Test device capable of simulating variable load and freeze-thaw coupling effect of concrete pier stud in cold region

Abstract

The invention relates to the technical field of freeze-thaw tests, in particular to a test device capable of simulating the variable load and freeze-thaw coupling effect of a concrete pier stud in a cold region, which comprises a mounting frame, a pier stud, a loading mechanism, an adjusting mechanism, a freeze-thaw simulation mechanism and a connecting mechanism, a load sensor is arranged at the bottom of the inner wall of the mounting rack; the pier column is arranged in the mounting frame, and the bottom end of the pier column is movably connected with the load sensor through the bearing plate; the loading mechanism is arranged on the mounting rack, and one end of the loading mechanism extends into the mounting rack; the adjusting mechanism is arranged on the mounting frame; a plurality of freeze thawing simulation mechanisms are arranged; and the connecting mechanism is arranged in the mounting frame. Through the arrangement of the adjusting mechanism, in the process of carrying out a freeze-thaw cycle test on the pier column, the driving motor works to apply a variable load to the pier column through the loading disc, the change of the load borne by the pier column when a vehicle and other objects pass through a bridge is simulated, a more real application scene is simulated, and then the test error is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of freeze-thaw tests, and in particular to a test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions. Background Art

[0002] Concrete structures that have been in service for many years often have durability problems. The durability damage of concrete structures in my country is characterized by "rust in the south and frost in the north", and freeze-thaw damage is the main cause of concrete damage in cold northern regions. There are many theories about the freeze-thaw damage mechanism of concrete, including the expansion pressure theory and the penetration pressure theory. There is no definitive conclusion yet, but it is certain that freeze-thaw damage is closely related to water, that is, the saturated state of concrete will affect the degree of damage to concrete components. In addition, the freezing temperature and the salt content of the freezing medium will also affect the degree of damage to concrete. In particular, the substructure of bridges, which is mainly composed of piers, is often more severely damaged by freezing due to long-term contact with water. However, for the same pier, due to the difference in the relative position of the component to the water surface, it can also be divided into multiple parts such as the underwater area, the water level change area, and the above-water area. Environmental differences will lead to different degrees of freeze-thaw damage in various parts of the component.

[0003] The Chinese patent with the publication number CN114577627A discloses a freeze-thaw test device for reinforced concrete piers, including a component base, a pier, an inner cylinder and an insulation cylinder. A first partition is arranged in the inner cylinder to form several dry and wet environment chambers; the insulation cylinder is arranged outside the inner cylinder, and a second partition is arranged in the insulation cylinder to form several temperature control chambers; a temperature and humidity sensor is arranged in each dry and wet environment chamber, and a temperature sensor is arranged in each temperature control chamber; each dry and wet environment chamber is connected to a water pump or a humidity controller; each temperature control chamber is connected to a water bath; multiple temperature measuring elements are embedded in the pier, multiple extensometers are installed on the pier, a loading terminal is installed on the top of the pier, and a load sensor is installed at the bottom of the pier; the temperature and humidity sensor, the temperature sensor and the load sensor are connected to a control unit. The problem that the current environmental simulation room cannot consider the non-uniform freeze-thaw damage of the component and there is a great difference from the actual project is solved.

[0004] However, the above technical solution has the following shortcomings: the pier is loaded through the loading end, and the loading force is usually fixed during the test. In actual application scenarios, the load on the pier is usually variable, and the variable load will cause the stress inside the pier to change, resulting in a large error in the final test result. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the background technology and to propose a test device which can simulate the variable load and freeze-thaw coupling effect of concrete piers in cold regions.

[0006] The technical solution of the present invention is a test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions, comprising:

[0007] A mounting frame, the bottom of the inner wall of which is provided with a load sensor;

[0008] The pier column is arranged inside the mounting frame, and the bottom end of the pier column is movably connected to the load sensor through a bearing plate;

[0009] A loading mechanism is arranged on the mounting frame, one end of the loading mechanism extends into the mounting frame and contacts with the top end of the pier column;

[0010] An adjusting mechanism is arranged on the mounting frame, and one end of the adjusting mechanism is drivingly connected to the loading mechanism;

[0011] A plurality of freeze-thaw simulation mechanisms are provided, and the freeze-thaw simulation mechanisms are sleeved on the surface of the pier column to simulate different environments;

[0012] The connecting mechanism is arranged in the mounting frame and is used to connect the freeze-thaw simulation mechanisms.

[0013] Preferably, the loading mechanism includes a threaded barrel, a loading plate, a threaded rod and an adjusting plate; the threaded barrel passes through the mounting frame and is slidably connected to the mounting frame, the loading plate is located in the mounting frame and is fixedly connected to the threaded barrel, one end of the threaded rod is threadedly connected to the threaded barrel, one end of the threaded rod located outside the threaded barrel is fixedly connected to the adjusting plate, and the adjusting plate is transmission-connected to the adjusting mechanism.

[0014] Preferably, the adjustment mechanism includes an installation box, a driving assembly and a pressure assembly; the installation box is fixedly connected to the installation frame, one end of the loading mechanism extends to the interior of the installation box, one end of the driving assembly is arranged in the installation box, the pressure assembly is movably arranged in the installation box, one end of the pressure assembly is transmission connected to the loading mechanism, and the other end of the pressure assembly is transmission connected to the driving assembly.

[0015] Preferably, the pressure assembly includes a crankshaft, a rocker and a movable disk; the crankshaft is rotatably arranged in the installation box, the crankshaft is transmission-connected to the drive assembly, one end of the rocker is rotatably connected to the crankshaft, the other end of the rocker is rotatably connected to the movable disk, and the movable disk is rotatably connected to the adjusting disk.

[0016] Preferably, the drive assembly includes a drive motor, a drive worm and a drive worm wheel; the drive motor is fixedly connected to the mounting box, one end of the drive worm is transmission-connected to the output end of the drive motor, the other end of the drive worm extends into the mounting box, the drive worm wheel is fixedly connected to the crankshaft, and the drive worm and the drive worm wheel are meshed with each other.

[0017] Preferably, the freeze-thaw simulation mechanism includes a mounting tube, a refrigeration plate, a heating plate, a thermometer and a surface sensor; the mounting tube is sleeved on the outside of the pier and coincides with the central axis of the pier, the refrigeration plate, the heating plate, the thermometer and the surface sensor are all arranged in the mounting tube, and the surface sensor is in contact with the pier.

[0018] Preferably, the connecting mechanism includes a connecting ring, a connecting screw and a connecting ear; the connecting ring is sleeved on the surface of the loading disk and is slidably connected to the loading disk, the connecting ring is in contact with the freeze-thaw simulation mechanism at the top, a plurality of connecting screws are provided, the connecting ears are grouped in pairs and correspond one-to-one to the connecting screws, the lower connecting ear is fixedly connected to the supporting plate, the upper connecting ear is fixedly connected to the connecting ring, and the lower connecting ear is connected to the upper connecting ear through a connecting screw.

[0019] Preferably, a device box is fixedly connected to one side of the mounting frame, an operation panel and a display panel are arranged on the front of the device box, a water pump is arranged in the device box and is connected to the freeze-thaw simulation mechanism through a water pipe.

[0020] Compared with the prior art, the above technical solution of the present invention has the following beneficial technical effects:

[0021] The present invention uses the setting of the adjustment mechanism to drive the motor to apply a variable load to the pier through the loading plate during the freeze-thaw cycle test of the pier, simulating the load change on the pier when a vehicle or other object passes through the bridge, simulating a more realistic application scenario, and thus reducing the test error. By setting the freeze-thaw simulation mechanism, the freeze-thaw alternating environment is simulated, the actual environment of the bridge pier is reproduced, and the freeze-thaw test of the concrete pier is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A perspective view of an embodiment of the present invention;

[0023] Figure 2 A cross-sectional view of an embodiment of the present invention;

[0024] Figure 3 For the present invention Figure 2 A partial enlarged view of the middle A;

[0025] Figure 4 A schematic structural diagram of a load-bearing plate in an embodiment of the present invention;

[0026] Figure 5 This is a schematic structural diagram of a freeze-thaw simulation mechanism in an embodiment of the present invention.

[0027] Figure numerals: 1. mounting frame; 2. load sensor; 3. adjustment mechanism; 31. mounting box; 32. drive assembly; 321. drive motor; 322. drive worm; 323. drive worm wheel; 33. pressure assembly; 331. crankshaft; 332. rocker; 333. movable disk; 4. loading mechanism; 41. threaded barrel; 42. loading disk; 43. threaded rod; 5. freeze-thaw simulation mechanism; 51. mounting barrel; 52. refrigeration plate; 53. heating plate; 54. thermometer; 55. surface sensor; 6. connecting mechanism; 61. connecting ring; 62. connecting screw; 63. connecting ear; 7. pier; 8. load-bearing plate; 9. equipment box. DETAILED DESCRIPTION

[0028] Embodiment 1, as Figure 1-5 As shown, the present invention proposes a test device that can simulate the variable load and freeze-thaw coupling effect of concrete piers in cold regions, including a mounting frame 1, a pier 7, a loading mechanism 4, an adjustment mechanism 3, a freeze-thaw simulation mechanism 5 and a connection mechanism 6;

[0029] A load sensor 2 is provided at the bottom of the inner wall of the mounting frame 1, and the load sensor 2 is connected to the control system and the power supply through a wire;

[0030] The pier column 7 is arranged inside the mounting frame 1, and the bottom end of the pier column 7 is movably connected to the load sensor 2 through the bearing plate 8;

[0031] The loading mechanism 4 is arranged on the mounting frame 1, and one end of the loading mechanism 4 extends into the mounting frame 1 and contacts with the top end of the pier column 7;

[0032] The adjusting mechanism 3 is arranged on the mounting frame 1, and one end of the adjusting mechanism 3 is transmission-connected with the loading mechanism 4;

[0033] A plurality of freeze-thaw simulation mechanisms 5 are provided, and the freeze-thaw simulation mechanisms 5 are sleeved on the surface of the pier 7 for simulating different environments. A device box 9 is fixedly connected to one side of the mounting frame 1, and an operation panel and a display panel are provided on the front of the device box 9. A water pump is provided in the device box 9 and is connected to the freeze-thaw simulation mechanism 5 through a water pipe;

[0034] The connecting mechanism 6 is disposed in the mounting frame 1 , and is used to connect the freeze-thaw simulation mechanism 5 .

[0035] like Figure 2-3 As shown, the loading mechanism 4 includes a threaded barrel 41, a loading disk 42, a threaded rod 43 and an adjusting disk 44; the threaded barrel 41 passes through the mounting frame 1 and is slidably connected to the mounting frame 1, the loading disk 42 is located in the mounting frame 1 and is fixedly connected to the threaded barrel 41, one end of the threaded rod 43 is threadedly connected to the threaded barrel 41, and one end of the threaded rod 43 located outside the threaded barrel 41 is fixedly connected to the adjusting disk 44, and the adjusting disk 44 is transmission-connected to the adjusting mechanism 3.

[0036] like Figure 2-3 As shown, the adjustment mechanism 3 includes an installation box 31, a driving assembly 32 and a pressure assembly 33; the installation box 31 is fixedly connected to the installation frame 1, one end of the loading mechanism 4 extends to the interior of the installation box 31, one end of the driving assembly 32 is arranged in the installation box 31, and the pressure assembly 33 is movably arranged in the installation box 31, one end of the pressure assembly 33 is transmission connected to the loading mechanism 4, and the other end of the pressure assembly 33 is transmission connected to the driving assembly 32.

[0037] like Figure 3 As shown, the pressure-applying assembly 33 includes a crankshaft 331, a rocker 332 and a movable disk 333; the crankshaft 331 is rotatably arranged in the installation box 31, the crankshaft 331 is transmission-connected to the driving assembly 32, one end of the rocker 332 is rotatably connected to the crankshaft 331, the other end of the rocker 332 is rotatably connected to the movable disk 333, and the movable disk 333 is rotatably connected to the adjusting disk 44.

[0038] like Figure 3 As shown, the driving assembly 32 includes a driving motor 321, a driving worm 322 and a driving worm wheel 323; the driving motor 321 is fixedly connected to the installation box 31, the driving motor 321 is a variable frequency motor, and is connected to the control system and the power supply through a wire, one end of the driving worm 322 is transmission-connected to the output end of the driving motor 321, and the other end of the driving worm 322 extends into the installation box 31, the driving worm wheel 323 is fixedly connected to the crankshaft 331, and the driving worm 322 and the driving worm wheel 323 are meshed with each other.

[0039] like Figure 5 As shown, the freeze-thaw simulation mechanism 5 includes a mounting tube 51, a refrigeration plate 52, a heating plate 53, a thermometer 54 and a surface sensor 55; the mounting tube 51 is sleeved on the outer side of the pier 7 and coincides with the central axis of the pier 7, the refrigeration plate 52, the heating plate 53, the thermometer 54 and the surface sensor 55 are all arranged in the mounting tube 51, the surface sensor 55 is in contact with the pier 7, the refrigeration plate 52, the heating plate 53, the thermometer 54 and the surface sensor 55 are all connected to the control system and the power supply through wires, and the surface sensor 55 is used to monitor the frost heave coefficient and the thawing shrinkage of the pier 7.

[0040] like Figure 2-4 As shown, it is characterized in that the connecting mechanism 6 includes a connecting ring 61, a connecting screw 62 and a connecting ear 63; the connecting ring 61 is sleeved on the surface of the loading disk 42 and is slidably connected to the loading disk 42, the connecting ring 61 is in contact with the freeze-thaw simulation mechanism 5 at the top, a plurality of connecting screws 62 are provided, and the connecting ears 63 are grouped in pairs and correspond one to one to the connecting screws 62, the lower connecting ear 63 is fixedly connected to the supporting plate 8, the upper connecting ear 63 is fixedly connected to the connecting ring 61, and the lower connecting ear 63 is connected to the upper connecting ear 63 through the connecting screw 62.

[0041] Example 2: Based on the test device for simulating variable load and freeze-thaw coupling of cold region concrete piers in Example 1, this example proposes a freeze-thaw test method for cold region piers, and the specific steps are as follows:

[0042] S1, place the pier 7 on the bearing plate 8, put the freeze-thaw simulation mechanism 5 on the pier 7 and adjust the position, first rotate the adjustment disk 44 and the threaded rod 43 together, the threaded rod 43 rotates and cooperates with the threaded cylinder 41 to adjust the overall length of the loading mechanism 4 to a suitable size, when adjusting, observe the display panel of the equipment box 9 until the preload force on the pier 7 reaches the set value, stop rotating the adjustment disk 44, adjust the connecting mechanism 6, and the connecting ring 61 cooperates with the bearing plate 8 under the cooperation of the connecting screw 62 to connect and fix each freeze-thaw simulation mechanism 5;

[0043] S2, turning on the water pump, the refrigeration sheet 52, the thermometer 54 and the surface sensor 55 through the operation panel, the water pump works to adjust the water level in the freeze-thaw simulation mechanism 5 to a suitable position and then stops running, the refrigeration sheet 52 works to simulate the freezing environment of the pier 7, and the thermometer 54 and the surface sensor 55 record the temperature and possible deformation of the pier 7;

[0044] S3, turning on the water pump, the heating plate 53, the thermometer 54 and the surface sensor 55 through the operation panel, the water pump continuously running to simulate the water flow in the actual project, the heating plate 53 working to simulate the thawing process of the pier 7, the thermometer 54 and the surface sensor 55 record the temperature and possible deformation of the pier 7;

[0045] S4, continuing the freezing process after the melting is completed, and then performing freeze-thaw cycles in sequence;

[0046] S5. During the freeze-thaw cycle, the drive motor 321 is turned on through the operation panel. The drive motor 321 drives the drive worm 322 to rotate. The drive worm 322 rotates and drives the drive worm wheel 323 and the crankshaft 331 to rotate together through the meshing action. The crankshaft 331 rotates and drives the threaded rod 43 and the threaded barrel 41 to move downward through the rocker 332 and the movable disk 333. The threaded barrel 41 moves downward and applies a variable load to the pier 7 through the loading disk 42, simulating the load change on the pier 7 when a vehicle or other object passes through the bridge.

[0047] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto, and various changes can be made within the knowledge scope of technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions, characterized in that: include: A mounting frame (1) having a load sensor (2) disposed at the bottom of its inner wall; A pier column (7) is arranged inside the mounting frame (1), and the bottom end of the pier column (7) is movably connected to the load sensor (2) via a bearing plate (8); A loading mechanism (4) is arranged on the mounting frame (1), one end of the loading mechanism (4) extends into the mounting frame (1) and contacts the top end of the pier column (7); An adjusting mechanism (3) is arranged on the mounting frame (1), and one end of the adjusting mechanism (3) is drivingly connected to the loading mechanism (4); A plurality of freeze-thaw simulation mechanisms (5) are provided, and the freeze-thaw simulation mechanisms (5) are sleeved on the surface of the pier column (7) to simulate different environments; A connecting mechanism (6) is arranged in the mounting frame (1), and the connecting mechanism (6) is used to connect the freeze-thaw simulation mechanism (5).

2. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions according to claim 1, characterized in that: The loading mechanism (4) comprises a threaded barrel (41), a loading disc (42), a threaded rod (43) and an adjusting disc (44); the threaded barrel (41) passes through the mounting frame (1) and is slidably connected to the mounting frame (1); the loading disc (42) is located in the mounting frame (1) and is fixedly connected to the threaded barrel (41); one end of the threaded rod (43) is threadedly connected to the threaded barrel (41); one end of the threaded rod (43) located outside the threaded barrel (41) is fixedly connected to the adjusting disc (44); and the adjusting disc (44) is drivingly connected to the adjusting mechanism (3).

3. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions according to claim 2, characterized in that: The adjusting mechanism (3) comprises an installation box (31), a driving assembly (32) and a pressure assembly (33); the installation box (31) is fixedly connected to the installation frame (1); one end of the loading mechanism (4) extends into the interior of the installation box (31); one end of the driving assembly (32) is arranged in the installation box (31); the pressure assembly (33) is movably arranged in the installation box (31); one end of the pressure assembly (33) is transmission-connected to the loading mechanism (4); and the other end of the pressure assembly (33) is transmission-connected to the driving assembly (32).

4. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions according to claim 3, characterized in that: The pressure-applying assembly (33) comprises a crankshaft (331), a rocking arm (332) and a movable disk (333); the crankshaft (331) is rotatably arranged in the installation box (31), the crankshaft (331) is transmission-connected to the driving assembly (32), one end of the rocking arm (332) is rotatably connected to the crankshaft (331), the other end of the rocking arm (332) is rotatably connected to the movable disk (333), and the movable disk (333) is rotatably connected to the adjusting disk (44).

5. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions according to claim 4, characterized in that: The driving assembly (32) comprises a driving motor (321), a driving worm (322) and a driving worm wheel (323); the driving motor (321) is fixedly connected to the installation box (31); one end of the driving worm (322) is drivingly connected to the output end of the driving motor (321); the other end of the driving worm (322) extends into the installation box (31); the driving worm wheel (323) is fixedly connected to the crankshaft (331); and the driving worm (322) and the driving worm wheel (323) are meshed with each other.

6. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions according to claim 5, characterized in that: The freeze-thaw simulation mechanism (5) comprises a mounting tube (51), a refrigeration plate (52), a heating plate (53), a thermometer (54) and a surface sensor (55); the mounting tube (51) is sleeved on the outer side of the pier column (7) and coincides with the central axis of the pier column (7); the refrigeration plate (52), the heating plate (53), the thermometer (54) and the surface sensor (55) are all arranged in the mounting tube (51); and the surface sensor (55) is in contact with the pier column (7).

7. A test device capable of simulating variable load and freeze-thaw coupling effects of concrete piers in cold regions according to claim 6, characterized in that: The connecting mechanism (6) comprises a connecting ring (61), a connecting screw (62) and a connecting ear (63); the connecting ring (61) is sleeved on the surface of the loading plate (42) and is slidably connected to the loading plate (42); the connecting ring (61) is in contact with the freeze-thaw simulation mechanism (5) at the top; a plurality of connecting screws (62) are provided; the connecting ears (63) are arranged in groups of two and correspond one to one with the connecting screws (62); the lower connecting ear (63) is fixedly connected to the supporting plate (8); the upper connecting ear (63) is fixedly connected to the connecting ring (61); the lower connecting ear (63) is connected to the upper connecting ear (63) via the connecting screw (62).

8. The test device for simulating variable load and freeze-thaw coupling of concrete piers in cold regions according to claim 1, characterized in that: A device box (9) is fixedly connected to one side of the mounting frame (1); an operation panel and a display panel are provided on the front of the device box (9); a water pump is provided in the device box (9) and is connected to the freeze-thaw simulation mechanism (5) through a water pipe.

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