Steel bar drawing device for simulating underground energy storage chamber environment

Abstract

The utility model discloses a reinforcing steel bar drawing device for simulating an underground energy storage chamber environment, which comprises a reinforcing steel bar with the bottom embedded in the center of a concrete test block, a threaded rod is welded and fixed at the top end of the reinforcing steel bar, and the parts of the reinforcing steel bar extending out and embedded in concrete are respectively a loading section and a test section. The concrete test block is provided with a crack communicated to the surface of the steel bar test section; the electrochemical accelerated erosion mechanism comprises an erosion reactor and a detector; the cyclic load testing mechanism comprises a threaded knob, an upper limiting plate and a lower limiting plate, a compression spring is fixedly connected between the bottom of the upper limiting plate and the top of the lower limiting plate, and the compression spring is arranged on the outer sides of the threaded rod and the steel bar loading section in a surrounding mode. The device is simple and easy to implement, and simulates the deterioration process of the interface bonding performance of the reinforced concrete under the coupling action of test cyclic loading and solution erosion.

Description

Technical Field

[0001] The utility model belongs to the technical field of steel bar pulling test, and in particular relates to a steel bar pulling device in a simulated underground energy storage chamber environment. Background Art

[0002] Underground energy storage chambers are a potential technical solution for hydrogen energy storage in the future. However, during the service life of underground energy storage chambers, they will experience the coupling effect of high-pressure hydrogen storage and release cycles and groundwater erosion, which puts higher requirements on the service performance of the reinforced concrete structure of the chamber lining. The existing steel bar pulling device is not only bulky, complex in structure and cumbersome to operate, but also difficult to apply solution erosion while applying the pulling load, and it is difficult to use it to simulate the process of deterioration of the bond performance of the steel bar concrete interface in the underground chamber environment. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides a steel bar pulling device simulating an underground energy storage chamber environment to simulate the test of the deterioration process of the bond performance of the reinforced concrete interface under the coupling effect of cyclic load and solution erosion.

[0004] A steel bar pulling device for simulating an underground energy storage chamber environment, comprising: a steel bar pulling test piece, comprising a steel bar embedded in the center of a concrete test block at the bottom, a threaded rod welded and fixed to the top of the steel bar, a loading section and a test section respectively for the steel bar extending out and embedded in the concrete, and a crack connected to the surface of the steel bar test section on the concrete test block;

[0005] The electrochemical accelerated corrosion mechanism includes a corrosion reactor and a detector. The concrete test block is fixed in the corrosion reactor. The detector is electrically connected to the corrosion reactor and the steel bar loading section and is used to monitor the deterioration and corrosion of the steel bars.

[0006] The cyclic load testing mechanism comprises a threaded knob, an upper limit plate and a lower limit plate. The threaded knob is fixedly connected to the top of the upper limit plate and is threadedly connected to the threaded rod. The upper limit plate passes through the threaded rod and is slidably connected to the threaded rod. The lower limit plate passes through the steel bar and is fixedly connected to the top of the concrete test block. A compression spring is fixedly connected between the bottom of the upper limit plate and the top of the lower limit plate. The compression spring is arranged around the threaded rod and the outside of the steel bar loading section.

[0007] A further technical solution is: the corrosion reactor includes a reaction tank and a power supply, the reaction tank is filled with an corrosion solution and two steel plate electrodes whose bottoms are immersed in the corrosion solution, the two steel plate electrodes are electrically connected to the power supply anode through a wire, and the power supply cathode is electrically connected to the steel bar loading section through a wire.

[0008] A further technical solution is: the detector uses an electrochemical workstation, the working electrode of the electrochemical workstation is electrically connected to the steel bar loading section, the auxiliary electrode of the electrochemical workstation is electrically connected to one of the steel plate electrodes, and the bottom of the reference electrode of the electrochemical workstation is immersed in the corrosion solution of the reaction tank.

[0009] A further technical solution is: PVC pipes are provided at both ends of the steel bar test section, the steel bar portion between the two PVC pipes is a bonding area, and the surfaces of the two PVC pipes and the steel bar bonding area are bonded and fixed to the concrete test block.

[0010] A further technical solution is that the depth of the corrosive solution in the reaction tank is not deeper than the steel bar bonding area, but not deeper than the top surface of the concrete test block.

[0011] A further technical solution is that the cracks on the concrete test block are formed by inserting a foam partition into a concrete mold and then pouring.

[0012] A further technical solution is: the bottom surface of the concrete test block is sealed with epoxy resin.

[0013] Beneficial effects of the utility model:

[0014] The utility model can easily simulate the coupling effect of cyclic load and solution erosion on reinforced concrete structures in underground energy storage environments. It can simulate the underground erosion environment through the erosion reactor of the electrochemical accelerated erosion mechanism, and can also simulate the load pressure on the steel bars through the cyclic load test mechanism, so as to realize the coupling test of cyclic load and solution erosion on the steel bar bonding area at the same time.

[0015] The electrochemical accelerated corrosion mechanism of the utility model simulates the corrosion environment of an underground cavern through the corrosion reactor, and the corrosion solution reaches the steel bar surface through the cracks to corrode the steel bar bonding area. The cracks can be prefabricated by the foam plastic board, and the width and angle of the cracks can be changed to achieve different degrees of corrosion effects. During the accelerated corrosion process, the deterioration and corrosion of the steel bar are monitored in real time through the electrochemical workstation.

[0016] The cyclic load testing mechanism of the utility model adjusts the distance between the upper limit plate and the lower limit plate by rotating the threaded knob, thereby adjusting the deformation degree of the spring and changing the force applied. When a cyclic load needs to be applied to the steel bar pull-out specimen, the knob can be rotated back and forth periodically to achieve a cyclic change in the load. During the spring force application process, the force value is transmitted through the lower limit plate, which can make the concrete test block more evenly stressed, avoid uneven damage, and avoid non-uniform misalignment between the concrete test block and the steel bar; then according to Hu Ke's law, the tensile load intensity is displayed by the deformation and relative displacement of the spring.

[0017] Compared with the traditional steel bar pulling instrument, the cyclic load test mechanism of the utility model is more economical and applicable, and can ensure the operating reliability of the device in the salt spray environment. In addition, the erosion current will not affect the normal operation of the spring. And the size of the applied limit load can be changed by replacing springs with different elastic strengths, which is more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the steel bar pulling specimen from the front view.

[0019] Figure 2 It is a schematic diagram of the structure of the steel bar pulling specimen from a top view.

[0020] Figure 3 It is a schematic diagram of a cyclic load testing mechanism of the utility model.

[0021] Figure 4 It is a schematic diagram of the electrochemical accelerated corrosion mechanism of the utility model.

[0022] In the figure:

[0023] 1. Threaded knob, 2. Upper limit plate, 3. Lower limit plate, 4. Compression spring, 5. Power supply, 6. Threaded rod, 7. Steel plate electrode, 8. Reaction cell, 9. Crack, 10. Steel bar, 11. Electrochemical workstation, 12. PVC pipe, 13. Reference electrode, 14. Test section, 15. Loading section, 16. Bonding area, 17. Concrete specimen. DETAILED DESCRIPTION

[0024] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0025] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] A steel bar pulling device simulating an underground energy storage chamber environment, such as Figure 1-Figure 4 As shown, including:

[0028] A steel bar pulling test piece includes a steel bar 10 whose bottom is buried in the center of a concrete test block 17, a threaded rod 6 is welded and fixed to the top of the steel bar 10, and the parts of the steel bar 10 extending out and buried in the concrete test block 17 are respectively a loading section 15 and a test section 14, and a crack 9 connected to the surface of the steel bar test section 14 is provided on the concrete test block 17;

[0029] The electrochemical accelerated corrosion mechanism includes a corrosion reactor and a detector. The concrete test block 17 is fixed in the corrosion reactor. The detector is electrically connected to the corrosion reactor and the steel bar loading section 15 and is used to monitor the deterioration and corrosion of the steel bar 10.

[0030] The cyclic load testing mechanism includes a threaded knob 1, an upper limit plate 2 and a lower limit plate 3. The threaded knob 1 is fixedly connected to the top of the upper limit plate 2 and is threadedly connected to the threaded rod 6. The upper limit plate 2 passes through the threaded rod 6 and is slidably connected to the threaded rod 6. The lower limit plate 3 passes through the steel bar 10 and is fixedly connected to the top of the concrete test block 17. A compression spring 4 is fixedly connected between the bottom of the upper limit plate 2 and the top of the lower limit plate 3. The compression spring 4 is arranged around the outside of the threaded rod 6 and the steel bar loading section 15.

[0031] The corrosion reactor includes a reaction tank 8 and a power supply 5. The reaction tank 8 contains an corrosion solution and two steel plate electrodes 7 whose bottoms are immersed in the corrosion solution. The two steel plate electrodes 7 are electrically connected to the anode of the power supply 5 through a wire, and the cathode of the power supply 5 is electrically connected to the steel bar loading section 15 through a wire, thereby forming a closed loop to achieve the purpose of electrochemical accelerated corrosion. The corrosion solution can be selected according to the needs of the test. In this embodiment, a 5% NaCl solution is used.

[0032] The mechanism of action of the corrosion reactor to electrically simulate chloride ion corrosion is as follows: (1) Destruction of the surface passive film: After the chloride ions reach the surface of the steel bar, an acidic environment is formed in the local area. At this time, the passive film on the surface of the steel bar is continuously stimulated by external stimulation and is activated and destroyed; (2) Formation of corrosion electrode: The external chlorine-containing solution penetrates into the surface of the steel bar. After the chloride salts accumulate to the corresponding solubility, the passive film can be locally damaged. The damaged steel bar acts as an anode and combines with the dense synthetic film around it to form a standard electrode. Therefore, the local damage pits of the steel bar gradually appear. At this time, the reaction can be expressed as: Anode reaction: Fe+2Cl - →Fe 2+ +2Cl - +2e - , cathode reaction: O2+2H2O+4e - →4OH - (3) Accelerated corrosion: In this case, the cathode reaction generates white unstable Fe(OH)2 solid, which will be oxidized and decomposed into corrosion products such as Fe(OH)3, Fe2O·H2O, and Fe3O4. As the steel bar corrosion continues, Cl is not completely consumed and disappears. Instead, its own conductivity reduces the resistance of the corrosion path during the process, resulting in the continuous dissolution of the synthetic film, accelerating the corrosion rate and causing large-scale steel bar damage.

[0033] The detector uses an electrochemical workstation 11, the working electrode of the electrochemical workstation 11 is electrically connected to the steel bar loading section 15, the auxiliary electrode of the electrochemical workstation 11 is electrically connected to one of the steel plate electrodes 7, the bottom of the reference electrode 13 of the electrochemical workstation 11 is immersed in the corrosion solution of the reaction tank 8, and the reference electrode 13 uses an Ag / AgCl electrode. The electrochemical workstation 11 is used to analyze the deterioration and corrosion of the steel bar 10.

[0034] The cracks 9 on the concrete test block 17 are formed by inserting foam partitions in the concrete mold and then pouring. According to the test needs, several foam partitions of appropriate size and thickness are selected, and the position, shape and size of the cracks 9 are pre-designed. After the foam partitions are tightly fixed at the predetermined crack 9 position in the concrete mold, the concrete is evenly poured in the mold to form the preset cracks 9 on the concrete test block 17. Through the foam partitions, the width and angle of the cracks 9 can be adjusted to achieve different degrees of erosion effects.

[0035] PVC tubes 12 are sleeved at both ends of the steel bar test section 14, and the portion of the steel bar 10 between the two PVC tubes 12 is a bonding area 16. The surfaces of the two PVC tubes 12 and the steel bar bonding area 16 are bonded and fixed to the concrete test block 17. The inner diameter of the PVC tube 12 matches the outer diameter of the steel bar 10. By arranging the PVC tubes 12 at both ends of the steel bar test section 14, local damage to the top of the concrete test block 17 during the pull-out test and the influence of the internal pressure stress arch on the bonding performance are avoided.

[0036] The depth of the corrosive solution in the reaction tank 8 does not exceed the steel bar bonding area 16 , but does not exceed the top surface of the concrete test block 17 , thereby ensuring the experimental effect on the steel bar test section 14 and avoiding affecting the steel bar loading section 15 .

[0037] The bottom surface of the concrete test block 17 is sealed with epoxy resin to prevent the penetration of the corrosive solution, thereby effectively improving the durability and stability of the concrete test block 17 .

[0038] The height of the concrete test block 17 is the sum of the heights of the two PVC pipes 12 and the height of the steel bar bonding area 16. Specifically, the cross-sectional dimensions of the concrete test block 17 are 100 mm×100 mm, and the height is 150 mm.

[0039] When in use, the cyclic load test mechanism is started by turning on the power supply 5 to simulate the corrosion environment of the steel bar 10, and the degradation and corrosion of the steel bar 10 is monitored by the electrochemical workstation 11. The test personnel can change the width and angle of the crack 9 to achieve different degrees of corrosion effect; the knob can be rotated back and forth periodically to achieve periodic changes in the load, thereby simulating the application of cyclic load to the steel bar pulling specimen, and finally the test result of the steel bar 10 pulling is judged by measuring the relative displacement between the concrete test block 17 and the steel bar 10. The test personnel can change the size of the ultimate load applied by the device by replacing the compression spring 4 with different elastic strengths, but it is not suitable for the application of ultra-high strength loads.

[0040] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A steel bar pulling device simulating an underground energy storage chamber environment, characterized in that: include: The steel bar pulling test piece includes a steel bar embedded in the center of a concrete test block, a threaded rod is welded and fixed to the top of the steel bar, and the parts of the steel bar extending out and embedded in the concrete are the loading section and the test section respectively. The concrete test block is provided with a crack connected to the surface of the steel bar test section; The electrochemical accelerated corrosion mechanism includes a corrosion reactor and a detector. The concrete test block is fixed in the corrosion reactor. The detector is electrically connected to the corrosion reactor and the steel bar loading section and is used to monitor the deterioration and corrosion of the steel bars. The cyclic load testing mechanism comprises a threaded knob, an upper limit plate and a lower limit plate. The threaded knob is fixedly connected to the top of the upper limit plate and is threadedly connected to the threaded rod. The upper limit plate passes through the threaded rod and is slidably connected to the threaded rod. The lower limit plate passes through the steel bar and is fixedly connected to the top of the concrete test block. A compression spring is fixedly connected between the bottom of the upper limit plate and the top of the lower limit plate. The compression spring is arranged around the threaded rod and the outside of the steel bar loading section.

2. The steel bar pulling device in a simulated underground energy storage chamber environment according to claim 1, characterized in that: The corrosion reactor comprises a reaction tank and a power supply. The reaction tank is filled with an corrosion solution and two steel plate electrodes whose bottoms are immersed in the corrosion solution. The two steel plate electrodes are electrically connected to the power supply anode through a wire, and the power supply cathode is electrically connected to the steel bar loading section through a wire.

3. The steel bar pulling device in a simulated underground energy storage chamber environment according to claim 2, characterized in that: The detector uses an electrochemical workstation, the working electrode of the electrochemical workstation is electrically connected to the steel bar loading section, the auxiliary electrode of the electrochemical workstation is electrically connected to one of the steel plate electrodes, and the bottom of the reference electrode of the electrochemical workstation is immersed in the corrosion solution of the reaction tank.

4. The steel bar pulling device in a simulated underground energy storage chamber environment according to claim 1, characterized in that: PVC pipes are provided at both ends of the steel bar test section, the steel bar portion between the two PVC pipes is the bonding area, and the surfaces of the two PVC pipes and the steel bar bonding area are bonded and fixed to the concrete test block.

5. The steel bar pulling device in a simulated underground energy storage chamber environment according to claim 4, characterized in that: The depth of the corrosive solution in the reaction tank is above the steel bar bonding area but does not exceed the top surface of the concrete specimen.

6. The steel bar pulling device in a simulated underground energy storage chamber environment according to claim 1, characterized in that: The cracks on the concrete test blocks were formed by inserting foam partitions into the concrete mold and then pouring.

7. The steel bar pulling device in a simulated underground energy storage chamber environment according to claim 1, characterized in that: The bottom surface of the concrete specimens was sealed with epoxy resin.

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