High-voltage electrochemical accelerated dissolution-seepage test system and method suitable for anti-seepage curtain bodies

Abstract

The present invention discloses a high-voltage electrochemical accelerated corrosion-seepage test system and method suitable for anti-seepage curtains. The system includes a test chamber for mounting test specimens and providing a test environment, an encapsulation module for encapsulating the test chamber by water injection, and a pressurization module for applying osmotic pressure to the test chamber. The present invention allows electrochemical corrosion to be performed during the osmotic pressurization and high-temperature process of the test specimen, transforming contact corrosion on the specimen surface into osmotic corrosion within the specimen. This method not only replicates the erosion conditions caused by the coupling of multiple factors under natural conditions, improving test accuracy, but also significantly accelerates the corrosion process and saves time and costs.

Description

Technical Field

[0001] The invention relates to a hydraulic concrete test, and in particular to a high-voltage electrochemical accelerated dissolution-seepage test system and method suitable for an anti-seepage curtain body. Background Art

[0002] A curtain is a continuous water-blocking curtain formed by injecting slurry into the cracks and pores of a rock or soil layer. It is used to reduce seepage and lower osmotic pressure. Due to the interaction between groundwater and the curtain material, groundwater flow can not only cause physical wear (i.e., abrasion) but also trigger chemical reactions. Firstly, hydration products such as calcium hydroxide in the cement-based curtain react easily with acidic substances in the groundwater, leading to dissolution and loss. This osmotic dissolution gradually accumulates over time, altering the curtain's microstructure, increasing porosity and permeability, and ultimately weakening the curtain's anti-seepage performance. Secondly, curtain dissolution is often more pronounced in specific areas, such as the bottom and upstream sides, where the hydraulic head pressure is greater, the seepage rate is faster, and the dissolution is more intense. Therefore, the dissolution rate of the curtain in natural environments is largely dependent on the calcium ion dissolution rate and hydraulic head pressure. In addition, environmental factors such as groundwater temperature will also affect the rate and extent of dissolution. A certain range of temperature can accelerate the rate of chemical reactions, increase the solubility of certain substances, and reduce the viscosity and density of water, thereby accelerating the chemical decomposition and dissolution of the curtain material.

[0003] Long-term erosion and damage to anti-seepage curtains are common in large-scale engineering projects, including reservoirs, dams, foundation pits, underground engineering, water transfer tunnels in high-head environments, and river and seawall construction. Accurately describing the relationship between changes in the curtain's anti-seepage performance and its degree of damage is crucial for predicting its durability. However, accelerating the curtain's dissolution process and simulating natural dissolution processes remain key challenges in curtain seepage and dissolution research.

[0004] Laboratory experiments on accelerated dissolution and seepage of curtain bodies are crucial for revealing the mechanism of groundwater seepage-chemical coupling and the evolution of permeability characteristics under load, as well as establishing and validating models and numerical analysis methods for coupled groundwater seepage, chemical reaction, and solute migration in curtain bodies. Currently, domestic and international researchers have developed numerous experimental devices for accelerated dissolution and seepage coupling of hydraulic concrete, including high hydraulic gradient accelerated dissolution devices, chemical reagent accelerated dissolution experimental methods based on ammonium nitrate solution, and electrochemical accelerated dissolution test devices. However, most current experimental devices fail to perform curtain body dissolution and seepage tests under multi-factor coupling conditions, and the test cycles are long. Furthermore, although electrochemical accelerated dissolution is currently a relatively efficient method for accelerating curtain body dissolution, it is primarily used for contact dissolution tests under normal pressure and cannot be effectively applied to seepage dissolution tests under high water pressure conditions. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-voltage electrochemical accelerated dissolution-seepage test system suitable for anti-seepage curtain bodies, and a high-voltage electrochemical accelerated dissolution-seepage test method suitable for anti-seepage curtain bodies based on the above system. The present invention can realize electrochemical dissolution during the process of osmotic pressurization and high temperature of the specimen, and convert the contact dissolution only on the surface of the specimen into osmotic dissolution inside the specimen. It can not only restore the erosion situation caused by the coupling of multiple factors in the natural state, improve the test accuracy, but also greatly accelerate the dissolution process and save time costs.

[0006] The technical solution adopted in the present invention is:

[0007] A high-voltage electrochemical accelerated dissolution-seepage test system suitable for an anti-seepage curtain body, comprising a test chamber for installing a test piece and providing a test environment, a packaging module for packaging the test chamber by injecting water, and a pressurizing module for applying osmotic pressure to the test chamber; a test piece installation position is provided in the middle of the test chamber, and after the test piece is installed, the test chamber can be separated into a cathode chamber and an anode chamber, the inner walls of the cathode chamber and the anode chamber are both provided with an insulating layer, and the open ends are closed by respective airtight covers and insulating parts, the interiors of the cathode chamber and the anode chamber are provided with respective temperature sensors, electrodes and ceramic heating elements, the upper parts of the cathode chamber and the anode chamber are provided with respective safety valves and water injection ports, and the lower parts are provided with respective water outlets, the safety valves of the cathode chamber and the anode chamber are respectively connected to respective exhaust gas containers through pipelines with valves, and the cathode chamber and the anode chamber are respectively connected to respective exhaust gas containers through pipelines with valves. The water inlet of the chamber can be closed or externally connected, and the water outlets of the cathode chamber and the anode chamber are respectively connected to their respective reaction liquid containers through pipelines with valves, and a pressure sensor is installed inside the cathode chamber; the packaging module includes a water pump, the inlet end of the water pump is connected to the deionized water container through a pipeline with a valve, and the outlet end is connected to the water inlet of the cathode chamber and the anode chamber through pipelines with valves; the pressurizing module includes a pressure transmission device and a high-precision hydraulic pump, the pressure transmission device includes a hydraulic cavity, the two ends of the hydraulic cavity are open, and the ceramic piston slides in the middle without disengagement. The inlet end of the high-precision hydraulic pump is connected to the hydraulic oil tank through a pipeline with a valve, and the outlet end is connected to one end of the hydraulic cavity through a pipeline with a pressure sensor. The hydraulic oil tank is used to store non-conductive hydraulic oil, and the other end of the hydraulic cavity is directly connected to the cathode chamber through a pipeline.

[0008] Preferably, the cathode chamber temperature sensor, cathode chamber electrode, cathode chamber ceramic heating element, cathode chamber pressure sensor, anode chamber temperature sensor, anode chamber electrode, anode chamber ceramic heating element, pressure sensor between the high-precision hydraulic pump and the hydraulic chamber, and the high-precision hydraulic pump are electrically connected to the power supply and numerical control module respectively, and the power supply and numerical control module are electrically connected to the host computer; the power supply and numerical control module are used to provide power to each detection component and each actuator and control the action of each actuator according to the instructions of the host computer; the host computer can control each actuator through the power supply and numerical control module according to the input setting information and the feedback information of each detection component to obtain the required test temperature and test osmotic pressure, and can automatically calculate and draw the dissolution rate change curve and permeability characteristic change curve under the influence of different current, voltage, temperature and osmotic pressure based on the test data.

[0009] Preferably, the test chamber is made of stainless steel resistant to high pressure material, the inner wall insulation layers of the cathode chamber and the anode chamber are both made of silicone rubber pads, and the ends of the cathode chamber and the anode chamber are sealed by respective airtight covers with epoxy resin.

[0010] Preferably, the inlet end of the high-precision hydraulic pump and the valve are connected to the recovery oil tank via a pipeline with a safety piece.

[0011] Preferably, the airtight covers of the cathode chamber and the anode chamber are both installed and fixed by fastening bolts.

[0012] Preferably, the test chamber is in the shape of a horizontal cylinder and is elevated and supported by a bracket.

[0013] Preferably, the cathode chamber temperature sensor and the anode chamber temperature sensor are pressure thermometers.

[0014] A high-voltage electrochemical accelerated corrosion-seepage test method applicable to an anti-seepage curtain body is based on the above-mentioned high-voltage electrochemical accelerated corrosion-seepage test system applicable to an anti-seepage curtain body, comprising the following steps:

[0015] Step S1: Processing the test piece

[0016] After the specimen is cured at room temperature, the current resistivity of the specimen is measured first, and then a vacuum water saturation test is performed to measure the resistivity of the specimen after vacuum water saturation.

[0017] Step S2: Packaging the test piece

[0018] First, open the airtight covers of the cathode chamber and the anode chamber, then install the specimen on the specimen installation position in the middle of the test chamber, and make good insulation and water isolation between the specimen and the test chamber, so that the specimen separates the test chamber into the cathode chamber and the anode chamber and the solutions in the cathode chamber and the anode chamber can only form a circuit through the specimen after being energized, and then close the airtight covers of the cathode chamber and the anode chamber; then turn on the water pump and the corresponding valves, so that the water pump injects the extracted deionized water into the cathode chamber until the cathode chamber and one side of the hydraulic cavity are filled with deionized water, and the ceramic piston moves to one end close to the high-precision hydraulic pump, then turn off the water pump to stop water injection and let it stand for a while; then observe whether the anode chamber has any water leakage, and after confirming that it is sealed intact, first close the corresponding valve of the cathode chamber water injection port, then close the cathode chamber water injection port, then turn on the water pump and the corresponding valve, so that the water pump injects the extracted deionized water into the anode chamber until the anode chamber is filled with deionized water, then turn off the water pump and the corresponding valves, and then close the anode chamber water injection port, and the specimen in the test chamber is in a packaged state;

[0019] Step S3: Infiltration and dissolution of test piece

[0020] Turn on the ceramic heating elements in the cathode chamber and the anode chamber, and heat the cathode chamber and the anode chamber to the required test temperature and maintain it under the feedback of the temperature sensors in the cathode chamber and the anode chamber; turn on the high-precision hydraulic pump and the corresponding valves, so that the high-precision hydraulic pump pushes the extracted hydraulic oil into the hydraulic cavity to pressurize the ceramic piston, and the ceramic piston pushes deionized water into the cathode chamber to pressurize the cathode chamber; under the feedback of the pressure sensor between the high-precision hydraulic pump and the hydraulic cavity and the pressure sensor on the cathode chamber, pressurize the cathode chamber to the required test osmotic pressure and maintain it; turn on the electrodes in the cathode chamber and the anode chamber, and the current flows through the anode chamber. The cathode chamber electrodes, the test piece, and the cathode chamber electrodes form a circuit. Under the test temperature and test osmotic pressure, the electrochemical corrosion of the test piece changes from contact corrosion to osmotic corrosion, the corrosion rate is greatly increased, and a water electrolysis reaction occurs. The cathode chamber and the anode chamber produce hydrogen and oxygen respectively. If the internal pressure of the cathode chamber rises to the critical pressure of the cathode chamber safety valve, the cathode chamber safety valve automatically opens to restore the critical pressure and discharges hydrogen to the cathode chamber exhaust gas container. If the internal pressure of the anode chamber rises to the critical pressure of the anode chamber safety valve, the anode chamber safety valve automatically opens to restore the critical pressure and discharges oxygen to the anode chamber exhaust gas container.

[0021] Step S4: Replace the reaction solution and infiltrate and dissolve the specimen

[0022] After the solution in the test chamber has reacted for a certain period of time, the output pressure of the high-precision hydraulic pump is slowly reduced until the value of the pressure sensor between the high-precision hydraulic pump and the hydraulic chamber drops to the indoor atmospheric pressure and the ceramic piston is reset, the high-precision hydraulic pump and the corresponding valve are closed, and then after the value of the cathode chamber pressure sensor is no higher than the indoor atmospheric pressure, the corresponding valve is opened to allow the cathode chamber reaction liquid container and the anode chamber reaction liquid container to collect the cathode chamber reaction solution and the anode chamber reaction solution respectively, and then measure the volume, ion concentration, and precipitate composition of the reaction solution collected by the cathode chamber reaction liquid container and the anode chamber reaction liquid container, measure and calculate the molar mass of the gas collected by the cathode chamber exhaust gas container and the anode chamber exhaust gas container, and infer the mass of water participating in the water electrolysis reaction; then open the water pump, the cathode chamber water injection port, the anode chamber water injection port and the corresponding valve, so that the water pump injects the extracted deionized water into and cleans the cathode chamber and the anode chamber, and close the corresponding valve after rinsing; then fill the cathode chamber and the anode chamber with water according to the method in step S2, so that the test piece in the test chamber is in a sealed state; then penetrate and dissolve the test piece according to the method in step S3;

[0023] Step S5: Remove the test piece

[0024] Repeat step S4 to replace the reaction solution multiple times and penetrate and dissolve the test piece. Then, drain the reaction solution in the cathode chamber and the anode chamber, open the airtight covers of the cathode chamber and the anode chamber, and then remove the test piece.

[0025] Preferably, in step S1, the process of the vacuum water saturation test is: first place the specimen in a container that can be vacuumed, then start the vacuum pump, reduce the air pressure in the container to 1-5 kPa and maintain it for a period of time, and then, while the vacuum pump continues to work, inject distilled water or deionized water into the container until the specimen is completely immersed and maintain it for a period of time, then return to normal pressure and continue to immerse for a period of time, and finally take out the specimen and measure the resistivity of the specimen after vacuum water saturation.

[0026] Preferably, in step S3, the test temperature is below 80°C, the test osmotic pressure is within 2 MPa, the anode chamber electrode and the cathode chamber electrode operate in a constant voltage or constant current mode, and the critical pressure of the cathode chamber safety valve and the anode chamber safety valve is set to 100.1% of the test osmotic pressure.

[0027] The beneficial effects of the present invention are:

[0028] The present invention can realize electrochemical dissolution during the process of osmotic pressure and high temperature on the specimen, and convert the contact dissolution only on the surface of the specimen into osmotic dissolution inside the specimen. It can not only restore the erosion situation of multiple factors coupled in the natural state and improve the test accuracy, but also greatly accelerate the dissolution process and save time cost. Specifically, the dissolution process is accelerated in three aspects: first, electrochemical accelerated dissolution is adopted, and the movement speed of calcium ions in the pore solution is accelerated by the action of electromotive force; second, the reaction is carried out at a relatively high constant temperature, which makes the reaction rate faster and increases the solubility of substances such as calcium ions in the aqueous solution; third, osmotic pressure is only applied in the cathode chamber. During the reaction, calcium ions will continuously move toward the cathode, and the dissolution process will start first. Therefore, osmotic pressure is only applied in the cathode chamber, so that the contact dissolution occurring on the surface of the specimen is expanded into osmotic dissolution, thereby accelerating the dissolution process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Schematic diagram of a high-voltage electrochemical accelerated dissolution-seepage test system applicable to an anti-seepage curtain body in Example 1 of the present invention.

[0031] Figure 2 yes Figure 1 Front view of the middle test chamber.

[0032] Figure 3 yes Figure 1 Side view of the middle test chamber.

[0033] Figure 4 yes Figure 1 Top view of the test chamber.

[0034] Figure 5 Schematic diagram of a high-voltage electrochemical accelerated dissolution-seepage test system applicable to an anti-seepage curtain body in the second embodiment of the present invention.

[0035] In the figure: 1-deionized water container; 2-hydraulic oil tank; 3-first hydraulic valve; 4-second hydraulic valve; 5-safety plate; 6-high-precision hydraulic pump; 7-pressure sensor; 8-water pump; 9-pressure transmission device; 10-third hydraulic valve; 11-fastening bolt; 12-cathode chamber airtight cover; 13-cathode chamber temperature sensor; 14-cathode chamber safety valve; 15-anode chamber safety valve; 16-cathode chamber electrode; 17-cathode chamber ceramic heating element; 18-test specimen; 19-anode chamber ceramic heating element; 20-anode chamber electrode; 21-fourth hydraulic valve; 22 - positive chamber airtight cover; 23 - anode chamber exhaust gas container; 24 - cathode chamber exhaust gas container; 25 - fifth hydraulic valve; 26 - anode chamber reaction liquid container; 27 - sixth hydraulic valve; 28 - cathode chamber reaction liquid container; 29 - power supply and CNC module; 30 - host computer; 31 - anode chamber temperature sensor; 32 - bracket; 33 - ceramic piston; 34 - cathode chamber water inlet; 35 - anode chamber water inlet; 36 - cathode chamber water outlet; 37 - anode chamber water outlet; 38 - cathode chamber pressure sensor; 39 - seventh hydraulic valve; 40 - eighth hydraulic valve; 41 - test chamber. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0039] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0041] Example 1

[0042] The existing electrochemical corrosion method only stops at contact corrosion on the surface of the specimen 18. The corrosion depth is often only a few millimeters in two months. The corrosion rate is slow, and the existing electrochemical corrosion method cannot restore the corrosion situation under the natural state caused by the coupling of multiple factors. In response to the above problems, this embodiment provides a high-voltage electrochemical accelerated corrosion-seepage test system suitable for anti-seepage curtain bodies, such as Figures 1 to 4 As shown, it includes a test chamber 41 for mounting the test piece 18 and providing a test environment, a packaging module for packaging the test chamber 41 by injecting water, and a pressurizing module for applying osmotic pressure to the test chamber 41; wherein:

[0043] like Figures 1 to 4 As shown, a test piece installation position is provided in the middle of the test chamber 41. After the test piece 18 is installed, the test chamber 41 can be divided into a cathode chamber and an anode chamber. The inner walls of the cathode chamber and the anode chamber are both provided with an insulating layer, and the open ends are closed by respective airtight covers (12, 22) in combination with insulating parts. The interiors of the cathode chamber and the anode chamber are provided with respective temperature sensors (13, 31), electrodes (16, 20) and ceramic heating elements (17, 19). The upper parts of the cathode chamber and the anode chamber are provided with respective safety valves (14, 15) and water injection ports (34, 35), and the lower parts are provided with Respective water outlets (36, 37), the safety valves (14, 15) of the cathode chamber and the anode chamber are connected to the respective waste gas containers (24, 23) through pipelines with valves (seventh hydraulic valve 39, eighth hydraulic valve 40), the water inlets (34, 35) of the cathode chamber and the anode chamber can be closed or connected to the outside, the water outlets (36, 37) of the cathode chamber and the anode chamber are connected to the respective reaction liquid containers (28, 26) through pipelines with valves (sixth hydraulic valve 27, fifth hydraulic valve 25), and a pressure sensor 38 is installed inside the cathode chamber;

[0044] like Figure 1As shown, the encapsulation module includes a water pump 8 and a deionized water container 1, the inlet end of the water pump 8 is connected to the deionized water container 1 through a pipeline with a valve (second hydraulic valve 4), and the outlet end is connected to the water injection ports (34, 35) of the cathode chamber and the anode chamber respectively through pipelines with valves (third hydraulic valve 10, fourth hydraulic valve 21);

[0045] like Figure 1 and Figure 4 As shown, the pressurizing module includes a pressure transmission device 9, a high-precision hydraulic pump 6 and a hydraulic oil tank 2. The pressure transmission device 9 includes a hydraulic chamber with openings at both ends and a ceramic piston 33 slidingly fitted in the middle without falling out. The inlet end of the high-precision hydraulic pump 6 is connected to the hydraulic oil tank 2 through a pipeline with a valve (a first hydraulic valve 3), and the outlet end is connected to one end of the hydraulic chamber through a pipeline with a pressure sensor 7. The hydraulic oil tank 2 is used to store non-conductive hydraulic oil, and the other end of the hydraulic chamber is directly connected to the cathode chamber through a pipeline.

[0046] Regarding the sealing of the test chamber 41, in this embodiment, preferably: the test chamber 41 is made of stainless steel resistant high-pressure material, the inner wall insulation layers of the cathode chamber and the anode chamber are both made of silicone rubber pads, and the ends of the cathode chamber and the anode chamber are sealed by respective airtight covers (12, 22) in combination with epoxy resin.

[0047] In order to improve the safety of the pressurizing module during pressurization, in this embodiment, preferably: Figure 1 As shown, the inlet end of the high-precision hydraulic pump 6 and the valve (the first hydraulic valve 3) are connected to the recovery oil tank through a pipeline with a safety piece 5.

[0048] like Figure 1 As shown, in this embodiment, preferably, the airtight covers (12, 22) of the cathode chamber and the anode chamber are both fixed by fastening bolts 11, which are convenient for assembly and disassembly. Figures 1 to 4 As shown, in this embodiment, preferably, the test chamber 41 is horizontally cylindrical and is elevated and supported by a bracket 32, which is easy to manufacture and install. In this embodiment, preferably, the cathode chamber temperature sensor 13 and the anode chamber temperature sensor 31 are pressure thermometers, which are suitable for sealed high-pressure vessels and have high accuracy.

[0049] Example 2

[0050] This embodiment provides another high-voltage electrochemical accelerated corrosion-seepage test system suitable for anti-seepage curtain bodies, such as Figure 5As shown, the main difference from Example 1 is the addition of a power supply and numerical control module 29 and a host computer 30, wherein: the cathode chamber temperature sensor 13, the cathode chamber electrode 16, the cathode chamber ceramic heating element 17, the cathode chamber pressure sensor 38, the anode chamber temperature sensor 31, the anode chamber electrode 20, the anode chamber ceramic heating element 19, the pressure sensor 7 between the high-precision hydraulic pump 6 and the hydraulic chamber, and the high-precision hydraulic pump 6 are electrically connected to the power supply and numerical control module 29, respectively, and the power supply and numerical control module 29 is electrically connected to the host computer 30; the power supply and numerical control module 29 is used to provide power for each detection component and each actuator and control the action of each actuator according to the instructions of the host computer 30; the host computer 30 can control each actuator through the power supply and numerical control module 29 according to the input setting information and the feedback information of each detection component to obtain the required test temperature and test osmotic pressure, and can automatically calculate and draw the dissolution rate change curve and the permeability characteristic change curve under the influence of different current, voltage, temperature and osmotic pressure according to the test data. This embodiment can realize automatic temperature and pressure control of the test by adding a power supply and numerical control module 29 and a host computer 30, and the test results can be displayed quickly and intuitively.

[0051] Example 3

[0052] This embodiment provides a high-voltage electrochemical accelerated corrosion-seepage test method applicable to an anti-seepage curtain body, based on the high-voltage electrochemical accelerated corrosion-seepage test system applicable to an anti-seepage curtain body in the above-mentioned embodiment 1 or embodiment 2, including the following steps:

[0053] Step S1: Processing the test piece 18

[0054] After the specimen 18 is cured in a room temperature environment (curing time is generally up to one month), the current resistivity of the specimen 18 is first measured, and then a vacuum water saturation test is performed to measure the resistivity of the specimen 18 after vacuum water saturation.

[0055] The process of the vacuum water saturation test is as follows: first, place the specimen 18 in a container that can be vacuumed, then start the vacuum pump, reduce the air pressure in the container to 1-5 kPa and maintain it for a period of time (e.g., 3 hours), and then, while the vacuum pump continues to work, inject distilled water or deionized water into the container until the specimen 18 is completely immersed and maintain it for a period of time (e.g., 1 hour), then return to normal pressure and continue to immerse for a period of time (e.g., 18±2 hours), and finally take out the specimen 18 and measure the resistivity of the specimen 18 after vacuum water saturation.

[0056] In this embodiment, the test specimen is a standard cylindrical anti-seepage curtain specimen of Φ100mm×20mm, and the entire system is adapted thereto. Of course, other types of hydraulic concrete specimens can also be used for testing.

[0057] Step S2: Packaging the test piece 18

[0058] First, open the airtight covers (12, 22) of the cathode chamber and the anode chamber, then install the test specimen 18 on the test specimen installation position in the middle of the test chamber 41, and ensure insulation and watertightness between the test specimen 18 and the test chamber 41 (for example, apply silicone rubber at the gap), so that the test specimen 18 separates the test chamber 41 into the cathode chamber and the anode chamber, and the solutions in the cathode chamber and the anode chamber can only form a circuit through the test specimen 18 after being energized, and then close the airtight covers (12, 22) of the cathode chamber and the anode chamber;

[0059] Then, the water pump 8 and the corresponding valves are turned on (the second hydraulic valve 4 and the third hydraulic valve 10 are turned on, and the fourth hydraulic valve 21, the fifth hydraulic valve 25, and the sixth hydraulic valve 27 are turned off), so that the water pump 8 injects the extracted deionized water into the cathode chamber until the cathode chamber and one side of the hydraulic cavity are filled with deionized water and the ceramic piston 33 moves to the end close to the high-precision hydraulic pump 6. Then, the water pump 8 is turned off to stop the water injection and the chamber is left to stand for a period of time (e.g., 30 minutes).

[0060] Then observe whether there is any water leakage in the anode chamber. After confirming that it is sealed intact, first close the valve corresponding to the cathode chamber water injection port 34 (the third hydraulic valve 10), then close the cathode chamber water injection port 34, and then open the water pump 8 and the corresponding valves (the second hydraulic valve 4 and the fourth hydraulic valve 21 are opened, and the third hydraulic valve 10, the fifth hydraulic valve 25, and the sixth hydraulic valve 27 are closed), so that the water pump 8 can inject the extracted deionized water into the anode chamber until the anode chamber is filled with deionized water, then close the water pump 8 and the corresponding valves (the second hydraulic valve 4 and the fourth hydraulic valve 21 are closed), and then close the anode chamber water injection port 35. The test piece 18 in the test chamber 41 is in a sealed state.

[0061] Step S3: Infiltration and dissolution of the specimen 18

[0062] Turn on the ceramic heating elements (17, 19) of the cathode chamber and the anode chamber, and heat the cathode chamber and the anode chamber to the desired test temperature and maintain the temperature under the feedback of the temperature sensors (13, 31) of the cathode chamber and the anode chamber;

[0063] Open the high-precision hydraulic pump 6 and the corresponding valves (the first hydraulic valve 3, the seventh hydraulic valve 39, and the eighth hydraulic valve 40) so that the high-precision hydraulic pump 6 pushes the extracted hydraulic oil into the hydraulic chamber to apply pressure to the ceramic piston 33, and the ceramic piston 33 pushes deionized water into the cathode chamber to pressurize the cathode chamber. Based on the feedback from the pressure sensor 7 between the high-precision hydraulic pump 6 and the hydraulic chamber and the pressure sensor 38 on the cathode chamber, the cathode chamber is pressurized to the required test osmotic pressure and maintained there;

[0064] The electrodes (16, 20) of the cathode chamber and the anode chamber are turned on, and the current forms a circuit through the anode chamber electrode 20, the test piece 18, and the cathode chamber electrode 16. Under the test temperature and test osmotic pressure, the electrochemical corrosion of the test piece 18 changes from contact corrosion to osmotic corrosion, the corrosion rate is greatly increased, and an electrolytic water reaction occurs. The cathode chamber and the anode chamber produce hydrogen and oxygen respectively. If the internal pressure of the cathode chamber rises to the critical pressure of the cathode chamber safety valve 14, the cathode chamber safety valve 14 automatically opens to restore to below the critical pressure and discharges hydrogen to the cathode chamber exhaust gas container 24. If the internal pressure of the anode chamber rises to the critical pressure of the anode chamber safety valve 15, the anode chamber safety valve 15 automatically opens to restore to below the critical pressure and discharges oxygen to the anode chamber exhaust gas container 23.

[0065] In this step, the test temperature is below 80°C, the test osmotic pressure is within 2 MPa (determined according to the specimen material), the anode chamber electrode 20 and the cathode chamber electrode 16 operate in a constant voltage or constant current mode (as the dissolution reaction continues, the specimen resistance will continue to decrease, so a constant voltage or constant current mode is adopted), and the critical pressure of the cathode chamber safety valve 14 and the anode chamber safety valve 15 is set to 100.1% of the test osmotic pressure.

[0066] Step S4: Replace the reaction solution and infiltrate and dissolve the test piece 18

[0067] After the solution in the test chamber has reacted for a certain period of time (the reaction time of the solution is determined by parameters such as voltage, pressure, and temperature, and the solution is generally replaced every 10 days), the output pressure of the high-precision hydraulic pump 6 is slowly reduced until the value of the pressure sensor 7 between the high-precision hydraulic pump 6 and the hydraulic chamber drops to the indoor atmospheric pressure and the ceramic piston 33 is reset. Then, the high-precision hydraulic pump 6 and the corresponding valves (the first hydraulic valve 3, the seventh hydraulic valve 39, and the eighth hydraulic valve 40) are closed. Then, after the value of the cathode chamber pressure sensor 38 is no higher than the indoor atmospheric pressure, the corresponding valves (the fifth hydraulic valve 25 and the sixth hydraulic valve 27) are opened, so that the cathode chamber reaction liquid container 28 and the anode chamber reaction liquid container 26 collect the cathode chamber reaction solution and the anode chamber reaction solution, respectively. Then, the volume, ion concentration, and precipitate composition of the reaction solution collected in the cathode chamber reaction liquid container 28 and the anode chamber reaction liquid container 26 are measured, and the molar mass of the gas collected in the cathode chamber exhaust gas container 24 and the anode chamber exhaust gas container 23 are measured and calculated, and the mass of the water participating in the water electrolysis reaction is estimated.

[0068] Then, the water pump 8, the cathode chamber water injection port 34, the anode chamber water injection port 35, and the corresponding valves (the second hydraulic valve 4, the third hydraulic valve 10, and the fourth hydraulic valve 21 are opened) are opened, so that the water pump 8 injects the extracted deionized water into and cleans the cathode chamber and the anode chamber. After rinsing, the corresponding valves are closed (the fifth hydraulic valve 25 and the sixth hydraulic valve 27 are closed).

[0069] Then, water is injected into the cathode chamber and the anode chamber in the manner described in step S2, so that the test piece 18 in the test chamber 41 is in a sealed state;

[0070] Then, the test piece 18 is infiltrated and eroded in the manner of step S3.

[0071] Step S5: Remove the test piece

[0072] Repeat step S4 to replace the reaction solution multiple times and penetrate and dissolve the test piece 18, then first drain the reaction solution in the cathode chamber and the anode chamber, then open the airtight covers (12, 22) of the cathode chamber and the anode chamber, and then remove the test piece 18.

[0073] From the above scheme, we can see that:

[0074] The present invention can realize electrochemical dissolution during the process of osmotic pressure and high temperature on the specimen 18, and transform the contact dissolution only on the surface of the specimen 18 into osmotic dissolution inside the specimen 18, which can not only restore the erosion situation of multiple factors coupled in the natural state and improve the test accuracy, but also greatly accelerate the dissolution process and save time cost. Specifically, the dissolution process is accelerated in three aspects: First, electrochemical accelerated dissolution is adopted, and the movement speed of calcium ions in the pore solution is accelerated by the action of electromotive force; second, the reaction is carried out at a relatively high constant temperature, which makes the reaction rate faster and increases the solubility of substances such as calcium ions in the aqueous solution; third, osmotic pressure is only applied in the cathode chamber. During the reaction, calcium ions will continuously move toward the cathode, and the dissolution process will start first. Therefore, osmotic pressure is only applied in the cathode chamber, so that the contact dissolution occurring on the surface of the specimen 18 is expanded into osmotic dissolution, thereby accelerating the dissolution process.

[0075] The difficulty of the present invention is how to combine high hydraulic gradient dissolution and electrochemical dissolution, because traditional high hydraulic gradient dissolution requires a hydraulic pump to inject water to directly apply osmotic pressure to the specimen, and traditional electrochemical dissolution requires power to form a circuit through the anode-specimen-cathode. If water is injected by a hydraulic pump to apply pressure, direct power supply during this process will cause damage to the instruments and equipment, and may also cause leakage safety accidents. In order to solve the above difficulties, the present application adopts the following solution: a high-precision hydraulic pump 6 is used to extract hydraulic oil to pressurize the ceramic piston 33, and the ceramic piston 33 pressurizes the cathode chamber through deionized water, that is, the isotropy of the pressure of the closed liquid is used to apply osmotic pressure to the cathode chamber. The hydraulic oil and the ceramic piston 33 are both non-conductive, and the inner walls and open ends of the cathode chamber and the anode chamber are insulated to ensure that no leakage or short circuit will occur after power is turned on, making it possible to perform electrochemical dissolution of the specimen 18 during the osmotic pressurization process; the cathode chamber ceramic heating element 17 and the anode chamber ceramic heating element 19 are used for heating. The ceramic heating element has good insulation and heating properties, and can maintain a constant temperature for a long time while continuing to heat and insulate.

[0076] When the specimen is subjected to infiltration pressurization and electrochemical dissolution during high temperature, a water electrolysis reaction will occur in the cathode chamber and the anode chamber, generating gas, which will increase the pressure in a closed environment. When the pressure is too high, the gas will be discharged using the safety valves (14, 15) in the cathode chamber and the anode chamber, and the solution will not be discharged, which ensures that the reaction is carried out under constant pressure and the safety of the test is guaranteed.

[0077] The invention is applicable to anti-seepage curtain bodies and also to other types of hydraulic concrete test pieces, and can study the seepage corrosion mechanism and seepage-chemical coupling effect thereof under natural conditions.

[0078] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

Claims

1. A high-voltage electrochemical accelerated corrosion-seepage test system suitable for anti-seepage curtains, characterized by: It includes a test chamber for installing test specimens and providing a test environment, a packaging module for packaging the test chamber by water injection, a pressurizing module for applying osmotic pressure to the test chamber, and a host computer; a test specimen installation position is provided in the middle of the test chamber, and the test chamber can be separated into a cathode chamber and an anode chamber after the test specimen is installed. The inner walls of the cathode chamber and the anode chamber are both provided with an insulating layer, and the open ends are closed by respective airtight covers and insulating parts. The interiors of the cathode chamber and the anode chamber are provided with respective temperature sensors, electrodes and ceramic heating elements. The upper parts of the cathode chamber and the anode chamber are provided with respective safety valves and water injection ports, and the lower parts are provided with respective water outlets. The safety valves of the cathode chamber and the anode chamber are respectively connected to their respective exhaust gas containers through pipelines with valves. The water injection ports of the cathode chamber and the anode chamber can be selected to be closed or externally connected. The water outlets of the cathode chamber and the anode chamber are respectively connected to their respective reaction liquid containers through pipelines with valves, and a pressure sensor is installed inside the cathode chamber; the packaging module includes The invention relates to a water pump, wherein the inlet end of the water pump is connected to the deionized water container through a pipeline with a valve, and the outlet end is connected to the water inlet of the cathode chamber and the anode chamber respectively through pipelines with valves; the pressurizing module includes a pressure transmission device and a high-precision hydraulic pump, the pressure transmission device includes a hydraulic chamber, both ends of the hydraulic chamber are open, and a ceramic piston is slidably fitted in the middle without falling out, the inlet end of the high-precision hydraulic pump is connected to the hydraulic oil tank through a pipeline with a valve, and the outlet end is connected to one end of the hydraulic chamber through a pipeline with a pressure sensor, the hydraulic oil tank is used to store non-conductive hydraulic oil, and the other end of the hydraulic chamber is directly connected to the cathode chamber through a pipeline; the upper computer can control each actuator through the power supply and CNC module according to the input setting information and the feedback information of each detection component to obtain the required test temperature and test osmotic pressure, and can automatically calculate and draw the dissolution rate change curve and permeation characteristic change curve under the influence of different current, voltage, temperature and osmotic pressure according to the test data.

2. The high-voltage electrochemical accelerated corrosion-seepage test system for an anti-seepage curtain according to claim 1, characterized in that: The cathode chamber temperature sensor, cathode chamber electrode, cathode chamber ceramic heating element, cathode chamber pressure sensor, anode chamber temperature sensor, anode chamber electrode, anode chamber ceramic heating element, pressure sensor between the high-precision hydraulic pump and the hydraulic chamber, and the high-precision hydraulic pump are electrically connected to the power supply and CNC module respectively, and the power supply and CNC module are electrically connected to the host computer; the power supply and CNC module are used to provide power to each detection component and each actuator and control the action of each actuator according to the instructions of the host computer.

3. The high-voltage electrochemical accelerated corrosion-seepage test system for an anti-seepage curtain according to claim 1 or 2, characterized in that: The test chamber is made of stainless steel and high-pressure resistant material. The inner wall insulation layers of the cathode chamber and the anode chamber are both made of silicone rubber pads. The ends of the cathode chamber and the anode chamber are sealed by their own airtight covers with epoxy resin.

4. The high-voltage electrochemical accelerated corrosion-seepage test system for an anti-seepage curtain according to claim 1 or 2, characterized in that: The inlet end of the high-precision hydraulic pump and the valve are connected to the recovery tank through a pipeline with a safety piece.

5. The high-voltage electrochemical accelerated corrosion-seepage test system for an anti-seepage curtain according to claim 1 or 2, characterized in that: The airtight covers of the cathode chamber and the anode chamber are both installed and fixed by fastening bolts.

6. The high-voltage electrochemical accelerated corrosion-seepage test system for an anti-seepage curtain according to claim 1 or 2, characterized in that: The test chamber is in the shape of a horizontal cylinder and is elevated and supported by a bracket.

7. The high-voltage electrochemical accelerated corrosion-seepage test system for an anti-seepage curtain according to claim 1 or 2, characterized in that: The cathode chamber temperature sensor and the anode chamber temperature sensor are pressure thermometers.

8. A high-voltage electrochemical accelerated corrosion-seepage test method suitable for anti-seepage curtain bodies, characterized in that: The high-voltage electrochemical accelerated dissolution-seepage test system for an anti-seepage curtain body according to any one of claims 1 to 7 comprises the following steps: Step S1: Processing the test piece After the specimen is cured at room temperature, the current resistivity of the specimen is measured first, and then a vacuum water saturation test is performed to measure the resistivity of the specimen after vacuum water saturation. Step S2: Packaging the test piece First, open the airtight covers of the cathode chamber and the anode chamber, then install the specimen on the specimen installation position in the middle of the test chamber, and make good insulation and water isolation between the specimen and the test chamber, so that the specimen separates the test chamber into the cathode chamber and the anode chamber and the solutions in the cathode chamber and the anode chamber can only form a circuit through the specimen after being energized, and then close the airtight covers of the cathode chamber and the anode chamber; then turn on the water pump and the corresponding valves, so that the water pump injects the extracted deionized water into the cathode chamber until the cathode chamber and one side of the hydraulic cavity are filled with deionized water, and the ceramic piston moves to one end close to the high-precision hydraulic pump, then turn off the water pump to stop water injection and let it stand for a while; then observe whether the anode chamber has any water leakage, and after confirming that it is sealed intact, first close the corresponding valve of the cathode chamber water injection port, then close the cathode chamber water injection port, then turn on the water pump and the corresponding valve, so that the water pump injects the extracted deionized water into the anode chamber until the anode chamber is filled with deionized water, then turn off the water pump and the corresponding valves, and then close the anode chamber water injection port, and the specimen in the test chamber is in a packaged state; Step S3: Infiltration and dissolution of test piece Turn on the ceramic heating elements in the cathode chamber and the anode chamber, and heat the cathode chamber and the anode chamber to the required test temperature and maintain it under the feedback of the temperature sensors in the cathode chamber and the anode chamber; turn on the high-precision hydraulic pump and the corresponding valves, so that the high-precision hydraulic pump pushes the extracted hydraulic oil into the hydraulic cavity to pressurize the ceramic piston, and the ceramic piston pushes deionized water into the cathode chamber to pressurize the cathode chamber; under the feedback of the pressure sensor between the high-precision hydraulic pump and the hydraulic cavity and the pressure sensor on the cathode chamber, pressurize the cathode chamber to the required test osmotic pressure and maintain it; turn on the electrodes in the cathode chamber and the anode chamber, and the current flows through the anode chamber. The cathode chamber electrodes, the test piece, and the cathode chamber electrodes form a circuit. Under the test temperature and test osmotic pressure, the electrochemical corrosion of the test piece changes from contact corrosion to osmotic corrosion, the corrosion rate is greatly increased, and a water electrolysis reaction occurs. The cathode chamber and the anode chamber produce hydrogen and oxygen respectively. If the internal pressure of the cathode chamber rises to the critical pressure of the cathode chamber safety valve, the cathode chamber safety valve automatically opens to restore the critical pressure and discharges hydrogen to the cathode chamber exhaust gas container. If the internal pressure of the anode chamber rises to the critical pressure of the anode chamber safety valve, the anode chamber safety valve automatically opens to restore the critical pressure and discharges oxygen to the anode chamber exhaust gas container. Step S4: Replace the reaction solution and infiltrate and dissolve the specimen After the solution in the test chamber has reacted for a certain period of time, the output pressure of the high-precision hydraulic pump is slowly reduced until the value of the pressure sensor between the high-precision hydraulic pump and the hydraulic chamber drops to the indoor atmospheric pressure and the ceramic piston is reset, the high-precision hydraulic pump and the corresponding valve are closed, and then after the value of the cathode chamber pressure sensor is no higher than the indoor atmospheric pressure, the corresponding valve is opened to allow the cathode chamber reaction liquid container and the anode chamber reaction liquid container to collect the cathode chamber reaction solution and the anode chamber reaction solution respectively, and then measure the volume, ion concentration, and precipitate composition of the reaction solution collected by the cathode chamber reaction liquid container and the anode chamber reaction liquid container, measure and calculate the molar mass of the gas collected by the cathode chamber exhaust gas container and the anode chamber exhaust gas container, and infer the mass of water participating in the water electrolysis reaction; then open the water pump, the cathode chamber water injection port, the anode chamber water injection port and the corresponding valve, so that the water pump injects the extracted deionized water into and cleans the cathode chamber and the anode chamber, and close the corresponding valve after rinsing; then fill the cathode chamber and the anode chamber with water according to the method in step S2, so that the test piece in the test chamber is in a sealed state; then penetrate and dissolve the test piece according to the method in step S3; Step S5: Remove the test piece Repeat step S4 to replace the reaction solution multiple times and penetrate and dissolve the test piece. Then, drain the reaction solution in the cathode chamber and the anode chamber, open the airtight covers of the cathode chamber and the anode chamber, and then remove the test piece.

9. The high-voltage electrochemical accelerated corrosion-seepage test method for an anti-seepage curtain according to claim 8, characterized in that: In step S1, the process of the vacuum water saturation test is: first, place the specimen in a container that can be vacuumed, then start the vacuum pump, reduce the air pressure in the container to 1-5 kPa and maintain it for a period of time, and then, while the vacuum pump continues to work, inject distilled water or deionized water into the container until the specimen is completely immersed and maintain it for a period of time, then return to normal pressure and continue to immerse for a period of time, and finally take out the specimen and measure the resistivity of the specimen after vacuum water saturation.

10. The high-voltage electrochemical accelerated corrosion-seepage test method for an anti-seepage curtain according to claim 8, characterized in that: In step S3, the test temperature is below 80°C, the test osmotic pressure is within 2 MPa, the anode chamber electrode and the cathode chamber electrode operate in a constant voltage or constant current mode, and the critical pressure of the cathode chamber safety valve and the anode chamber safety valve is set to 100.1% of the test osmotic pressure.

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