A kind of marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious material

Abstract

This invention discloses a marine dry-wet-freeze-thaw erosion testing device suitable for solid waste cementitious materials, belonging to the field of building material durability testing technology. It includes an upper dry-wet circulation chamber and a lower freeze-thaw chamber separated by partitions and sealing plates. The freeze-thaw chamber has a shared refrigerant chamber, within which multiple specimen boxes arranged in an array are detachably installed. The specimen boxes are immersed in the refrigerant, which indirectly cools the erosion solution water bath in the freeze-thaw unit chamber through the box walls. A rigid lifting component suspends a specimen basket from the top. After the basket descends and the sealing plate is opened, it enters the freeze-thaw unit chamber for freeze-thaw circulation, then rises back to the dry-wet circulation chamber for spraying and drying. This invention achieves isolation between the upper and lower chambers and physical separation of the refrigerant and erosion solution through the sealing plate and indirect cooling. The basket facilitates clean transfer of specimens, and the multi-station array ensures that each specimen experiences a consistent temperature field and erosion environment, enabling high-throughput parallel testing.

Description

Technical Field

[0001] This invention relates to the field of building material durability testing technology, and in particular to a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials. Background Technology

[0002] With the rapid development of marine engineering construction, a large number of concrete structures are subjected to the coupled effects of multiple environmental factors such as alternating wet and dry conditions, freeze-thaw cycles, and corrosion by chloride and sulfate ions, leading to increasingly prominent durability deterioration problems. In recent years, the preparation of cementitious materials using industrial solid wastes such as granulated blast furnace slag, fly ash, steel slag, red mud, and desulfurization gypsum has become an important direction for green building materials and the resource utilization of solid waste. However, the composition and pore structure of the hydration products of solid waste cementitious materials differ from those of ordinary silicate cement. If traditional durability testing equipment designed for ordinary concrete is used, its applicability is significantly insufficient: the core hydration products in the solid waste system are highly sensitive to temperature, and the high-temperature drying conditions of 80°C in traditional standards can easily lead to dehydration and decomposition of the products, thereby changing the actual degradation mechanism of the material in the actual marine environment; at the same time, the porosity of solid waste materials is high in the early stage of hydration, and the use of single strong hot air forced drying can easily generate capillary negative pressure due to rapid evaporation of water, causing drying shrinkage microcracks. This non-corrosive physical damage will seriously interfere with the assessment of erosion resistance; in addition, solid waste materials have significant secondary hydration characteristics and a long hydration cycle. The frequent manual sampling and cross-equipment transfers in traditional tests introduce abrupt changes in temperature and humidity fields, which will seriously interfere with its long-term hydration process.

[0003] Existing technologies include several concrete durability testing devices, but they generally suffer from the following shortcomings: There is a lack of reliable physical isolation between the cooling medium and the corrosive solution; after long-term operation, the coolant is easily contaminated by the corrosive solution, leading to a continuous decline in cooling efficiency; and the dilution of the corrosive solution by the coolant causes gradual distortion of the test data. The transfer of specimens between different test environments is highly dependent on manual operation or complex mechanical transmission mechanisms. During the transfer process, exposure of the specimens to air can easily cause sudden temperature field changes, and the solution carried on the specimen surface is prone to leakage, resulting in cross-contamination. Single-station or low-throughput designs result in low efficiency for parallel comparative tests, with a complete test cycle for a set of mix proportions often lasting several months. There is a lack of in-situ online monitoring methods to continuously acquire key deterioration parameters such as specimen quality changes without interrupting the test; operators need to periodically stop the machine to take samples, which reduces the temporal resolution of the test data and introduces additional human error due to the sampling operation.

[0004] Therefore, developing a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials, enabling it to automatically complete the coupled operation of dry-wet cycles and freeze-thaw cycles within the same closed chamber, achieving reliable physical isolation between the cooling medium and the erosion solution, as well as clean transfer of specimens between different environmental conditions, and possessing in-situ online weighing function to continuously track the quality evolution of specimens, thereby avoiding systematic errors introduced by cross-equipment transfer, media cross-contamination, and manual sampling operations in traditional test schemes, and truly reflecting the durability degradation process of solid waste cementitious materials in marine environments, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials. It can automatically complete the coupled operation of dry-wet cycle and freeze-thaw cycle in the same closed cavity, realize reliable physical isolation between the cooling medium and the erosion solution, and clean transfer of specimens between different environmental conditions. It also has an in-situ online weighing function to continuously track the quality evolution of specimens, thereby avoiding the systematic errors introduced by cross-equipment transfer, cross-contamination of media and manual sampling operations in traditional test schemes, and truly reflecting the durability degradation process of solid waste cementitious materials in marine environment.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials, comprising a dry-wet circulation chamber, a freeze-thaw chamber, a partition, a sealing plate, a rigid lifting component, a weighing and hanging assembly, a specimen basket, a drive module, a refrigeration unit, a liquid storage tank, an atomizing spray device, and a drying device. The partition is disposed between the dry-wet circulation chamber and the freeze-thaw chamber, dividing them into two independent chambers arranged vertically. The partition has at least one channel connecting the upper and lower chambers, and the sealing plate is disposed at the channel to open or close the channel. The freeze-thaw chamber has a shared refrigerant chamber containing refrigerant. At least one specimen box is detachably installed inside the refrigerant chamber. The specimen box is a heat-conducting container with an open top, and its internal space forms a freeze-thaw unit chamber. The freeze-thaw unit chamber is used to contain the erosion solution to form a water bath, in which the solid waste cementitious material specimen is placed. The specimen box is at least partially immersed in the refrigerant, and its outer surface is in direct contact with the refrigerant for heat exchange. The cold or heat of the refrigerant is indirectly conducted to the erosion solution inside the freeze-thaw unit chamber through the box wall. The rigid lifting member is installed on the top of the dry-wet circulation chamber. The lower end of the rigid lifting member is fixedly connected to the weighing hanging assembly. The specimen basket is suspended below the weighing hanging assembly. The drive module is connected to the rigid lifting member for driving the rigid lifting member to reciprocate between set lifting and lowering positions in the vertical direction. The refrigeration unit is connected to the refrigerant chamber through a refrigerant inlet and a refrigerant outlet, and is used to cool the refrigerant in the refrigerant chamber. The refrigerant chamber is equipped with a temperature sensor and a heating and insulation device, which are used to detect the refrigerant temperature and work with the refrigeration unit to control the refrigerant temperature within a set range. Both the atomizing spray device and the drying device are located inside the dry-wet circulation chamber, and the liquid storage tank is connected to the atomizing spray device through a spray pipeline.

[0007] Preferably, the specimen box is configured as a cubic box structure with an open top.

[0008] Preferably, the test specimen box is detachably disposed in the refrigerant chamber via a limiting installation structure, and the top opening of the test specimen box is connected to the channel hole of the partition.

[0009] Preferably, the number of rigid lifting components is set to at least one, and the number of channels opened on the rigid lifting components, the specimen box and the partition are matched. Each rigid lifting component is provided with an independent specimen basket at its lower end, and the multiple specimen baskets can be raised and lowered independently or synchronously.

[0010] Preferably, the number of the test specimen boxes is set to multiple, and they are arranged in an array in the refrigerant chamber, with multiple test specimen boxes sharing the same refrigerant chamber; The coolant in the coolant chamber does not come into direct contact with the corrosive solution in the freeze-thaw unit chamber. The cooling capacity of the coolant is indirectly conducted to the corrosive solution and the solid waste cementitious material specimen through the wall of the specimen box.

[0011] Preferably, the sealing plate is slidably mounted on the partition and the channel is opened or closed by a drive mechanism. When the specimen basket is located in the dry-wet circulation chamber, the sealing plate is in a closed state to seal and isolate the upper and lower cavities; when the specimen basket needs to be raised or lowered through the channel, the sealing plate is opened to allow passage.

[0012] Preferably, the outer periphery of the weighing hanging assembly is provided with a sealing structure, and when the specimen basket descends to a predetermined position in the freeze-thaw chamber, the sealing structure forms a sealing fit with the inner wall of the channel hole of the partition.

[0013] Preferably, a weighing sensor is embedded inside the weighing suspension assembly. The weighing sensor is connected in series between the lower end of the rigid lifting member and the suspension point of the specimen basket. It only bears axial tensile load and is not affected by the sliding friction of the rigid lifting member or its own weight.

[0014] Preferably, the specimen basket is a hollow cage-shaped frame structure, which is composed of a top suspension frame, vertical support rods and a bottom load-bearing base plate connected in sequence. The top suspension frame is suspended and connected to the weighing end of the weighing sensor. The vertical support rods and the bottom load-bearing base plate form a self-draining channel. During the process of the specimen basket rising from the freeze-thaw unit cavity to the dry-wet circulation chamber, the residual solution adhering to the wall of the specimen basket and the surface of the specimen flows back into the freeze-thaw unit cavity naturally through the self-draining channel under the action of gravity.

[0015] Preferably, the drying device includes an air supply device and a heating device, both of which are installed on the inner wall of the dry-wet circulation chamber. The air supply device and the heating device can operate independently or in combination, corresponding to normal temperature air drying mode, static drying mode and hot air circulation mode.

[0016] Preferably, a temperature and humidity sensor is installed on the inner wall of the wet and dry circulation chamber, a wet and dry circulation chamber door is installed on the front of the wet and dry circulation chamber, and a control system is installed on the outer side of the wet and dry circulation chamber. The control system is electrically connected to the drive module, the refrigeration unit, the atomizing spray device, the drying device, the temperature and humidity sensor, the weighing sensor, and the sealing pressure plate, and is used to set test parameters, monitor the operating status, and record weighing, temperature and humidity, and test sequence data.

[0017] Preferably, the control system has a pre-set freeze-thaw-wet coupled corrosion test timing program. The timing program controls the drive module, sealing plate, refrigeration unit, atomizing spray device and drying device to operate alternately according to a preset cycle to simulate the freeze-thaw-wet coupled corrosion process of the specimen.

[0018] A method for marine dry-wet-freeze-thaw erosion testing of solid waste cementitious materials includes the following steps: S1. Place the solid waste cementitious material specimen into the specimen basket and set the test parameters through the control system; S2. The sealing plate slides open, and the drive module drives the specimen basket to descend and enter the freeze-thaw unit cavity through the rigid lifting component. After the specimen basket descends to the position, the elastic sealing component on the outer periphery of the weighing hanging component seals with the channel hole of the partition. The etching solution is injected into the freeze-thaw unit cavity until the specimen is completely submerged. The refrigerant is cooled by the refrigeration unit. The refrigerant indirectly cools the etching solution water bath through the wall of the specimen box, so that the solid waste cementitious material specimen completes a single freeze-thaw cycle under the set temperature regime. S3. After the freeze-thaw cycle is completed, the corrosive solution in the freeze-thaw unit cavity is emptied. The rigid lifting component drives the specimen basket to rise, and the elastic seal on the outer periphery of the weighing hanging component disengages from the sealing fit with the partition channel hole. After the specimen basket rises to the position, the sealing pressure plate slides to close, separating the upper and lower independent cavities. S4. The specimen is sprayed with a misting spray device in the wet-dry cycle chamber, and then dried by a drying device to form a single wet-dry cycle; after drying, the mass of the specimen is collected and read by the weighing sensor in the weighing hanging assembly. S5. Repeat steps S2 to S4 until the set total number of cycles is reached.

[0019] Preferably, the test also includes a phased manual inspection step. The control system presets one or more target pause cycles N. When the test runs to the preset Nth cycle, and the current freeze-thaw cycle ends, the specimen basket is raised to the wet-dry cycle chamber, and the sealing plate closes the upper and lower cavities, the control system automatically triggers the pause program, releases the electronic lock of the wet-dry cycle chamber door, and issues a manual sampling prompt. After the specimen is manually removed, the external test is completed, and the specimen is returned to its original position, the control system executes the breakpoint continuation, automatically recalibrates the zero point of the weighing sensor, and continues to run the subsequent cycles.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are as follows: 1) By setting up independent upper and lower chambers and using a rigid lifting device and specimen basket for vertical transfer, this invention achieves automatic coupling operation of wet-dry cycle and freeze-thaw cycle within the same closed device. After completing the freeze-thaw cycle in the freeze-thaw chamber, the specimen can be directly lifted to the wet-dry cycle chamber for spraying and drying, without the need for manual opening of the chamber doors or handling of the specimen. This design effectively avoids the problems of temperature field abrupt changes and disruption of freeze-thaw curve continuity caused by specimen exposure to room temperature during cross-equipment transfer in traditional solutions. Especially for solid waste cementitious materials with long secondary hydration cycles and continuously evolving microstructures, integrated closed operation minimizes the interference of external environmental fluctuations on the internal hydration process of the specimen, ensuring the natural continuity of the material degradation process. The sealing plate remains closed during non-transfer periods, minimizing heat and medium exchange between the upper and lower chambers, saving energy consumption for heating and cooling, and ensuring the long-term stability of the temperature field in the freeze-thaw chamber. 2) This invention employs an indirect cooling structure consisting of a shared refrigerant bath and detachable specimen boxes. The glycol-based refrigerant in the refrigerant chamber conducts cooling energy to the corrosion solution water bath in the freeze-thaw unit chamber within the specimen box through the box wall. The refrigerant and corrosion solution are physically isolated by the box wall throughout the process, preventing contact between them. This fundamentally eliminates the bidirectional cross-contamination problem of refrigerant contamination by the corrosion solution and corrosion solution dilution by the refrigerant, which occurs after long-term operation in traditional direct-contact cooling schemes. It effectively avoids refrigeration failure caused by an increase in the refrigerant's freezing point and distortion of test results caused by changes in the corrosion solution concentration. Simultaneously, all specimen boxes share the same refrigerant bath, allowing the refrigerant to flow freely between boxes. Combined with a circulating stirrer, this maintains temperature field uniformity, ensuring that the temperature difference between specimen boxes does not exceed ±0.5℃. This guarantees that specimens in different workstations undergo a completely consistent freeze-thaw temperature process, eliminating test errors introduced by inconsistent temperature fields. 3) This invention embeds a weighing sensor within the weighing suspension assembly and connects it in series between the lower end of the rigid lifting member and the suspension point of the specimen basket. This ensures the sensor bears only the axial tensile load of the specimen and basket, unaffected by the sliding friction of the rigid lifting member or its own weight. This allows for in-situ, high-precision acquisition of specimen mass after the drying stage. The sensor's range and accuracy are rationally configured, and combined with the data processing method of averaging multiple consecutive samples, it effectively eliminates interference from environmental vibrations affecting repeated readings. This design allows operators to obtain mass change data after each wet-dry cycle without removing the specimen from the device, avoiding the disturbance to the specimen's surface condition and internal temperature and humidity field caused by frequent sampling in traditional methods. It also significantly improves the temporal resolution and convenience of data acquisition, providing a reliable monitoring method for studying the mass evolution of solid waste cementitious materials during long-term erosion. 4) In this invention, the specimen basket adopts a hollow cage-like frame structure. The hollow mesh on its four walls and the drainage holes at the bottom together form a complete self-draining channel. During the process of the specimen basket rising from the freeze-thaw unit chamber to the wet-dry circulation chamber, the residual corrosive solution adhering to the basket wall and the specimen surface can flow back into the freeze-thaw unit chamber naturally under the action of gravity through the self-draining channel. This avoids cross-contamination and solution loss caused by the solution being carried to the wet-dry circulation chamber. It also ensures that the specimen enters the spraying and drying stage in a relatively dry initial state, which is beneficial to improving the consistency of the wet-dry cycle effect. With the sealing plate closing in time after the specimen basket rises to the position, the entire transfer process achieves a clean transition of the specimen between different test environments. This reduces the need for manual intervention and reduces the impact of solution cross-contamination on test conditions during long-term tests. 5) The air supply and heating devices in this invention can operate independently or in combination as needed for the experiment, corresponding to three drying modes: ambient temperature air drying, static drying, and hot air circulation. Operators can flexibly choose a gentler drying method to avoid product decomposition and shrinkage cracks caused by high temperatures or strong convection, given the poor thermal stability and high early porosity of the hydration products of solid waste cementitious materials. They can also select an accelerated drying mode to improve experimental efficiency. This multi-mode adjustable design allows the same device to meet the specific experimental requirements of solid waste cementitious materials while also being compatible with marine durability tests of other types of materials such as ordinary silicate cement concrete and ultra-high performance concrete, significantly broadening the applicability and flexibility of the equipment. 6) By setting up multiple test specimen boxes in a matrix array and ensuring that each unit shares a refrigerant bath to maintain a consistent temperature field, the present invention allows operators to conduct parallel comparative tests on multiple groups of specimens with different mix ratios under identical freeze-thaw and wet / dry conditions. This effectively eliminates the systematic errors introduced by fluctuations in equipment operating status and environmental conditions when traditional single-station equipment is used for batch testing. Optimizing the mix proportion of solid waste cementitious materials involves multiple dimensions such as the type and dosage of activator, water-cement ratio, and solid waste compounding ratio, resulting in a large workload for experiments. The multi-unit high-throughput design of this invention can significantly shorten the cycle of mix proportion screening and durability comparison tests, improving R&D efficiency. At the same time, each specimen basket in the same device has independent lifting capabilities, providing a structural basis for conducting orthogonal comparisons of different test regimes. More importantly, since all specimen boxes are immersed in the same coolant bath and the coolant is forced to convect under the action of a circulating stirrer, there is no temperature gradient between the stations. The freeze-thaw or isothermal immersion temperature regime experienced by each group of specimens is completely consistent, fundamentally eliminating the dispersion of parallel test data caused by temperature field differences, which is something that independent multi-cavity equipment cannot guarantee. 7) This invention is particularly applicable to the durability assessment of solid waste cementitious materials: the hydration products of solid waste cementitious materials (such as hydrated calcium silicate gel CSH and ettringite AFt) are easily dehydrated and decomposed under traditional 80℃ drying conditions, altering the actual degradation mechanism of the material; at the same time, the secondary hydration cycle of solid waste materials is long, and the sudden changes in temperature and humidity introduced by traditional cross-equipment transfer can seriously interfere with the long-term hydration process. This invention, through an integrated closed design—coupling the dry-wet cycle and freeze-thaw cycle within the same device, and ensuring that the specimen is not exposed to the external environment throughout the process—fundamentally avoids high-temperature drying damage and transfer disturbances, making the degradation process of solid waste cementitious materials closer to natural service conditions, which is impossible to achieve with traditional single environmental chambers or combined equipment. This invention, through physical isolation of the refrigerant and corrosive medium, in-situ transfer of specimens, and online weighing monitoring, realizes continuous simulation of the long-term service behavior of solid waste cementitious materials under freeze-thaw-dry-wet coupling. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the overall structure of a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials according to the present invention. Figure 2 This is a schematic diagram of the internal structure of a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials according to the present invention. Figure 3 This is a schematic diagram showing the opening and closing states of the sealing pressure plate in this invention; Figure 4 This is a schematic diagram of the suspended basket in this invention.

[0023] Explanation of reference numerals in the attached drawings: 1. Drive module; 2. Rigid lifting component; 3. Wet and dry suspension assembly; 4. Dry and wet circulation chamber; 5. Air supply device; 6. Control system; 7. Specimen basket; 8. Door of dry and wet circulation chamber; 9. Sealing plate; 10. Partition; 11. Freeze-thaw chamber; 12. Liquid storage tank; 13. Refrigeration unit; 14. Refrigerant inlet; 15. Heating device; 16. Temperature and humidity sensor; 17. Atomizing spray device; 18. Spray pipeline; 19. Specimen box; 20. Freeze-thaw unit cavity; 21. Refrigerant cavity; 22. Temperature sensor; 23. Refrigerant outlet. Detailed Implementation

[0024] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] like Figure 1-4 As shown, a marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials includes a dry-wet circulation chamber 4, a freeze-thaw chamber 11, a partition 10, a sealing pressure plate 9, a rigid lifting component 2, a weighing and hanging assembly 3, a specimen basket 7, a drive module 1, a refrigeration unit 13, a liquid storage tank 12, an atomizing spray device 17, and a drying device. The partition 10 is disposed between the dry-wet circulation chamber 4 and the freeze-thaw chamber 11, dividing them into two independent chambers arranged vertically. The partition 10 has at least one channel connecting the upper and lower chambers. The sealing pressure plate 9 is disposed at the channel to open or close the channel. The freeze-thaw chamber 11 has a shared refrigerant chamber 21 inside, which contains refrigerant. Multiple specimen boxes 19 are detachably installed inside the refrigerant chamber 21. Each specimen box 19 is a cubic box with an open top, and its internal space forms a freeze-thaw unit chamber 20. The freeze-thaw unit chamber 20 is used to contain an erosion solution to form a water bath, in which solid waste cementitious material specimens are placed. Each specimen box 19 is at least partially immersed in the refrigerant, and its outer surface directly contacts the refrigerant for heat exchange. Cold or heat is indirectly conducted to the erosion solution inside the freeze-thaw unit chamber 20 through the box wall. The rigid lifting member 2 is installed on the top of the dry and wet circulation chamber 4. The lower end of the rigid lifting member 2 is fixedly connected to the weighing hanging assembly 3. The specimen basket 7 is suspended below the weighing hanging assembly 3. The drive module 1 is connected to the rigid lifting member 2 for driving the rigid lifting member 2 to reciprocate between the set lifting and lowering positions in the vertical direction. The refrigeration unit 13 is connected to the refrigerant chamber 21 through the refrigerant inlet 14 and the refrigerant outlet 23, and is used to cool the refrigerant in the refrigerant chamber 21. The refrigerant chamber 21 is equipped with a temperature sensor 22 and a heating and insulation device, which are used to detect the refrigerant temperature and cooperate with the refrigeration unit 13 to control the refrigerant temperature within a set range. Both the atomizing spray device 17 and the drying device are located inside the dry-wet circulation chamber 4, and the liquid storage tank 12 is connected to the atomizing spray device 17 through the spray pipe 18.

[0026] Specifically, the device is a vertical cabinet structure with a total height of 1800-2000mm (the above parameters are only preferred embodiments and do not constitute a limitation on the scope of protection of this invention), a width of 1000-1200mm, and a depth of 700-900mm. The cabinet is welded from 304 stainless steel plate, and the exposed surface is treated with pickling, passivation, and electrostatic spraying. An 80-120mm thick rigid polyurethane foam insulation layer is filled between the outer wall and the inner liner. Four universal casters with brakes are installed at the bottom of the cabinet. The freeze-thaw chamber 11 is slidably installed inside the cabinet via a slide rail. The slide rail is equipped with a limit device that automatically locks when pulled out to a predetermined position to prevent slippage. When the flange of the specimen box 19 adopts a larger outer... When extending the dimensions, the flange may interfere with the sealing plate 9 or the bottom plate of the wet-dry circulation chamber 4. In this case, the test specimen box 19 can be removed or installed from below by pulling the freeze-thaw chamber 11 out along the slide rail as a whole. If the flange size is small and does not interfere with the sealing plate 9 and the bottom plate of the wet-dry circulation chamber 4, the box can also be directly inserted or removed from one side of the wet-dry circulation chamber 4 through the partition 10 channel for cleaning the refrigerant chamber 21 and routine maintenance. The partition 10 is made of 316L stainless steel plate with a thickness of 10mm, and the plate surface has channel holes with the same cross-sectional dimensions as the freeze-thaw unit chamber 20. The drive module 1 integrates the drive unit and the weighing unit. The drive unit uses a 57-type stepper motor with a rated torque of 2.5N. m is connected to the rigid lifting component 2 via a flexible coupling; when the rigid lifting component 2 adopts a ball screw pair, the screw diameter can be selected as 20mm, the lead is 5mm, the effective stroke is 450mm, the material is 40Cr alloy steel, the surface is heat treated and hard chrome plated, and the plating thickness is not less than 20μm. The upper end of the screw is installed on the top frame through a rolling bearing, the bearing seat is filled with low temperature resistant grease, and the lower end is suspended without a lower bearing seat.

[0027] Specifically, the test specimen box 19 is detachably installed in the refrigerant chamber 21 through a limiting installation structure, and the top opening of the test specimen box 19 is connected to the channel hole of the partition 10.

[0028] Specifically, the specimen box 19 is formed by bending and welding 2-3mm thick 316L stainless steel plate. The box body is a cubic structure with an open top surface. The upper edge has an outwardly extending flange for overlapping and positioning with the partition 10. The cross-sectional dimensions of the inner cavity are consistent with the dimensions of the channel holes on the partition 10. The box wall is electrolytically polished to ensure thermal conductivity and corrosion resistance. The bottom of the box body has reinforcing ribs to meet the strength requirements for bearing the corrosive solution and the total weight of the specimens. The refrigerant chamber 21 is an integral bath located inside the freeze-thaw chamber 11, lined with 316L stainless steel plate. The volume of the bath is sufficient to completely immerse all specimen boxes 19 in refrigerant. The refrigerant inlet 14 and refrigerant outlet 23 are both located at the bottom of the refrigerant chamber 21 and are connected to the refrigeration unit 13 through insulated pipes to form a closed circulation loop. A circulation pump with a flow rate of 10-30L / min is installed in the loop. The refrigeration unit 13... An axial cooling fan and a finned radiator are installed on the condenser side to dissipate heat outward through forced air cooling. The atomizing spray device 17 consists of a stainless steel body and a precision ceramic nozzle core, with a droplet size of 10-100μm, a spray angle of 60°-80°, and an effective coverage radius of not less than 200mm. The spray pipeline 18 is equipped with an electromagnetic shut-off valve, a Y-type filter, a micro diaphragm pump, and a pressure gauge in sequence. A peristaltic pump can also be used to replace the diaphragm pump for liquid supply. The liquid storage tank 12 is divided into three independent liquid storage compartments, each with an effective volume of 20L, which respectively store artificial seawater prepared according to standards, a sodium chloride and sodium sulfate composite salt solution, and a spare test solution. After switching through an electromagnetic valve group, they are connected to the spray pipeline 18. In addition to being suitable for solid waste cementitious materials, this device can also be used for marine engineering durability testing of ordinary silicate cement concrete, ultra-high performance concrete, and fiber-reinforced matrix composite materials.

[0029] Specifically, the number of rigid lifting components 2 is set to at least one, and the number of channels opened on the rigid lifting components 2, the specimen box 19 and the partition 10 are matched. Each rigid lifting component 2 is provided with an independent specimen basket 7 at its lower end, and multiple specimen baskets 7 can be raised and lowered independently or synchronously.

[0030] Specifically, the rigid lifting component 2 can be one of the following: ball screw pair, electric push rod, cylinder, hydraulic cylinder or gear rack mechanism, with the corresponding drive module 1 providing lifting power; the rigid lifting component 2 is equipped with a linear guide rail guiding mechanism to ensure that the vertical deviation of the lifting movement is not greater than 1mm / m; each rigid lifting component 2 can be equipped with an independent drive unit, and its operating status can be controlled by the control system 6 to achieve independent lifting, or it can be linked by the same drive unit to achieve synchronous lifting.

[0031] Specifically, the number of test specimen boxes 19 is set to multiple, arranged in an array within the refrigerant chamber 21. All test specimen boxes share the same refrigerant chamber 21 and the same refrigeration unit 13. The upper edge of each test specimen box 19 has an outwardly extending flange that overlaps the upper surface of the partition 10, suspending and positioning the test specimen box 19 at the channel hole of the partition 10. The test specimen box 19 can be inserted from one side of the dry-wet circulation chamber 4 through the channel on the partition 10. During installation, it is aligned with the channel hole and inserted vertically. Once the flange falls onto the upper surface of the partition 10, it is positioned without the need for additional fasteners. During disassembly, the box body is lifted upward to remove it from the channel hole. The coolant in the coolant chamber 21 does not come into direct contact with the erosion solution in the freeze-thaw unit chamber 20. The cooling capacity is indirectly conducted to the erosion solution and the specimen through the specimen box 19.

[0032] Specifically, in this exemplary embodiment, multiple test specimen boxes are arranged in a 3×3 matrix array within the refrigerant chamber 21, with a total of 9 test specimen boxes 19. The spacing between adjacent unit boxes is not less than 20mm to ensure sufficient flow of the refrigerant between the boxes. A circulating stirrer is installed in the refrigerant chamber 21 to maintain temperature field uniformity and ensure that the refrigerant temperature in contact with the outer surface of each test specimen box 19 is consistent, with the temperature difference between units not exceeding ±0.5℃. At least one temperature sensor 22 is installed in the refrigerant chamber 21 for real-time acquisition of the refrigerant temperature signal. An electric heating tube is installed at the bottom or side wall of the refrigerant chamber 21 as a heating and heat preservation device. The heating tube uses a 316L stainless steel sheath and has a power of 2-3kW. The refrigerant can be, for example, ethylene glycol-based or food-grade propylene glycol-based refrigerant with a volume concentration of not less than 40%, a freezing point not higher than -35℃, and a thermal conductivity not less than 0.4W / (m·K).

[0033] Specifically, the refrigeration unit 13 can use, for example, a fully enclosed scroll compressor with R404A refrigerant, or a reciprocating compressor with R449A refrigerant. Smaller devices can also use a semiconductor refrigeration array. Temperature control adopts a segmented PID algorithm. During the heating and cooling stages, the refrigeration and heating power are adjusted through PID calculations. During the constant temperature stage, it switches to pure proportional control, which can control the refrigerant temperature at any set temperature point within the range of -30℃ to 80℃, with a temperature control accuracy of ±0.5℃. After the refrigerant temperature stabilizes, the temperature is indirectly conducted to the etching solution inside the test specimen box 19 through the wall surface, so that the temperature of the etching solution meets the temperature control requirements for constant temperature immersion in the sulfate corrosion resistance test in GB / T50082 standard (such as 25~30℃), realizing the compatible switching between the freeze-thaw cycle mode and the constant temperature etching immersion mode of this device. The multi-unit array structure can simultaneously carry out parallel comparative tests of multiple sets of test specimens under completely consistent temperature field and dry and wet conditions, eliminating environmental errors caused by batch testing and greatly improving the efficiency of mix ratio optimization tests.

[0034] Specifically, the sealing plate 9 is slidably mounted on the partition 10 and is controlled by a drive mechanism to open or close the channel. When the specimen basket 7 is located in the dry-wet circulation chamber 4, the sealing plate 9 is in a closed state to seal and isolate the upper and lower cavities; when the specimen basket 7 needs to be raised or lowered through the channel, the sealing plate 9 is opened to allow passage.

[0035] Specifically, the sealing plate 9 is slidably mounted on the partition plate 10. The driving mechanism can be a pneumatic push rod, a stepper motor with linear guide rail or an electromagnetic drive structure to control the sealing plate 9 to slide open and close in a straight line. The sealing plate 9 remains normally closed when there is no external force driving it, and is only opened when the specimen basket 7 is raised and lowered.

[0036] Specifically, an elastic sealing ring is installed on the outer periphery of the weighing hanging assembly 3. The elastic sealing ring is made of silicone rubber or fluororubber and its outer diameter is larger than the channel hole diameter of the partition plate 10 in its natural state. When the specimen basket 7 is lowered to the predetermined position in the freeze-thaw chamber 11, the elastic sealing ring is compressed between the weighing hanging assembly 3 and the inner wall of the channel hole to form a sealing fit.

[0037] Specifically, a weighing sensor is embedded inside the weighing suspension assembly 3. The weighing sensor is connected in series between the lower end of the rigid lifting member 2 and the suspension point of the specimen basket 7. It only bears axial tensile load and is not affected by the sliding friction of the rigid lifting member 2 or its own weight.

[0038] Specifically, the weighing range of the load cell can be configured from 0 to 50 kg according to the total weight of the specimen and the basket, and the overall accuracy can reach ±0.1 g. Temperature compensation circuits are set on both sides of the sensor to automatically correct zero drift caused by changes in ambient temperature. The signal line of the load cell is shielded and then connected to the data acquisition module of the control system 6. The sampling frequency can be set to 10 Hz. After the acquired data is processed, the weight of the specimen basket 7 is automatically deducted to obtain the net mass of the specimen.

[0039] Specifically, the specimen basket 7 is a hollow cage-shaped frame structure, which is composed of a top suspension frame, vertical support rods and a bottom load-bearing base plate connected in sequence. The top suspension frame is suspended and connected to the weighing end of the weighing sensor. The vertical support rods and the bottom load-bearing base plate form a self-draining channel. During the process of the specimen basket 7 rising from the freeze-thaw unit cavity 20 to the dry-wet circulation chamber 4, the residual solution adhering to the wall surface of the specimen basket 7 and the surface of the specimen flows back into the freeze-thaw unit cavity 20 naturally through the self-draining channel under the action of gravity.

[0040] Specifically, the internal clearance of the specimen basket 7 can be customized according to the standard specimen size, and can accommodate specimens of various specifications such as mortar blocks, mortar strips, concrete prism blocks or concrete cube blocks; the hollow grid on the four walls and the drainage holes at the bottom together form a continuous self-draining channel. During the rise of the specimen basket 7, the attached corrosive solution can be completely returned to the freeze-thaw unit cavity 20 under the action of gravity, avoiding the solution being carried into the wet-dry circulation chamber 4 and causing cross-contamination. At the same time, it ensures that the specimen enters the wet-dry circulation stage in a relatively dry state, improving the consistency of the wet-dry circulation effect each time.

[0041] Specifically, the drying device includes an air supply device 5 and a heating device 15. Both the air supply device 5 and the heating device 15 are installed on the inner wall of the dry and wet circulation chamber 4. The air supply device 5 and the heating device 15 can operate independently or in combination, corresponding to the normal temperature air drying mode, the static drying mode and the hot air circulation mode.

[0042] Specifically, the air supply device 5 uses a variable frequency speed-regulating centrifugal fan with a rated air volume of 500 m³ / h and an air pressure of 200 Pa. The air inlet is equipped with a replaceable primary air filter, and the air outlet is equipped with an adjustable-angle air guide plate. The heating device 15 uses a finned stainless steel sheathed electric heating tube with a total power of 1.5 kW. The heating temperature can be controlled by adjusting the output power. In the normal temperature air drying mode, only the air supply device 5 operates, and room temperature air flow removes moisture from the surface of the specimen. In the static drying mode, only the heating device 15 operates, and natural convection raises the temperature inside the cavity to achieve drying. In the hot air circulation mode, the air supply device 5 and the heating device 15 operate simultaneously, and hot air circulates inside the cavity to accelerate the rate of moisture evaporation.

[0043] Specifically, the device also supports independent operation of the wet-dry cycle mode. After turning off the freeze-thaw related functions, it can independently complete single wet-dry alternating tests such as resistance to sulfate attack and resistance to chloride ion penetration. It can also independently run the constant temperature drying function to test the water loss and cracking behavior of the specimen.

[0044] Specifically, a temperature and humidity sensor 16 is installed on the inner wall of the wet and dry circulation chamber 4, a wet and dry circulation chamber door 8 is installed on the front of the wet and dry circulation chamber 4, and a control system 6 is installed on the outer side of the wet and dry circulation chamber 4. The control system 6 is electrically connected to the drive module 1, the refrigeration unit 13, the atomizing spray device 17, the drying device, the temperature and humidity sensor 16, the weighing sensor, and the sealing pressure plate 9, respectively, and is used to set test parameters, monitor the operating status, and record weighing, temperature and humidity, and test sequence data.

[0045] Specifically, the control system 6 is pre-set with a freeze-thaw-wet coupled corrosion test timing program. The timing program controls the drive module 1, sealing plate 9, refrigeration unit 13, atomizing spray device 17 and drying device to operate alternately according to a preset cycle, so as to realize the simulation of the freeze-thaw-wet coupled corrosion process of the specimen.

[0046] Specifically, the temperature and humidity sensor 16 uses an industrial-grade temperature and humidity transmitter with a temperature measurement range of -40℃ to 85℃ and an accuracy of ±0.3℃, and a humidity measurement range of 0 to 100%RH with an accuracy of ±2%RH. The probe extends approximately 30mm into the dry-wet circulation chamber 4, and a silicone rubber sealing gasket is installed between the sensor housing and the chamber wall. The dry-wet circulation chamber door 8 is fitted with a double-layer hollow tempered glass observation window, with a transparent conductive film coated on the inner surface of the glass and connected to a low-voltage power supply for electric heating and defogging. The door is equipped with an electronic locking device. The control system 6 is based on a programmable logic controller with no fewer than 32 I / O points. It has a built-in real-time clock and power-off retention memory, and is equipped with a 7-inch color industrial touch screen. It has built-in modules for setting test parameters, real-time status monitoring, historical data query, and fault alarm recording. The test sequence supports multi-segment programmable configuration, allowing customization of freeze-thaw temperature change rate, constant temperature duration, spray drying parameters, and alternating dry-wet and freeze-thaw sequences.

[0047] Specifically, the control system 6 is equipped with a lifting interlock logic between the sealing plate 9 and the rigid lifting component 2. The rigid lifting component 2 is only allowed to rise or fall after the sealing plate 9 is fully opened, and the sealing plate 9 is only allowed to close after the rigid lifting component 2 is in position. At the same time, a liquid level interlock is set. When the liquid level in the dry-wet circulation chamber 4 is higher than the upper surface of the partition 10, the opening of the sealing plate 9 is forcibly prohibited. When the temperature of the refrigerant deviates from the target value by more than 5°C, the system determines that the temperature difference exceeds the limit fault, automatically suspends the test, and issues an audible and visual alarm. The system has built-in alarm protection functions for low refrigerant level, low corrosive solution level, disconnection of temperature and humidity sensor, over-range of weighing sensor, and overload of drive motor. Any alarm trigger will automatically execute the safety process of pausing, maintaining the status, and prompting manual intervention. The control system also has a power failure resume function. After the equipment is powered off, it automatically saves the current operating status and cycle count. After the power is restored, it can continue to run from the break point without having to start the test from the beginning.

[0048] A method for marine dry-wet-freeze-thaw erosion testing of solid waste cementitious materials includes the following steps: S1. Place the solid waste cementitious material specimen into the specimen basket 7 and set the test parameters through the control system 6. S2. The sealing plate 9 slides open, and the drive module 1 drives the specimen basket 7 to descend and enter the freeze-thaw unit cavity 20 through the rigid lifting component 2. After the specimen basket 7 descends to the position, the elastic sealing component on the outer periphery of the weighing hanging component 3 seals with the channel hole of the partition plate 10. The etching solution is injected into the freeze-thaw unit cavity 20 until the specimen is completely submerged. The refrigerant is cooled by the refrigeration unit 13. The refrigerant indirectly cools the etching solution water bath through the wall of the specimen box 19, so that the solid waste cementitious material specimen completes a single freeze-thaw cycle under the set temperature regime. S3. After the freeze-thaw cycle is completed, the corrosive solution in the freeze-thaw unit cavity 20 is emptied. The rigid lifting component 2 drives the specimen basket 7 to rise. The elastic seal on the outer periphery of the weighing hanging assembly 3 disengages from the sealing fit with the channel hole of the partition plate 10. After the specimen basket 7 rises to the position, the sealing pressure plate 9 slides to close, separating the upper and lower independent cavities. S4. The specimen is sprayed with atomizing spray device 17 in the dry-wet cycle chamber 4, and then dried by the drying device to form a single dry-wet cycle; after drying, the specimen mass is collected and read by the weighing sensor in the weighing hanging assembly 3. S5. Repeat steps S2 to S4 until the set total number of cycles is reached.

[0049] Specifically, before the test, the specimens need to be cured to the specified age under standard conditions of 20±2℃ and relative humidity of not less than 95%. After being removed, the surface free water is wiped off and the initial mass is weighed, and then the specimens are placed into the specimen basket 7. In step S2, the rigid lifting component 2 drives the specimen basket 7 to rise and fall at a uniform speed of 15mm / s. When injecting the etching solution into the freeze-thaw unit cavity 20, the liquid level should be at least 20mm higher than the upper surface of the specimen. During the freeze-thaw cycle, the cooling rate is set to 2℃ / min and the heating rate is set to 1.5℃ / min. The low temperature and high temperature stages are kept at a constant temperature for 4 hours. The temperature change rate and the constant temperature time can also be customized according to the test requirements, which is compatible with the cycle requirements of the rapid freeze-thaw method in GB / T 50082-2024 standard. During the test, two temperature curves are collected in real time: the temperature of the refrigerant in the refrigerant cavity 21 and the temperature of the specimen center.

[0050] Specifically, in step S4, the spraying duration can be adjusted within the range of 1 to 4 hours. During the spraying process, the air supply device 5 operates at a low speed with an air volume of 100 to 200 m³ / h to promote uniform distribution of droplets. After spraying, the device is left to stand for 5 minutes to allow the surface droplets to drip off fully. Then, the drying device is started and operated for 1 to 4 hours. The drying temperature can be adjusted within the range of 30 to 60°C. After drying, the weighing sensor continuously samples 10 times with a sampling interval of 0.1 seconds. The maximum and minimum values ​​are removed, and the average value is taken. The net mass of the specimen is obtained by automatically deducting the weight of the basket. This net mass is stored together with the temperature, humidity, timestamp, and other parameters of this cycle.

[0051] Specifically, it also includes a phased manual inspection step. The control system 6 presets one or more target pause cycles N. When the test runs to the preset Nth cycle, and the current freeze-thaw cycle ends, the specimen basket 7 is raised into the wet-dry cycle chamber 4, and the sealing plate 9 closes the upper and lower cavities, the control system automatically triggers the pause program, releases the electronic lock of the wet-dry cycle chamber door 8, and issues a manual sampling prompt. After the specimen is manually removed, the external test is completed, and the specimen is returned to its original position, the control system executes the breakpoint continuation, automatically recalibrates the zero point of the weighing sensor, and continues to run the subsequent cycles.

[0052] Specifically, after entering the pause procedure, the refrigeration unit 13 and the electric heating tube continue to maintain the set temperature state in the refrigerant chamber 21 to avoid energy waste caused by fluctuations in the temperature field of the lower chamber; the sealing plate 9 remains closed and locked, completely isolating the lower freeze-thaw chamber 11, and only the dry-wet circulation chamber 4 can be opened through the dry-wet circulation chamber door 8; at this time, the specimen has just been lifted from the erosion solution water bath, is in a naturally saturated state and has no free water droplets on the surface, and can be directly taken out for external non-destructive testing such as dynamic elastic modulus and ultrasonic testing; after the operator puts the specimen back in its original position and closes the dry-wet circulation chamber door 8, he clicks the continue command, and the control system 6 first triggers the weighing sampling process to record the current initial data, automatically recalibrates the zero point of the weighing sensor, and then continues the subsequent cycle according to the originally set test parameters to ensure the continuity of the test process and data.

[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A marine dry-wet-freeze-thaw erosion test device suitable for solid waste cementitious materials, characterized in that: The system includes a wet-dry circulation chamber (4), a freeze-thaw chamber (11), a partition (10), a sealing plate (9), a rigid lifting component (2), a weighing hanging assembly (3), a specimen basket (7), a drive module (1), a refrigeration unit (13), a liquid storage tank (12), an atomizing spray device (17), and a drying device. The partition (10) is located between the wet-dry circulation chamber (4) and the freeze-thaw chamber (11), dividing them into two independent chambers arranged vertically. The partition (10) has at least one channel connecting the upper and lower chambers. The sealing plate (9) is located at the channel and is used to open or close the channel. The freeze-thaw chamber (11) is provided with a common refrigerant chamber (21) inside. The refrigerant chamber (21) contains a refrigerant. At least one specimen box (19) is detachably installed in the refrigerant chamber (21). The specimen box (19) is a heat-conducting container with an open top. Its internal space forms a freeze-thaw unit chamber (20). The freeze-thaw unit chamber (20) is used to contain the erosion solution to form a water bath. The solid waste cementitious material specimen is placed in the water bath. The specimen box (19) is at least partially immersed in the refrigerant. Its outer surface directly contacts the refrigerant for heat exchange. The cold or heat of the refrigerant is indirectly conducted to the erosion solution inside the freeze-thaw unit chamber (20) through the box wall. The rigid lifting member (2) is installed on the top of the dry and wet circulation chamber (4). The lower end of the rigid lifting member (2) is fixedly connected to the weighing hanging assembly (3). The specimen basket (7) is suspended below the weighing hanging assembly (3). The drive module (1) is connected to the rigid lifting member (2) for driving the rigid lifting member (2) to reciprocate between the set lifting and lowering positions in the vertical direction. The refrigeration unit (13) is connected to the refrigerant chamber (21) through the refrigerant inlet (14) and the refrigerant outlet (23) to cool the refrigerant in the refrigerant chamber (21); the refrigerant chamber (21) is equipped with a temperature sensor (22) and a heating and insulation device to detect the refrigerant temperature and cooperate with the refrigeration unit (13) to control the refrigerant temperature within a set range; The atomizing spray device (17) and the drying device are both located inside the dry and wet circulation chamber (4), and the liquid storage tank (12) is connected to the atomizing spray device (17) through the spray pipeline (18).

2. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 1, characterized in that: The test specimen box (19) is configured as a cubic box structure with an open top. The test specimen box (19) is detachably installed in the refrigerant chamber (21) through a limiting installation structure, and the top opening end of the test specimen box (19) is connected to the channel hole of the partition (10).

3. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 1, characterized in that: The number of the rigid lifting parts (2) is set to at least one, and the number of channels opened on the rigid lifting parts (2), the specimen box (19) and the partition (10) are matched. Each rigid lifting part (2) is provided with an independent specimen basket (7) at its lower end. Multiple specimen baskets (7) can be raised and lowered independently or synchronously.

4. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 3, characterized in that: The number of the test specimen boxes (19) is set to be multiple, and they are arranged in an array in the refrigerant chamber (21). Multiple test specimen boxes (19) share the same refrigerant chamber (21). The coolant in the coolant chamber (21) does not come into direct contact with the erosion solution in the freeze-thaw unit chamber (20). The cooling capacity of the coolant is indirectly conducted to the erosion solution and solid waste cementitious material specimens through the wall of the specimen box (19).

5. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 1, characterized in that: The sealing plate (9) is slidably mounted on the partition (10) and the channel is opened or closed by the drive mechanism. When the specimen basket (7) is located in the dry and wet circulation chamber (4), the sealing plate (9) is in the closed state to seal and isolate the upper and lower cavities. When the specimen basket (7) needs to be lifted and lowered through the channel, the sealing plate (9) is opened to allow passage.

6. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 1, characterized in that: The outer periphery of the weighing hanging assembly (3) is provided with a sealing structure. When the specimen basket (7) is lowered to a predetermined position in the freeze-thaw chamber (11), the sealing structure forms a sealing fit with the inner wall of the channel hole of the partition (10).

7. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 6, characterized in that: The weighing hanging assembly (3) is equipped with a weighing sensor. The weighing sensor is connected in series between the lower end of the rigid lifting member (2) and the suspension point of the specimen basket (7). It only bears the axial tensile load and is not affected by the sliding friction of the rigid lifting member (2) and its own weight.

8. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 7, characterized in that: The specimen basket (7) is a hollow cage-shaped frame structure, which is composed of a top suspension frame, vertical support rods and a bottom load-bearing base plate connected in sequence. The top suspension frame is suspended and connected to the weighing end of the weighing sensor. The vertical support rods and the bottom load-bearing base plate form a self-draining channel. During the process of the specimen basket (7) rising from the freeze-thaw unit cavity (20) to the dry-wet circulation chamber (4), the residual solution attached to the wall of the specimen basket (7) and the surface of the specimen flows back into the freeze-thaw unit cavity (20) naturally through the self-draining channel under the action of gravity.

9. The marine dry-wet-freeze-thaw erosion test device for solid waste cementitious materials according to claim 1, characterized in that: A temperature and humidity sensor (16) is installed on the inner wall of the dry and wet circulation chamber (4), a dry and wet circulation chamber door (8) is installed on the front of the dry and wet circulation chamber (4), and a control system (6) is installed on the outside of the dry and wet circulation chamber (4). The drying device includes an air supply device (5) and a heating device (15). The air supply device (5) and the heating device (15) are both installed on the inner wall of the dry and wet circulation chamber (4) and can be operated independently or in combination. The control system (6) is electrically connected to the drive module (1), the refrigeration unit (13), the atomizing spray device (17), the drying device, the temperature and humidity sensor (16), the weighing sensor, and the sealing plate (9). The control system (6) is pre-set with a freeze-thaw-dry-wet coupling erosion test timing program, which is used to control the drive module (1), the sealing plate (9), the refrigeration unit (13), the atomizing spray device (17), and the drying device to operate alternately according to a preset cycle.

10. A marine dry-wet-freeze-thaw erosion test method applicable to solid waste cementitious materials, characterized in that: The marine dry-wet-freeze-thaw erosion test apparatus for solid waste cementitious materials according to any one of claims 1 to 9 includes the following steps: S1. Place the solid waste cementitious material specimen into the specimen basket (7) and set the test parameters through the control system (6); S2. The sealing plate (9) slides open, and the driving module (1) drives the specimen basket (7) to descend and enter the freeze-thaw unit cavity (20) through the rigid lifting part (2). After the specimen basket (7) descends to the position, the elastic sealing part on the outer periphery of the weighing hanging assembly (3) seals with the channel hole of the partition (10). The erosion solution is injected into the freeze-thaw unit cavity (20) until the specimen is completely submerged. The coolant is cooled by the refrigeration unit (13). The coolant indirectly cools the erosion solution water bath through the wall of the specimen box (19), so that the solid waste cementitious material specimen completes a single freeze-thaw cycle under the set temperature regime. S3. After the freeze-thaw cycle is completed, the corrosive solution in the freeze-thaw unit cavity (20) is emptied. The rigid lifting component (2) drives the specimen basket (7) to rise. The elastic seal on the outer periphery of the weighing hanging component (3) disengages from the sealing fit with the channel hole of the partition plate (10). After the specimen basket (7) rises to the position, the sealing pressure plate (9) slides to close, separating the upper and lower independent cavities. S4. The specimen is sprayed in the wet-dry cycle chamber (4) by the atomizing spray device (17) and then dried by the drying device to form a single wet-dry cycle. After drying, the specimen mass is collected and read by the weighing sensor in the weighing hanging assembly (3). S5. Repeat steps S2 to S4 until the set total number of cycles is reached.

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