Device and method for testing hydraulic concrete under coupling of frost heaving, freeze thawing and impact grinding

Abstract

The invention discloses a device and a method for testing hydraulic concrete under coupling of frost heaving, freeze thawing and impact grinding, the device comprises a rotating mechanism, the top of the rotating mechanism is connected with a simulation mechanism, and the side wall of the simulation mechanism is connected with a recovery weighing mechanism; the method comprises the following steps: putting a concrete test block into a concrete mounting rotating groove, sequentially carrying out frost heaving, freeze thawing and impact grinding treatment, opening a valve after the treatment is finished, completely discharging a mixture of iron sand, concrete chippings and water into a container, filtering the mixture through a micro-filtration membrane, completely discharging water into a pure water discharging box, starting a vibration table and an electromagnet after the treatment is finished, and discharging the water into a water storage tank; all the iron sand is adsorbed to the electromagnet, the mass of the remaining concrete chippings in the filter box is weighed, and the damage rate is calculated according to the mass of the concrete chippings and the initial mass of the concrete test block. The device can simulate the coupling effect of three environments of concrete frost heaving, freeze thawing and impact grinding of the hydraulic structure in the cold region, and the compounding degree with the actual operation working condition is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete performance testing methods, and specifically relates to a test device for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion, and also relates to a test method for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion. Background Art In the field of water conservancy projects, especially the construction of water conservancy facilities in cold regions, significant challenges are faced due to frost heaving, freeze - thaw, and abrasion of concrete materials.

[0002] Some large reservoir dams in Northeast China are mainly composed of hydraulic concrete. Located in cold regions, the winter temperature is extremely low. During years of operation, the dams have experienced severe frost heaving and freeze - thaw damage many times. In winter, the water inside the dam concrete quickly freezes and expands in volume, generating huge pressure on the dam structure, resulting in multiple cracks and spalling on the surface and inside of the dam. This not only affects the anti - seepage performance of the dam but also may become a channel for water flow penetration, further exacerbating the damage of the dam. In the spring snow - melting season, as the temperature rises, the snow and ice on the dam melt, forming high - speed water flow that scours the dam surface, and the abrasion effect further intensifies the wear and spalling of the surface of the hydraulic concrete.

[0003] However, most of the existing test methods only study single frost heaving, freeze - thaw, or abrasion phenomena and cannot comprehensively simulate the complex environment experienced by hydraulic concrete in water conservancy projects. Summary of the Invention

[0004] The purpose of the present invention is to provide a test device for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion, which solves the problem that the existing methods can only conduct tests on single frost heaving or single freeze - thaw or single abrasion phenomena.

[0005] Another purpose of the present invention is to provide a test method for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion.

[0006] The technical solution adopted by the present invention is that a test device for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion includes a rotating mechanism. The top of the rotating structure is connected with a simulation mechanism, and a recovery weighing mechanism is connected to the side wall of the simulation mechanism. The characteristics of the present invention also lie in: The rotating mechanism includes a first motor. The output shaft of the first motor is connected to the bottom of a concrete installation rotating groove with an open top, and a second heating wire is laid on the inner bottom of the concrete installation rotating groove.

[0007] The simulation mechanism includes a box body with an open bottom. The outer wall at the bottom end of the box body contacts the inner wall at the top end of the concrete installation rotating groove. The contact surface between the box body and the concrete installation rotating groove is stepped. A first heating wire is sleeved on the outer wall of the box body. An extendable stirring device is arranged inside the box body. Above the box body, there are a water storage tank, an iron sand storage tank, and a nitrogen storage tank. One end of pipeline A is connected to the water storage tank, and the other end extends into the interior of the box body. A liquid level float valve and a water storage tank valve are arranged on pipeline A. The liquid level float valve is arranged inside the box body. One end of pipeline B is connected to the iron sand storage tank, and the other end extends into the interior of the box body. An iron sand box valve is arranged on pipeline B. One end of pipeline C is connected to the nitrogen storage tank, and the other end extends into the interior of the box body. The end of pipeline C extending into the box body is connected to a spiral pipeline, and the spiral pipeline is connected to the inner top wall of the box body. A nitrogen storage tank valve is arranged on pipeline C.

[0008] The extendable stirring device includes a bracket. One end of the bracket is connected to the side wall of the box body, and the other end is connected to a second motor. The output shaft of the second motor is connected to the fixed end of the electric telescopic rod, and the end of the telescopic end of the electric telescopic rod is provided with blades.

[0009] A water tank flowmeter is arranged on pipeline A.

[0010] The recycling and weighing mechanism includes a filter box and pipeline D. A vibrating table is arranged on the inner bottom of the filter box, an electronic scale is arranged on the vibrating table, and a container with an open top is arranged on the electronic scale. An electromagnet is arranged on the inner top of the filter box, and the electromagnet is arranged corresponding to the container. One end of pipeline D is communicated with the box body, and the other end passes through the top of the filter box and extends into the container. Through holes are arranged on the side wall of the container, and one end of pipeline E is connected to the through holes. The other end of pipeline E passes through the filter box and is connected to a pure water discharge box. A valve is arranged on pipeline D.

[0011] A microfiltration membrane is arranged at the through holes.

[0012] Another technical solution adopted by the present invention is a test method for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion. A test device for hydraulic concrete under the coupling of frost heaving - freeze - thaw - abrasion is used. The specific steps are as follows: Put the concrete test block into the concrete installation rotating groove, carry out frost heaving treatment for 24h - 72h, after completion, carry out freeze - thaw treatment for 24h - 72h, after completion, carry out abrasion treatment for 24h - 72h. After completion, open the valve, discharge all the mixture of iron sand, concrete debris and water into the container, and after filtering through the microfiltration membrane, discharge all the water into the pure water discharge box. After completion, start the vibrating table and the electromagnet, adsorb all the iron sand onto the electromagnet, weigh the mass of the remaining concrete debris in the filter box through the electronic scale, and calculate the damage rate according to the mass of the concrete debris and the initial mass of the concrete test block.

[0013] The characteristics of the present invention also lie in: The implementation is carried out according to the following steps: Step 1: Weigh the initial mass of the concrete test block. After weighing, remove the box body, place the concrete test block into the concrete installation and rotation groove, and then place the box body on the concrete installation and rotation groove so that the two are in contact; Step 2: Turn off the first heating wire, the second heating wire, the iron sand box valve, and the valve. Open the water storage tank valve, add the water in the water storage tank into the box body. When the liquid level float ball valve closes after reaching the set water level, stop adding water. At the same time, close the water storage tank valve, then open the nitrogen storage tank valve, input the nitrogen in the nitrogen storage tank into the box body to cool down the water. After reaching the set temperature, close the nitrogen storage tank valve, and subject the water to freeze expansion for 24h - 72h, then the water freezes into ice blocks, generating a static load on the concrete test block; Step 3: Open the nitrogen storage tank valve again to fill the box body with nitrogen to freeze the ice blocks for 4h, and then turn on the first heating wire to heat the iron sand-containing ice blocks for 4h, and cycle in turn until 24h - 72h. After this process ends, the ice blocks melt into water; Step 4: Open the iron sand box valve, add iron sand into the box body to the set addition amount. After adding, start the electric telescopic rod, extend the blade into the water-iron sand mixture, close the electric telescopic rod, start the second motor, drive the electric telescopic rod to rotate, so that the blade stirs the water-iron sand mixture evenly. Close the second motor, and then open the nitrogen storage tank valve to input nitrogen into the box body to turn the water-iron sand mixture into iron sand-containing ice blocks, and then close the nitrogen storage tank valve; Step 5: Turn on the second heating wire. When the surface of the iron sand-containing ice block in contact with the concrete test block melts through heat transfer from the concrete test block and the rest remains solid, turn off the second heating wire, start the first motor, drive the concrete installation and rotation groove to rotate, thereby driving the concrete test block to rotate, and the melted iron sand-containing ice blocks at the bottom abrade the concrete test block for 24h - 72h; Step 6: After the abrasion ends, turn on the first heating wire to completely melt the iron sand-containing ice blocks, open the valve, completely drain the mixture of water, iron sand, and concrete debris generated after abrasion into the filter box, and after filtering through the microfiltration membrane, the water is completely drained into the pure water discharge box, and the concrete debris and iron sand remain in the filter box; Step 7: Start the electromagnet and the vibrating table, and adsorb all the iron sand onto the electromagnet under the action of the vibrating table and the electromagnet. Then weigh the mass of the concrete debris in the container with an electronic scale; Step 8: Calculate the damage rate through formula (1) , and the expression is: (1) In formula (1), M1 represents the mass of the concrete debris; M0 represents the initial mass of the concrete test block.

[0014] The beneficial effects of the present invention are as follows: (1) The test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention can simulate the coupling effects of frost heaving, freeze-thaw and abrasion of concrete in hydraulic structures in cold regions, and has a high degree of compounding with the actual operating conditions; (2) The test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention drives the concrete test block to rotate through the first motor, and simulates the abrasion environment through the action of the water and iron sand mixture, further improving the operability, comprehensiveness and accuracy of the test; (3) The test method for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention can improve the abrasion efficiency during the test by using iron sand to simulate water sand, and can also completely adsorb the iron sand through the adsorption action of the electromagnet, so as to separate it from the concrete debris, so as to quickly and accurately obtain the mass of the concrete debris. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention; Figure 2 is a schematic connection diagram of the concrete installation rotating groove and the box body in the test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention; Figure 3 is a schematic structural diagram of the telescopic stirring device in the test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention. In the figure, 1. Water storage tank, 2. Iron sand storage tank, 3. Nitrogen storage tank, 4. Water tank flowmeter, 5. Iron sand box valve, 6. Liquid level float ball valve, 7. Telescopic stirring device, 8. Spiral pipeline, 9. First heating wire, 10. Concrete test block, 11. Second heating wire, 12. Concrete installation rotating groove, 13. First motor, 14. Filter box, 15. Box body, 16. Electromagnet, 17. Microfiltration membrane, 18. Pure water discharge box, 19. Electronic scale, 20. Nitrogen storage tank valve, 21. Bracket, 22. Second motor, 23. Electric telescopic rod, 24. Blade, 25. Valve, 26. Water storage tank valve, 27. Vibration table, 28. Container. Detailed Embodiments

[0016] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0017] Example 1 The test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion of the present invention has a structure as Figure 1As shown in the figure, it includes a rotating mechanism. The top of the rotating mechanism is connected with a simulation mechanism. The rotating mechanism is used to drive the simulation mechanism to rotate, facilitating the simulation of the impact of the abrasive environment on concrete specimens. The simulation mechanism is used to simulate the impact of freeze-thaw and frost heaving environments on concrete specimens. A recovery weighing mechanism is connected to the side wall of the simulation mechanism. The recovery weighing mechanism is used to recover iron sand and water, and weigh the concrete debris generated by the concrete specimens after the test. The operation is convenient and the results obtained are accurate.

[0018] The rotating mechanism includes a first motor 13. The output shaft of the first motor 13 is connected to the bottom of the concrete installation rotating groove 12 with an open top. The concrete installation rotating groove 12 is used to hold the concrete specimen 10. The output shaft of the first motor 13 is arranged vertically upward. The rotation of the first motor 13 drives the concrete installation rotating groove 12 to rotate, thereby driving the concrete specimen 10 to rotate, so as to simulate the impact of the abrasive environment on the concrete specimen. A second heating wire 11 is laid on the inner bottom of the concrete installation rotating groove 12. The second heating wire 11 is used for heating to melt the interface formed by the iron sand ice block and the concrete specimen 10 in the later stage, so as to simulate the impact of the abrasive environment on the concrete specimen.

[0019] Embodiment 2 On the basis of Embodiment 1, the simulation mechanism includes a box body 15 with an open bottom. The outer wall of the bottom end of the box body 15 is in contact with the inner wall of the top end of the concrete installation rotating groove 12. As Figure 2 shown, the contact surface between the box body 15 and the concrete installation rotating groove 12 is stepped, and lubricating oil is applied on the contact surface to form a seal, ensuring no water leakage and no displacement during the test. During the test, the concrete installation rotating groove 12 rotates and the box body 15 does not move. A first heating wire 9 is sleeved on the outer wall of the box body 15. The first heating wire 9 is used for heating to melt the water and iron sand ice block formed in the later stage, so as to simulate the impact of the freeze-thaw environment on the concrete specimen 10.

[0020] Inside the box body 15, a telescopic stirring device 7 is arranged. Above the box body 15, a water storage tank 1, an iron sand storage tank 2 and a nitrogen storage tank 3 are arranged. The water storage tank 1 is filled with water, which is used to simulate the influence of frost heaving, freeze-thaw and abrasion environments on the concrete test block 10. The iron sand storage tank 2 is filled with iron sand, which is used to simulate the influence of the abrasion environment on the concrete test block 10. The nitrogen storage tank 3 is filled with nitrogen, which is used for cooling and to simulate the influence of frost heaving, freeze-thaw and abrasion environments on the concrete test block 10. One end of the pipeline A is connected to the water storage tank 1, and the other end of the pipeline A extends into the interior of the box body 15. A liquid level float valve 6 and a water storage tank valve 26 are arranged on the pipeline A. The liquid level float valve 6 is arranged inside the box body 15, and the liquid level float valve 6 is used to control the addition amount of water. The iron sand storage tank 2 is used to control that water will not be added into the box body 15 under the condition of no test. One end of the pipeline B is connected to the iron sand storage tank 2, and the other end of the pipeline B extends into the interior of the box body 15. An iron sand box valve 5 is arranged on the pipeline B. One end of the pipeline C is connected to the nitrogen storage tank 3, and the other end of the pipeline C extends into the interior of the box body 15. One end of the pipeline C extending into the box body 1 is connected to a spiral pipeline 8, and the spiral pipeline 8 is connected to the inner top wall of the box body 1. A nitrogen storage tank valve 20 is arranged on the pipeline C.

[0021] A window is arranged on the side wall of the iron sand storage tank 2. An organic glass is arranged on the window, and scales are arranged on the organic glass, which are used to observe the addition amount of iron sand.

[0022] Example 3 On the basis of Example 2, as Figure 3 shown, the telescopic stirring device 7 includes a bracket 21. One end of the bracket 21 is connected to the side wall of the box body 15, and the other end of the bracket 21 is connected to the second motor 22. The output shaft of the second motor 22 is connected to the fixed end of the electric telescopic rod 23. The electric telescopic rod 23 is arranged in the axial direction of the box body 15. The end of the telescopic end of the electric telescopic rod 23 is provided with a blade 24. The second motor 22 drives the electric telescopic rod 23 to rotate, and the electric telescopic rod 23 drives the blade to rotate, so as to stir the water and iron sand added into the box body 15 and make them mix evenly, so as to improve the accuracy and reliability of subsequent experiments. The electric telescopic rod 23 can be telescoped. When stirring is required, the electric telescopic rod 23 extends and is placed in the water and iron sand mixture. When stirring stops, the electric telescopic rod 23 retracts, so that the blade is completely outside the water. A water tank flowmeter 4 is arranged on the pipeline A, which is used to record the water flow.

[0023] Example 4 On the basis of Embodiment 3, the recovery weighing mechanism includes a filter box 14 and a pipeline D. A vibrating table 27 is arranged on the inner bottom of the filter box 14. An electronic scale 19 is arranged on the vibrating table 27. A container 28 with an open top is arranged on the electronic scale 19. An electromagnet 16 is arranged on the inner top of the filter box 14. The electromagnet 16 is used to adsorb iron sand. The top wall of the filter box 14 where the electromagnet 16 is arranged is detachably connected to the other side walls of the filter box 14, which is convenient for opening the top wall to take out the adsorbed iron sand. The electromagnet 15 is arranged corresponding to the container 28. The electronic scale 19 is used to weigh the mass of the concrete debris. The vibrating table 27 is used for vibration to vibrate out the iron sand mixed in the concrete debris, so as to adsorb all the iron sand. The container 28 is used to hold the mixture of water, iron sand and concrete debris. One end of the pipeline D is communicated with the box body 15, and the other end of the pipeline D passes through the top of the filter box 14 and extends into the container 28. Through holes are arranged on the side wall of the container 28. One end of a pipeline E is connected to the through holes, and the other end of the pipeline E passes through the filter box 14 and is connected to a pure water discharge box 18 (that is, there is a hole on the side wall of the filter box 14, the pipeline E passes through the hole, and the diameter of the hole is larger than the diameter of the pipeline E). A valve 25 is arranged on the pipeline D. A microfiltration membrane 17 is arranged at the through holes. The microfiltration membrane 17 is used to filter the iron sand and concrete debris, so that the iron sand and concrete debris are left in the filter box 14.

[0024] Embodiment 5 The test method for hydraulic concrete under frost heave - freeze - thaw - abrasion coupling of the present invention adopts the above - mentioned test device for hydraulic concrete under frost heave - freeze - thaw - abrasion coupling. The specific steps are as follows: Put the concrete test block 10 into the concrete installation and rotation groove 12, carry out frost heave treatment for 24h - 72h. After completion, carry out freeze - thaw treatment for 24h - 72h. After completion, carry out abrasion treatment for 24h - 72h. After completion, open the valve 25, drain all the mixture of iron sand, concrete debris and water into the container 28, and drain all the water into the pure water discharge box 18 after filtering through the microfiltration membrane 17. After completion, start the vibrating table 27 and the electromagnet 16, adsorb all the iron sand onto the electromagnet 16, weigh the mass of the remaining concrete debris in the filter box 14 through the electronic scale 19, and calculate the damage rate according to the mass of the concrete debris and the initial mass of the concrete test block 10.

[0025] Embodiment 6 The test method for hydraulic concrete under frost heave - freeze - thaw - abrasion coupling of the present invention is specifically implemented according to the following steps: Step 1, weigh the initial mass of the concrete test block 10. After weighing, remove the box body 15, put the concrete test block 10 into the concrete installation and rotation groove 12, and then place the box body 15 on the concrete installation and rotation groove 12 so that the two are in contact. Step 2, Frost heaving treatment: Turn off the first heating wire 9, the second heating wire 11, the iron sand box valve 5, and the valve 25. Open the water storage tank valve 26, add the water in the water storage tank 1 into the box body 15. When the liquid level float ball valve 6 closes after reaching the set water level, stop adding water. At the same time, close the water storage tank valve 26. Then open the nitrogen storage tank valve 20, input the nitrogen in the nitrogen storage tank 3 into the box body 15 to cool down the water. After reaching the set temperature, close the nitrogen storage tank valve 20, and perform frost heaving on the water for 24h to 72h, then the water freezes into ice cubes, generating static load on the concrete test block. Step 3, Freeze-thaw treatment: Open the nitrogen storage tank valve 20 again to fill nitrogen into the box body 15 to freeze the ice cubes for 4h. Then open the first heating wire 9 to heat the iron sand-containing ice cubes for 4h, and cycle in turn until 24h to 72h. After this process, the ice cubes melt into water. Step 4, Open the iron sand box valve 5, add iron sand into the box body 15 to the set addition amount. After adding, start the electric telescopic rod 23, extend the blade 24 into the water-iron sand mixture, close the electric telescopic rod 23, start the second motor 22, drive the electric telescopic rod 23 to rotate, so that the blade 24 stirs the water-iron sand mixture evenly. Close the second motor 22 and start the electric telescopic rod 23 to retract, making the blade 24 completely outside the water. Then open the nitrogen storage tank valve 20 to input nitrogen into the box body 15, making the water-iron sand mixture become iron sand-containing ice cubes, and close the nitrogen storage tank valve 20. Step 5, Abrasion treatment: Open the second heating wire 11. When the surface of the iron sand-containing ice cubes in contact with the concrete test block 10 melts through the heat transfer of the concrete test block 10 and the rest remains solid, close the second heating wire 11, start the first motor 13, drive the concrete installation rotating groove 12 to rotate, thereby driving the concrete test block 10 to rotate. Then the iron sand-containing ice cubes melted at the bottom abrade the concrete test block 10 for 24h to 72h. Step 6, After the abrasion is completed, open the first heating wire 9 to completely melt the iron sand-containing ice cubes. Open the valve 25, completely discharge the mixture of water, iron sand and concrete debris generated after abrasion into the container 28, and after filtering through the microfiltration membrane 17, the water is completely discharged into the pure water discharge tank 18, and the concrete debris and iron sand still remain in the container 28. Step 7, Start the electromagnet 16 and the vibration table 27. Through the action of the vibration table 27 and the electromagnet 16, adsorb all the iron sand onto the electromagnet 16. Then weigh the mass of the concrete debris in the container 28 through the electronic scale 19. Step 8, Calculate the damage rate through formula 1 , and the expression is: (1) In formula 1, M1 represents the mass of the concrete debris; M0 represents the initial mass of the concrete test block 10.

[0026] Example 7 Step 1: Weigh the initial mass of the concrete test block 10. The initial mass of the concrete test block 10 is 16.595 kg. After weighing, remove the box body 15, place the concrete test block 10 into the concrete installation and rotation groove 12, and then place the box body 15 on the concrete installation and rotation groove 12 to make them contact each other; Step 2: Frost heaving treatment: Turn off the first heating wire 9, the second heating wire 11, the iron sand box valve 5, and the valve 25. Open the water storage tank valve 26, add the water in the water storage tank 1 into the box body 15. When the liquid level float ball valve 6 closes after reaching the set water level, stop adding water. At the same time, close the water storage tank valve 26. Then open the nitrogen storage tank valve 20, input the nitrogen in the nitrogen storage tank 3 into the box body 15 to cool the water. After reaching the set temperature, close the nitrogen storage tank valve 20 and conduct frost heaving on the water for 24 h, then the water freezes into ice cubes, generating a static load on the concrete test block; Step 3: Freeze-thaw treatment: Open the nitrogen storage tank valve 20 again to fill nitrogen into the box body 15 to freeze the ice cubes for 4 h, and then turn on the first heating wire 9 to heat the iron sand-containing ice cubes for 4 h. Cycle in this way until 24 h. After this process ends, the ice cubes melt into water; Step 4: Open the iron sand box valve 5, add iron sand into the box body 15 to the set addition amount. After adding, start the electric telescopic rod 23, extend the blade 24 into the water-iron sand mixture, close the electric telescopic rod 23, start the second motor 22, drive the electric telescopic rod 23 to rotate, so that the blade 24 stirs the water-iron sand mixture evenly. Close the second motor 22 and start the electric telescopic rod 23 to retract, so that the blade 24 is completely outside the water. Then open the nitrogen storage tank valve 20 to input nitrogen into the box body 15, making the water-iron sand mixture become iron sand-containing ice cubes, and close the nitrogen storage tank valve 20; Step 5: Abrasion treatment: Turn on the second heating wire 11. When the surface of the iron sand-containing ice cubes in contact with the concrete test block 10 melts through the heat transfer of the concrete test block 10 and the rest remains solid, turn off the second heating wire 11, start the first motor 13, drive the concrete installation and rotation groove 12 to rotate, thereby driving the concrete test block 10 to rotate, and the melted iron sand-containing ice cubes at the bottom abrade the concrete test block 10 for 24 h; Step 6: After the abrasion ends, turn on the first heating wire 9 to completely melt the iron sand-containing ice cubes. Open the valve 25 to completely drain the mixture of water, iron sand, and concrete debris generated after abrasion into the filter box 14. After filtering through the microfiltration membrane 17, the water is completely drained into the pure water discharge box 18, and the concrete debris and iron sand still remain in the filter box 14; Step 7: Activate the electromagnet 16, the electronic scale and the vibration system 19. Under the action of the vibration motor and the electromagnet 16, all the iron sand is adsorbed onto the electromagnet 16. Then, the electronic scale weighs the mass of the concrete debris in the filter box 14. Step 8: The mass of the concrete debris is 0.863 kg. The damage rate is calculated to be 5.2% through formula (1).

[0027] Example 8 The difference from Example 7 is that the initial mass of the concrete test block 10 is 16.869 kg, the times of frost heaving treatment, freeze-thaw treatment and abrasion treatment are all 48 h, the mass of the concrete debris is 2.144 kg, and the damage rate is 12.7%.

[0028] Example 9 The difference from Example 7 is that the initial mass of the concrete test block 10 is 16.476 kg, the times of frost heaving treatment, freeze-thaw treatment and abrasion treatment are all 72 h, the mass of the concrete debris is 2.796 kg, and the damage rate is 17%.

Claims

1. A test device for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion, characterized in that, It includes a rotating mechanism, a simulation mechanism is connected to the top of the rotating structure, and a recovery weighing mechanism is connected to the side wall of the simulation mechanism.

2. The hydraulic concrete test device under the coupling of frost heaving, freeze-thaw and abrasion according to claim 1, characterized in that, The rotating mechanism includes a first motor (13), the output shaft of the first motor (13) is connected to the bottom of a concrete installation rotating groove (12) with an open top, and a second heating wire (11) is laid on the inner bottom of the concrete installation rotating groove (12).

3. The hydraulic concrete test device under the coupling of frost heaving, freeze-thaw and abrasion according to claim 2, wherein The simulation mechanism includes a box body (15) with an open bottom, the outer wall of the bottom end of the box body (15) is in contact with the inner wall of the top end of the concrete installation rotating groove (12), the contact surface between the box body (15) and the concrete installation rotating groove (12) is stepped, a first heating wire (9) is sleeved on the outer wall of the box body (15), a telescopic stirring device (7) is arranged inside the box body (15), a water storage tank (1), an iron sand storage tank (2) and a nitrogen storage tank (3) are arranged above the box body (15), one end of a pipeline A is connected to the water storage tank (1), the other end of the pipeline A extends into the inside of the box body (15), a liquid level float ball valve (6) and a water storage tank valve (26) are arranged on the pipeline A, the liquid level float ball valve (6) is arranged inside the box body (15), one end of a pipeline B is connected to the iron sand storage tank (2), the other end of the pipeline B extends into the inside of the box body (15), an iron sand box valve (5) is arranged on the pipeline B, one end of a pipeline C is connected to the nitrogen storage tank (3), the other end of the pipeline C extends into the inside of the box body (15), one end of the pipeline C extending into the box body (1) is connected to a spiral pipeline (8), the spiral pipeline (8) is connected to the inner top wall of the box body (1), and a nitrogen storage tank valve (20) is arranged on the pipeline C.

4. The hydraulic concrete test device under the coupling of frost heaving - freeze - thaw - abrasion according to claim 3, characterized in that, The telescopic stirring device (7) includes a bracket (21), one end of the bracket (21) is connected to the side wall of the box body (15), the other end of the bracket (21) is connected to a second motor (22), the output shaft of the second motor (22) is connected to the fixed end of an electric telescopic rod (23), and a blade (24) is arranged at the end of the telescopic end of the electric telescopic rod (23).

5. The hydraulic concrete test device under the coupling of frost heaving - freeze - thaw - abrasion according to claim 4, characterized in that, A water tank flowmeter (4) is arranged on the pipeline A.

6. The hydraulic concrete test device under the coupling of frost heaving - freeze - thaw - abrasion according to claim 5, wherein, The recovery weighing mechanism includes a filter box (14) and a pipeline D, a vibrating table (27) is arranged on the inner bottom of the filter box (14), an electronic scale (19) is arranged on the vibrating table (27), a container (28) with an open top is arranged on the electronic scale (19), an electromagnet (16) is arranged on the inner top of the filter box (14), the electromagnet (15) is arranged corresponding to the container (28), one end of the pipeline D is communicated with the box body (15), the other end of the pipeline D passes through the top of the filter box (14) and extends into the container (28), through holes are arranged on the side wall of the container (28), one end of a pipeline E is connected to the through holes, the other end of the pipeline E passes through the filter box (14) and is connected to a pure water discharge box (18), and a valve (25) is arranged on the pipeline D.

7. The hydraulic concrete test device under the coupling of frost heaving - freeze - thaw - abrasion according to claim 6, characterized in that, A microfiltration membrane (17) is arranged at the through hole.

8. Test method for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion, characterized in that, Adopt the hydraulic concrete test device under the coupling of frost heaving - freeze - thaw - abrasion as described in claim 7. The specific steps are as follows: Place the concrete test block (10) into the concrete installation and rotation tank (12), conduct frost heaving treatment for 24h - 72h. After completion, conduct freeze - thaw treatment for 24h - 72h. After completion, conduct abrasion treatment for 24h - 72h. After completion, open the valve (25), drain all the mixture of iron sand, concrete debris and water into the container (28), and after filtering through the micro - filter membrane (17), drain all the water into the pure water discharge tank (18). After completion, start the vibration table (27) and the electromagnet (16), adsorb all the iron sand onto the electromagnet (16), weigh the mass of the remaining concrete debris in the filter box (14) through the electronic scale (19), and calculate the damage rate according to the mass of the concrete debris and the initial mass of the concrete test block (10).

9. The test method for hydraulic concrete under the coupling of frost heaving, freeze-thaw and abrasion according to claim 8, characterized in that, Specifically, it is implemented according to the following steps: Step 1, weigh the initial mass of the concrete test block (10). After weighing, remove the box body (15), place the concrete test block (10) into the concrete installation and rotation tank (12), and then place the box body (15) on the concrete installation and rotation tank (12) to make them in contact; Step 2, close the first heating wire (9), the second heating wire (11), the iron sand box valve (5), the valve (25), open the water storage tank valve (26), add the water in the water storage tank (1) into the box body (15). When the set water level is reached, the liquid level float ball valve (6) closes, then stop adding water. At the same time, close the water storage tank valve (26), then open the nitrogen storage tank valve (20), input the nitrogen in the nitrogen storage tank (3) into the box body (15) to cool the water. When the set temperature is reached, close the nitrogen storage tank valve (20), conduct frost heaving on the water for 24h - 72h, then the water freezes into ice blocks, generating static load on the concrete test block; Step 3, open the nitrogen storage tank valve (20) again to fill nitrogen into the box body (15) to freeze the ice blocks for 4h, then open the first heating wire (9) to heat the iron - sand ice blocks for 4h, and cycle in turn until 24h - 72h. After this process is completed, the ice blocks melt into water; Step 4, open the iron sand box valve (5), add iron sand into the box body (15) to the set addition amount. After adding, start the electric telescopic rod (23), extend the blade (24) into the water - iron sand mixture, close the electric telescopic rod (23), start the second motor (22), drive the electric telescopic rod (23) to rotate, so that the blade (24) stirs the water - iron sand mixture evenly. Close the second motor (22), then open the nitrogen storage tank valve (20) to input nitrogen into the box body (15) to turn the water - iron sand mixture into iron - sand ice blocks, and close the nitrogen storage tank valve (20); Step 5: Turn on the second heating wire (11). When the surface of the iron sand ice block in contact with the concrete test block (10) melts through heat transfer from the concrete test block (10) and the rest remains solid, turn off the second heating wire (11) and start the first motor (13) to drive the concrete installation rotating groove (12) to rotate, thereby driving the concrete test block (10) to rotate. Then, the melted iron sand ice block at the bottom abrades the concrete test block (10) for 24 h to 72 h. Step 6: After the abrasion ends, turn on the first heating wire (9) to completely melt the iron sand ice block. Open the valve (25) to completely drain the mixture of water, iron sand, and concrete debris generated after abrasion into the filter box (14). After filtration through the microfiltration membrane (17), the water is completely drained into the pure water discharge box (18), and the concrete debris and iron sand remain in the filter box (14). Step 7: Start the electromagnet (16) and the vibrating table (27). Under the action of the vibrating table (27) and the electromagnet (16), all the iron sand is adsorbed onto the electromagnet (16). Then, weigh the mass of the concrete debris in the container (28) using the electronic scale (19). Step 8, calculate the damage rate using formula (1) , and the expression is: （1） In formula (1), M1 represents the mass of the concrete debris; M0 represents the initial mass of the concrete test block (10).

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