Device and method for detecting crack resistance of asphalt concrete pavement in severe cold area

Abstract

The invention discloses a device and a method for detecting the crack resistance of an asphalt concrete pavement in a severe cold region, and belongs to the technical field of pavement detection. According to the device for detecting the crack resistance of the asphalt concrete pavement in the severe cold area, a workbench is located above a supporting seat, and an angle adjusting mechanism is arranged between the supporting seat and the workbench; the workbench comprises a mounting seat, a test board is arranged in the mounting seat in a sliding manner, a clamping groove is formed in the upper surface of the test board, a fixing mechanism is arranged in the test board, a medium pipe is arranged in the clamping groove, a spraying mechanism for spraying a sample is arranged above the test board, and a test mechanism for testing the sample is arranged above the mounting seat. With the adoption of the device and the method for detecting the crack resistance of the asphalt concrete pavement in the severe cold area, various service environments can be simulated, and the problem that the accuracy of the crack resistance detection of the concrete pavement is relatively poor due to the fact that an existing detection device cannot effectively simulate the real condition of the concrete pavement is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of road surface detection, and in particular to a device and method for detecting the anti-cracking performance of asphalt concrete road surfaces in severely cold regions. Background Art

[0002] With the continuous development of transportation infrastructure, concrete pavements have become widely used in cold regions. However, the unique climatic conditions in these regions, such as extreme low temperatures, frequent freeze-thaw cycles, and large diurnal temperature swings, pose significant challenges to the durability and performance of concrete pavements. Cracking is a particularly prominent problem. Pavement cracking not only affects road smoothness and driving comfort, but also reduces the pavement's bearing capacity, allows moisture to penetrate the base layer, accelerates structural damage, increases maintenance costs, and even threatens driving safety.

[0003] At present, the testing methods for the crack resistance of concrete pavements are mainly divided into two categories: indoor test and on-site test. Commonly used methods for indoor test include the small beam bending test and the ring test. The small beam bending test evaluates the low-temperature crack resistance of asphalt mixtures by measuring their bending properties at specific temperatures and loading rates. However, the accuracy of evaluating the crack resistance of concrete pavements based solely on the bending properties at specific temperatures and loading rates is relatively poor. The ring test is mainly used to evaluate the crack resistance of cementitious materials, etc., and has limitations in simulating the actual cracking conditions of concrete pavements in extremely cold regions.

[0004] Existing patent CN202411820283.4 discloses a semi-flexible pavement crack resistance performance detection device, including a body, a pressure measuring assembly, a tensile measuring assembly and a temperature control assembly; the body is provided with a workbench and a switch door; the switch door is located above the workbench; the pressure measuring assembly includes a hydraulic cylinder, an output shaft, a pressure sensor, a pressure piece and a support assembly; the tensile measuring assembly includes a connecting plate, a first mounting piece, a second mounting piece and a tensile measuring piece; an air outlet is provided in the body, and the temperature control assembly is arranged inside the body and is located below the workbench, and the output end of the temperature control assembly is connected to the air outlet. This semi-flexible pavement crack resistance detection device solves the technical problem that the existing semi-flexible pavement detection device has a relatively cumbersome technical problem of measuring and analyzing the crack resistance of the semi-flexible pavement due to multiple factors. However, the above patent can only perform the compressive and tensile properties of the samples at different temperatures. The situation of the concrete pavement under actual working conditions is more complicated, and the accuracy of the concrete crack resistance detection under actual working conditions is relatively low. Summary of the Invention

[0005] The purpose of the present invention is to provide a device and method for detecting the crack resistance of asphalt concrete pavements in severe cold regions, so as to solve the problem that the existing detection devices cannot effectively simulate the actual conditions of concrete pavements, resulting in poor accuracy in detecting the crack resistance of concrete pavements.

[0006] To achieve the above-mentioned objectives, the present invention provides a device for detecting the crack resistance of asphalt concrete pavements in severely cold areas, comprising a support seat and a workbench, the workbench being located above the support seat, and an angle adjustment mechanism for adjusting the angle of the workbench being provided between the support seat and the workbench; the workbench comprising a mounting seat, a groove being provided on the top of the mounting seat, a test bench being slidingly provided in the groove, a slot for clamping a sample being provided on the upper surface of the test bench, a fixing mechanism for fixing the sample being provided in the test bench, a medium pipe for heating or cooling the sample being provided inside the slot, the medium pipe being connected to an external medium tank, a spray mechanism for spraying the sample being provided above the test bench, and a test mechanism for testing the sample being provided above the mounting seat.

[0007] Preferably, the angle adjustment mechanism includes a fixed seat, the fixed seat is fixedly arranged in the middle of one end of the base, and a slide is slidably arranged inside the fixed seat, and a sliding structure is provided on the fixed seat to drive the slide to slide horizontally on the fixed seat; guide posts are fixedly arranged on both sides of the slide, and guide grooves are provided on both sides of the fixed seat for the guide posts to pass through, the guide posts are hinged on the guide posts, and a second rotating shaft is provided at the top of the transmission plate, and a third fixed plate rotatably connected to the second rotating shaft is provided on the mounting seat, one end of the mounting seat is fixedly provided with a second fixed plate, the second fixed plate is rotatably connected to the first rotating shaft, the first rotating shaft is provided on the first fixed plate, and the first fixed plate is fixedly arranged on one end of the base away from the fixed seat; when the mounting seat is parallel to the base, the third fixed plate contacts the upper surface of the base to support the mounting seat.

[0008] Preferably, the sliding structure includes a screw rod, which is rotatably connected to the fixed seat through a bearing, a threaded hole for the screw rod to pass through and adapt to the screw rod is provided on the sliding seat, and a motor for driving the screw rod to rotate is provided on the fixed seat; and a guide rail is provided on the base to guide the horizontal sliding of the sliding seat.

[0009] Preferably, the fixing mechanism includes a top block, which is located in the card slot and is slidably connected to the card slot. A first mounting slot and a second mounting slot that are connected are provided inside the test bench, and the second mounting slot is provided outside the first mounting slot. A transmission seat is provided for vertical sliding in the first mounting slot, and the top block is fixedly connected to the transmission seat. A spring that applies an upward thrust to the transmission seat is provided at the bottom of the transmission seat and the first mounting slot, and a slide is provided for horizontal sliding in the second mounting slot. The slide and the transmission seat are hinged by several parallel connecting rods, and a splint is fixedly provided on the top of the slide. A through hole for the splint to pass through is provided on the side wall of the card slot, and the splint is sealingly and slidably connected to the through hole. A rubber sealing anti-slip pad is provided at the end of the splint that contacts the sample, and the medium tube is located below the splint.

[0010] Preferably, a positioning block is provided at each of the four corners of the card slot, the positioning block is fixedly connected to the test bench, a guide bar is provided on the side wall of the positioning block close to the splint for guiding the horizontal sliding of the splint, the splint and the positioning block are sealed and slidably connected, the splint, the positioning block and the sample are spliced into a sealed temperature regulating chamber, the medium tube is evenly laid on the side wall of the temperature regulating chamber, and a temperature sensor for testing the internal temperature of the temperature regulating chamber is provided in the temperature regulating chamber.

[0011] Preferably, the spray mechanism includes two relatively arranged spray units, the spray unit includes a mounting plate, the mounting plate is fixedly connected to the test bench through a vertical plate, a first slider and a second slider are slidably provided at both ends of the mounting plate, a power structure for driving the first slider and the second slider to slide relative to each other is provided on the mounting plate, a swing rod is provided in the middle of the first slider and the second slider, a limiting groove is provided on the top of the swing rod, a fixing pin is fixedly provided on the first slider and the second slider, the fixing pin is located in the limiting groove and is slidably connected to the limiting groove, and the middle part of the swing rod is hinged to the mounting plate; a water pipe is provided between the bottoms of the swing rods of the two spray units, and a plurality of nozzles are provided on the water pipe.

[0012] Preferably, the power structure includes a pushing cylinder, which is arranged on a mounting plate, and a piston rod of the pushing cylinder is connected to the first slider. Slide grooves are respectively provided at both ends of the mounting plate, and the first slider and the second slider are respectively located in the slide grooves at both ends of the mounting plate and are slidably connected to the slide grooves. The middle part of the mounting plate is rotatably connected to a rotating rod, one end of the rotating rod is hinged to the first slider through a first connecting rod, and the other end of the rotating rod is hinged to the second slider through a second connecting rod.

[0013] Preferably, the testing mechanism includes a support frame, a U-shaped support frame fixedly set on a mounting seat, a lifting hydraulic cylinder is set on the support frame, a mounting frame is set at the bottom end of the piston rod of the lifting hydraulic cylinder, a test wheel is rotatably set on the mounting frame, and a pressure sensor is set between the piston rod and the mounting frame.

[0014] Preferably, the mounting seat is provided with a power element for driving the test bench to slide, the power element is an electric cylinder, an air cylinder or a hydraulic cylinder, the piston rod of the power element is connected to the test bench, a track is provided in the mounting seat for guiding the sliding of the test bench, and a drain pipe is provided on the mounting seat to discharge the accumulated water in the groove; an industrial camera is provided on the mounting seat for shooting the test process of the sample.

[0015] The detection method based on the above-mentioned asphalt concrete pavement crack resistance detection device in severe cold areas includes the following steps: S1. The motor drives the screw to rotate, which drives the slide to slide horizontally on the base. The slide drives the transmission plate to rotate through the guide column. The transmission plate drives the mounting base to rotate around the first rotation axis through the second rotation axis and the third fixed plate to adjust the angle of the mounting base. S2. Place the specimen in the slot and start the lifting hydraulic cylinder. The lifting hydraulic cylinder drives the mounting frame downward via the piston rod, which in turn drives the test wheel downward. The test wheel applies downward pressure to the specimen, which in turn applies downward pressure to the top block, which drives the transmission seat downward. The spring is compressed, and the transmission seat drives the slide plate to slide toward the transmission seat via the connecting rod. The slide plate drives the clamping plate to slide synchronously, and the clamping plate slides along the guide bar and is clamped to the side wall of the specimen. The clamping plate, specimen, and positioning block form a closed temperature adjustment chamber. S3, the lifting hydraulic cylinder continues to drive the test wheel to move downward until the pressure sensor reaches the set pressure; S4. Start the power element, which drives the test bench to slide back and forth in the mounting seat. Relative sliding occurs between the specimen and the test wheel. The crack resistance of the specimen under the set load is studied. The industrial camera captures pictures and videos of the specimen during the test. S5. The external medium tank, under the action of the circulation pump, introduces cooling or heating medium into the medium pipe to provide a service environment of a specific temperature for the specimen; S6. Turn on the water pump and start the telescopic cylinder. The telescopic cylinder drives the first slider to slide in the slide groove. The first slider drives the rotating rod to rotate through the first connecting rod. The rotating rod drives the second slider to slide through the second connecting rod. The first and second sliders drive the swing rod to swing. The swing rod drives the water pipe to swing. The water pipe drives the nozzle to spray water onto the surface of the sample, providing a freeze-thaw or rain-resistant service environment for the sample.

[0016] The advantages and positive effects of the device and method for detecting the crack resistance of asphalt concrete pavement in severe cold regions of the present invention are: 1. An angle adjustment mechanism for adjusting the angle of the workbench is provided between the support seat and the workbench. The angles of both ends or both sides of the workbench are adjusted by the angle adjustment mechanism, so that concrete pavement samples serving on curves, uphills and downhills can be tested, thereby improving the adaptability of the detection device and facilitating the accuracy of sample testing.

[0017] 2. The test bench is equipped with a slot and a fixture for securing the specimen. This fixture improves specimen stability. Positioning blocks are located at each corner of the slot. The clamping plates, positioning blocks, and specimen are joined to form a sealed temperature-regulating chamber. Dielectric tubes are evenly laid along the sidewalls of the chamber, providing a specific temperature environment for the specimen. This facilitates research on the crack resistance of specimens under varying temperatures or temperature fluctuations, improving test accuracy.

[0018] 3. This invention uses a spray mechanism to spray water onto the sample surface, simulating a rainy service environment. Combined with a dielectric tube, it simulates a freeze-thaw service environment, improving test accuracy. The nozzle swings under the action of a swinging rod, improving the uniformity of the water spray on the sample.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the three-dimensional structure of an embodiment of the present invention; Figure 2 Schematic diagram of the side structure of an embodiment of the present invention; Figure 3 A schematic diagram of the three-dimensional structure of a workbench according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the front view of the workbench structure of an embodiment of the present invention; Figure 5 Schematic diagram of the three-dimensional structure of the spray mechanism on the workbench according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the top view of the spray mechanism on the workbench according to an embodiment of the present invention; Figure 7 Schematic diagram of the three-dimensional structure of the spray unit on the workbench according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the three-dimensional structure of a test bench according to an embodiment of the present invention; Figure 9 A schematic diagram of the cross-sectional structure of a test bench according to an embodiment of the present invention; Figure 10 For attachment Figure 9 Middle A enlarged view; Figure 11 Schematic diagram of the three-dimensional structure of the support base according to an embodiment of the present invention.

[0021] Reference numerals 1. Support base; 11. Base; 12. Fixed base; 13. Motor; 14. Sliding base; 15. Screw; 16. Guide groove; 17. Guide column; 18. Transmission plate; 19. First fixed plate; 110. First rotating shaft; 111. Second rotating shaft; 2. Workbench; 21. Mounting base; 22. Test bench; 23. Power element; 24. Support frame; 25. Lifting hydraulic cylinder; 26. Pressure sensor; 27. Mounting frame; 28. Test wheel; 29. Vertical plate; 210. Mounting plate; 211. Slide; 212. First slider; 213. Second slider; 214. Push cylinder; 215. First connecting rod; 216. Rotating rod; 217. Second connecting rod; 218 , swing rod; 219, limit groove; 220, water pipe; 221, nozzle; 222, slot; 223, top block; 224, positioning block; 225, medium pipe; 226, first mounting slot; 227, transmission seat; 228, second mounting slot; 229, slide plate; 230, connecting rod; 231, splint; 232, spring; 233, guide bar; 234, second fixed plate; 235, third fixed plate; 236, track. DETAILED DESCRIPTION

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is usually placed when in use. These are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. In the event of any inconsistency, the meaning described in this specification or the meaning derived from the contents recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0024] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 、 Figure 2A device for testing the crack resistance of asphalt concrete pavements in severely cold regions comprises a support base 1 and a workbench 2. The workbench 2 is positioned above the support base 1, which is fixed to the ground. An angle adjustment mechanism is provided between the support base 1 and the workbench 2 to adjust the angle of the workbench 2. This mechanism adjusts the angles of both ends or sides of the workbench 2, enabling testing of concrete pavement specimens in service on curves, uphill slopes, and downhill slopes, improving the adaptability of the testing device.

[0026] like Figure 11 As shown. The angle adjustment mechanism includes a fixed seat 12, which is fixedly arranged in the middle of one end of the base 11. A slide seat 14 is slidably arranged inside the fixed seat 12, and guide posts 17 are fixedly arranged on both sides of the slide seat 14. Guide grooves 16 are provided on both sides of the fixed seat 12 for the guide posts 17 to pass through, and the guide posts 17 are slidably connected to the guide grooves 16. A transmission plate 18 is hinged on the guide post 17, and a second rotating shaft 111 is fixedly provided on the top of the transmission plate 18. A third fixed plate 235 rotatably connected to the second rotating shaft 111 is fixedly provided on the mounting seat 21, and a through hole is provided on the third fixed plate 235 for the second rotating shaft 111 to pass through. A second fixed plate 234 is fixedly provided at one end of the mounting seat 21, and a through hole is provided on the second fixed plate 234 for the first rotating shaft 110 to pass through, and the second fixed plate 234 is rotatably connected to the first rotating shaft 110. The first rotating shaft 110 is fixedly mounted on the first fixing plate 19, which is fixedly mounted on an end of the base 11 away from the fixing base 12. When the mounting base 21 is parallel to the base 11, the third fixing plate 235 contacts the upper surface of the base 11, supporting the mounting base 21 and improving its stability.

[0027] The fixed base 12 is provided with a sliding structure that drives the slide 14 to slide horizontally on the fixed base 12. The sliding structure includes a screw 15, which is rotatably connected to the fixed base 12 via a bearing. The slide 14 is provided with a threaded hole that allows the screw 15 to pass through and is compatible with the screw 15. The fixed base 12 is provided with a motor 13 that drives the screw 15 in rotation. A guide rail is fixed to the base 11 to guide the horizontal sliding of the slide 14. The guide rail is parallel to the screw 15.

[0028] like Figure 3 、 Figure 4 As shown. The workbench 2 includes a mounting base 21, the top of which is provided with a groove, in which a test bench 22 is slidably mounted. Mounting base 21 is provided with a power element 23 that drives the test bench 22 to slide. Power element 23 can be an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder. The piston rod of power element 23 is fixedly connected to the test bench 22. A track 236 is fixedly mounted within mounting base 21 to guide the sliding of test bench 22. Mounting base 21 is provided with a drain pipe 220 to drain water accumulated in the groove.

[0029] like Figure 8 、 Figure 9 As shown. The upper surface of the test bench 22 is provided with a slot 222 for securing the specimen, and a fixing mechanism for securing the specimen is provided within the test bench 22. The fixing mechanism includes a top block 223, which is positioned within and slidably connected to the slot 222. The interior of the test bench 22 is provided with a first mounting slot 226 and a second mounting slot 228, which are connected. The second mounting slot 228 is provided outside the first mounting slot 226. In this embodiment, the second mounting slots 228 are provided on all four sides of the first mounting slot 226.

[0030] A transmission seat 227 is vertically slidably provided in the first mounting groove 226, and the top block 223 is fixedly connected to the transmission seat 227. A spring 232 is provided at the bottom of the transmission seat 227 and the first mounting groove 226 to apply an upward thrust to the transmission seat 227. A slide plate 229 is horizontally slidably provided in the second mounting groove 228, and the slide plate 229 is hinged to the transmission seat 227 via a plurality of parallel connecting rods 230. A splint 231 is fixedly provided at the top of the slide plate 229. A through hole is provided on the side wall of the slot 222 for the splint 231 to pass through, and the splint 231 is sealed and slidably connected to the through hole via a rubber sealing gasket. A rubber sealing anti-slip pad is provided at the end of the splint 231 that contacts the sample.

[0031] Such as Figure 10 As shown. A positioning block 224 is provided at each of the four corners of the card slot 222, and the positioning block 224 is fixedly connected to the test bench 22. A guide bar 233 that guides the horizontal sliding of the splint 231 is provided on the side wall of the positioning block 224 near the splint 231, and the splint 231 and the positioning block 224 are sealed and slidably connected. The splint 231, the positioning block 224 and the sample are spliced into a sealed temperature regulating chamber, and the medium tube 225 is evenly laid on the side wall of the temperature regulating chamber. The medium tube 225 is located below the splint 231, and the medium tube 225 is connected to an external medium tank. A temperature sensor for testing the internal temperature of the temperature regulating chamber is provided in the temperature regulating chamber. The medium tube 225 provides a specific temperature environment for the sample, which is convenient for studying the crack resistance of the sample under different temperatures or temperature changes.

[0032] like Figure 5 、 Figure 6 、 Figure 7As shown. A spray mechanism for spraying the specimen is located above the test bench 22. The spray mechanism comprises two opposing spray units. The spray units include a mounting plate 210, which is fixedly connected to the test bench 22 via a vertical plate 29. A first slider 212 and a second slider 213 are slidably mounted at each end of the mounting plate 210. A power structure is provided on the mounting plate 210 to drive the first and second sliders 212, 213 to slide relative to each other. The power structure includes a push cylinder 214, which is mounted on the mounting plate 210. The piston rod of the push cylinder 214 is fixedly connected to the first slider 212. Slide slots 211 are provided at each end of the mounting plate 210. The first and second sliders 212, 213 are located within and slidably connected to the slide slots 211 at each end of the mounting plate 210. Driven by the push cylinder 214, the first and second sliders 212, 213 slide horizontally along the slide slots 211. A rotating rod 216 is rotatably connected to the middle of the mounting plate 210 . One end of the rotating rod 216 is hinged to the first slider 212 via a first connecting rod 215 , and the other end of the rotating rod 216 is hinged to the second slider 213 via a second connecting rod 217 .

[0033] A swinging rod 218 is installed in the middle of each of the first and second sliders 212, 213. A limit slot 219 is located at the top of each swinging rod 218. A fixing pin is fixed to each of the first and second sliders 212, 213. The fixing pin is located within the limit slot 219 and slidably connected to the limit slot 219. The first and second sliders 212, 213 drive the swinging rod 218 to swing through the fixing pin and the limit slot 219. The middle of the swinging rod 218 is hinged to the mounting plate 210. A water pipe 220 is installed between the bottoms of the swinging rods 218 of the two spray units. This water pipe 220 is connected to an external water pump and is equipped with several nozzles. This spray mechanism allows water to be sprayed onto the specimen surface to simulate rainy service conditions. Combined with the medium pipe 225, this simulates freeze-thaw service conditions, improving test accuracy. The nozzles swing under the action of the swinging rod 218, improving the uniformity of the water spray on the specimen.

[0034] A testing mechanism for testing specimens is located above mounting base 21. This testing mechanism includes a U-shaped support frame 24, fixed to mounting base 21. A lifting hydraulic cylinder 25 is fixed to support frame 24. A mounting frame 27 is attached to the bottom end of the piston rod of lifting hydraulic cylinder 25, and a test wheel 28 is rotatably mounted on mounting frame 27. A pressure sensor 26 is located between the piston rod and mounting frame 27. This pressure sensor is used to measure the pressure applied to the specimen and simulate a specific pressure load.

[0035] Mounting base 21 is equipped with an industrial camera that records the test process, facilitating recording and more accurate analysis of the test process. The industrial camera, temperature sensor, water pump, circulation pump, power element 23, air cylinder, hydraulic cylinder, and other electrical components are all connected to the controller using existing technology as needed.

[0036] The detection method based on the above-mentioned asphalt concrete pavement crack resistance detection device in severe cold areas includes the following steps: S1. The motor 13 drives the screw rod 15 to rotate, and the screw rod 15 drives the slide 14 to slide horizontally on the base 11. The slide 14 drives the transmission plate 18 to rotate through the guide column 17. The transmission plate 18 drives the mounting base 21 to rotate around the first rotating shaft 110 through the second rotating shaft 111 and the third fixed plate 235 to adjust the angle of the mounting base 21.

[0037] S2. Place the specimen in slot 222 and activate hydraulic cylinder 25. This piston rod drives mounting bracket 27 downward, which in turn drives test wheel 28 downward. Test wheel 28 applies downward pressure to the specimen, which in turn applies downward pressure to top block 223. Top block 223 drives transmission base 227 downward, compressing spring 232. Transmission base 227 drives slide plate 229 toward transmission base 227 via connecting rod 230. Slide plate 229 drives clamping plate 231 to slide synchronously. Clamping plate 231 slides along guide bar 233 and clamps against the side wall of the specimen. Clamping plate 231, the specimen, and positioning block 224 form a closed temperature-regulating chamber.

[0038] S3: The lifting hydraulic cylinder 25 continues to drive the test wheel 28 to move downward until the pressure sensor 26 reaches the set pressure.

[0039] S4. Activate power element 23, which drives test platform 22 to slide back and forth within mounting base 21. Relative sliding occurs between the specimen and test wheel 28, allowing the specimen's crack resistance to be studied under a set load. An industrial camera captures images and videos of the specimen during testing.

[0040] S5. Under the action of the circulation pump, the external medium tank introduces cooling or heating medium into the medium pipe 225 to provide a service environment of a specific temperature for the sample.

[0041] S6. Turn on the water pump and start the telescopic cylinder. The telescopic cylinder drives the first slider 212 to slide in the slide groove 211. The first slider 212 drives the rotating rod 216 to rotate through the first connecting rod 215. The rotating rod 216 drives the second slider 213 to slide through the second connecting rod 217. The first slider 212 and the second slider 213 drive the swing rod 218 to swing. The swing rod 218 drives the water pipe 220 to swing. The water pipe 220 drives the nozzle 221 to spray water onto the surface of the sample, providing a freeze-thaw or rain-resistant service environment for the sample.

[0042] Therefore, the device and method for detecting the anti-cracking performance of asphalt concrete pavements in cold regions described in the present invention can simulate a variety of service environments, solving the problem that the existing detection devices cannot effectively simulate the actual conditions of concrete pavements, resulting in poor accuracy in detecting the anti-cracking performance of concrete pavements.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A device for detecting the crack resistance of asphalt concrete pavement in severe cold regions, characterized by: It includes a support base and a workbench. The workbench is located above the support base. An angle adjustment mechanism for adjusting the angle of the workbench is arranged between the support base and the workbench. The workbench includes a mounting base. A groove is arranged on the top of the mounting base. A test bench is slidingly arranged in the groove. A card slot for clamping the sample is arranged on the upper surface of the test bench. A fixing mechanism for fixing the sample is arranged in the test bench. A medium pipe for heating or cooling the sample is arranged inside the card slot. The medium pipe is connected to an external medium tank. A spray mechanism for spraying the sample is arranged above the test bench. A test mechanism for testing the sample is arranged above the mounting base.

2. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 1 is characterized in that: The cam is fixedly mounted on the support frame, and the cam is mounted on a support structure configured to move the cam face forwardly and backward, wherein the cam face is configured to move the cam face forwardly and downward, and the cam face is mounted on a support structure configured to move the cam face forwardly and downward, 3. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 2, characterized in that: The sliding structure includes a screw rod, which is rotatably connected to the fixed seat through a bearing. The sliding seat is provided with a threaded hole for the screw rod to pass through and adapt to the screw rod. The fixed seat is provided with a motor for driving the screw rod to rotate; the base is provided with a guide rail that guides the horizontal sliding of the sliding seat.

4. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 3, characterized in that: The fixing mechanism includes a top block, which is located in the card slot and is slidably connected to the card slot. A first mounting slot and a second mounting slot that are connected are provided inside the test bench, and the second mounting slot is provided outside the first mounting slot. A transmission seat is provided for vertical sliding in the first mounting slot, and the top block is fixedly connected to the transmission seat. A spring that applies an upward thrust to the transmission seat is provided at the bottom of the transmission seat and the first mounting slot. A slide is provided for horizontal sliding in the second mounting slot. The slide and the transmission seat are hinged by several parallel connecting rods. A splint is fixedly provided on the top of the slide, and a through hole for the splint to pass through is provided on the side wall of the card slot. The splint is sealed and slidably connected to the through hole. A rubber sealing anti-slip pad is provided at the end of the splint that contacts the sample, and the medium tube is located below the splint.

5. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 4, characterized in that: A positioning block is respectively provided at the four corners of the card slot, and the positioning block is fixedly connected to the test bench. A guide bar is provided on the side wall of the positioning block close to the splint for guiding the horizontal sliding of the splint. The splint and the positioning block are sealed and slidably connected. The splint, the positioning block and the sample are spliced into a sealed temperature regulating chamber. The medium tube is evenly laid on the side wall of the temperature regulating chamber. A temperature sensor for testing the internal temperature of the temperature regulating chamber is provided in the temperature regulating chamber.

6. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 5, characterized in that: The spray mechanism includes two relatively arranged spray units, and the spray unit includes a mounting plate, which is fixedly connected to the test bench through a vertical plate, and a first slider and a second slider are respectively slidably provided at both ends of the mounting plate. A power structure for driving the first slider and the second slider to slide relative to each other is provided on the mounting plate, and a swing rod is provided in the middle of the first slider and the second slider, and a limiting groove is provided on the top of the swing rod. A fixing pin is fixedly provided on the first slider and the second slider, and the fixing pin is located in the limiting groove and is slidably connected to the limiting groove. The middle part of the swing rod is hinged to the mounting plate; a water pipe is provided between the bottoms of the swing rods of the two spray units, and a plurality of nozzles are provided on the water pipe.

7. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 6, characterized in that: The power structure includes a pushing cylinder, which is arranged on a mounting plate. The piston rod of the pushing cylinder is connected to the first slider. Slide grooves are respectively provided at both ends of the mounting plate. The first slider and the second slider are respectively located in the slide grooves at both ends of the mounting plate and are slidably connected to the slide grooves. The middle part of the mounting plate is rotatably connected to a rotating rod. One end of the rotating rod is hinged to the first slider through a first connecting rod, and the other end of the rotating rod is hinged to the second slider through a second connecting rod.

8. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 7, characterized in that: The testing mechanism includes a support frame, a U-shaped support frame fixedly set on a mounting seat, a lifting hydraulic cylinder is set on the support frame, a mounting frame is set at the bottom end of the lifting hydraulic cylinder piston rod, a test wheel is rotatably set on the mounting frame, and a pressure sensor is set between the piston rod and the mounting frame.

9. The device for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 8, characterized in that: The mounting seat is provided with a power element for driving the test bench to slide. The power element is an electric cylinder, an air cylinder or a hydraulic cylinder. The piston rod of the power element is connected to the test bench. A track is provided in the mounting seat to guide the sliding of the test bench. The mounting seat is provided with a drainage pipe for discharging the accumulated water in the groove; the mounting seat is provided with an industrial camera for shooting the test process of the sample.

10. A detection method for detecting the crack resistance of asphalt concrete pavement in severe cold regions according to claim 9, characterized in that: The following steps are involved: S1. The motor drives the screw to rotate, which drives the slide to slide horizontally on the base. The slide drives the transmission plate to rotate through the guide column. The transmission plate drives the mounting base to rotate around the first rotation axis through the second rotation axis and the third fixed plate to adjust the angle of the mounting base. S2. Place the specimen in the slot and start the lifting hydraulic cylinder. The lifting hydraulic cylinder drives the mounting frame downward via the piston rod, which in turn drives the test wheel downward. The test wheel applies downward pressure to the specimen, which in turn applies downward pressure to the top block, which drives the transmission seat downward. The spring is compressed, and the transmission seat drives the slide plate to slide toward the transmission seat via the connecting rod. The slide plate drives the clamping plate to slide synchronously, and the clamping plate slides along the guide bar and is clamped to the side wall of the specimen. The clamping plate, specimen, and positioning block form a closed temperature adjustment chamber. S3, the lifting hydraulic cylinder continues to drive the test wheel to move downward until the pressure sensor reaches the set pressure; S4. Start the power element, which drives the test bench to slide back and forth in the mounting seat. Relative sliding occurs between the specimen and the test wheel. The crack resistance of the specimen under the set load is studied. The industrial camera captures pictures and videos of the specimen during the test. S5. The external medium tank, under the action of the circulation pump, introduces cooling or heating medium into the medium pipe to provide a service environment of a specific temperature for the specimen; S6. Turn on the water pump and start the telescopic cylinder. The telescopic cylinder drives the first slider to slide in the slide groove. The first slider drives the rotating rod to rotate through the first connecting rod. The rotating rod drives the second slider to slide through the second connecting rod. The first and second sliders drive the swing rod to swing. The swing rod drives the water pipe to swing. The water pipe drives the nozzle to spray water onto the surface of the sample, providing a freeze-thaw or rain-resistant service environment for the sample.

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