Freeze thawing-wind erosion-load coupled concrete damage test device and method

Abstract

The invention discloses a freeze thawing-wind erosion-load coupled concrete damage test device and method, and relates to the technical field of concrete performance test devices. The freeze thawing-wind erosion-load coupled concrete damage test device comprises a test box, a sand blowing assembly and a temperature control assembly, the test box is provided with a test cavity, a press machine used for clamping a concrete block and applying a load is arranged on the test box, the sand blowing assembly comprises a sand blowing pipe used for conveying wind sand to the concrete block, and the temperature control assembly is arranged on the sand blowing pipe. The included angle between the axis of the sand blowing pipe and the axis of the air supply pipe is adjustable, and the temperature control assembly is used for adjusting the temperature in the test cavity. The freeze-thaw-wind erosion-load coupled concrete damage test device can simulate a complex concrete service environment under the coupling action of freeze-thaw cycle, wind sand erosion and axial load, and more accurately reflect the initial damage evolution of the service concrete and the durability degradation law of the concrete with initial damage; and the accuracy of experimental research is improved.

Description

Technical Field

[0001] The invention relates to the technical field of concrete performance test devices, and in particular to a freeze-thaw-wind erosion-load coupled concrete damage test device and method. Background Art

[0002] Under the environmental conditions of large temperature differences and strong winds and sand in the Northwest Plateau, the concrete structures in service face the dual damage of freeze-thaw cycles and wind-sand erosion. In an environment with drastic fluctuations in temperature between day and night, the water inside the concrete freezes and melts repeatedly, resulting in volume changes that lead to the formation and expansion of microcracks inside the concrete. At the same time, strong winds carry a large amount of sand, which abrades the surface of the concrete, weakening its anti-erosion ability and accelerating the degradation of the material. In addition, the concrete structure is always under load during its service. The application of loads will cause stress concentration, further enhancing the cumulative damage effect of freeze-thaw and wind-sand erosion. The coupling effects of freeze-thaw, wind-sand erosion and loads overlap and interact with each other, forming a complex coupling damage mechanism, which causes the concrete to deteriorate much faster than a single factor, and there is a significant acceleration effect between multiple factors.

[0003] In related technologies, most test devices can only simulate the effect of a single factor, such as a single freeze-thaw cycle or a single wind and sand erosion. The so-called freeze-thaw cycle and wind and sand erosion coupling test actually applies these two factors in sequence, which is an indirect coupling. It fails to truly achieve the coupling of freeze-thaw cycle and wind and sand erosion, and often ignores the load factors in the service process of concrete. As a result, the test results of existing test devices are difficult to truly and accurately reflect the initial damage evolution of concrete in service in the complex environment of the northwestern plateau and its relationship with durability degradation. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a freeze-thaw-wind erosion-load coupled concrete damage test device. The freeze-thaw-wind erosion-load coupled concrete damage test device can simulate the complex service environment of concrete in the northwestern plateau area under the coupling of freeze-thaw cycles, wind and sand erosion and axial loads according to test requirements, ensure the authenticity of the test results, more accurately reflect the initial damage evolution of serving concrete under the coupling of large temperature differences and strong wind and sand and the durability degradation law of concrete with initial damage, and improve the accuracy of experimental research.

[0006] The embodiment of the present invention also provides a freeze-thaw-wind erosion-load coupled concrete damage test method.

[0007] The freeze-thaw-wind erosion-load coupled concrete damage test device of the embodiment of the present invention comprises:

[0008] A test box, the test box having a test cavity, a press for applying a load is provided on the test box, a movable end of the press extends into the test cavity and a first clamping plate is provided at the end, a second clamping plate is provided in the test box corresponding to the first clamping plate, and the first clamping plate and the second clamping plate are used to clamp a concrete block;

[0009] A sand blowing assembly, the sand blowing assembly comprising a blower, an air supply pipe, a sand container, a feeding pipe and a sand blowing pipe, one end of the air supply pipe is connected to the blower and the other end extends into the test chamber, the sand container is connected to the air supply pipe through the feeding pipe, the sand blowing pipe is movably arranged at the end of the air supply pipe relative to the test box, and the angle between the axis of the sand blowing pipe and the axis of the air supply pipe is adjustable;

[0010] A temperature control component includes a heating unit and a cooling unit for adjusting the air temperature in the test chamber.

[0011] The freeze-thaw-wind erosion-load coupled concrete damage testing device of the embodiment of the present invention can simulate the complex service environment of concrete in the northwestern plateau area under the coupling of freeze-thaw cycles, wind and sand erosion and axial load according to test requirements, ensure the authenticity of the test results, and more accurately reflect the initial damage evolution of serving concrete under the coupling of large temperature differences and strong wind and sand and the durability degradation law of concrete with initial damage, thereby improving the accuracy of experimental research.

[0012] In some embodiments, it includes a bracket and a connecting pipe, the bracket is connected to the test box and includes a vertical plate segment and a horizontal plate segment, the vertical plate segment is provided with a ball hinge hole, the connecting pipe can be flexibly deformed or elastically folded, the connecting pipe is connected between the air supply pipe and the sand blowing pipe, the fixed sleeve on the sand blowing pipe is provided with a ball hinge block, and the ball hinge block is hingedly matched with the ball hinge hole.

[0013] In some embodiments, it includes a connecting member, an electric hydraulic push rod and a driving member, the connecting member is arranged on the sand blowing pipe, the electric hydraulic push rod is arranged on the horizontal plate section, the driving member is arranged on the movable end of the electric hydraulic push rod and slidingly cooperates with the connecting member, and the driving member is used to drive the sand blowing pipe to rotate around the ball hinge hole.

[0014] In some embodiments, it includes a fixed plate and a first drive motor, the fixed plate is fixedly disposed in the test chamber, a first drive shaft is fixedly disposed on the horizontal plate section, the first drive shaft is rotatably disposed on the fixed plate, and the first drive motor is transmission-connected to the first drive shaft and is used to drive the bracket to swing around the first drive shaft.

[0015] In some embodiments, a heat exchange box is included, the heat exchange box has a first port and a second port, the air supply pipe includes a first pipe section and a second pipe section, the first pipe section is connected to the first port, the second pipe section is connected to the second port, the heating unit and the cooling unit are arranged in the heat exchange box and are used to adjust the temperature of the air in the heat exchange box;

[0016] And / or, the test box is provided with a temperature and humidity sensor and a humidity adjustment unit, the humidity adjustment unit is used to adjust the humidity of the air in the test chamber, and the temperature and humidity sensor is used to monitor the temperature and humidity in the test chamber.

[0017] In some embodiments, a first clamping plate is rotatably provided on the first clamping plate, and a second clamping plate is rotatably provided on the second clamping plate. The first clamping plate and the second clamping plate are used to clamp the concrete block and drive the concrete block to rotate.

[0018] In some embodiments, a second drive motor is included, a second drive shaft is coaxially and fixedly provided on the second clamping plate, the second drive shaft passes through the second clamping plate, and the second drive motor is fixedly provided on the second clamping plate and is used to drive the second drive shaft to rotate.

[0019] In some embodiments, a receiving hopper is included, the bottom of the test box is connected to a discharge hopper, the discharge hopper is provided with a discharge port, the receiving hopper is arranged corresponding to the discharge port and is used to receive the sand discharged from the test box;

[0020] And / or, the test box is provided with a pressure regulating valve, and the pressure regulating valve is used to connect the test chamber with the environment outside the test chamber to adjust the air pressure in the test chamber.

[0021] In some embodiments, a movable tube is included, which is slidably mounted on the sand blowing tube and is adapted to the size of the sand blowing tube. A fastener is threadedly connected to the movable tube, and the fastener is used to press against the sand blowing tube to fix the position of the movable tube.

[0022] The freeze-thaw-wind erosion-load coupled concrete damage test method of the embodiment of the present invention comprises the freeze-thaw-wind erosion-load coupled concrete damage test device of any of the above embodiments, and the test method comprises the following steps:

[0023] S1: clamping the concrete block by the first clamping plate and the second clamping plate, and applying a set load to the concrete block by a press;

[0024] S2: The temperature of the air in the test chamber is raised or lowered by the temperature control component, and the air blower is turned on to deliver air to the test chamber to verify the temperature in the test chamber so that the air temperature in the test chamber meets the requirements of the freeze-thaw cycle experiment under external air supply.

[0025] S3: Start the sand blowing component. The air in the air supply pipe carries the sand discharged from the feeding pipe and impacts the concrete block through the sand blowing pipe. The air supply volume of the air blower, the feeding speed of the feeding pipe and the sand blowing angle of the sand blowing pipe are adjusted to simulate the wind and sand erosion environment in the natural environment.

[0026] S4: After setting the freeze-thaw cycle and wind-sand erosion, turn off the sand blowing component and the temperature control component, increase the load applied by the press on the concrete block until the concrete block is destroyed, and record the set load parameters, environmental condition parameters and stress change curve of the concrete block in the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a freeze-thaw-wind erosion-load coupled concrete damage test device according to an embodiment of the present invention.

[0028] Figure 2 It is a schematic structural diagram of a test box in a freeze-thaw-wind erosion-load coupled concrete damage test device according to an embodiment of the present invention.

[0029] Figure 3 It is a schematic diagram of the connection between the bracket and the fixing plate in the freeze-thaw-wind erosion-load coupled concrete damage test device according to an embodiment of the present invention.

[0030] Figure 4 It is a structural schematic diagram of a sand blowing pipe in a freeze-thaw-wind erosion-load coupled concrete damage test device according to an embodiment of the present invention.

[0031] Reference numerals:

[0032] Test box 1; press machine 11; first clamping plate 12; first clamping plate 121; second clamping plate 13; second clamping plate 131; concrete block 14; temperature and humidity sensor 15; humidity adjustment unit 16; second drive motor 17; discharge hopper 18; pressure regulating valve 19;

[0033] Sand blowing assembly 2; blower 21; air supply pipe 22; sand container 23; feed pipe 24; sand blowing pipe 25; ball joint block 251; connector 252; slide groove 2521; slide hole 2522; connecting pipe 26; movable pipe 27; fastener 28;

[0034] Temperature control component 3; heating unit 31; cooling unit 32;

[0035] Controller 4;

[0036] Bracket 5; vertical plate section 51; ball hinge hole 511; horizontal plate section 52; electric hydraulic push rod 53; driving member 54; connecting rod 541; sliding rod 542;

[0037] Fixed plate 6;

[0038] A first drive motor 7;

[0039] Heat exchange box 8;

[0040] Receiving hopper 9. DETAILED DESCRIPTION

[0041] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0042] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the freeze-thaw-wind erosion-load coupled concrete damage test device of the embodiment of the present invention comprises a test box 1, a sand blowing component 2 and a temperature control component 3. The test box 1 has a test cavity. A press 11 for applying a load is provided on the test box 1. The movable end of the press 11 extends into the test cavity and a first clamping plate 12 is provided at the end. A second clamping plate 13 is provided in the test box 1 corresponding to the first clamping plate 12. The first clamping plate 12 and the second clamping plate 13 are used to clamp a concrete block 14. The sand blowing component 2 comprises an air supply The test chamber comprises a machine 21, an air supply pipe 22, a sand cylinder 23, a feeding pipe 24 and a sand blowing pipe 25. One end of the air supply pipe 22 is connected to the air supply machine 21 and the other end extends into the test chamber. The sand cylinder 23 is connected to the air supply pipe 22 through the feeding pipe 24. The sand blowing pipe 25 is movably arranged at the end of the air supply pipe 22 relative to the test chamber 1. The angle between the axis of the sand blowing pipe 25 and the axis of the air supply pipe 22 is adjustable. The temperature control component 3 includes a heating unit 31 and a cooling unit 32 for adjusting the air temperature in the test chamber.

[0043] When the freeze-thaw-wind erosion-load coupled concrete damage test device of the embodiment of the present invention is in use, the first clamping plate 12 can be driven to move by the movable end of the press 11, and the concrete block 14 can be clamped and fixed in the test chamber by the first clamping plate 12 and the second clamping plate 13, and pressure is applied to the concrete block 14 by the press 11 to simulate the stress condition of the concrete block 14 in a natural environment. The temperature in the test chamber can be adjusted by the temperature control component 3 to achieve a cyclic change of the increase and decrease of the air temperature in the test chamber, thereby simulating the freeze-thaw cycle of the concrete block 14 in a natural environment, and the wind and sand erosion of the concrete block 14 can be achieved by the wind and sand transported by the sand blowing pipe 25, and the wind and sand erosion can be more realistically simulated by the adjustable sand blowing angle of the sand blowing pipe 25, and at the same time, the freeze-thaw cycle, wind and sand erosion and axial load can be synchronously applied to the complex environment in which the concrete block 14 serves, thereby ensuring the authenticity of the test results.

[0044] The freeze-thaw-wind erosion-load coupled concrete damage testing device of the embodiment of the present invention can simulate the complex service environment of concrete in the northwestern plateau area under the coupling of freeze-thaw cycles, wind and sand erosion and axial load according to test requirements, ensure the authenticity of the test results, and more accurately reflect the initial damage evolution of serving concrete under the coupling of large temperature differences and strong wind and sand and the durability degradation law of concrete with initial damage, thereby improving the accuracy of experimental research.

[0045] Optionally, a controller 4 is included, which is provided with a display screen and control buttons. The controller 4 is electrically connected to the press 11, the air blower 21, the heating unit 31 and the refrigeration unit 32 to control the start and stop operations of the press 11, the air blower 21, the heating unit 31 and the refrigeration unit 32.

[0046] Optionally, the heating unit 31 is a heater, the cooling unit 32 is a refrigerator, and the air supply fan 21 is an air compressor.

[0047] Optionally, a valve is provided on the feed pipe 24 , and the valve is used to control the opening and closing of the feed pipe 24 and to adjust the falling flow rate of sand in the feed pipe 24 .

[0048] Optionally, the test box 1 is provided with a box door, and the box door is provided with a glass window to facilitate observation of the test process in the test chamber.

[0049] In some embodiments, Figure 2 and Figure 3 As shown, it includes a bracket 5 and a connecting pipe 26. The bracket 5 is connected to the test box 1 and includes a vertical plate section 51 and a horizontal plate section 52. The vertical plate section 51 is provided with a ball hinge hole 511. The connecting pipe 26 can be flexibly deformed or elastically folded. The connecting pipe 26 is connected between the air supply pipe 22 and the sand blowing pipe 25. The sand blowing pipe 25 is fixedly sleeved with a ball hinge block 251. The ball hinge block 251 is hinged to the ball hinge hole 511. The air blowing pipe is assembled on the vertical plate section 51 through the hinge block. The air blowing pipe can be rotated around the ball center of the ball hinge hole 511 to adjust the air outlet angle of the air blowing pipe, thereby realizing wind and sand erosion under different parameters of the concrete block 14, ensuring the accuracy of the simulation of the wind and sand erosion environment, and being easy to operate and adjust.

[0050] Optionally, the connecting pipe 26 is a rubber hose.

[0051] Optionally, the connecting pipe 26 is a corrugated pipe, which can be made of metal or rubber.

[0052] In some embodiments, Figure 2 and Figure 3As shown, it includes a connecting member 252, an electric hydraulic push rod 53 and a driving member 54. The connecting member 252 is arranged on the sand blowing tube 25, the electric hydraulic push rod 53 is arranged on the horizontal plate section 52, and the driving member 54 is arranged on the movable end of the electric hydraulic push rod 53 and slidably cooperates with the connecting member 252. The driving member 54 is used to drive the sand blowing tube 25 to rotate around the ball-ream hole 511.

[0053] Specifically, the cross section of the connecting member 252 is U-shaped and includes a limit plate and connecting plates arranged on both sides of the limit plate. The connecting plate is fixedly connected to the sand blowing tube 25. A slide groove 2521 is limited between the connecting member 252 and the sand blowing tube 25. A slide hole 2522 extending along the axial direction of the sand blowing tube 25 is provided on the limit plate. The driving member 54 is T-shaped and includes a connecting rod 541 and a slide rod 542. One end of the connecting rod 541 is fixedly connected to one end of the electric hydraulic push rod 53. The slide rod 542 is vertically and fixedly arranged on the other end of the connecting rod 541. The connecting rod 541 passes through the slide hole 2522 and extends into the slide groove 25 21, the slide bar 542 slides and fits in the slide groove 2521, and the diameter of the slide bar 542 is adapted to the size of the slide groove 2521. When the electric hydraulic push rod 53 is extended, the slide bar 542 moves in the slide groove 2521 in a direction away from the ball hinge hole 511 to drive the outlet of the sand blowing tube 25 to move in a direction away from the horizontal plate section 52. When the electric hydraulic push rod 53 is shortened, the slide bar 542 moves in the slide groove 2521 in a direction close to the ball hinge hole 511 to drive the outlet of the sand blowing tube 25 to move in a direction close to the horizontal plate section 52, thereby realizing the control and adjustment of the swing of the sand blowing tube 25.

[0054] Optionally, the bracket 5 is T-shaped or L-shaped, and one end of the horizontal plate section 52 is fixedly connected to the inner wall of the test box 1 .

[0055] Optionally, the electric hydraulic push rod 53 is electrically connected to the control machine, and the operation of the electric hydraulic push rod 53 can be controlled by the controller 4 .

[0056] In some embodiments, Figure 2 and Figure 3 As shown, it includes a fixed plate 6 and a first drive motor 7. The fixed plate 6 is fixed in the test chamber. A first drive shaft is fixed on the horizontal plate section 52. The first drive shaft is rotatably arranged on the fixed plate 6. The first drive motor 7 is transmission-connected to the first drive shaft and is used to drive the bracket 5 to swing around the first drive shaft.

[0057] Specifically, the bracket 5 is L-shaped, the first drive motor 7 is fixedly arranged on the fixed plate 6, the first drive motor 7 is provided with a first gear on the output shaft, the first drive shaft on the horizontal plate section 52 passes through the fixed plate 6, the first drive shaft is provided with a second gear, the first gear and the second gear are meshed for transmission, and the first drive motor 7 rotates, the first gear drives the second gear to rotate, and then drives the bracket 5 to rotate around the first drive shaft, so as to adjust the sand blowing angle of the sand blowing tube 25 in the horizontal direction, which is convenient to operate and ensures the simulation of the change of the blowing angle in the wind and sand erosion environment, so as to ensure the accuracy of the measurement data.

[0058] Optionally, the first drive shaft extends along the extension direction of the vertical plate segment 51 , and the axis of the first drive shaft passes through the center of the ball hinge hole 511 .

[0059] Optionally, the first drive motor 7 is a stepping motor and is electrically connected to the controller 4 , and the controller 4 can control the rotation angle and rotation direction of the first drive motor 7 .

[0060] In some embodiments, Figure 1 As shown, it includes a heat exchange box 8, the heat exchange box 8 has a first port and a second port, the air supply pipe 22 includes a first pipe section and a second pipe section, the first pipe section is connected to the first port, and the second pipe section is connected to the second port, and the heating unit 31 and the cooling unit 32 are arranged in the heat exchange box 8 and are used to adjust the temperature of the air in the heat exchange box 8;

[0061] Specifically, the heat exchange box 8 has a heat exchange cavity, and a first port and a second port strongly connected to the heat exchange are respectively provided on opposite sides of the heat exchange box 8, and a heating unit 31 and a refrigeration unit 32 are respectively provided on the side walls of the heat exchange box 8, and the air outlets of the heating unit 31 and the refrigeration unit 32 are respectively connected to the heat exchange cavity, and the two ends of the first pipe section are respectively connected to the air supply fan 21 and the first port, and the two ends of the second pipe section are respectively connected to the second port and the sand blowing pipe 25. By preheating or precooling the air in the heat exchange cavity, it is ensured that the temperature of the wind and sand blown out through the sand blowing pipe 25 is the same as the air temperature in the test cavity, avoiding a large temperature difference that affects the air temperature in the test cavity, and at the same time avoiding the wind and sand erosion point on the concrete block 14 at the set temperature. The test of the concrete block 14 adds uncertainty factors to avoid being suddenly subjected to a large temperature difference. The authenticity of the experimental results can be guaranteed, and the initial damage evolution of the serving concrete under the coupling of large temperature difference and strong wind and sand and the durability degradation law of the concrete with initial damage are more accurately reflected, thereby improving the accuracy of the experimental research.

[0062] In some embodiments, Figure 2As shown, the test box 1 is provided with a temperature and humidity sensor 15 and a humidity adjustment unit 16. The humidity adjustment unit 16 is used to adjust the humidity of the air in the test chamber, and the temperature and humidity sensor 15 is used to monitor the temperature and humidity in the test chamber. By setting the humidity adjustment unit 16, the erosion of the concrete block 14 in the natural environment can be further simulated, and the temperature and humidity of the air in the test chamber can be accurately controlled by the temperature and humidity sensor 15, which is convenient to operate.

[0063] Optionally, the humidity adjustment unit 16 is a humidifier, and the humidifier and the temperature and humidity sensor 15 are both electrically connected to the controller 4 .

[0064] In some embodiments, Figure 2 As shown, a first clamping plate 121 is rotatably provided on the first clamping plate 12, and a second clamping plate 131 is rotatably provided on the second clamping plate 13. The first clamping plate 121 and the second clamping plate 131 are used to clamp the concrete block 14 and drive the concrete block 14 to rotate. By providing the first clamping plate 121 and the second clamping plate 131, when the first clamping plate 12 and the second clamping plate 13 clamp the concrete block 14, the rotation of the concrete block 14 can be adjusted by rotating the first clamping plate 121 and the second clamping plate 131, thereby adjusting the wind and sand erosion position of the concrete block 14, and the operation is convenient.

[0065] Optionally, the first clamping plate 12 and the first clamping plate 121 are connected via a rotating bearing, and the second clamping plate 131 and the second clamping plate 131 are also connected via a rotating bearing.

[0066] In some embodiments, Figure 2 As shown, it includes a second drive motor 17, a second drive shaft is coaxially and fixedly provided on the second clamping plate 131, the second drive shaft passes through the second clamping plate 13, and the second drive motor 17 is fixedly provided on the second clamping plate 13 and is used to drive the second drive shaft to rotate.

[0067] Specifically, the second clamping plate 13 is fixed in the test cavity by a diagonal brace, the second drive motor 17 is fixedly arranged on the side of the second clamping plate 13 facing away from the first clamping plate 12, the second drive shaft on the second clamping plate 131 passes through the second clamping plate 13, and the output shaft of the second drive motor 17 is connected to the second drive shaft through a coupling. The second drive motor 17 can directly drive the second clamping plate 131 to rotate, thereby realizing the rotation adjustment of the concrete block 14.

[0068] Optionally, the second drive motor 17 is electrically connected to the controller 4 .

[0069] In some embodiments, Figure 2 As shown, it includes a receiving hopper 9, and a discharge hopper 18 is connected to the bottom of the test box 1. The discharge hopper 18 is provided with a discharge port. The receiving hopper 9 is arranged corresponding to the discharge port and is used to receive the sand discharged from the test box 1.

[0070] Specifically, the discharge port of the discharge hopper 18 is set at the end of the discharge hopper 18 with a smaller diameter, and a discharge pipe is provided on the discharge port, a control valve is provided on the discharge pipe, and a receiving box is provided at the end of the discharge pipe. A receiving hopper 9 is movably provided in the receiving box. The height of the receiving hopper 9 is the same as the height of the receiving box, and the top of the receiving hopper 9 is provided with an annular sealing strip extending along the circumferential direction. A plurality of handles are provided at intervals on the circumferential side of the receiving hopper 9, and an observation window is provided on the receiving hopper 9. By opening the control valve, the sand in the discharge hopper 18 enters the receiving hopper 9 through the discharge pipe. The height of the sand in the receiving hopper 9 can be observed through the observation window, so as to close the control valve in time, and seal the gap between the receiving hopper 9 and the top wall of the receiving box through the sealing strip to ensure that the sand does not fly during the discharging process, which is environmentally friendly and tidy.

[0071] Alternatively, a discharge port is provided on the inclined side wall of the discharge hopper 18, and a discharge plate is provided corresponding to the discharge port. A receiving trough is provided inclined corresponding to the discharge port below the discharge hopper 18, and a receiving hopper 9 is provided corresponding to the discharge end of the receiving trough. By opening the discharge plate, sand enters the receiving trough through the discharge port and is finally collected in the receiving hopper 9.

[0072] In some embodiments, Figure 1 and Figure 2 As shown, the test box 1 is provided with a pressure regulating valve 19, which is used to connect the test chamber with the environment outside the test chamber 1 to adjust the air pressure in the test chamber. By setting the pressure regulating valve 19, when the gas pressure in the test chamber is relatively high, the pressure regulating valve 19 can be automatically opened to discharge part of the gas, thereby ensuring that the air pressure in the test chamber is the same as the ambient pressure under natural regulation, thereby ensuring accurate simulation of the service environment of the concrete block 14.

[0073] In some embodiments, Figure 4 As shown, it includes a movable tube 27, which is slidably mounted on the sand blowing tube 25 and matched with the size of the sand blowing tube 25. A fastener 28 is threadedly connected to the movable tube 27. The fastener 28 is used to press against the sand blowing tube 25 to fix the position of the movable tube 27. By moving the position of the movable tube 27 on the sand blowing tube 25, the use length of the sand blowing tube 25 can be increased, which is convenient for controlling the position where the wind and sand enter the test chamber, and the operation is convenient.

[0074] Optionally, the fastener 28 is a fastening bolt.

[0075] The following describes a freeze-thaw-wind erosion-load coupled concrete damage test method according to an embodiment of the present invention.

[0076] The freeze-thaw-wind erosion-load coupled concrete damage test method of the embodiment of the present invention comprises the freeze-thaw-wind erosion-load coupled concrete damage test device of any of the above embodiments, and the test method comprises the following steps:

[0077] S1: clamping the concrete block by the first clamping plate and the second clamping plate, and applying a set load to the concrete block by a press;

[0078] S2: The temperature of the air in the test chamber is raised and lowered by the temperature control component to create an ice melting environment for the concrete blocks, and the air blower is turned on to supply air to the test chamber to verify whether the temperature in the test chamber meets the experimental requirements. The set temperatures of the refrigeration unit and the heating unit are adjusted to make the air temperature in the test chamber meet the requirements of the freeze-thaw cycle experiment under the condition of external air supply;

[0079] S3: Start the sand blowing component. The air in the air supply pipe carries the sand discharged from the feeding pipe and impacts the concrete block through the sand blowing pipe. The air supply volume of the air blower, the feeding speed of the feeding pipe and the sand blowing angle of the sand blowing pipe are adjusted to simulate the wind and sand erosion environment in the natural environment.

[0080] S4: After setting the freeze-thaw cycle and wind-sand erosion, turn off the sand blowing component and the temperature control component, increase the load applied by the press on the concrete block until the concrete block is destroyed, and record the set load parameters, environmental condition parameters and stress change curve of the concrete block in the test.

[0081] The freeze-thaw-wind erosion-load coupled concrete damage test method of the embodiment of the present invention can simulate the complex service environment of concrete in the northwestern plateau area under the coupling of freeze-thaw cycles, wind and sand erosion and axial loads, ensure the authenticity of the test results, and more accurately reflect the initial damage evolution of serving concrete under the coupling of large temperature differences and strong wind and sand and the durability degradation law of concrete with initial damage, thereby improving the accuracy of experimental research.

[0082] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0083] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0084] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0086] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0087] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A freeze-thaw-wind erosion-load coupled concrete damage test device, characterized in that: include: A test box, the test box having a test cavity, a press for applying a load is provided on the test box, a movable end of the press extends into the test cavity and a first clamping plate is provided at the end, a second clamping plate is provided in the test box corresponding to the first clamping plate, and the first clamping plate and the second clamping plate are used to clamp a concrete block; A sand blowing assembly, the sand blowing assembly comprising a blower, an air supply pipe, a sand container, a feeding pipe and a sand blowing pipe, one end of the air supply pipe is connected to the blower and the other end extends into the test chamber, the sand container is connected to the air supply pipe through the feeding pipe, the sand blowing pipe is movably arranged at the end of the air supply pipe relative to the test box, and the angle between the axis of the sand blowing pipe and the axis of the air supply pipe is adjustable; A temperature control component includes a heating unit and a cooling unit for adjusting the air temperature in the test chamber.

2. The freeze-thaw-wind erosion-load coupled concrete damage test device according to claim 1 is characterized in that: It includes a bracket and a connecting pipe, the bracket is connected to the test box and includes a vertical plate segment and a horizontal plate segment, the vertical plate segment is provided with a ball hinge hole, the connecting pipe can be flexibly deformed or elastically folded, the connecting pipe is connected between the air supply pipe and the sand blowing pipe, the fixed sleeve on the sand blowing pipe is provided with a ball hinge block, and the ball hinge block is hingedly matched with the ball hinge hole.

3. The freeze-thaw-wind erosion-load coupled concrete damage test device according to claim 2 is characterized in that: It includes a connecting piece, an electric hydraulic push rod and a driving piece, wherein the connecting piece is arranged on the sand blowing pipe, the electric hydraulic push rod is arranged on the horizontal plate section, the driving piece is arranged on the movable end of the electric hydraulic push rod and slidably cooperates with the connecting piece, and the driving piece is used to drive the sand blowing pipe to rotate around the ball hinge hole.

4. The freeze-thaw-wind erosion-load coupled concrete damage test device according to claim 2, characterized in that: It includes a fixed plate and a first driving motor, the fixed plate is fixedly arranged on the test cavity, the first driving shaft is fixedly arranged on the horizontal plate section, the first driving shaft is rotatably arranged on the fixed plate, and the first driving motor is transmission-connected with the first driving shaft and is used to drive the bracket to swing around the first driving shaft.

5. The freeze-thaw-wind erosion-load coupled concrete damage test device according to claim 1, characterized in that: The heat exchange box comprises a first port and a second port, the air supply pipe comprises a first pipe section and a second pipe section, the first pipe section is connected to the first port, the second pipe section is connected to the second port, the heating unit and the cooling unit are arranged in the heat exchange box and are used to adjust the temperature of the air in the heat exchange box; And / or, the test box is provided with a temperature and humidity sensor and a humidity adjustment unit, the humidity adjustment unit is used to adjust the humidity of the air in the test chamber, and the temperature and humidity sensor is used to monitor the temperature and humidity in the test chamber.

6. The freeze-thaw-wind-erosion-load coupled concrete damage test device according to claim 1, characterized in that: A first clamping plate is rotatably provided on the first clamping plate, and a second clamping plate is rotatably provided on the second clamping plate. The first clamping plate and the second clamping plate are used to clamp the concrete block and drive the concrete block to rotate.

7. The freeze-thaw-wind-erosion-load coupled concrete damage test device according to claim 6, characterized in that: It comprises a second driving motor, a second driving shaft is coaxially and fixedly arranged on the second clamping plate, the second driving shaft passes through the second clamping plate, and the second driving motor is fixedly arranged on the second clamping plate and is used to drive the second driving shaft to rotate.

8. The freeze-thaw-wind erosion-load coupled concrete damage test device according to claim 1, characterized in that: It includes a receiving hopper, the bottom of the test box is connected to a discharge hopper, the discharge hopper is provided with a discharge port, the receiving hopper is arranged corresponding to the discharge port and is used to receive the sand discharged from the test box; And / or, the test box is provided with a pressure regulating valve, and the pressure regulating valve is used to connect the test chamber with the environment outside the test chamber to adjust the air pressure in the test chamber.

9. The freeze-thaw-wind erosion-load coupled concrete damage test device according to claim 1, characterized in that: It comprises a movable tube, which is slidably sleeved on the sand blowing tube and matched with the sand blowing tube in size. A fastener is threadedly connected on the movable tube, and the fastener is used to press against the sand blowing tube to fix the position of the movable tube.

10. A freeze-thaw-wind erosion-load coupled concrete damage test method, characterized in that: Based on the freeze-thaw-wind erosion-load coupled concrete damage test device according to any one of claims 1 to 9, the test method comprises the following steps: S1: clamping the concrete block by the first clamping plate and the second clamping plate, and applying a set load to the concrete block by a press; S2: The temperature of the air in the test chamber is raised or lowered by the temperature control component, and the air blower is turned on to deliver air to the test chamber to verify the temperature in the test chamber so that the air temperature in the test chamber meets the requirements of the freeze-thaw cycle experiment under external air supply. S3: Start the sand blowing component. The air in the air supply pipe carries the sand discharged from the feeding pipe and impacts the concrete block through the sand blowing pipe. The air supply volume of the air blower, the feeding speed of the feeding pipe and the sand blowing angle of the sand blowing pipe are adjusted to simulate the wind and sand erosion environment in the natural environment. S4: After setting the freeze-thaw cycle and wind-sand erosion, turn off the sand blowing component and the temperature control component, increase the load applied by the press on the concrete block until the concrete block is destroyed, and record the set load parameters, environmental condition parameters and stress change curve of the concrete block in the test.

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