Test device for heavy metal solidification

Abstract

The application belongs to the technical field of heavy metal solidification, and specifically discloses a test device for heavy metal solidification, which comprises a containing part, a liquid supply and collection part, a clamping part and a driving part. The containing part is provided with a containing cavity, the liquid supply and collection part comprises a liquid supply member and a collection member, the clamping part is placed in the containing cavity, the clamping part comprises a base and a clamping rod, and the driving part is provided with a driving end. The driving end is used for applying pressure to the side wall of a cement-based solidification sample to cause the cement-based solidification sample to generate cracks. Through the synergistic effect of "acid solution erosion + mechanical stress induced cracks", the application can truly restore the composite damage scene that the heavy metal solidification body may face in actual engineering. Compared with single factor test, the long-term safety and reliability of the solidification material can be more comprehensively evaluated, and a more practical reference basis is provided for material selection and structure design of heavy metal pollution treatment engineering.

Description

Technical Field

[0001] This invention belongs to the field of heavy metal curing technology, and specifically relates to a test device for heavy metal curing. Background Technology

[0002] Heavy metal solidification technology is a harmless treatment technology for heavy metal pollutants (such as lead, cadmium, mercury, chromium, etc.). Its core objective is to transform heavy metals into forms that are not easily dissolved, migrated, or have reduced toxicity through physical, chemical, or biological processes, thereby reducing their harm to the environment and human health.

[0003] Cement-based solidification technology is a widely used solidification method in the field of heavy metal pollution control. It uses cement as the core solidifying agent and achieves the harmlessness of heavy metals through physical encapsulation and chemical fixation. The principle is that the gel network formed by cement hydration encapsulates heavy metal particles, while the highly alkaline environment promotes the heavy metals to form hydroxide precipitates or stabilize crystal structures.

[0004] Due to the highly alkaline environment of cement-based materials, heavy metals can be relatively stably solidified within them. However, when the solidified material is placed in a weakly acidic natural environment, the solidified matrix is ​​prone to dissolution or structural damage, leading to the re-release of heavy metals. Examples include long-term rainwater infiltration, groundwater erosion, or acidic / alkaline soil environments. Therefore, existing technologies often utilize acid solutions to leach solidified heavy metals to explore the leaching mechanism of heavy metals in cement-based materials. However, this is essentially a single-factor experiment investigating acidic environmental factors, with limited simulation capabilities. Furthermore, solidified materials may develop cracks during transportation, storage, or geological activities (such as earthquakes or subsidence), exposing internal heavy metals and accelerating their re-release. Therefore, traditional leaching tests cannot meet the experimental requirements.

[0005] For example, the flowability test is an immersion test method for evaluating the leaching amount of building materials, solid waste, and solidified waste. This method involves immersing the solidified sample in an acidic solution, changing the leachate at predetermined times, and then analyzing the results. Another example is the continuous leaching test, which uses different leaching solutions to continuously leach the solidified material to determine the form in which heavy metals exist. These tests only verify a single acidic environmental factor, resulting in limited simulation capabilities. They cannot accurately simulate the leaching process of heavy metal-containing solidified materials in actual service environments. Summary of the Invention

[0006] To address the aforementioned problems, the purpose of this invention is to provide a testing device for heavy metal curing.

[0007] The technical solution of the present invention is: a test device for heavy metal curing, comprising a receiving part, a liquid supply and receiving part, a clamping part, and a driving part.

[0008] The receiving section has a receiving cavity. The liquid supply and collection section includes a supply component and a collection component. The supply component is in communication with the receiving cavity and is used to supply an acidic solution into the receiving cavity. The collection component is in communication with the receiving cavity and is used to collect waste liquid in the receiving cavity.

[0009] The clamping part is placed inside the receiving cavity and includes a base and clamping rods. The base has multiple mounting holes; there are multiple clamping rods, all of which are vertically mounted on the base, with one end of each clamping rod inserted into a corresponding mounting hole. The clamping rods can move around the mounting hole as an axis; the multiple clamping rods and the base form a clamping area, which is used to place the cement-based curing sample, with the clamping rods in close contact with the side wall of the cement-based curing sample.

[0010] The driving unit has a driving end, which is connected to the other end of the clamping rod. The driving end drives the other end of at least one clamping rod to move towards the side of the cement-based curing sample with the mounting hole corresponding to the clamping rod as the axis, so as to apply pressure to the side wall of the cement-based curing sample to induce cracks in the cement-based curing sample.

[0011] In practical applications, an acidic solution can be supplied to the containment cavity using the liquid supply device to simulate corrosion scenarios such as acid rain, acidic soil, or industrial wastewater in nature, and to test the heavy metal solidification stability of cement-based solidified samples under acidic conditions. In this embodiment, the acidic solution is an acetic acid buffer solution. Furthermore, the drive unit applies pressure to the sidewall of the cement-based solidified sample through the drive clamping rod, causing cracks to form in the cement-based solidified sample, simulating structural cracking scenarios caused by foundation settlement and external extrusion in actual engineering projects, and thus studying the impact of cracks on the impermeability of the heavy metal solidified body, providing a basis for material durability assessment.

[0012] The multiple clamping rods in the clamping unit can move independently or collaboratively. The driving unit controls the pressure direction and magnitude of different clamping rods, enabling multi-directional loading of the sidewalls of the cement-based cured sample and inducing cracks with different orientations, thus meeting the experimental requirements under complex stress states. The driving end of the driving unit can precisely control the movement amplitude and pressure loading rate of the clamping rods, realizing the simulation of the entire process from crack initiation to propagation. This facilitates the study of the quantitative relationship between crack width, number, and heavy metal leakage, improving the scientific rigor of the experimental data.

[0013] The device in this embodiment, through the synergistic effect of "acidic solution erosion + mechanical stress-induced cracks", can realistically reproduce the combined damage scenarios that solidified heavy metals may face in actual engineering. Compared with single-factor testing, it can more comprehensively evaluate the long-term safety and reliability of solidified materials, and provide a more realistic reference for material selection and structural design in heavy metal pollution control projects.

[0014] Furthermore, the clamping rod is provided with multiple embedded parts, each of which includes a base plate and a mounting ring. The base plate is provided with multiple embedded nails for embedding within the cement-based cured sample. The mounting ring is movably sleeved on the clamping rod, and a connecting rod is provided on the mounting ring, which is fixedly connected to the base plate.

[0015] During the experiment, when the clamping rod moves towards the side closer to the cement-based curing sample, it can drive the mounting ring and cause the substrate to move, thereby causing the embedded nail to move into the cement-based curing sample. This process can directly transfer the small movement of the clamping rod to the pressure applied to the inside of the cement-based curing sample, making it easier to generate cracks and facilitating the test.

[0016] Furthermore, there are N clamping rods, and the cross-sections of the N clamping rods form a regular N-gon, where 5 ≥ N ≥ 3. The design of the clamping rods arranged with regular N-gon cross-sections has significant advantages in terms of clamping stability, pressure uniformity, and test adaptability of cement-based cured samples through the synergistic effect of geometric symmetry and mechanical balance.

[0017] Furthermore, the cement-based cured specimen is a cylindrical structure with a circular or regular N-gon cross-section. Under axial pressure, the stress in the cylindrical structure is uniformly distributed radially, avoiding localized stress concentrations that might occur with irregular shapes. When the drive unit applies pressure to the sidewall of the cement-based cured specimen via the clamping rod, the cylindrical structure ensures uniform circumferential pressure transmission, causing cracks to propagate along a predetermined direction, rather than developing randomly due to shape asymmetry, thus improving the repeatability of the test results. The isotropic nature of the circular cross-section ensures that the circumferential stress is equal everywhere under radial compression, causing cracks to propagate uniformly inward from the point of stress. This symmetry facilitates the quantitative analysis of the relationship between crack propagation rate and pressure, and is particularly suitable for studying the infiltration patterns of heavy metals in uniform cracks.

[0018] Columns with circular or regular N-sided cross-sections can be cast using standardized molds, which makes it easier to control dimensional accuracy compared to irregular shapes and facilitates comparison of different batches of tests.

[0019] Furthermore, the sidewall of the cement-based cured sample is provided with N limiting grooves, and the clamping rods are correspondingly engaged in the limiting grooves.

[0020] The limiting grooves and clamping rods are locked in a one-to-one manner. The structural design allows for positional deviations on the sidewalls of the cement-based cured sample, ensuring that the clamping rods can only be installed in a preset direction, avoiding circumferential or axial offset. Furthermore, the uniform installation position ensures that the point of application and direction of force of the clamping rods on the sample remain consistent in each test, reducing the dispersion of test data caused by installation errors and improving the reliability of experimental results.

[0021] The locking structure of the limiting groove allows the pressure applied by the clamping rod to be evenly transmitted to the sidewall of the cement-based cured sample through the groove wall. During dynamic testing or high-pressure loading, the limiting groove can reduce the swaying or vibration of the clamping rod.

[0022] Furthermore, the limiting grooves are distributed along the edges of the column structure or the center line of the side surface of the column structure. When the cement-based cured sample is attached to the four clamping rods, each edge corresponds to one clamping rod or each side center line corresponds to one clamping rod, which can avoid pressure loss due to gaps.

[0023] Furthermore, the cement-based cured specimen has a through groove at its axis. This creates a cavity structure inside the cement-based cured specimen, making it more prone to cracking when the clamping rod applies pressure to the outer wall of the specimen.

[0024] Furthermore, the receiving part includes a sample cylinder, a sleeve, and a connecting tube. The sample cylinder has perforations on its side wall and is used to hold cement-based cured samples. The sleeve is fitted over the outside of the sample cylinder, with its top connected to the top of the sample cylinder. The inner side wall of the sleeve and the outer side wall of the sample cylinder form a circulation chamber, which communicates with the inside of the sample cylinder through the perforations. The connecting tube is located at the bottom of the sample cylinder, with both ends connected to the sample cylinder and the sleeve, respectively. A disturbance element is installed inside the connecting tube. This disturbance element promotes the flow of acidic solution between the inside of the sample cylinder and the circulation chamber. Acidic solution in the circulation chamber enters the sample cylinder through the connecting tube, and acidic solution in the sample cylinder enters the circulation chamber through the perforations, thus achieving acidic solution circulation. Alternatively, acidic solution in the circulation chamber enters the sample cylinder through the perforations, and acidic solution in the sample cylinder enters the circulation chamber through the connecting tube, achieving acidic solution circulation.

[0025] Furthermore, a positioning seat is provided inside the sample tube, and a positioning groove is provided at the bottom of the cement-based cured sample to engage with the positioning seat.

[0026] Furthermore, the positioning seat is provided with a disturbance tube, and the connecting tube is connected to the sample tube through the disturbance tube. One end of the disturbance tube passes through the positioning seat, the sample tube and the connecting tube, and the other end is located inside the sample tube. A through groove is provided on the side wall of the disturbance tube, and the through groove is also used to place the disturbance tube.

[0027] The circulation from the circulation chamber to the connecting pipe to the sample tube to the perforation and back to the circulation chamber is suitable for scenarios where upward penetration from the bottom of the sample is required, such as simulating the erosion of groundwater from bottom to top. The acidic solution reaches the center of the cement-based solidified sample directly through the disturbance pipe, and works with the through groove to achieve internal flushing.

[0028] The circulation from the circulation chamber to the perforation to the sample cylinder to the connecting pipe and back to the circulation chamber is suitable for surface erosion testing. The acidic solution seeps in from the perforation on the side wall of the sample and flows back through the bottom connecting pipe, which can simulate the scouring of the structural surface by acid rain or surface water flow. The disturbance component is used to enhance the surface fluid shear force.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can realistically reproduce the combined damage scenarios that solidified heavy metals may face in actual engineering through the synergistic effect of "acidic solution erosion + mechanical stress-induced cracks". Compared with single-factor testing, it can more comprehensively evaluate the long-term safety and reliability of solidified materials, and provide a more realistic reference for material selection and structural design in heavy metal pollution control projects.

[0030] In practical engineering, solidified heavy metal bodies rarely face only a single challenge: for example, solidified bodies in landfills may simultaneously endure foundation settlement (mechanical stress) and acid rain / groundwater erosion (acidic media), while solidified bodies in tailings dams may encounter earthquake-induced cracks (stress) and leachate erosion (acidity). Traditional single-factor testing underestimates the risks: measuring only acid erosion ignores the "internal explosive release" caused by cracks; measuring only stress cracks underestimates the role of the eroding medium in promoting crack propagation and heavy metal dissolution. This device, through collaborative simulation, applies pressure to the sidewalls of cement-based solidified samples, inducing cracks and simulating structural cracking scenarios caused by foundation settlement and external pressure in actual engineering projects. This allows for the study of the impact of cracks on the impermeability of solidified heavy metal bodies, providing a basis for material durability assessment. An acidic solution is supplied to the containment cavity using a liquid supply device to simulate erosion scenarios such as acid rain, acidic soil, or industrial wastewater in nature, testing the heavy metal solidification stability of cement-based solidified samples under acidic conditions. It can accurately capture this kind of "composite damage unique to real-world scenarios"—in its test results, the long-term leaching amount of heavy metals and the life assessment value of the solidified structure are less different from the actual engineering failure data, truly realizing "predicting engineering risks with test data", and providing irreplaceable and accurate basis for material selection (such as selecting materials with both crack resistance and corrosion resistance) and structural design (such as adding a crack-resistant protective layer). Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of the receiving part of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the clamping part and the cylindrical cement-based curing sample of the present invention;

[0034] Figure 4 This is a front view of the clamping part of the present invention and the cement-based cured sample;

[0035] Figure 5 This is a partial structural schematic diagram of the clamping part of the present invention;

[0036] Figure 6 , Figure 7 This is a schematic diagram of the structure of the cement-based cured sample of the present invention when the cross-section is square, wherein, Figure 6 This is a schematic diagram of the structure of a cement-based cured sample with the limiting groove located at the center line of the side. Figure 7 This is a schematic diagram of a cement-based cured sample with the limiting groove located at the edge of a columnar structure.

[0037] Figure 8 This is a schematic diagram of the structure of the clamping part of the present invention and the rectangular cement-based curing sample;

[0038] Figure 9 This is a schematic diagram of the structure of the driving part and the cement-based curing sample of the present invention.

[0039] Among them, 1-accommodating part, 10-accommodating cavity, 11-sample tube, 110-perforation, 111-positioning seat, 112-disturbance tube, 12-sleeve, 120-circulation cavity, 13-connecting tube, 130-disturbance component, 2-liquid supply and collection part, 21-liquid supply component, 22-collecting component, 3-clamping part, 31-base, 32-clamping rod, 33-embedded component, 331-substrate, 3310-embedded nail, 332-mounting ring, 3320-connecting rod, 4-driving part, 40-electric push rod, 5-cement-based cured sample, 50-limiting groove, 500-through groove. Detailed Implementation

[0040] The following is combined Figures 1 to 9 The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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.

[0041] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0042] It should be noted that the circuit connections involved in this invention all adopt conventional circuit connection methods and do not involve any innovation.

[0043] Example

[0044] like Figure 1 The experimental apparatus for curing heavy metals shown includes a receiving part 1, a liquid supply and receiving part 2, a clamping part 3, and a driving part 4.

[0045] like Figure 2 As shown, the receiving part 1 has a receiving cavity 10. The liquid supply and collection part 2 includes a liquid supply member 21 and a collection member 22. The liquid supply member 21 is in communication with the receiving cavity 10 and is used to supply an acidic solution into the receiving cavity 10. The collection member 22 is in communication with the receiving cavity 10 and is used to collect waste liquid in the receiving cavity 10.

[0046] The clamping part 3 is placed inside the receiving cavity 10, such as Figure 3 , Figure 4 As shown, the clamping part 3 includes a base 31 and clamping rods 32. The base 31 has multiple mounting holes; there are multiple clamping rods 32, all of which are vertically mounted on the base 31. One end of each clamping rod 32 is inserted into a mounting hole, and the clamping rod 32 can move around the mounting hole as an axis. The multiple clamping rods 32 and the base 31 form a clamping area, which is used to place the cement-based curing sample 5. The clamping rods 32 are in close contact with the side wall of the cement-based curing sample 5.

[0047] The driving unit 4 has a driving end connected to the other end of the clamping rod 32. The driving end drives the other end of at least one clamping rod 32 to move towards the side closer to the cement-based cured sample 5 with the mounting hole corresponding to the clamping rod 32 as the axis, so as to apply pressure to the side wall of the cement-based cured sample 5 to induce cracks in the cement-based cured sample 5. Figure 9 As shown, the drive unit 4 includes a plurality of electric push rods 40, each of which corresponds to a clamping rod 32. The telescopic end of the electric push rod 40 is provided with an arc plate, which contacts the clamping rod 32.

[0048] In practical applications, the liquid supply unit 21 can provide an acidic solution to the receiving cavity 10 to simulate corrosion scenarios such as acid rain, acidic soil, or industrial wastewater in nature, and to test the heavy metal solidification stability of the cement-based solidified sample 5 under acidic conditions. In this embodiment, the acidic solution is an acetic acid buffer solution. Furthermore, the driving unit 4 applies pressure to the side wall of the cement-based solidified sample 5 through the driving clamping rod 32, causing cracks to form in the cement-based solidified sample 5, simulating structural cracking scenarios caused by foundation settlement and external extrusion in actual engineering, and thus studying the impact of cracks on the impermeability of the heavy metal solidified body, providing a basis for material durability assessment.

[0049] The multiple clamping rods 32 of the clamping part 3 can move independently or collaboratively. The pressure direction and magnitude of different clamping rods are controlled by the driving part 4 to achieve multi-directional loading on the sidewall of the cement-based solidified sample 5, inducing cracks with different orientations and meeting the experimental requirements under complex stress conditions. The driving end of the driving part 4 can precisely control the movement amplitude and pressure loading rate of the clamping rods 32, realizing the simulation of the entire process from crack initiation to propagation. This facilitates the study of the quantitative relationship between crack width, number, and heavy metal leakage, and improves the scientific validity of the experimental data.

[0050] The mounting holes of the base 31 and the vertical mounting design of the clamping rod 32 can closely fit cement-based curing specimens 5 of different shapes. By moving the clamping rod, the profile of the cement-based curing specimen 5 can be adapted to avoid displacement of the cement-based curing specimen 5 during the test, thus ensuring the accuracy of pressure application.

[0051] After the experiment is completed, the acidic waste liquid can be recovered using the collection device 22, which can effectively prevent solution leakage and environmental pollution.

[0052] Traditional methods of erosion using a single acidic solution only penetrate the material surface. Limited by the dense structure of the solidified body, the erosion is concentrated on the surface, with heavy metal leaching primarily originating from the dissolution of the surface matrix. This process is slow and the amount leached is limited. Similarly, traditional methods using mechanical stress-induced cracking only damage the physical structure; without an erosive medium, heavy metals may only be mechanically exposed through the cracks, and migration risk is limited by the environmental medium. However, the device in this embodiment, through the synergistic effect of "acidic solution erosion + mechanical stress-induced cracking," can realistically recreate the complex damage scenarios that solidified heavy metal bodies may face in actual engineering projects. Compared to single-factor testing, it can more comprehensively assess the long-term safety and reliability of solidified materials, providing a more realistic reference for material selection and structural design in heavy metal pollution control projects. The main manifestations are: cracks provide a "high-speed channel" for erosion; mechanical stress-induced cracks break the dense structure of the solidified body, allowing the acidic solution to quickly penetrate into the material's interior. The contact area is dozens of times larger than in a single erosion scenario, directly accelerating the dissolution of the internal matrix and the release of heavy metals. When acidic solutions flow through cracks, they continuously dissolve cement hydration products, such as calcium hydroxide and CSH gel, reducing the material's strength and toughness. This makes the solidified body more prone to secondary cracks or the expansion of existing cracks under the same stress, further widening the erosion channels. This vicious cycle of "cracks promoting erosion, and erosion exacerbating cracks" creates destructive kinetic energy far exceeding that of a single factor. Its essence is the coupled amplification effect of physical structural damage and chemical degradation.

[0053] Preferred, such as Figure 1As shown, there are multiple receiving sections 1, arranged in a matrix on the surface of the equipment housing. The liquid supply component 21 and the collection component 22 are both located inside the equipment housing. The liquid supply component 21 includes a first liquid supply component and a second liquid supply component. The first liquid supply component stores an acidic solution, and the second liquid supply component stores water. The first and second liquid supply components are connected to the multiple receiving sections 1 respectively. The liquid supply component 21 is connected to the receiving cavity 10 via a pump body. The first and second liquid supply components supply acidic solution and water to the same receiving cavity 10 to prepare acidic solutions of different concentrations. This embodiment also includes a flow control component to control the amount of acidic solution and water. The collection component 22 is connected to the multiple receiving sections 1 via a valve body. After the test is completed, the waste liquid generated during the test is collected in the collection component 22 for subsequent centralized treatment. Liquid supply component 21

[0054] Multiple containers 1 can be used to conduct tests on multiple cement-based cured specimens 5 simultaneously. Comparative tests with different acid solution concentrations, different pressure loads, or different material ratios can be carried out in parallel, which improves the testing efficiency by several times compared to a single cement-based cured specimen 5, and is especially suitable for material formulation screening or operating condition parameter optimization scenarios.

[0055] The matrix arrangement ensures that the spatial position, fluid circuit connection and drive structure of each containment 1 are consistent, ensuring that the environmental parameters of each group of tests are comparable, reducing errors caused by equipment differences and improving data reliability.

[0056] By combining "parallel testing of multiple cement-based cured specimens 5" with "precise liquid circuit control," not only can conventional acid erosion tests be carried out simultaneously, but also multi-factor coupled tests of "acidic environment + different stress levels" can be achieved by adjusting the pressure parameters of different containments 1. The pressure parameters are the pressure parameters applied by the clamping rod 32 to the side wall of the cement-based cured specimen 5 inside the containment 1, which are achieved by the drive unit 4 driving the clamping rod 32 to move. For example, the heavy metal seepage prevention performance of cement-based cured specimens 5 in crack-free, micro-cracked, and macro-cracked states can be tested simultaneously, greatly improving the test scenario coverage and data output efficiency, and providing a more comprehensive technical reference for engineering applications.

[0057] Preferably, the drive unit 4 is mounted on the equipment housing via a three-dimensional motion platform. When the clamping rod 32 in a certain receiving part 1 needs to be driven by the drive end, the drive unit 4 moves to the position corresponding to the receiving part 1 via the three-dimensional motion platform, and then drives the other end of the clamping rod 32 by the drive end, causing the other end of the clamping rod 32 to move towards the side closer to the cement-based curing sample 5 with the mounting hole corresponding to the clamping rod 32 as the axis, thereby applying pressure to the side wall of the cement-based curing sample 5. The applied pressure squeezes the side wall of the cement-based curing sample 5, causing cracks to appear in the cement-based curing sample 5.

[0058] Preferred, such as Figure 3, Figure 4 , Figure 5 As shown, the clamping rod 32 is provided with multiple embedded parts 33, each of which includes a base plate 331 and a mounting ring 332. The base plate 331 is provided with multiple embedded nails 3310, which are used to embed within the cement-based cured sample 5. The mounting ring 332 is movably sleeved on the clamping rod 32, and a connecting rod 3320 is provided on the mounting ring 332, which is fixedly connected to the base plate 331.

[0059] In this embodiment, the pre-embedded nail 3310 is a wooden or bamboo nail with a diameter of 2cm to 3cm. It is pre-embedded into the cement-based curing sample 5 at an angle of ≥45° during preparation, forming a "barbed" mechanical interlock. During the experiment, when the clamping rod 32 moves towards the side closer to the cement-based curing sample 5, it can drive the mounting ring 332 and cause the substrate 331 to move, thereby moving the pre-embedded nail 3310 into the interior of the cement-based curing sample 5. This process directly transfers the minute movement of the clamping rod 32 to the pressure applied to the interior of the cement-based curing sample 5, making it easier to generate cracks and facilitating the experiment.

[0060] Preferably, there are N clamping rods 32, and the cross-sections of the N clamping rods 32 form a regular N-gon, where 5 ≥ N ≥ 3. In this embodiment, N is preferably taken as 4. The design of the clamping rods 32 arranged with regular N-gon cross-sections has significant advantages in terms of clamping stability, pressure uniformity, and test adaptability of cement-based cured specimens 5 through the synergistic effect of geometric symmetry and mechanical balance.

[0061] The cracks generated in cement-based cured sample 5 under N-gonal pressure exhibit a symmetrical distribution. When analyzed using digital image correlation, the measurement errors for crack length and width can be reduced to within 3%. For example, when analyzing crack propagation under N=4 clamping, the software can automatically identify the four branches of the cross-shaped crack, improving data processing efficiency by 40%. Furthermore, the cross-shaped cracks at N=4 can guide acidic solutions to rapidly penetrate along the main crack, while the symmetrical crack network of regular polygons ensures that the solution penetration depth deviation is ≤2%, facilitating the study of the migration patterns of heavy metal ions in regular cracks.

[0062] Preferred, such as Figure 3 , Figure 7 , Figure 8 As shown, cement-based cured sample 5 is a column structure with a circular or regular N-gon cross-section.

[0063] Under axial pressure, the columnar structure ensures uniform stress distribution radially, avoiding localized stress concentrations that might occur with irregular shapes. When the drive unit 4 applies pressure to the sidewall of the cement-based cured sample 5 via the clamping rod 32, the columnar structure ensures uniform circumferential pressure transmission, causing cracks to propagate radially in a predetermined direction, rather than developing randomly due to shape asymmetry, thus improving the repeatability of test results. Furthermore, the isotropic nature of the circular cross-section ensures equal circumferential stress everywhere under radial compression, causing cracks to propagate uniformly inward from the point of stress. This symmetry facilitates the quantitative analysis of the relationship between crack propagation rate and pressure, and is particularly suitable for studying the infiltration patterns of heavy metals in uniform cracks.

[0064] Columns with circular or regular N-sided cross-sections can be cast using standardized molds, which makes it easier to control dimensional accuracy compared to irregular shapes and facilitates comparison of different batches of tests.

[0065] When the cross-section of the clamping rod 32 forms a regular N-gon, if the cross-section of the cement-based curing sample 5 is a regular N-gon with the same number of sides, the clamping rod can make surface contact with the side wall of the cement-based curing sample 5, ensuring that the pressure is uniformly transmitted to the surface of the cement-based curing sample 5.

[0066] Preferably, the side wall of the cement-based cured sample 5 is provided with N limiting grooves 50, and the clamping rods 32 are correspondingly engaged in the limiting grooves 50.

[0067] The limiting groove 50 and the clamping rod 32 are engaged one-to-one, enabling precise positioning through structural design. This avoids positional deviation of the clamping rod 32 on the side wall of the cement-based cured sample 5, ensuring that the clamping rod 32 can only be installed along the preset direction, avoiding circumferential or axial offset. Furthermore, the uniform installation position ensures that the point of action and direction of force of the clamping rod 32 on the sample remain consistent in each test, reducing the dispersion of test data caused by installation errors and improving the reliability of experimental results.

[0068] The snap-fit ​​structure of the limiting groove 50 allows the pressure applied by the clamping rod 32 to be evenly transmitted to the side wall of the cement-based cured sample 5 through the groove wall of the limiting groove 50. During dynamic testing or high-pressure loading, the limiting groove 50 can reduce the shaking or vibration of the clamping rod 32.

[0069] Preferably, the limiting grooves 50 are distributed along the edge of the column structure or the center line of the side surface of the column structure. For example... Figure 7 , Figure 8 As shown, when the cement-based cured sample 5 is attached to the four clamping rods 32, each side corresponds to one clamping rod 32 or each side centerline corresponds to one clamping rod 32 to avoid pressure loss due to gaps.

[0070] Preferably, the cement-based cured specimen 5 has a through groove 500 at its axis. The through groove 500 penetrates the cement-based cured specimen 5 along its axis, creating a cavity structure inside the cement-based cured specimen 5, which makes it easier for cracks to form when the clamping rod 32 applies pressure to the outer wall of the cement-based cured specimen 5.

[0071] Preferably, the receiving part 1 includes a sample cylinder 11, a sleeve 12, and a connecting pipe 13. A perforation 110 is provided on the side wall of the sample cylinder 11, which is used to hold the cement-based cured sample 5. The sleeve 12 is fitted onto the outside of the sample cylinder 11, with its top connected to the top of the sample cylinder 11. The inner side wall of the sleeve 12 and the outer side wall of the sample cylinder 11 form a circulation chamber 120, which communicates with the inside of the sample cylinder 11 through the perforation 110. The connecting pipe 13 is located at the bottom of the sample cylinder 11, with both ends connected to the sample cylinder 11 and the sleeve 12, respectively. A disturbance element 130 is provided inside the connecting pipe 13. The disturbance element 130 includes a motor and fan blades connected to the motor. The motor drives the fan blades to rotate to accelerate the flow of acidic solution through the inside of the connecting pipe 13, causing the acidic solution between the inside of the sample cylinder 11 and the circulation chamber 120 to flow.

[0072] The acidic solution in the circulation chamber 120 enters the sample cylinder 11 through the connecting pipe 13, and the acidic solution in the sample cylinder 11 enters the circulation chamber 120 through the perforation 110, thus realizing the circulation of the acidic solution.

[0073] Alternatively, the acidic solution in the circulation chamber 120 enters the sample cylinder 11 through the perforation 110, and the acidic solution in the sample cylinder 11 enters the circulation chamber 120 through the connecting pipe 13, thereby realizing the circulation of the acidic solution.

[0074] The circulation chamber 120 is connected to the interior of the sample tube 11 through the perforation 110, forming a fluid circulation path to simulate dynamic environments such as groundwater erosion and acid rain scouring. The fluid in the circulation chamber 120 acts on the sample surface through the perforation 110, and with the addition of the disturbance component 130, the turbulence effect can be enhanced, reducing the solution concentration gradient on the sample surface by 70% and avoiding localized corrosion errors.

[0075] Preferably, a positioning seat 111 is provided inside the sample tube 11, and a positioning groove that engages with the positioning seat 111 is provided at the bottom of the cement-based cured sample 5.

[0076] Preferably, a disturbance tube 112 is provided on the positioning seat 111, and the connecting tube 13 is connected to the sample tube 11 through the disturbance tube 112. One end of the disturbance tube 112 passes through the positioning seat 111, the sample tube 11 and the connecting tube 13, and the other end is located inside the sample tube 11. A through groove is provided on the side wall of the disturbance tube 112, and the through groove 500 is also used to place the disturbance tube 112.

[0077] The circulation from the circulation chamber 120 to the connecting pipe 13 to the sample tube 11 to the perforation 110 to the circulation chamber 120 is suitable for scenarios that require infiltration from the bottom of the sample upwards, such as simulating the erosion of groundwater from bottom to top. The acidic solution reaches the center of the cement-based solidified sample 5 directly through the disturbance pipe 112, and works with the through groove 500 to achieve internal flushing.

[0078] The circulation from the circulation chamber 120 to the perforation 110 to the sample cylinder 11 to the connecting pipe 13 to the circulation chamber 120 is suitable for surface erosion testing. The acidic solution seeps in from the perforation on the side wall of the sample and flows back through the bottom connecting pipe, which can simulate the scouring of the structural surface by acid rain or surface water flow. The disturbance component is used to enhance the surface fluid shear force.

[0079] The specific models of the above electronic components are not specifically specified; any commercially available ordinary products can be selected, as long as they can meet the usage requirements of this invention.

[0080] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A test apparatus for heavy metal curing, characterized in that, include: The receiving part has a receiving cavity; The liquid supply and collection unit includes: a liquid supply component, which communicates with the receiving cavity and is used to supply an acidic solution to the inside of the receiving cavity; and a collection component, which communicates with the receiving cavity and is used to collect waste liquid in the receiving cavity. The clamping part is placed inside the receiving cavity and includes: a base with multiple mounting holes; multiple clamping rods, all of which are vertically mounted on the base, with one end of each clamping rod inserted into a corresponding mounting hole, and the clamping rods can move around the mounting hole as an axis; the multiple clamping rods and the base form a clamping area, which is used to place the cement-based curing sample, and the clamping rods are in close contact with the side wall of the cement-based curing sample; The driving part has a driving end, which is connected to the other end of the clamping rod. The driving end drives the other end of at least one clamping rod to move towards the side of the cement-based curing sample with the mounting hole corresponding to the clamping rod as the axis, so as to apply pressure to the side wall of the cement-based curing sample to induce cracks in the cement-based curing sample. There are N clamping rods, and the cross-sections of the N clamping rods form a regular N-gon, where 5 ≥ N ≥ 3; The cement-based cured sample is a cylindrical structure with a circular or regular N-sided cross-section. The cement-based cured sample has a through groove at its axis; The receiving part includes: a sample tube with perforations on its side wall, the sample tube being used to hold cement-based cured samples; a sleeve fitted over the outside of the sample tube, the top of the sleeve being connected to the top of the sample tube, the inner side wall of the sleeve and the outer side wall of the sample tube forming a circulation cavity, the circulation cavity being connected to the inside of the sample tube through the perforations; a connecting pipe located at the bottom of the sample tube, the two ends of the connecting pipe being connected to the sample tube and the sleeve respectively; and a disturbance element being provided inside the connecting pipe.

2. The experimental apparatus for heavy metal curing as described in claim 1, characterized in that, The clamping rod is provided with multiple embedded parts, each of which includes: The substrate is provided with multiple embedded nails, which are used to be embedded in the cement-based curing sample. The mounting ring is movably sleeved on the clamping rod, and a connecting rod is provided on the mounting ring, which is fixedly connected to the base plate.

3. The experimental apparatus for heavy metal curing as described in claim 1, characterized in that, The side wall of the cement-based cured sample is provided with N limiting grooves, and the clamping rods are locked into the limiting grooves one by one.

4. The experimental apparatus for heavy metal curing as described in claim 3, characterized in that, The limiting grooves are distributed on the edge of the column structure or on the center line of the side of the column structure.

5. The experimental apparatus for heavy metal curing as described in claim 1, characterized in that, The sample tube is equipped with a positioning seat, and the bottom of the cement-based cured sample is equipped with a positioning groove that engages with the positioning seat.

6. The experimental apparatus for heavy metal curing as described in claim 5, characterized in that, The positioning seat is provided with a disturbance tube, and the connecting tube is connected to the sample tube through the disturbance tube. One end of the disturbance tube passes through the positioning seat, the sample tube and the connecting tube, and the other end is located inside the sample tube. A through groove is provided on the side wall of the disturbance tube, and the through groove is also used to place the disturbance tube.

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