A fine separation-based RAP micro-surfacing road performance detection system

Abstract

This invention provides a road performance testing system for RAP micro-surfacing based on fine separation, relating to the field of performance testing technology. It includes: a test chamber assembly comprising a test chamber with a base mounted inside, and a test specimen mounted on the base; a power assembly mounted on the test chamber; a mounting assembly connected to the power assembly, the mounting assembly including a U-frame with symmetrical vertical slots, each slot containing a symmetrical guide rod connected to the U-frame; and a first test assembly including a mounting carriage. This invention addresses the shortcomings of existing technologies by developing a road performance testing system for RAP micro-surfacing based on fine separation. This system, through a four-level functional chain of "power-transmission-loading-sensing," achieves fine, repeatable, and quantifiable road performance testing of RAP micro-surfacing under straight-line, turning, variable-load, and multi-environment coupling conditions.

Description

Technical Field

[0001] This invention relates to the field of performance testing technology, and in particular to a road performance testing system for RAP micro-surfacing based on fine separation. Background Technology

[0002] In highway maintenance, recycled asphalt pavement (RAP) materials are reused by one-time crushing. The old asphalt pavement is ground and crushed, then mixed with recycling agents, cement, and aggregates before being repaved onto the road surface. The old road is then renovated through normal construction procedures.

[0003] Different particle sizes (0-3 mm and 0-5 mm) and different dosages (40%, 60%, 80%, 100%) of RAP have different effects on micro-surfacing performance. The road performance of RAP micro-surfacing based on fine separation can be investigated by wet tire abrasion test, loaded wheel sand adhesion test, and wheel rut deformation test.

[0004] Existing technologies, such as the invention of a wheel-pressure test device and method for road pavement fatigue-wear-damp heat, application number 202411196249.4, simulate real-world operating scenarios and comprehensively consider the impact of various adverse factors on the overall performance of the specimens, thereby enhancing the reliability of the test results.

[0005] Currently, there is a lack of a road performance testing system that can simulate the impact of different load conditions, such as wheels going straight and turning, on road surface performance.

[0006] Therefore, to address the above problems, a road performance testing system based on fine separation for RAP micro-surfacing is proposed. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention develops a road performance testing system for RAP micro-surface treatment based on fine separation. The entire system achieves fine, repeatable, and quantifiable road performance testing of RAP micro-surface treatment under straight-line, turning, variable load, and multi-environment coupling conditions through a four-level functional chain of "power-transmission-loading-sensing".

[0008] The technical solution to the technical problem solved by the present invention is as follows: The present invention provides a road performance testing system for RAP micro-surfacing based on fine separation, comprising: a test chamber assembly, including a test chamber, a base installed in the test chamber, a test specimen installed on the base, the test chamber isolating the test specimen from the outside world, and can precisely control boundary conditions such as temperature, humidity, and dust. The test specimen is higher than the base, which facilitates drainage when simulating rainy weather, while the base ensures that the test specimen is horizontal and stable, facilitating multiple test comparisons; a power assembly, installed on the test chamber, outputting motion; a mounting assembly, connected to the power assembly, the mounting assembly including a U-frame, the U-frame having symmetrical vertical grooves, each of the symmetrical vertical grooves having symmetrical guide vertical rods, each guide vertical rod being connected to the U-frame; a first test assembly including a mounting slide, each guide vertical rod passing through a corresponding mounting slide, the mounting slide being connected to a movable frame via symmetrical springs, each symmetrical spring looping around a corresponding guide vertical rod, the movable frame being connected to symmetrical L-mount plates, each symmetrical L-mount plate bearing axles, the axles being connected to straight wheels. The vertical displacement is converted into an adjustable wheel-road contact force by using a "spring-slide" system to simulate "vehicle straight-line crushing". The spring absorbs the impact, ensuring stable wheel load and avoiding rigid impact that could damage the specimen surface.

[0009] As an optimization, the test chamber is equipped with a guide groove, within which a slider is positioned. The slider is connected to a motor via a motor bracket. The motor's output shaft is connected to a vertical shaft, which is then connected to the slider via a bearing. The vertical shaft is housed within a vertical cylinder, with the upper end of the cylinder connected to the slider and the lower end connected to a U-frame. The vertical shaft connects to a large synchronous pulley, and the U-frame is connected to a small synchronous pulley via a bearing. An upper synchronous belt surrounds the large and small synchronous pulleys. The small synchronous pulley is connected to a splined shaft, which passes through the mounting slide and is housed within a splined tube shaft. The splined tube shaft is connected to the moving frame via a bearing, and the splined tube shaft connects to a first driving bevel gear. The wheel shaft connects to a first driven bevel gear, which meshes with the first driving bevel gear. By placing the splined shaft within the splined tube shaft and employing synchronous belt drive and bevel gear meshing, the motor's rotational motion is transmitted to the straight-line wheel, driving its rotation and enabling the entire vehicle to move forward. A single motor achieves two degrees of freedom: "vehicle forward movement + wheel rotation," resulting in a compact structure. The fitting method between the spline shaft and the spline tube shaft can transmit torque and allow vertical displacement, satisfying the changes in wheel-road clearance during loading.

[0010] As an optimization, a turning test component is also included. This component comprises an L-plate, with a bearing connecting the L-plate to a short splined tube shaft. The short splined tube shaft is connected to a corresponding moving frame via a bearing. A corresponding splined shaft is housed within the short splined tube shaft. The L-plate bearing connects to the central shaft of one synchronous pulley, and another synchronous pulley connects to the short splined tube shaft. A lower synchronous belt surrounds the two synchronous pulleys. The central shaft of one synchronous pulley connects to a second driving bevel gear. The L-plate bearing connects to a circular tube shaft, which in turn connects to a second driven bevel gear. The driven bevel gear meshes with the second driving bevel gear. A limit block and a horizontal spring are housed within the circular tube shaft. One end of the horizontal spring connects to the circular tube shaft, and the other end connects to the limit block. The limit block connects to a square shaft, which passes through the circular tube shaft and connects to a turning wheel. The L-plate rotatably connects to the piston rod of an adjusting hydraulic rod, which in turn rotatably connects to the corresponding moving frame. This adds a "turning test" function to the existing straight-line driving system. The steering angle of the turning wheel is changed by adjusting the L-plate and hydraulic rod, creating a comparative detection with the straight-moving wheel. This achieves a "straight-turn" composite driving condition without adding an extra motor, simulating vehicle lane changes and ramp driving.

[0011] As an optimization, the test chamber is connected to a pressure-regulating hydraulic rod, the piston rod of which is connected to a mounting plate, which in turn is connected to the mounting slide. A vertical force is applied to the mounting slide by the pressure-regulating hydraulic rod, thereby changing the spring compression and ultimately precisely controlling the contact stress between the straight wheel and the specimen. This achieves stepless adjustment of the wheel load from 0 to a set upper limit of kN, simulating vehicles with different axle loads. The hydraulic closed-loop control can maintain a constant wheel load or dynamically load according to sine, half-sine, and other waveforms to study the fatigue effect of dynamic load on the RAP micro-surface.

[0012] As an optimization, a gear is connected to the vertical shaft, and a rack is connected to the test chamber, with the gear meshing with the rack. Adding a gear to the vertical shaft, which meshes with the rack fixed to the test chamber, directly converts the motor rotation into the horizontal displacement of the slider.

[0013] As shown in the figure, the test chamber is connected to symmetrical guide crossbars, which pass through the U-frame to form a cantilever beam-type transverse guide rail. This restricts the U-frame to linear movement, preventing lateral bending moments on the motor shaft; it also improves system rigidity, reduces lateral swaying caused by reaction forces during loading, and ensures the wheel-road contact point position.

[0014] As an optimization, a sensor array is pre-embedded within the specimen. This may include strain gauges, fiber optic gratings, pressure cells, temperature and humidity probes, etc. Real-time data on internal stress, strain, temperature, and humidity of the RAP microsurface under wheel load is acquired; synchronized with external macroscopic indicators (wheel load, displacement, rotational speed), a "macro-micro" correlation is established for precise analysis of the damage mechanism of the RAP microsurface.

[0015] As an optimization, the U-frame is connected with symmetrical reinforcing rods. This improves the overall bending and torsional stiffness of the U-frame and reduces elastic deformation caused by reaction forces during loading. It also provides rigid mounting points for subsequent installation of additional equipment such as cameras and laser displacement gauges.

[0016] As an optimization, its usage is as follows: S1: Install water pipes and a heating module in the test chamber to simulate the effects of high temperature and rainfall on the specimen; S2: Install the specimen onto the base; S3: Control the extension of the pressure regulating hydraulic rod so that the straight wheel and the turning wheel contact the specimen; S4: Control the motor to rotate, so that the straight wheel and the turning wheel move forward, simulating a straight-line state; S5: Control the extension and retraction of the adjusting hydraulic rod to enable the turning wheel to turn. Due to the speed difference between the straight wheel and the turning wheel, the square shaft moves along the circular tube shaft, squeezing the horizontal spring and forming a drag mark. This can simulate the situation where the vehicle in front turns during an accident and the vehicle behind hits the vehicle in front and moves forward.

[0017] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. The above technical solutions have the following advantages or beneficial effects: (1) This system is a comprehensive platform for multi-condition, repeatable, and high-precision mechanical-environment coupling testing of recycled asphalt micro-surfaced specimens. Composite condition simulation: Through the same set of power and transmission mechanisms, it realizes three degrees of freedom motion of "vehicle straight driving + wheel rotation + controllable turning", realistically reproducing typical working conditions such as straight driving, lane changing, and ramp turning on highways. Parameters such as horizontal driving speed, turning radius, and loading frequency can be programmed to meet diverse test schemes. Precise wheel load control: The "flexible loading unit" composed of pressure-adjustable hydraulic rod and spring-slider frame can steplessly adjust the wheel load within the range of 0 to the set upper limit kN, and supports dynamic loading waveforms such as constant load, sine, half-sine, and pulse. Closed-loop control ensures wheel load stability and studies the effects of different axle loads and dynamic loads on the fatigue, permanent deformation, and spalling properties of micro-surfaced specimens. Synchronous monitoring: The pre-embedded sensor group inside the specimen acquires the "microscopic" responses such as stress, strain, temperature, and humidity in real time.

[0018] (2) This system uses a straight-line wheel to simulate straight-line driving and a turning wheel to simulate turning. Both can be tested simultaneously or separately. Under the conditions of Example 1, the turning wheel shows inclined scratches compared to the straight-line wheel. Under the conditions of Example 2, the turning wheel forms drag marks. Under the conditions of Example 3, due to the meshing of the gear and rack, the entire system moves forward, and the turning wheel forms inclined scratches on the specimen. Simulating multiple working conditions, this system realistically reflects the road performance of RAP micro-surfacing. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0021] Figure 2 For the present invention Figure 1 A magnified view of part A in the image.

[0022] Figure 3 This is a partially cut-out three-dimensional structural diagram of the present invention.

[0023] Figure 4 For the present invention Figure 3 A magnified view of part B in the image.

[0024] Figure 5 This is a partial three-dimensional structural diagram of the present invention. Figure 1 .

[0025] Figure 6 This is a partial three-dimensional structural diagram of the present invention. Figure 2 .

[0026] Figure 7 This is a partial three-dimensional structural diagram of the mounting component of the present invention.

[0027] Figure 8 This is a three-dimensional structural diagram of the first test component of the present invention.

[0028] Figure 9 This is a partial cutaway three-dimensional structural diagram of the turning test component of the present invention.

[0029] Figure 10 This is a partial three-dimensional structural diagram of the present invention. Figure 3 .

[0030] In the picture: 1. Test chamber assembly; 11. Test chamber; 12. Rack; 13. Guide groove; 14. Guide crossbar; 15. Specimen; 16. Base; 17. Sensor assembly. 2. Power components, 21. Motor, 22. Gear, 23. Slider, 24. Motor bracket, 25. Vertical shaft, 26. Large synchronous pulley, 27. Upper synchronous belt, 28. Small synchronous pulley, 29. Splined shaft; 3. Installation components: 31. Vertical cylinder, 32. U-frame, 33. Vertical groove, 34. Guide vertical rod, 35. Reinforcing rod; 4. First test component; 41. Pressure regulating hydraulic rod; 42. Mounting cross plate; 43. Mounting slide; 44. Spring; 45. Straight wheel; 46. L-mounting plate; 47. Wheel axle; 48. First driven bevel gear; 410. First driving bevel gear; 411. Moving frame; 412. Spline tube shaft. 5. Turning test assembly, 51. Short spline tube shaft, 52. Adjusting hydraulic rod, 53. Lower timing belt, 54. Second driving bevel gear, 55. Turning wheel, 56. Square shaft, 57. Round tube shaft, 58. Second driven bevel gear, 59. Timing wheel, 510. Limiting round block, 511. Horizontal spring, 512. L-plate. Detailed Implementation

[0031] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and processes are omitted to avoid unnecessarily limiting the invention. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] like Figures 1 to 10 As shown, a road performance testing system for RAP micro-surfacing based on fine separation includes: a test chamber component 1, comprising a test chamber 11, a base 16 installed inside the test chamber 11, and a test specimen 15 installed on the base 16. The test chamber 11 isolates the test specimen 15 from the outside environment, allowing precise control of boundary conditions such as temperature, humidity, and dust. The test specimen 15 is higher than the base 16, facilitating drainage during simulated rainy weather. Simultaneously, the base 16 ensures the test specimen 15 is level and stable, facilitating multiple comparative tests; a power component 2, installed on the test chamber 11, outputting motion; and a mounting component 3, connected to the power component 2, including a U-frame 32. The U-frame 32 is provided with symmetrical vertical grooves 33, and symmetrical guide vertical rods 34 are respectively provided in the symmetrical vertical grooves 33. Each guide vertical rod 34 is connected to the U-frame 32. The first test component 4 includes a mounting slide 43. Each guide vertical rod 34 passes through the corresponding mounting slide 43. The mounting slide 43 is connected to a moving frame 411 through symmetrical springs 44. The symmetrical springs 44 are respectively looped around the corresponding guide vertical rods 34. The moving frame 411 is connected to symmetrical L-mount plates 46. The symmetrical L-mount plates 46 are respectively connected to axles 47 by bearings. The axles 47 are connected to straight wheels 45. The vertical displacement is converted into an adjustable wheel-road contact force through the "spring-slide" to realize the simulation of "vehicle straight-line crushing". The springs 44 absorb the impact, ensure the wheel load is stable, and avoid rigid impact damage to the surface of the specimen.

[0033] like Figure 2 , 5As shown in Figures 6 and 8, the test chamber 11 is provided with a guide groove 13, and a slider 23 is provided in the guide groove 13. The slider 23 is connected to a motor 21 through a motor bracket 24. The output shaft of the motor 21 is connected to a vertical shaft 25. The vertical shaft 25 is connected to the slider 23 by a bearing. The vertical shaft 25 is located inside a vertical cylinder 31. The upper end of the vertical cylinder 31 is connected to the slider 23, and the lower end of the vertical cylinder 31 is connected to the U-frame 32. The vertical shaft 25 is connected to a large synchronous pulley 26, and the U-frame 32 is connected to a small synchronous pulley 26 by a bearing. A step wheel 28, with an upper synchronous belt 27 surrounding the large synchronous wheel 26 and the small synchronous wheel 28, the small synchronous wheel 28 connected to a splined shaft 29, the splined shaft 29 passing through the mounting slide 43, the splined shaft 29 being housed within a splined tube shaft 412, the splined tube shaft 412 bearing connected to the moving frame 411, the splined tube shaft 412 connected to a first driving bevel gear 410, and the wheel axle 47 connected to a first driven bevel gear 48, the first driven bevel gear 48 meshing with the first driving bevel gear 410. By placing the splined shaft 29 within the splined tube shaft 412, using synchronous belt drive and bevel gear meshing, the rotational motion of the motor 21 is transmitted to the straight wheel 45, driving the straight wheel 45 to rotate, thus achieving forward movement of the entire vehicle. A single motor achieves two degrees of freedom of "vehicle forward movement + wheel rotation," resulting in a compact structure. The fitting method between the spline shaft 29 and the spline tube shaft 412 can transmit torque and allow vertical displacement, satisfying the wheel-road clearance changes during loading.

[0034] like Figure 8-10 As shown, the test chamber 11 is connected to a pressure-adjusting hydraulic rod 41, the piston rod of which is connected to a mounting plate 42, which in turn is connected to the mounting slide 43. A vertical force is applied to the mounting slide 43 by the pressure-adjusting hydraulic rod 41, thereby changing the compression of the spring 44 and ultimately precisely controlling the contact stress between the straight wheel 45 and the specimen 15. This achieves stepless adjustment of the wheel load from 0 to a set upper limit of kN, simulating vehicles with different axle loads. The hydraulic closed-loop control can maintain a constant wheel load or dynamically load according to sine, half-sine, and other waveforms to study the fatigue effect of dynamic load on the RAP micro-surface.

[0035] like Figure 3 As shown, the test chamber 11 is connected to symmetrical guide crossbars 14, which pass through the U-frame 32 respectively, forming a "cantilever beam" type transverse guide rail. This restricts the U-frame 32 to move only in a straight line, avoiding lateral bending moment on the motor 21 shaft; it also improves system rigidity, reduces lateral swaying caused by reaction force during loading, and ensures the wheel-road contact point position.

[0036] like Figure 4As shown, the specimen 15 contains a pre-embedded sensor group 17. This may include strain gauges, fiber optic gratings, pressure cells, temperature and humidity probes, etc. It collects real-time data on the internal stress, strain, temperature, and humidity of the RAP microsurface under wheel load; synchronized with external macroscopic indicators (wheel load, displacement, rotational speed), it establishes a "macro-micro" correlation for precise analysis of the damage mechanism of the RAP microsurface.

[0037] like Figure 7 As shown, the U-frame 32 is connected to symmetrical reinforcing rods 35. This improves the overall bending and torsional stiffness of the U-frame 32 and reduces elastic deformation caused by reaction forces during loading. It also provides rigid mounting points for subsequent installation of additional equipment such as cameras and laser displacement gauges.

[0038] Each specimen contains RAP with different particle sizes (0-3 mm and 0-5 mm) and different dosages (40%, 60%, 80%, 100%). This allows for comparative testing.

[0039] Example 1: The slider 23 is fixedly connected to the test chamber 11.

[0040] The workflow of this embodiment is as follows: Water pipes and heating modules were installed in test chamber 11 to simulate the effects of high temperature and rainfall on the specimens.

[0041] The sensor group 17 monitors the temperature and humidity inside the test chamber 11 and monitors the pressure of the straight wheel 45 on the specimen 15.

[0042] The control motor 21 rotates, which drives the vertical shaft 25 and the large synchronous pulley 26 to rotate. The large synchronous pulley 26 drives the upper synchronous belt 27 to move. The upper synchronous belt 27 drives the small synchronous pulley 28, the spline shaft 29, the spline tube shaft 412 and the first driving bevel gear 410 to rotate. The first driving bevel gear 410 drives the first driven bevel gear 48, the wheel shaft 47 and the straight pulley 45 to rotate. The straight pulley 45 contacts the specimen 15 and rubs against the specimen 15 in place.

[0043] By controlling the extension and retraction of the pressure regulating hydraulic rod 41, the pressure regulating hydraulic rod 41 drives the mounting horizontal plate 42 to move downward, the mounting horizontal plate 42 drives the mounting slide 43 to move along the guide vertical rod 34, and the mounting slide 43 compresses the spring 44 to adjust the pressure between the straight wheel 45 and the specimen 15.

[0044] Example 2: The slider 23 can move along the guide groove 13.

[0045] The workflow of this embodiment is as follows: The straight wheel 45 rotates, rubs against the specimen 15, and moves along the surface of the specimen 15, thereby enabling the power assembly 2, the mounting assembly 3, and the first test assembly 4 to move in a straight line. The slider 23 moves along the guide groove 13, and the U-frame 32 moves along the guide crossbar 14.

[0046] Example 3: Figure 2 As shown, the vertical shaft 25 is connected to the gear 22, and the test chamber 11 is connected to the rack 12. The gear 22 meshes with the rack 12. By installing the gear 22 on the vertical shaft 25 and meshing with the rack 12 fixed on the test chamber 11, the rotation of the motor 21 is directly converted into the horizontal displacement of the slider 23.

[0047] The workflow of this embodiment is as follows: When the motor 21 rotates, it drives the gear 22 to rotate. The gear 22 meshes with the rack 12, enabling the gear 22 to move. This, in turn, enables the power assembly 2, the mounting assembly 3, and the first test assembly 4 to move in a straight line. The slider 23 moves along the guide groove 13, and the U-frame 32 moves along the guide crossbar 14, enabling the straight wheel 45 to move along the test piece 15.

[0048] Example 4: This example is a further elaboration based on Example 1, 2, or 3, such as... Figure 5 , 6 As shown in Figure 9, the system also includes a turning test assembly 5, which includes an L-plate 512. The L-plate 512 is bearing-connected to a short splined tube shaft 51, which is bearing-connected to a corresponding moving frame 411. A corresponding splined shaft 29 is disposed within the short splined tube shaft 51. The L-plate 512 is bearing-connected to the central shaft of one synchronous pulley 59, and another synchronous pulley 59 is connected to the short splined tube shaft 51. A lower synchronous belt 53 surrounds the two synchronous pulleys 59. The central shaft of one synchronous pulley 59 is connected to a second driving bevel gear 54. The L-plate 512 is bearing-connected to a round tube shaft 57. The circular tube shaft 57 is connected to a second driven bevel gear 58, which meshes with a second driving bevel gear 54. A limiting block 510 and a horizontal spring 511 are provided inside the circular tube shaft 57. One end of the horizontal spring 511 is connected to the circular tube shaft 57, and the other end is connected to the limiting block 510. The limiting block 510 is connected to a square shaft 56, which passes through the circular tube shaft 57 and is connected to a turning wheel 55. The L-plate 512 is rotatably connected to the piston rod of the adjusting hydraulic rod 52, which is rotatably connected to the corresponding moving frame 411. A "turning test" function is superimposed on the existing straight-line driving system. By changing the steering angle of the turning wheel 55 through the L-plate 512 and the adjusting hydraulic rod 52, a comparative detection with the straight-line wheel 45 is formed. A "straight-line-turning" composite working condition can be achieved without adding an additional motor, simulating vehicle lane changes and ramp driving.

[0049] The workflow of this embodiment is as follows: By controlling the extension and retraction of the hydraulic rod 52, the hydraulic rod 52 drives the L plate 512 to swing, the L plate 512 drives the hydraulic rod 52 to swing, and the L plate 512 drives the lower synchronous belt 53, a synchronous pulley 59, a second driving bevel gear 54, a round tube shaft 57, a second driven bevel gear 58, a square shaft 56, a limit block 510, a horizontal spring 511 and a turning wheel 55 to swing, so that the turning wheel 55 turns.

[0050] Under the premise of Embodiment 1, the scratches on the turning wheel 55 are inclined compared to those on the straight wheel 45.

[0051] Under the premise of Embodiment 2, since the turning test assembly 5 moves forward as a whole, the turning wheel 55 and the straight wheel 45 have the same wheel speed. The turning wheel 55 drives the square shaft 56 and the limiting block 510 to move within the circular tube shaft 57, compressing the horizontal spring 511. It is necessary to quickly control the reverse extension and retraction of the adjusting hydraulic rod 52. The turning wheel 55 forms drag marks.

[0052] Under the premise of Example 3, due to the meshing of the gear and rack, the whole is driven forward, and the turning wheel 55 forms an inclined scratch on the specimen 15.

[0053] Its usage method is as follows: S1: Install water pipes and heating modules in the test chamber 11 to simulate the effects of high temperature and rainfall on the specimens; S2: Install the specimen 15 onto the base 16; S3: Control the extension of the pressure regulating hydraulic rod 41 so that the straight wheel 45 and the turning wheel 55 contact the specimen 15; S4: Control the motor 21 to rotate, so that the straight wheel 45 and the turning wheel 55 move forward, simulating a straight-line state; S5: Control the extension and retraction of the adjusting hydraulic rod 52 to enable the turning wheel 55 to turn. Due to the speed difference between the straight wheel 45 and the turning wheel 55, the square shaft 56 moves along the round tube shaft 57, squeezing the horizontal spring 511 to form a drag mark, which can simulate the turning of the front vehicle and the rear vehicle hitting the front vehicle during an accident.

[0054] This system is a comprehensive platform for multi-condition, repeatable, and high-precision mechanical-environment coupled testing of micro-surfaced recycled asphalt specimens. Composite Condition Simulation: Through a single power and transmission mechanism, it achieves three degrees of freedom motion: vehicle straight-line driving + wheel rotation + controlled turning, realistically reproducing typical conditions such as highway straight-line driving, lane changing, and ramp turning. Parameters such as horizontal driving speed, turning radius, and loading frequency are all programmable to meet diverse test schemes. Precise Wheel Load Control: The "flexible loading unit" composed of a pressure-adjustable hydraulic rod 41 and a spring-slider frame can steplessly adjust the wheel load within the range of 0 to a set upper limit kN, and supports dynamic loading waveforms such as constant load, sine, half-sine, and pulse. Closed-loop control ensures wheel load stability, allowing for the study of the effects of different axle loads and dynamic loads on the fatigue, permanent deformation, and spalling properties of the micro-surfaced material. Synchronous Monitoring: The pre-embedded sensor group 17 inside the specimen acquires real-time "microscopic" responses such as stress, strain, temperature, and humidity.

[0055] This system uses a straight-line driving wheel 45 to simulate straight-line driving and a turning wheel 55 to simulate turning. Both can be tested simultaneously or separately. Under the conditions of Example 1, the turning wheel 55 shows a more inclined scratch compared to the straight-line driving wheel 45. Under the conditions of Example 2, the turning wheel 55 forms drag marks. Under the conditions of Example 3, due to the meshing of the gear and rack, the entire system moves forward, and the turning wheel 55 forms an inclined scratch on the specimen 15. Simulating multiple working conditions, this system realistically reflects the road performance of RAP micro-surfacing.

[0056] Although the specific embodiments of the invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the invention. Based on the technical solutions of the invention, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the invention.

Claims

1. A road performance testing system for RAP micro-surfacing based on fine separation, characterized in that, include: The test chamber assembly (1) includes a test chamber (11) in which a base (16) is installed and a test specimen (15) is installed on the base (16). The power unit (2) is installed on the test chamber (11); The mounting component (3) is connected to the power component (2). The mounting component (3) includes a U-frame (32). The U-frame (32) is provided with symmetrical vertical slots (33). Symmetrical guide rods (34) are respectively provided in the symmetrical vertical slots (33). Each guide rod (34) is connected to the U-frame (32). The first test component (4) includes a mounting carriage (43), each of the guide rods (34) passing through the corresponding mounting carriage (43). The mounting carriage (43) is connected to a movable frame (411) by symmetrical springs (44). The symmetrical springs (44) are respectively looped around the corresponding guide rods (34). The movable frame (411) is connected to symmetrical L-mount plates (46). The symmetrical L-mount plates (46) are respectively connected to axles (47) by bearings. The axles (47) are connected to straight wheels (45).

2. The RAP micro-surfacing performance testing system based on fine separation according to claim 1, characterized in that: The test chamber (11) is provided with a guide groove (13), and a slider (23) is provided in the guide groove (13). The slider (23) is connected to a motor (21) through a motor bracket (24). The output shaft of the motor (21) is connected to a vertical shaft (25). The vertical shaft (25) is connected to the slider (23) by a bearing. The vertical shaft (25) is set in a vertical cylinder (31). The upper end of the vertical cylinder (31) is connected to the slider (23), and the lower end of the vertical cylinder (31) is connected to the U-frame (32). The vertical shaft (25) is connected to a large synchronous pulley (26), and the U-frame (32) is connected to a small synchronous pulley by a bearing. The wheel (28) is surrounded by a timing belt (27) around the large timing wheel (26) and the small timing wheel (28). The small timing wheel (28) is connected to a spline shaft (29). The spline shaft (29) passes through the mounting slide (43). The spline shaft (29) is located inside a spline tube shaft (412). The spline tube shaft (412) is connected to the moving frame (411) by a bearing. The spline tube shaft (412) is connected to a first driving bevel gear (410). The wheel shaft (47) is connected to a first driven bevel gear (48). The first driven bevel gear (48) meshes with the first driving bevel gear (410).

3. The RAP micro-surfacing performance testing system based on fine separation according to claim 2, characterized in that: It also includes a turning test assembly (5), which includes an L-plate (512), the L-plate (512) bearing connected to a short spline tube shaft (51), the short spline tube shaft (51) bearing connected to a corresponding moving frame (411), the short spline tube shaft (51) having a corresponding spline shaft (29) inside, the L-plate (512) bearing connected to the central shaft of one synchronous pulley (59), the other synchronous pulley (59) connected to the short spline tube shaft (51), a lower synchronous belt (53) surrounding the two synchronous pulleys (59), the central shaft of one synchronous pulley (59) connected to a second driving bevel gear (54), the L-plate (512) bearing connected to a round tube shaft (57), the round tube shaft ( 57) Connect the second driven bevel gear (58), the second driven bevel gear (58) meshes with the second driving bevel gear (54), the circular tube shaft (57) is provided with a limiting block (510) and a horizontal spring (511), one end of the horizontal spring (511) is connected to the circular tube shaft (57), the other end of the horizontal spring (511) is connected to the limiting block (510), the limiting block (510) is connected to the square shaft (56), the square shaft (56) passes through the circular tube shaft (57), the square shaft (56) is connected to the turning wheel (55), the L plate (512) is rotatably connected to the piston rod of the adjusting hydraulic rod (52), and the adjusting hydraulic rod (52) is rotatably connected to the corresponding moving frame (411).

4. The RAP micro-surfacing performance testing system based on fine separation according to claim 3, characterized in that: The test chamber (11) is connected to a pressure regulating hydraulic rod (41), the piston rod of the pressure regulating hydraulic rod (41) is connected to a mounting plate (42), and the mounting plate (42) is connected to the mounting slide (43).

5. The RAP micro-surfacing performance testing system based on fine separation according to claim 2, characterized in that: The vertical shaft (25) is connected to the gear (22), the test chamber (11) is connected to the rack (12), and the gear (22) meshes with the rack (12).

6. The RAP micro-surfacing performance testing system based on fine separation according to claim 1, characterized in that: The test chamber (11) is connected to symmetrical guide crossbars (14), which pass through the U-frame (32) respectively.

7. The RAP micro-surfacing performance testing system based on fine separation according to claim 1, characterized in that: The test piece (15) contains a pre-embedded sensor group (17).

8. The RAP micro-surfacing performance testing system based on fine separation according to claim 1, characterized in that: The U-frame (32) is connected to symmetrical reinforcing rods (35).

9. The RAP micro-surfacing performance testing system based on fine separation according to claim 4, characterized in that: Its usage method is as follows: S1: Install water pipes and heating modules in the test chamber (11) to simulate the effects of high temperature and rainfall on the specimen; S2: Install the specimen (15) onto the base (16); S3: Control the extension of the pressure regulating hydraulic rod (41) so that the straight wheel (45) and the turning wheel (55) contact the specimen (15). S4: Control the motor (21) to rotate, so that the straight wheel (45) and the turning wheel (55) move forward, simulating a straight-line state; S5: Control the extension and retraction of the adjusting hydraulic rod (52) to realize the turning wheel (55) turning. Due to the speed difference between the straight wheel (45) and the turning wheel (55), the square shaft (56) moves along the round tube shaft (57), squeezing the horizontal spring (511) to form drag marks, which can simulate the turning of the front vehicle and the collision of the rear vehicle with the front vehicle during an accident.

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