Testing device for heavy metal solidification

Abstract

The invention belongs to the technical field of heavy metal curing, and particularly discloses a heavy metal curing test device which comprises a containing part, a liquid supplying and receiving 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 part and a collection part, the clamping part is placed in the containing cavity, the clamping part comprises a base and a clamping rod, the driving part is provided with a driving end, and the driving end is used for applying pressure to the side wall of the cement-based solidified sample to promote the cement-based solidified sample to generate cracks. Through the synergistic effect of acid solution erosion and mechanical stress induced crack, a composite damage scene possibly faced by a heavy metal solidified body in actual engineering can be truly reduced, and compared with a single factor test, the long-term safety and reliability of a solidified material can be more comprehensively evaluated, and the method has a good application prospect. And a reference basis closer to reality is provided for material selection and structural design of heavy metal pollution treatment engineering.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy metal solidification, and in particular relates to a test device for heavy metal solidification. Background Art

[0002] Heavy metal solidification technology is a harmless treatment technology for heavy metal pollutants (such as lead, cadmium, mercury, chromium, etc.). Its core goal is to convert heavy metals into forms that are difficult to dissolve, migrate, or have reduced toxicity through physical, chemical or biological effects, thereby reducing their harm to the environment and human health.

[0003] Cement-based curing technology is a widely used curing method for heavy metal pollution control. Using cement as the core curing agent, it renders heavy metals harmless through physical encapsulation and chemical fixation. The principle is that cement hydration forms a gel lattice that encapsulates heavy metal particles, while the highly alkaline environment causes the heavy metals to precipitate as hydroxides or stabilize their crystal structures.

[0004] Due to the highly alkaline environment of cement-based materials, heavy metals can be solidified relatively stably in cement-based materials. However, when the solidified material is in a weakly acidic natural environment, it is very easy for the solidification matrix to dissolve or the structure to be destroyed, resulting in the re-release of heavy metals, such as long-term rainwater infiltration, groundwater erosion or acid-base soil environment. Therefore, in the prior art, acid solutions are often used to leach solidified heavy metals to explore the leaching mechanism of heavy metals in cement-based materials. In fact, it is only a single-factor test exploration of acidic environmental factors, and the degree of simulation is limited. However, cracks may appear in the solidified material during transportation, stacking or geological activities (such as earthquakes and subsidence), thereby exposing the internal heavy metals and accelerating the re-release of heavy metals. Therefore, traditional leaching tests cannot meet the test requirements.

[0005] For example, the fluidity test is an immersion test method used to assess the leaching capacity of construction materials, bulk waste, and solidified waste. This method involves immersing the solidified material sample in an acidic solution, replacing the leachate at a predetermined interval, and analyzing the resulting solution. Another example is the continuous leaching test, which determines the presence of heavy metals in the solidified material by continuously leaching with different leaching solutions. These tests only validate a single acidic environmental factor, resulting in limited simulations. They cannot accurately simulate the leaching process of heavy metal-containing solidified materials in actual service environments. Summary of the Invention

[0006] In view of the above problems, the present invention aims to provide a heavy metal solidification test device.

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

[0008] The accommodating portion has an accommodating cavity. The liquid supply and receiving portion includes a liquid supply component and a collecting component. The liquid supply component is connected to the accommodating cavity and is used to provide acidic solution to the interior of the accommodating cavity. The collecting component is connected to the accommodating cavity and is used to collect waste liquid in the accommodating cavity.

[0009] The clamping portion is placed within the accommodating cavity and includes a base and clamping rods. The base has multiple mounting holes; multiple clamping rods are vertically mounted on the base, with one end of each clamping rod correspondingly inserted into a mounting hole. The clamping rods can move around the mounting hole as the axis. The clamping area formed between the multiple clamping rods and the base is used to place the cement-based cured sample in the clamping area, and the clamping rods are closely attached to the side wall of the cement-based cured sample.

[0010] 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 toward a side close to the cement-based cured sample with the mounting hole corresponding to the clamping rod as the axis, and is used to apply pressure to the side wall of the cement-based cured sample to cause cracks to form in the cement-based cured sample.

[0011] In actual use, the liquid supply component can be used to provide an acidic solution to the accommodating chamber, simulating natural erosion scenarios such as acid rain, acidic soil, or industrial wastewater, and testing 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. In addition, the driving unit applies pressure to the side wall of the cement-based solidified sample by driving the clamping rod, causing cracks to form in the cement-based solidified sample. This simulates the structural cracking scenarios caused by foundation settlement, external force extrusion, etc. in actual engineering projects, and further studies the impact of cracks on the anti-seepage performance of heavy metal solidified bodies, providing a basis for material durability assessment.

[0012] The multiple clamping rods in the clamping unit can move independently or in coordination. The drive unit controls the direction and magnitude of pressure applied to each clamping rod, enabling multi-directional loading of the sidewalls of cement-based cured specimens and inducing cracks with varying orientations, meeting the demands of testing under complex stress conditions. The drive unit's driver precisely controls the movement of the clamping rods and the rate of pressure applied, simulating the entire crack initiation and propagation process. This facilitates research into the quantitative relationship between crack width and number and heavy metal leakage, enhancing the scientific nature of the test data.

[0013] Through the synergistic effect of "acidic solution corrosion + mechanical stress-induced cracking", the device in this embodiment can truly restore the complex damage scenarios that heavy metal solid bodies may face in actual engineering projects. Compared with single-factor testing, it can more comprehensively evaluate the long-term safety and reliability of solidified materials, providing a more practical reference basis for material selection and structural design of 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, which are embedded in the cement-based cured sample. The mounting ring is movably mounted on the clamping rod and is provided with a connecting rod, which is fixedly connected to the base plate.

[0015] During the experiment, when the clamping rod moves toward the side close to the cement-based cured sample, it can drive the mounting ring and prompt the base plate to move, thereby moving the embedded nails into the interior of the cement-based cured sample. This process can directly transfer the tiny movement of the clamping rod to apply pressure to the interior of the cement-based cured sample, making it easier to generate cracks and facilitate 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 in a regular N-gon cross-section has significant advantages in terms of clamping stability, pressure uniformity, and test adaptability of cement-based cured specimens through the synergistic effect of geometric symmetry and mechanical balance.

[0017] Furthermore, the cement-based solidification specimen is a columnar structure, and the cross-section of the columnar structure is a circle or a regular N-gon. Under the action of axial pressure, the stress of the columnar structure is evenly distributed in the radial direction, avoiding the local stress concentration that may be caused by the irregular shape. When the driving part applies pressure to the side wall of the cement-based solidification specimen through the clamping rod, the columnar structure can ensure that the circumferential pressure is evenly transmitted, so that the cracks expand along the preset direction, rather than the cracks develop disorderly due to the asymmetric shape, thereby improving the repeatability of the test results. The isotropic characteristics of the circular cross-section make it so that when it is subjected to radial compression, the circumferential stress is equal everywhere, and the cracks will expand evenly inward from the stress point. This symmetry facilitates the quantitative analysis of the relationship between the crack expansion rate and pressure, and is particularly suitable for studying the penetration law of heavy metals in uniform cracks.

[0018] Columns with circular or regular N-gon cross-sections can be cast using standardized molds. Compared with irregular shapes, it is easier to control dimensional accuracy and facilitate comparison of different batches of tests.

[0019] Furthermore, N limiting grooves are provided on the side wall of the cement-based solidified sample, and the clamping rods are clamped in the limiting grooves one by one.

[0020] The limit slots are designed to engage the clamping rods in a one-to-one fashion. This allows for positional deviations on the sidewalls of cement-based curing specimens, ensuring the clamping rods can only be installed in the pre-set direction, avoiding circumferential or axial displacement. Furthermore, this uniform installation position ensures consistent application points and force directions for the clamping rods on the specimen throughout each test, reducing test data discrepancies caused by installation errors and improving the reliability of experimental results.

[0021] The clamping structure of the retaining groove allows the pressure applied by the clamping rod to be evenly transferred to the side walls of the cement-based cured specimen through the retaining groove walls. During dynamic testing or high-pressure loading, the retaining groove can reduce shaking or vibration of the clamping rod.

[0022] Furthermore, the limiting grooves are distributed along the edges of the column structure or the centerline of the side of the column structure. When the cement-based cured specimen is fitted with the four clamping rods, each edge corresponds to a clamping rod or each side centerline corresponds to a clamping rod, thereby avoiding pressure loss caused by gaps.

[0023] Furthermore, the axis of the cement-based solidified sample is provided with a through groove, so that a cavity structure is formed inside the cement-based solidified sample, and cracks are more likely to be generated when the clamping rod applies pressure to the outer wall of the cement-based solidified sample.

[0024] Furthermore, the accommodating portion includes a sample tube, a sleeve, and a connecting tube. The side wall of the sample tube is provided with a perforation, and the sample tube is used to place a cement-based solidified sample. The sleeve is sleeved on the outside of the sample tube, the top of the sleeve is connected to the top of the sample tube, the inner side wall of the sleeve and the outer side wall of the sample tube form a circulation chamber, and the circulation chamber is connected to the inside of the sample tube through the perforation. The connecting tube is provided at the bottom of the sample tube, and the two ends of the connecting tube are respectively connected to the sample tube and the sleeve; a disturbance piece is provided in the connecting tube. The disturbance piece can cause the acidic solution inside the sample tube to flow between the circulation chamber. The acidic solution in the circulation chamber enters the sample tube through the connecting tube, and the acidic solution in the sample tube enters the circulation chamber through the perforation, thereby realizing the circulation of the acidic solution. Alternatively, the acidic solution in the circulation chamber enters the sample tube through the perforation, and the acidic solution in the sample tube enters the circulation chamber through the connecting tube, thereby realizing the circulation of the acidic solution.

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

[0026] Furthermore, a disturbance tube is provided on the positioning seat, 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 and is connected to 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 cavity to the connecting pipe to the sample tube to the perforation and then to the circulation cavity is suitable for scenarios where penetration from the bottom of the sample is required, such as simulating the erosion of groundwater from bottom to top. The acidic solution goes directly to the center of the cement-based solidified sample through the disturbance pipe, and cooperates with the through-groove to achieve internal scouring.

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

[0029] Compared with the existing technology, the beneficial effect of the present invention is that: through the synergistic effect of "acidic solution corrosion + mechanical stress-induced cracks", the present invention can truly restore the complex damage scenarios that heavy metal solid bodies 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 practical reference basis for material selection and structural design of heavy metal pollution control projects.

[0030] In real-world projects, heavy metal solidification rarely faces a single challenge. For example, solidification in landfills may simultaneously withstand foundation settlement (mechanical stress) and acid rain / groundwater erosion (acidic media). Solidification in tailings dams may experience earthquake-induced cracking (stress) and leachate erosion (acidic media). Traditional single-factor testing underestimates these risks: measuring only acidic erosion ignores the "internal explosive release" caused by cracks; measuring only stress cracks underestimates the role of the erosive media in promoting crack propagation and heavy metal dissolution. This device, however, uses collaborative simulation to induce cracks in cement-based solidification specimens by applying pressure to their sidewalls. This simulates structural cracking scenarios caused by foundation settlement and external forces in real projects, allowing for investigation of the impact of cracks on the anti-seepage performance of heavy metal solidification, providing a basis for material durability assessment. A liquid supply component delivers an acidic solution to the containment chamber, simulating natural erosion scenarios such as acid rain, acidic soil, or industrial wastewater, to test the stability of heavy metal solidification in cement-based solidification specimens under acidic conditions. It can accurately capture this "composite damage unique to actual scenarios" - in its test results, the long-term leaching of heavy metals and the life assessment value of the solidified structure have reduced deviations 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 crack-resistant + corrosion-resistant dual-performance materials) and structural design (such as adding an anti-crack protective layer). BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a structural schematic diagram of the accommodation portion of the present invention; Figure 3 This is a schematic structural diagram of the clamping portion and the cylindrical cement-based solidified specimen of the present invention; Figure 4 is a front view of the clamping portion and the cement-based cured sample of the present invention; Figure 5 It is a partial structural schematic diagram of the clamping portion of the present invention; Figure 6 、 Figure 7 Schematic diagram of the structure of the cement-based solidified sample of the present invention when the cross section is square, wherein: Figure 6 This is a structural diagram of a cement-based solidified specimen with a limit groove located at the center line of the side. Figure 7 It is a structural diagram of a cement-based solidified specimen with a limiting groove located at the edge of a cylindrical structure; Figure 8 This is a schematic structural diagram of the clamping portion and the rectangular cement-based solidified specimen of the present invention; Figure 9 It is a structural schematic diagram of the driving part and cement-based curing sample of the present invention.

[0032] Among them, 1-accommodation part, 10-accommodation chamber, 11-sample tube, 110-perforation, 111-positioning seat, 112-disturbance tube, 12-sleeve, 120-circulation chamber, 13-connecting pipe, 130-disturbance piece, 2-liquid supply and collection part, 21-liquid supply part, 22-collecting part, 3-clamping part, 31-base, 32-clamping rod, 33-embedded part, 331-base plate, 3310-embedded nail, 332-mounting ring, 3320-connecting rod, 4-driving part, 40-electric push rod, 5-cement-based curing sample, 50-limiting groove, 500-through groove. DETAILED DESCRIPTION

[0033] The following combination Figures 1 to 9 , the specific embodiments of the present invention are described in detail. In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed or operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0035] It should be noted that the circuit connections involved in the present invention all adopt conventional circuit connection methods and do not involve any innovation.

[0036] Example like Figure 1The heavy metal solidification test device shown includes a containing portion 1 , a liquid supply and receiving portion 2 , a clamping portion 3 and a driving portion 4 .

[0037] like Figure 2 As shown, the receiving portion 1 has a receiving chamber 10. The liquid supply and receiving portion 2 includes a liquid supply member 21 and a collecting member 22. The liquid supply member 21 is in communication with the receiving chamber 10 and is used to provide an acidic solution to the interior of the receiving chamber 10. The collecting member 22 is in communication with the receiving chamber 10 and is used to collect waste liquid in the receiving chamber 10.

[0038] The clamping portion 3 is placed in the accommodating cavity 10, as shown in FIG. Figure 3 、 Figure 4 As shown, the clamping portion 3 includes a base 31 and clamping rods 32. The base 31 has multiple mounting holes; there are multiple clamping rods 32, each of which is vertically mounted on the base 31. One end of each clamping rod 32 is inserted into a mounting hole in a one-to-one correspondence, and the clamping rod 32 can move around the mounting hole as the axis. The clamping area formed between the multiple clamping rods 32 and the base 31 is used to place the cement-based cured sample 5 in the clamping area. The clamping rods 32 are closely attached to the side wall of the cement-based cured sample 5.

[0039] The driving part 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 toward the side close 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 cause cracks to form in the cement-based cured sample 5. Figure 9 As shown, the driving unit 4 includes a plurality of electric push rods 40 , and the electric push rods 40 correspond to the clamping rods 32 one by one. The telescopic ends of the electric push rods 40 are provided with arc plates, which are in contact with the clamping rods 32 .

[0040] In actual use, the liquid supply component 21 can be used to provide an acidic solution to the accommodating chamber 10, simulating natural erosion scenarios such as acid rain, acidic soil, or industrial wastewater, and testing 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. In addition, the driving unit 4 applies pressure to the sidewalls of the cement-based solidified sample 5 by driving the clamping rod 32, causing the cement-based solidified sample 5 to crack. This simulates the structural cracking scenario caused by foundation settlement, external force compression, etc. in actual engineering, and further studies the impact of cracks on the anti-seepage performance of the heavy metal solidified body, providing a basis for material durability evaluation.

[0041] The multiple clamping rods 32 of the clamping unit 3 can move independently or in coordination. The driving unit 4 controls the direction and magnitude of pressure applied to each clamping rod, achieving multi-directional loading on the sidewalls of the cement-based cured specimen 5 and inducing cracks with varying orientations, meeting the testing requirements under complex stress conditions. The driving end of the driving unit 4 precisely controls the movement amplitude and pressure loading rate of the clamping rods 32, simulating the entire crack initiation and propagation process. This facilitates the study of the quantitative relationship between crack width and number and heavy metal leakage, enhancing the scientific nature of the test data.

[0042] The vertical installation design of the mounting hole of the base 31 and the clamping rod 32 can closely fit cement-based cured samples 5 of different shapes. The clamping rod can adapt to the contour of the cement-based cured sample 5 by movement, thereby avoiding displacement of the cement-based cured sample 5 during the test and ensuring the accuracy of pressure application.

[0043] After the test is completed, the acid waste liquid is recovered by using the collecting member 22, which can effectively prevent the solution from leaking and polluting the environment.

[0044] In traditional methods, when a single acidic solution is used for erosion, the solution only penetrates through the surface of the material. Due to the dense structure of the solidified body, the erosion range is mostly concentrated in the surface layer. Heavy metal leaching mainly comes from the dissolution of the surface matrix, with a slow rate and limited leaching amount. In traditional methods, when a single mechanical stress is used to induce cracks, the cracks only cause physical structural damage. Without an erosive medium, heavy metals can only be mechanically exposed through the cracks, and the migration risk is limited by the environmental medium. However, the device of this embodiment, through the synergistic effect of "acidic solution erosion + mechanical stress-induced cracking", can realistically simulate the complex damage scenarios that heavy metal solidified bodies may face in actual projects. Compared with single-factor testing, it can more comprehensively evaluate the long-term safety and reliability of solidified materials, providing a more practical reference for material selection and structural design in heavy metal pollution control projects. The main manifestation is that the cracks provide a "high-speed channel" for erosion. The mechanical stress-induced cracks break down the dense structure of the solidified body, allowing the acidic solution to quickly penetrate into the material interior. The contact area increases by dozens of times compared to a single erosion scenario, directly accelerating the dissolution of the internal matrix and the release of heavy metals. As the acidic solution flows through the cracks, it continuously dissolves cement hydration products, such as calcium hydroxide and CSH gel, reducing the material's strength and toughness. This makes the solidified structure more susceptible to secondary cracking or the expansion of existing cracks under the same stress, further expanding the erosion pathways. This vicious cycle of "cracks promoting erosion, and erosion exacerbating cracks" generates destructive kinetic energy far exceeding that of a single factor. Its essence is the coupled amplification effect of physical structural damage and chemical degradation.

[0045] Preferably, Figure 1As shown, there are multiple accommodating parts 1, which are embedded in a matrix on the surface of the device housing. The liquid supply part 21 and the collecting part 22 are both arranged inside the device housing. The liquid supply part 21 includes a first liquid supply part and a second liquid supply part. The first liquid supply part is used to store acidic solution, and the second liquid supply part is used to store water. The first liquid supply part and the second liquid supply part are respectively connected to multiple accommodating parts 1. The liquid supply part 21 is connected to the accommodating cavity 10 through a pump body. The first liquid supply part and the second liquid supply part are respectively used to provide acidic solution and water to the same accommodating cavity 10 to prepare acidic solutions of different concentrations. This embodiment also has a flow control part, which is used to control the amount of acidic solution and water. The collecting part 22 is respectively connected to multiple accommodating parts 1 through a valve body. When the test is completed, the waste liquid generated by the test is collected in the collecting part 22 for subsequent centralized treatment. Liquid supply part 21

[0046] Multiple accommodating sections 1 can be used to simultaneously test multiple cement-based curing specimens 5. Comparative tests with varying acid solution concentrations, pressure loads, or material ratios can be conducted in parallel, increasing testing efficiency several times compared to a single cement-based curing specimen 5. This approach is particularly suitable for material formulation screening or operating parameter optimization.

[0047] The matrix arrangement keeps the spatial position, fluid connection and drive structure of each container 1 consistent, ensuring the comparability of environmental parameters for each group of tests, reducing errors caused by equipment differences, and improving data reliability.

[0048] Combining "parallel testing of multiple cement-based cured specimens 5" with "precise fluid control" not only allows for simultaneous conventional acid corrosion testing but also enables multi-factor coupled testing of "acidic environment + different stress levels" by adjusting the pressure parameters of different containment sections 1. The pressure parameter refers to the pressure applied by clamping rod 32 to the sidewalls of cement-based cured specimen 5 within containment section 1, which is achieved by driving clamping rod 32 by drive unit 4. For example, the heavy metal impermeability performance of cement-based cured specimen 5 can be tested simultaneously in the presence of cracks, microcracks, and macrocracks, significantly improving the test scenario coverage and data output efficiency, providing a more comprehensive technical reference for engineering applications.

[0049] Preferably, the driving part 4 is installed on the device housing through a three-dimensional motion platform. When the clamping rod 32 in a certain accommodating part 1 needs to be driven by the driving end, the driving part 4 moves to the position corresponding to the accommodating part 1 through the three-dimensional motion platform, and then uses the driving end to drive the other end of the clamping rod 32, causing the other end of the clamping rod 32 to move toward the side close to the cement-based cured 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 cured sample 5. The applied pressure squeezes the side wall of the cement-based cured sample 5, causing cracks in the cement-based cured sample 5.

[0050] Preferably, Figure 3、 Figure 4 、 Figure 5 As shown, the clamping rod 32 is provided with multiple embedded parts 33. Each embedded part 33 includes a base plate 331 and a mounting ring 332. The base plate 331 is provided with multiple embedded nails 3310, which are embedded in the cement-based cured specimen 5. The mounting ring 332 is movably mounted on the clamping rod 32. The mounting ring 332 is provided with a connecting rod 3320, which is fixedly connected to the base plate 331.

[0051] In this embodiment, the embedded nail 3310 is a wooden or bamboo nail with a diameter of 2-3 cm. During the preparation of the cement-based curing specimen 5, it is embedded in the cement-based curing specimen 5 at an angle of ≥45°, creating a "barbed" mechanical engagement. During experiments, when the clamping rod 32 moves toward the side of the cement-based curing specimen 5, it drives the mounting ring 332 and the base plate 331, thereby moving the embedded nail 3310 into the interior of the cement-based curing specimen 5. This process directly transfers the slight movement of the clamping rod 32 into the internal pressure of the cement-based curing specimen 5, making it easier to produce cracks and facilitating the testing process.

[0052] 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 4. The design of the clamping rods 32 arranged in a regular N-gon cross-section has significant advantages in terms of clamping stability, pressure uniformity, and test adaptability of the cement-based cured specimen 5 through the synergistic effect of geometric symmetry and mechanical balance.

[0053] Cracks produced in cement-based cured specimen 5 under regular N-polygon pressure exhibited a symmetrical distribution. Using digital image correlation analysis, the measurement error of crack length and width was reduced to less than 3%. For example, when analyzing crack propagation under N=4 clamping conditions, the software automatically identified the four branches of a cross-shaped crack, improving data processing efficiency by 40%. Furthermore, the cross-shaped cracks at N=4 allowed for rapid penetration of acidic solutions along the main cracks, while the symmetrical crack network of regular polygons maintained a solution penetration depth deviation of ≤2%, facilitating the study of heavy metal ion migration in regular cracks.

[0054] Preferably, Figure 3 、 Figure 7 、 Figure 8 As shown, the cement-based cured sample 5 is a columnar structure, and the cross section of the columnar structure is a circle or a regular N-gon.

[0055] Under the action of axial pressure, the columnar structure distributes stress uniformly in the radial direction, avoiding local stress concentration that may be caused by irregular shapes. When the driving unit 4 applies pressure to the side wall of the cement-based solidified sample 5 through the clamping rod 32, the columnar structure can ensure that the circumferential pressure is evenly transmitted, so that the cracks expand along a preset direction such as radially, rather than causing disordered development of cracks due to asymmetric shapes, thereby improving the repeatability of the test results. The isotropic characteristics of the circular cross-section make it so that when it is subjected to radial compression, the circumferential stress is equal everywhere, and the cracks will expand uniformly inward from the stress point. This symmetry facilitates the quantitative analysis of the relationship between crack expansion rate and pressure, and is particularly suitable for studying the penetration law of heavy metals in uniform cracks.

[0056] Columns with circular or regular N-gon cross-sections can be cast using standardized molds. Compared with irregular shapes, it is easier to control dimensional accuracy and facilitate comparison of different batches of tests.

[0057] When the cross section of the clamping rod 32 forms a regular N-gon, if the cross section of the cement-based cured sample 5 is a regular N-gon with the same number of sides, the clamping rod can achieve surface contact with the side wall of the cement-based cured sample 5, ensuring that pressure is evenly transmitted to the surface of the cement-based cured sample 5.

[0058] Preferably, N limiting grooves 50 are provided on the side wall of the cement-based solidified sample 5 , and the clamping rods 32 are clamped in the limiting grooves 50 in a one-to-one correspondence.

[0059] The one-to-one engagement between the retaining grooves 50 and the clamping rods 32 allows for precise positioning through structural design, preventing positional deviation of the clamping rods 32 on the sidewalls of the cement-based cured specimen 5. This ensures that the clamping rods 32 can only be installed in the predetermined direction, avoiding circumferential or axial displacement. Furthermore, this uniform installation position ensures that the point of action and direction of force applied by the clamping rods 32 on the specimen remain consistent throughout each test, reducing test data discrepancies caused by installation errors and improving the reliability of experimental results.

[0060] The clamping structure of the limiting groove 50 allows the pressure applied by the clamping rod 32 to be evenly transmitted to the sidewalls of the cement-based cured specimen 5 through the groove wall of the limiting groove 50. During dynamic testing or high-pressure loading, the limiting groove 50 can reduce shaking or vibration of the clamping rod 32.

[0061] Preferably, the limiting grooves 50 are distributed on the edge of the column structure or the center line of the side surface of the column structure. Figure 7 、 Figure 8 As shown, when the cement-based cured sample 5 is fitted with four clamping rods 32 , each side corresponds to a clamping rod 32 or each side center line corresponds to a clamping rod 32 , thereby avoiding pressure loss caused by gaps.

[0062] Preferably, the axis of the cement-based cured sample 5 is provided with a through groove 500. The through groove 500 penetrates the cement-based cured sample 5 along the axis of the cement-based cured sample 5, so that a cavity structure is formed inside the cement-based cured sample 5, which is more likely to cause cracks when the clamping rod 32 applies pressure to the outer wall of the cement-based cured sample 5.

[0063] Preferably, the accommodating portion 1 includes a sample tube 11, a sleeve 12, and a connecting tube 13. A perforation 110 is provided on the side wall of the sample tube 11, and the sample tube 11 is used to place the cement-based solidified sample 5. The sleeve 12 is sleeved on the outside of the sample tube 11, the top of the sleeve 12 is connected to the top of the sample tube 11, the inner wall of the sleeve 12 and the outer wall of the sample tube 11 form a circulation chamber 120, and the circulation chamber 120 is connected to the inside of the sample tube 11 through the perforation 110. The connecting tube 13 is provided at the bottom of the sample tube 11, and the two ends of the connecting tube 13 are respectively connected to the sample tube 11 and the sleeve 12; a disturbance member 130 is provided in the connecting tube 13. The disturbance member 130 includes a motor and a fan blade connected to the motor. The motor drives the fan blade to rotate to accelerate the acid solution through the inside of the connecting tube 13, thereby promoting the flow of the acid solution between the inside of the sample tube 11 and the circulation chamber 120.

[0064] The acidic solution in the circulation chamber 120 enters the sample cylinder 11 through the connecting tube 13 , and the acidic solution in the sample cylinder 11 enters the circulation chamber 120 through the perforation 110 , thereby realizing the circulation of the acidic solution.

[0065] 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 tube 13 , thereby realizing the circulation of the acidic solution.

[0066] Circulation chamber 120 communicates with the interior of sample tube 11 through perforation 110, forming a fluid circulation pathway to simulate dynamic environments such as groundwater erosion and acid rain erosion. The fluid in circulation chamber 120 acts on the sample surface through perforation 110. Combined with agitator 130, it enhances turbulence, reducing the solution concentration gradient on the sample surface by 70%, thus preventing localized corrosion errors.

[0067] Preferably, a positioning seat 111 is provided inside the sample tube 11 , and a positioning groove for engaging with the positioning seat 111 is provided at the bottom of the cement-based solidified sample 5 .

[0068] 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 and is connected to 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.

[0069] 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 where penetration from the bottom of the sample is required, such as simulating the erosion of groundwater from bottom to top. The acidic solution passes directly through the disturbance pipe 112 to the center of the cement-based solidified sample 5, and cooperates with the through-groove 500 to achieve internal flushing.

[0070] The circulation from the circulation chamber 120 to the perforation 110 to the sample tube 11 to the connecting pipe 13 to the circulation chamber 120 is suitable for surface erosion testing. The acidic solution penetrates from the perforation on the side wall of the sample and flows back through the bottom connecting pipe, which can simulate the erosion of the structure surface by acid rain or surface water flow, and cooperates with the disturbance piece to enhance the surface fluid shear force.

[0071] The specific models of the above electronic components are not particularly specified, and common products available on the market can be selected as long as they can meet the use requirements of the present invention.

[0072] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only 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 in the scope of protection of the present invention.

Claims

1. A heavy metal solidification test device, characterized in that: include: an accommodating portion having an accommodating cavity; The liquid supply and collection part includes: a liquid supply part, which is in communication with the accommodating chamber and is used to provide an acidic solution to the interior of the accommodating chamber; and a collecting part, which is in communication with the accommodating chamber and is used to collect waste liquid in the accommodating chamber. The clamping portion is placed in the accommodating cavity, and the clamping portion includes: a base having a plurality of mounting holes; a plurality of clamping rods, each of which is vertically mounted on the base, with one end of each clamping rod being inserted into the mounting hole in a one-to-one correspondence, and the clamping rod can move around the mounting hole as an axis; a clamping area is formed between the plurality of clamping rods and the base, and the clamping area is used to place the cement-based cured sample, and the clamping rods are closely attached to the side wall of the cement-based cured 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 toward a side close to the cement-based cured sample with the mounting hole corresponding to the clamping rod as the axis, and is used to apply pressure to the side wall of the cement-based cured sample to cause cracks to form in the cement-based cured sample.

2. A heavy metal solidification test device as claimed in claim 1, characterized in that: The clamping rod is provided with a plurality of embedded parts, each of which includes: A base plate is provided with a plurality of embedded nails, the embedded nails being used to be embedded in the cement-based curing sample; The mounting ring is movably sleeved on the clamping rod. The mounting ring is provided with a connecting rod, which is fixedly connected to the base plate.

3. A heavy metal solidification test device as claimed in claim 1, characterized in that: There are N clamping rods, and cross sections of the N clamping rods form a regular N-gon, where 5≥N≥3.

4. A heavy metal solidification test device as claimed in claim 3, characterized in that: The cement-based solidified sample is a columnar structure, and the cross section of the columnar structure is a circle or a regular N-gon.

5. A heavy metal solidification test device as claimed in claim 4, characterized in that: N limiting grooves are provided on the side wall of the cement-based solidified sample, and the clamping rods are clamped in the limiting grooves one by one.

6. A heavy metal solidification test device as claimed in claim 5, characterized in that: The limiting grooves are distributed on the edges of the column structure or the center lines of the side surfaces of the column structure.

7. A heavy metal solidification test device as claimed in claim 4, characterized in that: The axis of the cement-based curing specimen is provided with a through groove.

8. A heavy metal solidification test device as claimed in claim 7, characterized in that: The accommodating portion includes: The sample tube has a perforation on its side wall and is used to place cement-based solidified samples; The sleeve is sleeved on the outside of the sample tube, the top of the sleeve is connected to the top of the sample tube, the inner wall of the sleeve and the outer wall of the sample tube form a circulation cavity, and the circulation cavity is connected to the interior of the sample tube through the perforation; The connecting tube is arranged at the bottom of the sample tube, and the two ends of the connecting tube are respectively communicated with the sample tube and the sleeve; a disturbance piece is arranged in the connecting tube.

9. A heavy metal solidification test device as claimed in claim 8, characterized in that: A positioning seat is provided inside the sample tube, and a positioning groove which is engaged with the positioning seat is provided at the bottom of the cement-based solidified sample.

10. A heavy metal solidification test device according to claim 9, characterized in that: A disturbance tube is provided on the positioning seat, 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 and is connected to 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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