Sa-Sd steps, then labeling the datasets to obtain training and validation sets for training and validation 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. The method for testing the critical chloride ion concentration in reinforced concrete in ports according to claim 1, characterized in that: In Sh, based on the predicted voltage Vf1 and the rate of change n12, the specific formula for the voltage Vf used to accelerate chloride ion electromigration is as follows: In the formula, n i Let be the i-th rate of change, and a be a constant.

5. The method for testing the critical chloride ion concentration in reinforced concrete in ports according to claim 1, characterized in that: In S2, the passivation operation specifically includes: S2.1: Immerse the steel bar sample in a saturated calcium hydroxide solution; S2.2: Real-time acquisition of the open-circuit voltage on the surface of the steel bar sample; S2.3: When the open circuit is stable, the passivation operation ends.

6. The method for testing the critical chloride ion concentration in reinforced concrete in ports according to claim 1, characterized in that: In step S1, the preparation of several steel bar samples specifically involves: cutting steel bars with a diameter of 10 mm into 4 cm long sections, then grinding the steel bars with 60-grit, 80-grit, and 120-grit sandpaper to remove the oxide layer on the surface of the steel bars; then immersing them in deionized water for ultrasonic cleaning; then welding copper wires into the cleaned steel bars and placing them in epoxy resin to form the steel bar samples.

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

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

9. The method for testing the critical chloride ion concentration in reinforced concrete in ports 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 testing system for reinforced concrete in ports, characterized in that, The system employs the critical chloride ion concentration test method for reinforced concrete in ports as described in any one of claims 1-9, and the system comprises: A steel bar specimen preparation unit is used to prepare several steel bar specimens. A passivation operation unit, connected to the steel bar sample preparation unit, is used to perform a passivation operation on the steel bar sample; a reinforced concrete sample preparation unit, connected to the passivation operation unit, is used to prepare the passivated steel bar sample. The sample was placed in concrete to obtain a reinforced concrete specimen. A depassivation unit is connected to the reinforced concrete sample preparation unit and is used to perform a depassivation test on the reinforced concrete sample. The critical chloride ion concentration determination unit, connected to the depassivation unit, is used to monitor the electrochemical parameters of the reinforced concrete sample in real time. After the depassivation of the reinforced concrete sample is detected, the critical chloride ion concentration of the reinforced concrete sample is tested.

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