Testing device for simulating low-pressure and constant-temperature saline solution coupling erosion of concrete

Abstract

The invention relates to the field of durability of concrete structures, and discloses a test device for simulating low-pressure and constant-temperature saline solution coupling erosion of concrete, which comprises a bottom plate, four corners of the bottom of the bottom plate are provided with supporting legs, the side wall of the bottom plate is connected with a stair plate, and the top of the bottom plate is provided with a test mechanism. The test mechanism is connected with an erosion mechanism, the top of the bottom plate is provided with a sealing mechanism, the sealing mechanism is connected with a vacuumizing mechanism, and a clamping mechanism of an elastic anti-skid clamping block and a tensioning rope with self-adaptive capacity is designed. The mechanism adapts to the surface profiles of test blocks in different shapes through the elastic element, and the clamped concrete test blocks are integrally tightened through the tensioning rope, so that firm and stable clamping of cubic, cylindrical and irregular-shaped test blocks is realized, and looseness and displacement of the test blocks in the erosion process are effectively prevented. The problems that a traditional clamp can only clamp cubic concrete test blocks, and the clamp is not universal in fixation are solved.

Description

Technical Field

[0001] This invention belongs to the field of concrete structure durability, specifically a test device for simulating the erosion of concrete by coupling low air pressure and constant temperature salt solution. Background Technology

[0002] As my country's infrastructure construction expands into the western plateau and high-altitude regions, concrete structures face the dual challenges of low air pressure and high salinity. On the one hand, the atmospheric pressure in the Qinghai-Tibet Plateau is much lower than in the plains. This low-pressure environment affects the stability of air bubbles in freshly mixed concrete, leading to accelerated bubble coalescence and collapse, resulting in decreased air content, increased pore size, and deteriorated pore structure in hardened concrete. Furthermore, the accelerated evaporation of moisture under low-pressure conditions inhibits the full hydration reaction of cement, reducing the amount of hydration products generated and thus affecting the strength development of concrete. On the other hand, saline soils are widely distributed in the Qinghai-Tibet Plateau region, and lakes and rivers are rich in sulfate ions (SO42-). 2- ), chloride ions (Cl) - ), magnesium ions (Mg 2+ Corrosive salt ions such as SO42- and SO23- can be present. Low air pressure exacerbates concrete porosity deterioration, making it easier for these corrosive ions to penetrate the concrete interior through diffusion and infiltration, triggering a series of physicochemical reactions: SO42- 2- It reacts with cement hydration products to form expansive products such as ettringite or gypsum, generating expansion stress in the pores within the concrete; Cl - It can destroy the passivation film on the surface of steel bars, inducing and accelerating steel bar corrosion; Mg 2+ This will decompose the CSH gel, leading to insufficient filling of concrete pores and decreased strength. Under the erosion of rivers, waves, or rainwater, the concrete surface continuously peels off, exposing the internal structure and forming a vicious cycle of "damage-exposure-accelerated erosion," which greatly accelerates the deterioration of the concrete structure's performance.

[0003] Currently, research on concrete durability testing under the coupled effects of low pressure and salt solution erosion lacks dedicated equipment. Most domestic and international scholars only conduct single low pressure effect tests in low pressure test chambers or using high-altitude field environments. They cannot reproduce the synergistic effects of low pressure, salt chemical erosion, and dynamic water erosion under laboratory conditions. Furthermore, most studies focus on early-stage performance changes of concrete (such as within 28 days), lacking systematic observation data under long-term coupled environmental effects.

[0004] Therefore, existing technologies cannot realistically simulate the combined effects of low air pressure and salt solution erosion in high-altitude areas, and cannot accurately assess the long-term durability of concrete under harsh conditions coupled by multiple factors. Therefore, there is an urgent need to develop an experimental device and method capable of comprehensively controlling air pressure and salt solution erosion conditions to solve the aforementioned technical challenges. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the present invention provides a test device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete, which effectively solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a test device for simulating the coupling of low pressure and constant temperature salt solution to erode concrete, comprising a base plate, four corner legs at the bottom of the base plate, a stair tread connected to the side wall of the base plate, a test mechanism at the top of the base plate, an erosion mechanism connected to the test mechanism, a sealing mechanism at the top of the base plate, a vacuum mechanism connected to the sealing mechanism, a clamping mechanism inside the test mechanism, a control mechanism at the top of the base plate, and a filtering mechanism connected to the test mechanism; The testing mechanism is used to conduct erosion tests on concrete test blocks. The erosion mechanism is used to provide flowing water and erode the concrete test blocks. The sealing mechanism is used to seal the top of the vacuum chamber. The vacuum extraction mechanism is used to evacuate the vacuum chamber to facilitate low-pressure erosion tests. The clamping mechanism is used to clamp the concrete test blocks. The filtration mechanism is used to filter the wastewater generated during the erosion process for recycling and reuse. The control mechanism is used to control the entire testing process.

[0007] Preferably, the test mechanism includes a vacuum chamber that can be detachably installed at the middle position of the top of the base plate, a support platform is fixedly installed at the bottom inside the vacuum chamber, and a chassis is fixedly installed at the top of the support platform; The chassis is provided with drainage holes to facilitate the passage of water after erosion.

[0008] Preferably, the erosion mechanism includes a high-pressure pump base fixedly installed on the top right side of the base plate, a high-pressure pump installed on the high-pressure pump base, a water supply pipe connected to one end of the high-pressure pump, the other end of the water supply pipe passing through the vacuum chamber and communicating with the fixed annular frame, the fixed annular frame fixedly installed on the outside of the support platform, a rotating annular frame nested and rotatably connected to the fixed annular frame, the rotating annular frame communicating with the fixed annular frame, a plurality of connecting pipes connected to one end of the rotating annular frame, the other end of the connecting pipes connected to the riser, a grooved frame fixedly connected to the top of the riser, a nozzle adjusting shaft rotatably connected through the grooved frame, a nozzle fixing pipe fixedly installed on the outer surface of the nozzle adjusting shaft, a water supply hose connected to one end of the nozzle fixing pipe, the other end of the water supply hose connected to the riser and communicating with the riser, a fan-shaped nozzle fixedly connected to the first end of the F-shaped frame and communicating with the nozzle fixing pipe, and a pressure stabilizing pipe installed on the water supply pipe; The location where the water supply pipe passes through the vacuum chamber is sealed to prevent leakage.

[0009] Preferably, the sealing mechanism includes a column fixedly installed at the top edge of the base plate, an electric rotating shaft rotatably installed at the top of the column, an mounting plate fixedly installed on the outer surface of the electric rotating shaft, the mounting plate being rotatably connected to the column, a sealing electric push rod being fixedly connected to one end of the mounting plate, and a cover plate being fixedly installed at the other end of the sealing electric push rod, the cover plate sealing the vacuum chamber. An observation channel is machined through the cover plate, and an observation window is fixedly installed between the end walls of the observation channel to facilitate the observation of the interior of the vacuum chamber. An electric pressure relief valve for depressurizing the vacuum chamber is installed on the cover plate, and the electric pressure relief valve extends to the underside of the cover plate; A pressure sensor for monitoring air pressure inside the vacuum chamber is installed on the cover plate, and the pressure sensor extends into the vacuum chamber.

[0010] Preferably, the vacuuming mechanism includes a vacuum pump base fixedly installed on the upper part of the base plate, a vacuum pump installed on the top of the vacuum pump base, a vacuum tube connected to one end of the vacuum pump, and the other end of the vacuum tube connected to the cover plate and extending to the lower side of the cover plate.

[0011] Preferably, the clamping mechanism includes a clamping electric push rod fixedly installed on the bottom wall of the vacuum chamber. A lifting plate is fixedly connected to the top of the clamping electric push rod. The lifting plate is slidably connected to the inner surface of the vacuum chamber. A clamping frame is fixedly installed at the lower part of the lifting plate. The lower part of the clamping frame is provided with a plurality of clamping slots. A clamping screw is rotatably connected between the end walls of the clamping slots. The clamping screw extends into a bevel gear cavity provided in the clamping frame. A clamping drive bevel gear shaft is rotatably connected to the end wall of the bevel gear cavity. The clamping drive bevel gear shaft is fixedly installed in the clamping frame. The motor is connected to the drive shaft of the clamping drive bevel gear, which is fixedly connected to the end of the clamping drive bevel gear. The clamping drive bevel gear meshes with the clamping driven bevel gear. The clamping driven bevel gear is fixedly installed at the end of the clamping screw. A clamping nut plate is threaded to the outer surface of the clamping screw. The clamping nut plate is slidably connected to the end wall of the clamping groove. A sliding rod cylinder is fixedly installed on the lower inner surface of the clamping nut plate. A sliding rod is slidably connected to the sliding rod cylinder. A clamping spring is connected between the sliding rod and the bottom inner wall of the sliding rod cylinder. An elastic anti-slip clamping block is fixedly connected to the end of the sliding rod. The elastic anti-slip clamping block is provided in several parts, and several of the elastic anti-slip clamping blocks are fixedly installed at the end of the slide rod; The clamping mechanism further includes a tensioning assembly, which includes a worm chamber within a clamping frame. A worm is rotatably connected between the end walls of the worm chamber. The worm is poweredly connected to a tensioning motor fixedly installed within the clamping frame. A worm shaft is fixedly installed on the outer surface of the worm. The worm shaft meshes with a worm wheel. The worm wheel is fixedly installed on the outer surface of the worm wheel shaft. The worm wheel shaft is rotatably installed between the end walls of the worm chamber. A spool is fixedly installed on the outer surface of the worm wheel shaft. A tensioning rope is wound around the outer surface of the spool. The end of the tensioning rope passes through a threading channel provided on the end wall of the worm chamber and through a through hole provided on the elastic anti-slip clamping block. After passing through all the elastic anti-slip clamping blocks, the tensioning rope is fixedly connected to the first elastic anti-slip clamping block it passes through. The tensioning rope passes through a channel on the clamping nut plate. A supporting circular plate base is fixedly installed on the chassis, and a supporting circular plate is fixedly installed on the top of the supporting circular plate base. A concrete test block is placed on the supporting circular plate.

[0012] Preferably, the filtration mechanism includes one end of a return water pipe connected to the lower part of the vacuum chamber, the other end of the return water pipe connected to the inlet of the processing unit, the outlet of the processing unit connected to the high-pressure pump, and a filter installed on the return water pipe, the filter having several filter plates detachably installed. Each of the filter plates has a different filtration efficiency, which increases sequentially.

[0013] Preferably, the erosion mechanism further includes an adjustment mechanism, which includes a drive shaft rotatably mounted through the vacuum chamber. One end of the drive shaft is connected to a servo motor, which is mounted on top of a servo motor base. The servo motor base is mounted on the upper part of the base plate. A drive bevel gear is fixedly mounted on the other end of the drive shaft. The drive bevel gear meshes with a rack ring, which is fixedly mounted on the lower part of a rotating ring. The rotating ring is rotatably mounted on the side wall of the chassis. The riser is mounted on the rotating ring. An F-shaped bracket is fixedly mounted on the rotating ring. One end of a drive gear shaft is rotatably mounted on the F-shaped bracket. A drive gear is fixedly mounted on the other end of the drive gear shaft. The drive gear meshes with a ring rack, which is fixedly mounted on the upper part of the chassis. The outer surface of the drive gear shaft is fixedly mounted with... The device includes an active bevel gear that meshes with a driven bevel gear. The driven bevel gear is fixedly installed at the lower end of a bevel gear shaft, which is rotatably mounted on the F-shaped frame. A nozzle adjustment active bevel gear is fixedly installed at the upper end of the bevel gear shaft, meshing with a nozzle adjustment driven bevel gear. The nozzle adjustment driven bevel gear is fixedly installed at the end of an incomplete gear shaft, which is rotatably mounted on the groove frame. An incomplete gear is fixedly installed on the outer surface of the incomplete gear shaft, meshing with a drive rack. The drive rack is symmetrically fixedly installed on the inner surface of a rectangular frame, which is slidably connected to the end wall of the groove frame. A nozzle adjustment rack is fixedly installed on the outer side of the rectangular frame, meshing with a drive rack. The drive rack is fixedly installed at one end of the nozzle adjustment shaft. When the incomplete gear meshes with different drive racks, the rectangular frame moves in opposite directions.

[0014] Preferably, the control mechanism includes a table fixedly mounted on the upper part of the base plate, a control host placed on the table, the control host being connected to electrical components in the system via wires, and a seat mounted on the base plate on the left side of the table.

[0015] Preferably, a concrete test block rack is installed on the upper part of the base plate, and concrete test blocks of different shapes are placed in the concrete test block rack.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention provides an experimental device for simulating the erosion of concrete by the coupling of low-pressure air and constant-temperature salt solution, and designs a self-adaptive "elastic anti-slip clamping block + tension rope" clamping mechanism. This mechanism adapts to the surface contours of specimens of different shapes through elastic elements, and then uses tension ropes to tighten the clamped concrete specimens as a whole, achieving a firm and stable clamping of cubic, cylindrical, and irregularly shaped specimens, effectively preventing loosening and displacement of the specimens during the erosion process. This solves the problem that traditional clamps can only clamp cubic concrete specimens and that the clamps are not universally compatible.

[0017] 2. This invention provides an experimental device for simulating the coupled erosion of concrete by low-pressure air and constant-temperature salt solution, employing a combination system of a ring slide rail and a fan-shaped nozzle driven by a servo motor. This system allows the nozzle to automatically oscillate up and down while making circular motion, thus creating dynamic, multi-angle, three-dimensional erosion of the fixed specimen. Compared to traditional unidirectional fixed erosion methods, this erosion mode more realistically simulates the erosive effects of rivers and waves on the concrete surface in nature, improving the accuracy of the experiment.

[0018] 3. This invention provides an experimental device for simulating the coupled erosion of concrete by low-pressure and constant-temperature salt solutions. It is used to study the deterioration and damage of concrete under four environments: low pressure, chemical erosion by salt solutions, dynamic water erosion, and temperature changes, achieving multi-factor coupled environmental simulation. By adjusting different salt solutions and concentrations, and controlling the main unit to input different low pressures, water erosion velocities, and solution temperatures, the deterioration factors of concrete structures such as bridge piers in actual high-altitude engineering projects under river and lake environments are reproduced. This invention solves the problem that existing experimental devices can only simulate single factors (such as only low pressure, only salt solution immersion, or only mechanical erosion) or simple superpositions. It can reflect the deterioration and damage of concrete structures under the combined effects of temperature, low pressure, and dynamic water erosion by salt solutions, providing a corresponding research basis for studying the performance degradation laws of concrete structures in high-altitude environments. Furthermore, by integrating multiple systems onto a relatively compact platform, it has the advantages of small equipment size, low manufacturing cost, and low energy consumption compared to building a large environmental simulation chamber. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the first orientation of an experimental device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete, according to the present invention. Figure 2This is a schematic diagram of the second orientation of an experimental device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete, according to the present invention. Figure 3 This is a third-direction structural schematic diagram of an experimental device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete, according to the present invention. Figure 4 This is a schematic diagram of the first disassembled structure of an experimental device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete in this invention. Figure 5 This is a schematic diagram of the second disassembled structure of an experimental device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete in this invention. Figure 6 This is a schematic diagram of the third disassembled structure of an experimental device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete in this invention. Figure 7 This is a first partial cross-sectional view of a test device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete, according to the present invention. Figure 8 This is a second partial cross-sectional view of a test device for simulating the coupling of low air pressure and constant temperature salt solution to erode concrete, as described in this invention. Figure 9 This is a schematic diagram of the combined structure of the clamping mechanism and the erosion mechanism in this invention; Figure 10 This is a schematic diagram of the clamping mechanism in the first direction of the present invention; Figure 11 This is a schematic diagram of the second direction structure of the clamping mechanism in this invention. Figure 12 for Figure 4 Enlarged structural diagram at point A; Figure 13 for Figure 7 Enlarged structural diagram at point B; Figure 14 for Figure 8 A magnified structural diagram at point C.

[0021] In the diagram: 1-Base plate, 2-Outer leg, 3-Stair tread, 4-Control host, 5-Vacuum pump, 6-Vacuum pump base, 7-Vacuum tube, 8-Servo motor base, 9-Servo motor, 10-Vacuum chamber, 11-Filter, 12-Processing unit, 13-High-pressure pump base, 14-High-pressure pump, 15-Pressure stabilizing pipe, 16-Water supply pipe, 17-Return water pipe, 18-Cover plate, 19-Enclosed electric push rod, 20-Mounting plate, 21-Pressure sensor, 22-Concrete test block, 23 - Concrete test block rack, 24- Column, 25- Electric pressure relief valve, 26- Observation window, 27- Drive shaft, 28- Clamping electric push rod, 29- Lifting plate, 30- Chassis, 31- Ring rack, 32- Clamping frame, 34- Supporting circular plate, 36- Drive bevel gear, 37- Support platform, 38- Supporting circular plate seat, 40- Rotating ring frame, 41- Fixed ring frame, 42- Filter plate, 43- Observation channel, 44- Connecting pipe, 45- Rotating ring, 46- Riser, 47- Electric 48-Rotating shaft, 49-Rack and pinion ring, 50-Clamping nut plate, 51-Clamping groove, 52-Elastic anti-slip clamping block, 53-Groove frame, 54-Tightening rope, 55-Slide rod cylinder, 56-Slide rod, 57-Clamping screw, 58-Sprinkler head fixing tube, 59-Water supply hose, 60-F-shaped frame, 61-Drive gear shaft, 62-Drive gear, 63-Driven bevel gear, 64-Bevel gear shaft, 65-Sprinkler head adjusting shaft, 66-Fan-shaped nozzle, 67-Sprinkler head adjustment 68 - Rack, 69 - Rectangular frame, 70 - Incomplete gear, 71 - Nozzle adjustment driven bevel gear, 72 - Nozzle adjustment driving bevel gear, 73 - Drive rack, 74 - Bevel gear cavity, 75 - Clamping driving bevel gear shaft, 76 - Clamping driving bevel gear, 77 - Clamping driven bevel gear, 78 - Clamping spring, 79 - Worm cavity, 80 - Worm, 81 - Worm shaft, 82 - Worm wheel, 83 - Worm wheel shaft, 84 - Thread wheel, 85 - Seat, 86 - Table. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1-14As shown, the present invention provides a test device for simulating the coupling of low pressure and constant temperature salt solution to erode concrete. The components of the device are made of corrosion-resistant, wear-resistant, pressure-resistant, and heat-resistant materials. The device includes a base plate 1, with four support legs 2 at the bottom corners of the base plate 1. A stair tread 3 is connected to the side wall of the base plate 1. A test mechanism is provided on the top of the base plate 1. The test mechanism is connected to an erosion mechanism. A sealing mechanism is provided on the top of the base plate 1. A vacuuming mechanism is connected to the sealing mechanism. A clamping mechanism is provided inside the test mechanism. A control mechanism is provided on the top of the base plate 1. A filtering mechanism is connected to the test mechanism. The test mechanism is used to conduct erosion tests on the concrete specimen 22. The erosion mechanism is used to provide dynamic water and erode the concrete specimen 22. The sealing mechanism is used to seal the top of the vacuum chamber 10. The vacuum extraction mechanism is used to evacuate the vacuum chamber 10 to facilitate low-pressure erosion tests. The clamping mechanism is used to clamp the concrete specimen 22. The filtration mechanism is used to filter the wastewater generated during the erosion process and recycle it. The control mechanism is used to control the entire test process. The empty chamber adopts a cylindrical structure (for better stress distribution) and is made of high-strength corrosion-resistant materials (such as 316 stainless steel or anodized aluminum).

[0024] Advantageously, the test mechanism includes a vacuum chamber 10 that can be detachably installed at the top center of the base plate 1, a support platform 37 that is fixedly installed on the bottom inner side of the vacuum chamber 10, and a chassis 30 that is fixedly installed on the top of the support platform 37. The chassis 30 is provided with a drainage hole to facilitate the passage of water after erosion.

[0025] Advantageously, the erosion mechanism includes a high-pressure pump base 13 fixedly installed on the top right side of the base plate 1. A high-pressure pump 14 is installed on the high-pressure pump base 13. One end of a water supply pipe 16 is connected to the high-pressure pump 14. The other end of the water supply pipe 16 passes through the vacuum chamber 10 and communicates with the fixed annular frame 41. The fixed annular frame 41 is fixedly installed on the outside of the support platform 37. A rotating annular frame 40 is nested and rotatably connected to the fixed annular frame 41. The rotating annular frame 40 communicates with the fixed annular frame 41. Several connecting pipes 44 are connected to one end of each of the rotating annular frame 44. The other end of each connecting pipe 44 is connected to a riser 46. A grooved frame 52 is fixedly connected to the top of the riser 46. A nozzle adjusting shaft 65 is rotatably connected to the top. A nozzle fixing pipe 57 is fixedly installed on the outer surface of the nozzle adjusting shaft 65. The tail end of the nozzle fixing pipe 57 is connected to one end of a water supply hose 58. The other end of the water supply hose 58 is connected to the riser 46 and communicates with the inside of the riser 46. A fan-shaped nozzle 66 is fixedly connected to the head end of the F-shaped frame 59 and communicates with the inside of the nozzle fixing pipe 57. A pressure stabilizing pipe 15 is installed on the water supply pipe 16 to eliminate pressure fluctuations caused by water pump pulsation and nozzle movement, and to provide a stable water source. The high-pressure pump 14 is a high-pressure centrifugal pump: a corrosion-resistant, high-lift centrifugal pump is selected to provide sufficient jet pressure. The fan-shaped nozzle 66 is an industrial stainless steel fan-shaped nozzle to provide a flat and uniform water curtain. The water supply pipe 16 is sealed at the point where it passes through the vacuum chamber 10 to prevent leakage; The erosion mechanism further includes an adjustment mechanism, which comprises a drive shaft 27 rotatably mounted through the vacuum chamber 10. One end of the drive shaft 27 is connected to a servo motor 9, which is mounted on top of a servo motor base 8. The servo motor base 8 is mounted on the upper part of the base plate 1. A drive bevel gear 36 is fixedly mounted on the other end of the drive shaft 27. The drive bevel gear 36 meshes with a rack ring 48, which is fixedly mounted on the lower part of a rotating ring 45. The rotating ring 45 is rotatably mounted on the side wall of the chassis 30. The riser 46 is mounted on the rotating ring 45. An F-shaped bracket 59 is fixedly mounted on the rotating ring 45. One end of a drive gear shaft 60 is rotatably mounted on the F-shaped bracket 59. A drive gear 62 is fixedly mounted on the other end of the drive gear shaft 60. The drive gear 62 meshes with a ring rack 31, which is fixedly mounted on the upper part of the chassis 30. A drive bevel gear is fixedly mounted on the outer surface of the drive gear shaft 60. Wheel 61, the driving bevel gear 61 meshes with the driven bevel gear 63, the driven bevel gear 63 is fixedly installed at the lower end of the bevel gear shaft 64, the bevel gear shaft 64 is rotatably mounted on the F-shaped frame 59, the upper end of the bevel gear shaft 64 is fixedly installed with a nozzle adjustment driving bevel gear 72, the nozzle adjustment driving bevel gear 72 meshes with a nozzle adjustment driven bevel gear 70, the nozzle adjustment driven bevel gear 70 is fixedly installed at the end of the incomplete gear shaft 71, the incomplete gear shaft 71 rotates The incomplete gear 69 is fixedly mounted on the outer surface of the incomplete gear shaft 71 and is meshed with the drive rack 73. The drive rack 73 is symmetrically fixedly mounted on the inner surface of the rectangular frame 68. The rectangular frame 68 is slidably connected to the end wall of the groove frame 52. The nozzle adjusting rack 67 is fixedly mounted on the outer side of the rectangular frame 68 and is meshed with 88. 88 is fixedly mounted on one end of the nozzle adjusting shaft 65. When the incomplete gear 69 meshes with different drive racks 73, the rectangular frame 68 moves in opposite directions. During operation, the high-pressure pump 14 is energized, causing it to start supplying water. Water flows through the water supply pipe 16 into the pressure stabilizing pipe 15, where it is stabilized before entering the fixed annular frame 41. From there, it enters the rotating annular frame 40 and then the riser pipe 46 via the connecting pipe 44. The cooperation between the rotating annular frame 40 and the fixed annular frame 41 solves the problem of water pipe entanglement during rotation. Water then flows through the water delivery hose 58 into the nozzle fixing pipe 57 and through the F-shaped bracket 5... 9 enters the fan-shaped nozzle 66 and is sprayed out onto the concrete test block 22 to conduct an erosion test on the concrete test block 22. The servo motor 9 is started, thereby driving the drive shaft 27 to rotate, which in turn drives the drive bevel gear 36 to rotate. The drive bevel gear 36 meshes with the rack ring 48, thereby driving the rack ring 48 to rotate, which in turn drives the rotating ring 45 to rotate, thereby driving the riser 46 to move. The rotating ring 45 rotates, thereby driving the F-shaped frame 59 to rotate, and the drive gear... 62 engages with the surface of the annular rack 31, thereby driving the drive gear shaft 60 to rotate, which in turn drives the drive bevel gear 61 to rotate. The drive bevel gear 61 meshes with the driven bevel gear 63, thereby driving the bevel gear shaft 64 to rotate, which in turn drives the nozzle adjusting drive bevel gear 72 to rotate. The nozzle adjusting drive bevel gear 72 meshes with the nozzle adjusting driven bevel gear 70, thereby driving the incomplete gear shaft 71 to rotate, which in turn drives the incomplete gear 69 to rotate. The incomplete gear 69 meshes with the drive rack 73. The rectangular frame 68 moves when the incomplete gear 69 engages with different drive racks 73, causing the rectangular frame 68 to move in different directions, resulting in the rectangular frame 68 reciprocating up and down, which in turn causes the fan-shaped nozzle 66 to swing up and down, achieving better erosion and eroding multiple positions and surfaces of the concrete test block 22.

[0026] Advantageously, the sealing mechanism includes a column 24 fixedly installed at the top edge of the base plate 1, an electric rotating shaft 47 rotatably installed at the top of the column 24, an mounting plate 20 fixedly installed on the outer surface of the electric rotating shaft 47, the mounting plate 20 being rotatably connected to the column 24, a sealing electric push rod 19 being fixedly connected to one end of the lower part of the mounting plate 20, and a cover plate 18 being fixedly installed at the other end of the sealing electric push rod 19, the cover plate 18 sealing the vacuum chamber 10; An observation channel 43 is machined through the cover plate 18, and an observation window 26 is fixedly installed between the end walls of the observation channel 43 to facilitate the observation of the interior of the vacuum chamber 10. An electric pressure relief valve 25 for depressurizing the vacuum chamber 10 is installed on the cover plate 18, and the electric pressure relief valve 25 extends to the underside of the cover plate 18. A pressure sensor 21 for monitoring the air pressure inside the vacuum chamber 10 is installed on the cover plate 18, and the pressure sensor 21 extends into the vacuum chamber 10; During operation, the electric rotating shaft 47 is energized, thereby driving the mounting plate 20 to rotate, which in turn drives the closed electric push rod 19 to rotate, thereby driving the cover plate 18 to rotate to the upper side of the vacuum chamber 10. The closed electric push rod 19 is then energized, thereby pushing the cover plate 18 downward to close the upper side of the vacuum chamber 10, thus sealing the vacuum chamber 10. The pressure sensor 21 monitors the pressure inside the vacuum chamber 10, and the electric pressure relief valve 25 relieves pressure in the vacuum chamber 10.

[0027] Advantageously, the vacuum pumping mechanism includes a vacuum pump base 6 fixedly installed on the upper part of the base plate 1, a vacuum pump 5 installed on the top of the vacuum pump base 6, a vacuum tube 7 connected to one end of the vacuum pump 5, and the other end of the vacuum tube 7 connected to the cover plate 18 and extending to the lower side of the cover plate 18. The vacuum pump 5 is a rotary vane vacuum pump or a dry vortex vacuum pump to ensure that the air pressure in the chamber can be quickly pumped to and stabilized at the target low pressure value. A high-precision air pressure sensor monitors the pressure in the chamber in real time, and the signal is transmitted to the control host. By controlling the start and stop of the vacuum pump and the electric pressure relief valve, the pressure can be accurately and stably controlled. During operation, the vacuum pump 5 is started, thereby extracting the gas in the vacuum chamber 10 through the vacuum tube 7 to create a low-pressure environment in the vacuum chamber 10.

[0028] Advantageously, the clamping mechanism includes a clamping electric push rod 28 fixedly installed on the bottom wall of the vacuum chamber 10. A lifting plate 29 is fixedly connected to the top of the clamping electric push rod 28. The lifting plate 29 is slidably connected to the inner surface of the vacuum chamber 10. A clamping frame 32 is fixedly installed at the lower part of the lifting plate 29. The lower part of the clamping frame 32 is provided with a plurality of clamping slots 50. A clamping screw 56 is rotatably connected between the end walls of the clamping slots 50. The clamping screw 56 extends into the bevel gear cavity 74 provided in the clamping frame 32. A clamping drive bevel gear shaft 75 is rotatably connected to the end wall of the bevel gear cavity 74. The clamping drive bevel gear shaft 75 is fixedly installed in the clamping frame 32. The motor is connected to the drive bevel gear shaft 75. The drive bevel gear 76 is fixedly connected to the end of the drive bevel gear shaft 75. The drive bevel gear 76 meshes with the driven bevel gear 77. The driven bevel gear 77 is fixedly installed at the end of the drive screw 56. The outer surface of the drive screw 56 is threaded with a clamping nut plate 49. The clamping nut plate 49 is slidably connected between the end walls of the clamping groove 50. A sliding rod cylinder 54 is fixedly installed on the lower inner surface of the clamping nut plate 49. A sliding rod 55 is slidably connected to the sliding rod cylinder 54. A clamping spring 78 is connected between the sliding rod 55 and the bottom inner wall of the sliding rod cylinder 54. An elastic anti-slip clamping block 51 is fixedly connected to the end of the sliding rod 55. A plurality of elastic anti-slip clamping blocks 51 are provided, and several of the elastic anti-slip clamping blocks 51 are fixedly installed at the end of the slide rod 55; The clamping mechanism further includes a tensioning assembly. The tensioning assembly includes a clamping frame 32 with a worm gear cavity 79. A worm gear 80 is rotatably connected to the end wall of the worm gear cavity 79. The worm gear 80 is poweredly connected to a tensioning motor fixedly installed within the clamping frame 32. A worm shaft 81 is fixedly installed on the outer surface of the worm gear 80, meshing with a worm wheel 82. The worm wheel 82 is fixedly installed on the outer surface of a worm wheel shaft 83, which is rotatably installed between the end walls of the worm gear cavity 79. A spool 84 is fixedly mounted on the outer surface of the worm gear shaft 83. A tension rope 53 is wound around the outer surface of the spool 84. The end of the tension rope 53 passes through a wire-passing channel provided on the end wall of the worm cavity 79 and through a through hole provided on the elastic anti-slip clamping block 51. After passing through all the elastic anti-slip clamping blocks 51, the tension rope 53 is fixedly connected to the first elastic anti-slip clamping block 51 it passes through. The tension rope 53 passes through a channel on the clamping nut plate 49. A supporting circular plate seat 38 is fixedly installed on the chassis 30, and a supporting circular plate 34 is fixedly installed on the top of the supporting circular plate seat 38. A concrete test block 22 is placed on the supporting circular plate 34. During operation, the clamping motor is started, which drives the clamping drive bevel gear shaft 75 to rotate, thereby driving the clamping drive bevel gear 76 to rotate. The clamping drive bevel gear 76 meshes with the clamping driven bevel gear 77, thereby driving the clamping screw 56 to rotate, which in turn drives the clamping nut plate 49 to move, which in turn drives the slide cylinder 54 to move, which in turn drives the slide rod 55 to move. This causes the elastic anti-slip clamping block 51 to move and clamp the concrete test block 22. During clamping, the clamping spring 78 is compressed. At this time, the tensioning motor is started, which drives the worm 80 to rotate, thereby driving the worm shaft 81 to rotate. The worm shaft 81 meshes with the worm wheel 82, thereby driving the worm wheel shaft 83 to rotate, which in turn drives the reel 84 to rotate, which in turn drives the tension rope 53 to move, retracting and winding the tension rope 53 onto the reel 84. The elastic anti-slip clamping blocks 51 are pulled tightly onto the concrete specimen 22, thereby clamping the concrete specimen 22. This allows for clamping of different shapes. The elastic anti-slip clamping blocks 51 adapt to the surface of the concrete specimen 22 and clamp tightly. When adapting to different shapes, the corresponding clamping springs 78 are always in a compressed state, achieving better clamping of the concrete specimen 22 and preventing shaking. After clamping, the clamping electric push rod 28 is energized, causing the lifting plate 29 to move downwards, which in turn causes the clamping frame 32 to move downwards, thus causing the concrete specimen 22 to move downwards, bringing it into contact with the supporting circular plate 34. The supporting circular plate 34 supports the concrete specimen 22, further increasing its stability and facilitating better testing.

[0029] Advantageously, the filtration mechanism includes one end of a return water pipe 17 connected to the lower part of the vacuum chamber 10, the other end of the return water pipe 17 connected to the inlet of the processing unit 12, the outlet of the processing unit 12 connected to the high-pressure pump 14, a filter 11 installed on the return water pipe 17, and a plurality of filter plates 42 detachably installed on the filter 11. The processing unit 12 is equipped with a heater, a compressor, a heat exchanger and a circulating water pump. Water flows through the unit through the circulating pump to maintain a constant water temperature. A water tank is connected to the return water pipe 17 between the processing unit 12 and the filter 12. The solution in the water tank can be replaced and can store aqueous solutions or salt solutions. Each of the filter plates 42 has a different filtration efficiency, which increases sequentially. During operation, the water in the vacuum chamber 10 is filtered through the filter 11 via the return water pipe 17 and then enters the water tank. The solution in the water tank enters the processing unit 12, and after being processed by the processing unit 12, it enters the high-pressure pump 14 for recycling. The water is heated or cooled in the processing unit 12.

[0030] Advantageously, the control mechanism includes a table 86 fixedly installed on the upper part of the base plate 1, a control host 4 placed on the table 86, the control host 4 being connected to the electrical components in the system via wires, and a seat 85 installed on the base plate 1 on the left side of the table 86. During operation, the target air pressure, target water flow rate, and target water temperature are set and controlled through the control host 4. All key parameters such as cabin air pressure, water pump frequency, water flow rate, water flow rate, water temperature, and running time are displayed and recorded in real time. Corresponding automatic alarm and shutdown functions are set for overpressure, overtemperature, low water level, and motor overload.

[0031] Advantageously, a concrete test block rack 23 is installed on the upper part of the base plate 1. Concrete test blocks 22 of different shapes are placed in the concrete test block rack 23. The concrete test blocks 22 on the concrete test block rack 23 are numbered to facilitate better testing.

[0032] 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.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A test apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete, characterized in that: Includes a base plate (1), the base plate (1) has four corner support legs (2) at its bottom, a stair plate (3) is connected to the side wall of the base plate (1), a test mechanism is provided on the top of the base plate (1), the test mechanism is connected to an erosion mechanism, a sealing mechanism is provided on the top of the base plate (1), a vacuuming mechanism is connected to the sealing mechanism, a clamping mechanism is provided inside the test mechanism, a control mechanism is provided on the top of the base plate (1), and a filtering mechanism is connected to the test mechanism; The test mechanism is used to conduct erosion tests on the concrete test block (22). The erosion mechanism is used to provide dynamic water and erode the concrete test block (22). The sealing mechanism is used to seal the top of the vacuum chamber (10). The vacuum pumping mechanism is used to evacuate the vacuum chamber (10) to facilitate low-pressure erosion tests. The clamping mechanism is used to clamp the concrete test block (22). The filtration mechanism is used to filter the wastewater generated during the erosion process and recycle it. The control mechanism is used to control the entire test process.

2. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 1, characterized in that: The test mechanism includes a vacuum chamber (10) that can be detachably installed at the top center of the base plate (1), a support platform (37) is fixedly installed on the bottom inner side of the vacuum chamber (10), and a chassis (30) is fixedly installed on the top of the support platform (37). The chassis (30) is provided with a drainage hole to facilitate the passage of water after erosion.

3. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 2, characterized in that: The erosion mechanism includes a high-pressure pump base (13) fixedly installed on the top right side of the base plate (1). A high-pressure pump (14) is installed on the high-pressure pump base (13). One end of a water supply pipe (16) is connected to the high-pressure pump (14). The other end of the water supply pipe (16) passes through the vacuum chamber (10) and communicates with the fixed ring frame (41). The fixed ring frame (41) is fixedly installed on the outside of the support platform (37). A rotating ring frame (40) is nested and rotatably connected to the fixed ring frame (41). The rotating ring frame (40) communicates with the fixed ring frame (41). Several connecting pipes (44) are connected to one end of the rotating ring frame (40). The other end of the connecting pipe (44) is connected to the riser (46). A grooved frame (52) is fixedly connected to the top of the riser (46). A nozzle adjusting shaft (65) is rotatably connected through the grooved frame (52). A nozzle fixing pipe (57) is fixedly installed on the outer surface of the nozzle adjusting shaft (65). The tail end of the nozzle fixing pipe (57) is connected to one end of a water supply hose (58). The other end of the water supply hose (58) is connected to the riser (46) and communicates with the inside of the riser (46). A fan-shaped nozzle (66) is fixedly connected to the head of the F-shaped frame (59) and communicates with the inside of the nozzle fixing pipe (57). A pressure stabilizing pipe (15) is installed on the water supply pipe (16). The water supply pipe (16) is sealed at the point where it passes through the vacuum chamber (10) to prevent leakage.

4. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 3, characterized in that: The sealing mechanism includes a column (24) fixedly installed at the top edge of the base plate (1), an electric rotating shaft (47) rotatably installed on the top of the column (24), an mounting plate (20) fixedly installed on the outer surface of the electric rotating shaft (47), the mounting plate (20) rotatably connected to the column (24), a sealing electric push rod (19) is fixedly connected to one end of the lower part of the mounting plate (20), and a cover plate (18) is fixedly installed on the other end of the sealing electric push rod (19), the cover plate (18) sealing the vacuum chamber (10); An observation channel (43) is machined through the cover plate (18), and an observation window (26) is fixedly installed between the end walls of the observation channel (43) to facilitate the observation of the interior of the vacuum chamber (10); An electric pressure relief valve (25) for depressurizing the vacuum chamber (10) is installed on the cover plate (18), and the electric pressure relief valve (25) extends to the underside of the cover plate (18); A pressure sensor (21) for monitoring the air pressure inside the vacuum chamber (10) is installed on the cover plate (18), and the pressure sensor (21) extends into the vacuum chamber (10).

5. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 4, characterized in that: The vacuum pumping mechanism includes a vacuum pump base (6) fixedly installed on the upper part of the base plate (1), a vacuum pump (5) is installed on the top of the vacuum pump base (6), one end of a vacuum tube (7) is connected to the vacuum pump (5), and the other end of the vacuum tube (7) is connected to the cover plate (18) and extends to the lower side of the cover plate (18).

6. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 5, characterized in that: The clamping mechanism includes a clamping electric push rod (28) fixedly installed on the bottom wall of the vacuum chamber (10). A lifting plate (29) is fixedly connected to the top of the clamping electric push rod (28). The lifting plate (29) is slidably connected to the inner surface of the vacuum chamber (10). A clamping frame (32) is fixedly installed at the lower part of the lifting plate (29). The lower part of the clamping frame (32) is provided with several clamping slots (50). A clamping screw (56) is rotatably connected between the end walls of the clamping slots (50). The clamping screw (56) extends into the bevel gear cavity (74) provided in the clamping frame (32). A clamping active bevel gear shaft (75) is rotatably connected to the end wall of the bevel gear cavity (74). The clamping active bevel gear shaft (75) is connected to a clamping motor fixedly installed in the clamping frame (32). The power connection includes a clamping active bevel gear (76) fixedly connected to the end of the clamping active bevel gear shaft (75), which meshes with a clamping driven bevel gear (77). The clamping driven bevel gear (77) is fixedly installed at the end of the clamping screw (56). A clamping nut plate (49) is threadedly connected to the outer surface of the clamping screw (56). The clamping nut plate (49) is slidably connected between the end walls of the clamping groove (50). A sliding rod cylinder (54) is fixedly installed on the lower inner surface of the clamping nut plate (49). A sliding rod (55) is slidably connected to the sliding rod cylinder (54). A clamping spring (78) is connected between the sliding rod (55) and the inner bottom wall of the sliding rod cylinder (54). An elastic anti-slip clamping block (51) is fixedly connected to the end of the sliding rod (55). The elastic anti-slip clamping block (51) is provided in several parts, and several of the elastic anti-slip clamping blocks (51) are fixedly installed at the end of the slide rod (55); The clamping mechanism further includes a tensioning assembly, which includes a clamping frame (32) with a worm chamber (79) inside. A worm (80) is rotatably connected to the end wall of the worm chamber (79). The worm (80) is poweredly connected to a tensioning motor fixedly installed in the clamping frame (32). A worm shaft (81) is fixedly installed on the outer surface of the worm (80). The worm shaft (81) meshes with a worm wheel (82). The worm wheel (82) is fixedly installed on the outer surface of a worm wheel shaft (83). The worm wheel shaft (83) is rotatably installed at the end of the worm chamber (79). Between the walls, a spool (84) is fixedly installed on the outer surface of the worm shaft (83), and a tension rope (53) is wound around the outer surface of the spool (84). The end of the tension rope (53) passes through the wire channel provided on the end wall of the worm cavity (79), and passes through the through hole provided on the elastic anti-slip clamping block (51). After passing through all the elastic anti-slip clamping blocks (51), the tension rope (53) is fixedly connected to the first elastic anti-slip clamping block (51) it passes through. The tension rope (53) passes through the channel on the clamping nut plate (49). A supporting circular plate seat (38) is fixedly installed on the chassis (30), and a supporting circular plate (34) is fixedly installed on the top of the supporting circular plate seat (38). A concrete test block (22) is placed on the supporting circular plate (34).

7. The experimental apparatus for simulating the coupled erosion of concrete by low-pressure air and constant-temperature salt solution according to claim 6, characterized in that: The filtration mechanism includes one end of a return water pipe (17) connected to the lower part of the vacuum chamber (10), the other end of the return water pipe (17) connected to the inlet of the processing unit (12), the outlet of the processing unit (12) connected to the high-pressure pump (14), and a filter (11) installed on the return water pipe (17). The filter (11) is detachably equipped with several filter plates (42). Each of the filter plates (42) has a different filtration efficiency, which increases sequentially.

8. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 7, characterized in that: The erosion mechanism also includes an adjustment mechanism, which includes a drive shaft (27) rotatably mounted through the vacuum chamber (10). One end of the drive shaft (27) is connected to a servo motor (9), which is mounted on top of a servo motor base (8). The servo motor base (8) is mounted on the upper part of the base plate (1). A drive bevel gear (36) is fixedly mounted on the other end of the drive shaft (27). The drive bevel gear (36) meshes with a rack ring (48), which is fixedly mounted on the lower part of a rotating ring (45). The rotating ring (45) is rotatably mounted on the side wall of the chassis (30), the riser (46) is mounted on the rotating ring (45), an F-shaped bracket (59) is fixedly mounted on the rotating ring (45), one end of the drive gear shaft (60) is rotatably mounted on the F-shaped bracket (59), and a drive gear (62) is fixedly mounted on the other end of the drive gear shaft (60). The drive gear (62) meshes with a ring rack (31), the ring rack (31) is fixedly mounted on the upper part of the chassis (30), and a drive bevel gear is fixedly mounted on the outer surface of the drive gear shaft (60). The gear (61) has a drive bevel gear (61) meshing with a driven bevel gear (63). The driven bevel gear (63) is fixedly mounted on the lower end of the bevel gear shaft (64). The bevel gear shaft (64) is rotatably mounted on the F-shaped frame (59). A nozzle adjustment drive bevel gear (72) is fixedly mounted on the upper end of the bevel gear shaft (64). The nozzle adjustment drive bevel gear (72) meshes with a nozzle adjustment driven bevel gear (70). The nozzle adjustment driven bevel gear (70) is fixedly mounted on the end of the incomplete gear shaft (71). The incomplete gear shaft (71) rotates. An incomplete gear (69) is fixedly installed on the outer surface of the incomplete gear shaft (71) and mounted on the groove frame (52). The incomplete gear (69) meshes with the drive rack (73). The drive rack (73) is symmetrically fixedly installed on the inner surface of the rectangular frame (68). The rectangular frame (68) is slidably connected to the end wall of the groove frame (52). A nozzle adjusting rack (67) is fixedly installed on the outer side of the rectangular frame (68). The nozzle adjusting rack (67) meshes with (88). The (88) is fixedly installed on one end of the nozzle adjusting shaft (65). When the incomplete gear (69) meshes with different drive racks (73), the rectangular frame (68) moves in opposite directions.

9. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 8, characterized in that: The control mechanism includes a table (86) fixedly installed on the upper part of the base plate (1), a control host (4) is placed on the table (86), the control host (4) is connected to the electrical components in the system through wires, and a seat (85) is installed on the base plate (1) on the left side of the table (86).

10. The experimental apparatus for simulating the coupling of low-pressure air and constant-temperature salt solution to erode concrete according to claim 9, characterized in that: A concrete test block rack (23) is installed on the upper part of the base plate (1), and concrete test blocks (22) of different shapes are placed in the concrete test block rack (23).

Images