Pavement long-term performance tester with simulated high temperature and precipitation environment

Abstract

The present invention provides a long-term pavement performance tester capable of simulating high temperature and precipitation environments. The tester comprises a frame, a motor, a control box, a wheel frame, and a wheel. A housing is fixed to the outer surface of the frame, and a test chamber with an open lower end is formed within the housing. The tester is characterized in that it includes a spray system and a heating device. The spray system comprises a water tank, a spray water pump, a solenoid valve, an annular water pipe, and a spray head. The spray heads are evenly arranged on the annular water pipe. The water inlet of the spray water pump is connected to the bottom of the water tank via an outlet pipe, and the water outlet of the spray water pump is connected to the annular water pipe via a solenoid valve. The heating device comprises a heating pipe. The asphalt pavement rutting tester of the present invention simulates an "all-weather natural environment" for asphalt pavements and can effectively simulate high summer temperatures and rainfall environments, making the long-term performance test of the pavement more closely resemble the actual use conditions of asphalt pavements.

Description

Technical Field

[0001] The present invention relates to a pavement long-term performance tester, and more particularly to a pavement long-term performance tester capable of simulating high temperature and precipitation environments. Background Art

[0002] To evaluate the long-term performance of asphalt pavements, fatigue cracking and rutting tests are conducted on the pavement under simulated vehicle loads. Currently, these tests are typically performed using a rutting tester and accelerated loading equipment. During the rutting test, a square asphalt slab (typically 305mm x 305mm) with a thickness between 40 and 100mm is prepared from the asphalt mixture. This slab is then placed in the tester, and a counterweight is used to apply a load to a simulated wheel. The simulated wheel is then driven back and forth across the slab until the desired number of movements is reached. The rutting depth is then analyzed to evaluate the asphalt mixture's rutting resistance. Accelerated loading equipment often employs a hydraulic loading system to simulate heavy vehicle loading on the pavement. Either a reciprocating or circular loading system can be used.

[0003] However, existing rutting testers operate in an idealized environment, employing a constant loading rate and fixed wheel pressure. These tests typically fail to simulate the actual operating environment of asphalt mixtures after they are laid on the roadbed, and are unable to simulate the temperature and precipitation conditions experienced in actual use. While accelerated loading test systems can realistically simulate vehicle loads, their bulk, inconvenience in mobility, inaccurate load measurements during movement, difficulty simulating the pavement's operating environment, and the inability to monitor test data in real time significantly limit their widespread application. Asphalt pavements are subject to a wide range of environmental factors during actual use. For example, in the hot summer, pavement temperatures often reach 40°C to 60°C, or even higher, contributing to the risk of rutting. Furthermore, precipitation can also affect the performance of the asphalt concrete on the pavement. Rainfall, especially in the summer, increases the hydrodynamic pressure within the pavement, causing delamination of the pavement material. The combined effects of high temperature and hydrodynamic pressure exacerbate pavement damage, a dynamic process that cannot be simulated by existing rutting testers and accelerated loading equipment.

[0004] Existing rutting testing machines can only perform rutting tests and analysis on rutting plates formed by asphalt concrete materials within the laboratory. However, the actual shear and deformation resistance of asphalt pavements is not only related to the material, but also to the asphalt mixture's paving process, base layer, and roadbed conditions. Although accelerated loading equipment can simulate full-scale pavement, it is difficult to accurately load the equipment during the test and cannot simulate environmental factors. Therefore, by developing and promoting the use of long-term pavement performance testers, it will be possible to more accurately and scientifically analyze the long-term performance, paving process, base layer, and roadbed conditions of asphalt pavements, bridge decks, and airport pavements. This will provide guidance for asphalt pavement construction, thereby extending the pavement's lifespan and reducing the project cost throughout its entire life cycle. Summary of the Invention

[0005] In order to overcome the disadvantages of the above technical problems, the present invention provides a pavement long-term performance tester capable of simulating high temperature and precipitation environments.

[0006] The present invention provides a pavement long-term performance tester capable of simulating high temperature and precipitation environments, comprising a frame, a motor, a control box, a wheel frame, and a wheel. A housing is fixed to the outer surface of the frame, and the interior of the housing forms a test chamber with an open lower end. The motor and control box are fixed to the frame, and the wheel frame and wheel are located in the test chamber. The wheel is mounted on the wheel frame and applies pressure to an asphalt pavement to be tested. The motor drives the wheel frame to rotate via a transmission mechanism, and the wheel follows the rotation of the wheel frame to achieve rolling of the asphalt pavement. The apparatus is characterized in that it includes a spray system and a heating device. The spray system comprises a water tank, a spray water pump, a solenoid valve, an annular water pipe, and a spray head. The water tank is fixed to the housing, and the annular water pipe is fixed to the wheel frame. A plurality of spray heads are evenly arranged on the annular water pipe for spraying water onto the asphalt pavement in the test chamber. The water inlet of the spray water pump is connected to the bottom of the water tank via a water outlet pipe, and the water outlet of the spray water pump is connected to the annular water pipe via a solenoid valve. The heating device comprises a heating pipe disposed in the test chamber, and the heating pipe is connected to a heating power supply in the control box.

[0007] The present invention has a pavement long-term performance tester capable of simulating high temperature and precipitation environments. A plurality of laser rangefinders for measuring rutting depth are evenly arranged on the outer shell above the asphalt pavement. A pavement temperature sensor for measuring the temperature of the asphalt pavement is fixed on the outer shell above the asphalt pavement. An air temperature sensor for measuring the ambient temperature of the air in the test chamber is arranged on the outer shell. A photoelectric switch for measuring the number of rotations of the wheel frame is arranged on the outer shell.

[0008] The present invention provides a pavement long-term performance tester capable of simulating high temperature and precipitation environments. The control box is provided with a control circuit consisting of a PLC controller and a frequency converter. The outputs of an air temperature sensor and a pavement temperature sensor are connected to an analog input port of the PLC controller after being isolated by an isolator. The output of a photoelectric switch is connected to a switch input terminal of the PLC controller. A laser rangefinder is connected to the PLC controller via an RS485 bus. A heating tube includes a 1# heating lamp and a 2# heating lamp. The power supply circuits of the 1# heating lamp, the 2# heating lamp, the spray water pump, and the solenoid valve are connected in series with the normally open points of relays K1, K2, K3, and K4, respectively. The coils of relays K1, K2, K3, and K4 are connected to different switch output terminals of the PLC controller.

[0009] The power supply is connected to the power input terminal of the motor through the frequency converter, and the control terminal of the frequency converter is connected to the signal output terminal of the PLC logic controller; the forward control terminal and the reverse control terminal of the frequency converter are respectively connected in series with the normally open point of relay K5 and the normally open point of relay K6, and the coil of relay K5 and the coil of relay K6 are respectively connected to different switching output terminals of the PLC controller.

[0010] The pavement long-term performance tester with a simulated high temperature and precipitation environment of the present invention comprises a transmission mechanism consisting of a fixed shaft, a driving bevel gear, a driven bevel gear, an inner sleeve and an outer sleeve; a bracket is fixed above the frame; the fixed shaft is fixed to the bracket; the lower end of the fixed shaft extends into the test cavity; the inner sleeve is rotatably arranged on the periphery of the lower end of the fixed shaft; a bolt supporting the inner sleeve is fixed to the lower end of the fixed shaft; the driven bevel gear is fixed to the upper end of the inner sleeve; the driving bevel gear meshes with the driven bevel gear; the driving bevel gear is fixed to the output shaft of the motor; the outer sleeve is located on the periphery of the inner sleeve; key slots are provided on the outer surface of the inner sleeve and on the inner surface of the outer sleeve along the length thereof; the inner sleeve and the outer sleeve are connected via keys located in the key slots;

[0011] The wheel frame consists of an outer ring plate and three webs. The three webs are horizontal, and the angle between two adjacent webs is 120°. The inner ends of the webs are fixed to the outer sleeve, and the outer ring plate is fixed to the three webs with the fixed axis as the center of the circle, and the wheel is fixed to the webs.

[0012] The pavement long-term performance tester capable of simulating high temperature and precipitation environments of the present invention has a detachable counterweight fixed on the outer ring plate.

[0013] The present invention has a pavement long-term performance tester that simulates high temperature and precipitation environments. The wheel is fixed to the inverted U-shaped wheel frame via a wheel axle. The inverted U-shaped wheel frame is connected to the web via a connecting rod. A support spring for shock absorption is provided on the periphery of the connecting rod.

[0014] The pavement long-term performance tester of the present invention has a simulated high temperature and precipitation environment. Screws are provided on the four corners of the frame. The screws are connected to the frame in the form of threaded connections. A walking wheel is fixed to the lower end of the screw, and a handwheel for rotating the screw is fixed to the upper end of the screw.

[0015] The beneficial effects of the present invention are as follows: the asphalt pavement rutting tester of the present invention is provided with a frame, a shell, a motor, a control box, a wheel frame and a wheel. The motor drives the wheel frame to rotate through a transmission mechanism so as to carry out a long-term performance test of the vehicle on the asphalt pavement; by setting a spray system composed of a water tank, a spray water pump, an electromagnetic valve, an annular water pipe and a spray head, and a heating device composed of a heating pipe arranged in the test chamber, the ambient temperature in the test chamber and the temperature of the asphalt pavement are controlled, and the rainfall state in the natural environment is simulated, thereby realizing the "all-weather natural environment" simulation of the asphalt pavement, which is beneficial to the real simulation of the summer high temperature and summer rainfall environment of the asphalt pavement to be tested, so that the long-term performance test of the pavement is closer to the actual use condition of the asphalt pavement, and is beneficial to obtain long-term performance test data of the pavement that is more in line with the actual application of the road.

[0016] Furthermore, by arranging pavement and air temperature sensors, laser rangefinders, and photoelectric switches on the outer shell, automatic measurement of rutting depth, measurement of air temperature in the test chamber and temperature of the asphalt pavement, and automatic vehicle number of wheel revolutions are achieved, which is conducive to the automatic execution of rutting test parameters after setting.

[0017] Furthermore, by providing an inner sleeve and an outer sleeve connected by a keyway and key in the transmission mechanism between the motor and wheel carrier, not only does the motor drive the wheel carrier and wheel to rotate, but the outer sleeve also descends with the inner sleeve under the downward pressure of the counterweight. This ensures that the full weight of the counterweight remains applied to the wheel as the rutting depth increases during the test, ensuring that the pressure exerted by the tire on the asphalt pavement remains constant. Furthermore, by adjusting the counterweight, different vehicle loads and tire-to-pavement pressures can be simulated.

[0018] Furthermore, by setting screws at the four corners of the frame and setting handwheels and walking wheels at the upper and lower ends of the screws, the entire pavement long-term performance tester can be pushed to an actual paved asphalt road for testing, so as to analyze the long-term performance indicators of the asphalt paved road and provide opinions and guidance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a front view of the pavement long-term performance tester of the present invention;

[0020] Figure 2 It is a rear view of the pavement long-term performance tester of the present invention;

[0021] Figure 3 It is a left side view of the pavement long-term performance tester of the present invention;

[0022] Figure 4 It is a right side view of the pavement long-term performance tester of the present invention;

[0023] Figure 5 A top view of the pavement long-term performance tester of the present invention;

[0024] Figure 6 A perspective view of the pavement long-term performance tester of the present invention;

[0025] Figure 7 A perspective view of the pavement long-term performance tester of the present invention;

[0026] Figure 8 This is a three-dimensional diagram of the pavement long-term performance tester of the present invention with the outer shell removed;

[0027] Figure 9 for Figure 5 Cross-sectional view of section AA;

[0028] Figure 10 for Figure 9 A partial enlarged view of the middle B area;

[0029] Figure 11 This is a control principle diagram of the pavement long-term performance tester of the present invention;

[0030] Figure 12 The figure is a connection circuit diagram of the PLC controller and the peripheral relays in the present invention;

[0031] Figure 13 This is a schematic diagram showing the connection between the temperature sensor and the control circuit in the present invention;

[0032] Figure 14 This is the wiring schematic diagram of the frequency converter in the present invention.

[0033] In the figure: 1 frame, 2 shell, 3 test chamber, 4 motor, 5 bracket, 6 control box, 7 water tank, 8 heating pipe, 9 wheel frame, 10 wheel, 11 water outlet pipe, 12 spray water pump, 13 solenoid valve, 14 annular water pipe, 15 sprinkler head, 16 touch screen, 17 observation window, 18 laser rangefinder, 19 air temperature sensor, 20 pavement temperature sensor, 21 photoelectric switch, 22 fixed shaft, 23 web, 24 inner ring plate, 25 outer ring plate, 26 driving bevel gear, 27 driven bevel gear, 28 inner sleeve, 29 outer sleeve, 30 bolt, 31 keyway, 32 key, 33 counterweight, 34 support spring, 35 inverted U-shaped wheel frame, 36 connecting rod, 37 lead screw, 38 walking wheel, 39 handwheel, 40 test foundation, 41 asphalt pavement, 42 PLC controller, 43 inverter. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0035] like Figures 1 to 5 As shown, the front view, rear view, left view, right view and top view of the pavement long-term performance tester of the present invention are respectively given, Figure 6 and Figure 7 Its stereogram is given, Figure 8 A three-dimensional view with the outer casing removed shows the pavement long-term performance tester, which consists of a frame 1, outer casing 2, motor 4, bracket 5, control box 6, water tank 7, heating pipe 8, wheel frame 9, wheel 10, water outlet pipe 11, spray pump 12, solenoid valve 13, annular water pipe 14, spray head 15, and heating pipe 8. Frame 1 serves as a fixture and support. Frame 1 is in the shape of a cube or rectangular parallelepiped. A metal plate is attached to and fixed to the outer surface of frame 1 to form outer casing 2. The interior of outer casing 2 defines a test chamber 3, open only at the lower end. Wheel frame 9 and wheels 10 are located within test chamber 3. Three wheels 10 are shown, evenly fixed to wheel frame 9. Motor 4 and control box 6 are both fixed above outer casing 2. Motor 4 drives wheel frame 9 through a transmission mechanism, which in turn rotates wheels 10, thereby rolling the asphalt pavement 41 to perform a rutting test.

[0036] The illustrated water tank 9, spray pump 12, solenoid valve 13, annular water pipe 14, and sprinkler head 15 constitute a sprinkler system that simulates a rainfall environment on the asphalt pavement 41 within the test chamber 3. The water tank 9, spray pump 12, and solenoid valve 13 are all fixed to the upper surface of the housing 2. The annular water pipe 14 is fixed to the wheel frame 9 within the test chamber 3. The sprinkler head 15 is fixed downwardly to the annular water pipe 14 and communicates with the annular water pipe 14. The water inlet of the spray pump 12 communicates with the bottom of the water tank 9, and the water outlet of the spray pump 12 communicates with the annular water pipe 14 via the solenoid valve 13. Thus, the spray pump 12 pumps water from the water tank 7 and sprays it through the sprinkler head 15 onto the asphalt pavement 41 to be tested, simulating rainfall.

[0037] The test chamber 3 shown is provided with two heating tubes 8 (respectively designated as heating tube #1 and heating tube #2). The heating tubes 8 form a heating device. The heating tubes 8 are connected to a heating power supply via a control circuit in a control box 6. Under the control of the control circuit, the heating tubes 8 are used to control and adjust the ambient temperature in the test chamber 3 and the temperature of the asphalt pavement 41.

[0038] As can be seen, the use of a heating device to regulate and control the ambient temperature in the test chamber 3 and the temperature of the asphalt pavement 41 can simulate the high-temperature air and road conditions of summer, facilitating analysis of rutting test data on the asphalt pavement 41 under high-temperature conditions. The spray system can simulate precipitation conditions on the asphalt pavement 41, allowing for rutting tests under rainfall to analyze the pavement's rutting performance under these conditions.

[0039] Four downward-facing laser rangefinders 18 are fixed to the housing 2 above the asphalt pavement 41. Specifically, the laser rangefinders 18 are located above the ruts created by the wheels 10 on the asphalt pavement 41 to measure the depth of the ruts. A pavement temperature sensor 20 is also fixed to the housing 2 above the asphalt pavement 41. This infrared temperature sensor enables non-contact measurement of the pavement temperature, allowing the road surface to be heated to the desired temperature using the heating tube 8. An air temperature sensor 19 is also provided on the housing 2. This air temperature sensor 19 measures the ambient air temperature within the test chamber 3 and can be a conventional temperature sensor. To measure the number of revolutions completed by the wheels 10, a photoelectric switch 21 is provided on the housing 2. If three webs 23 are used on the wheel carrier 9, the photoelectric switch 21 counts one revolution for every three switch signals input.

[0040] During the test, to facilitate observation of the conditions within the test chamber 3, the housing 2 is provided with two glass-sealed observation windows 17. The control box 6 is provided with a touchscreen 16 for displaying information and entering test parameters, such as the motor 4 speed, forward or reverse rotation, pavement temperature, total number of rotations, spray cycle, and spray duration. It also displays the real-time motor speed, air temperature, pavement temperature, and the rutting depths measured by the laser rangefinders 18.

[0041] like Figure 9 As shown, given Figure 5 The cross-sectional view of section AA, Figure 10 Given Figure 9 The partial enlarged view of the middle B area shows a transmission mechanism consisting of a fixed shaft 22, a driving bevel gear 26, a driven bevel gear 27, an inner sleeve 28, and an outer sleeve 29. A bracket 5 is fixed above the frame 1. The fixed shaft 22 is fixed to the bracket 5 in an upright state, and the lower end of the fixed shaft 22 passes through the outer shell 2 and extends into the test cavity 3. The inner sleeve 28 is located on the periphery of the lower end of the fixed shaft 22, and the inner sleeve 28 can rotate freely along the fixed shaft 22. A bolt 30 is fixed to the lower end of the fixed shaft 22 to limit the inner sleeve 28. A driven bevel gear 27 with a tooth surface tilted upward is fixed to the upper end of the inner sleeve 28. The driving bevel gear 26 is fixed to the output shaft of the motor 4, and the driving bevel gear 26 is meshed with the driven bevel gear 27.

[0042] The outer sleeve 29 is positioned around the inner sleeve 28, with a clearance fit between them. Key slots 31 are defined on the outer surface of the inner sleeve 28 and the inner surface of the outer copper sleeve 29. The length of the key slots 31 runs along the lengths of the inner and outer sleeves 28 and 29, respectively. The inner and outer sleeves 28 and 29 are connected via a key 32 positioned within the key slots 31. Thus, as the motor 4 rotates the inner sleeve 28 through the meshing of the driving bevel gear 26 and the driven bevel gear 27, the inner sleeve 28 drives the outer sleeve 29 to rotate synchronously with it through the key connection. Simultaneously, as the rutting depth increases, the outer sleeve 29 descends along with the wheel carrier 9.

[0043] The wheel carrier 9 shown is composed of an outer ring plate 25 and three web plates 23. The outer ring plate 25 is annular, with the three web plates 23 arranged at a 120° angle relative to each other. The inner ends of the web plates 23 are fixed to the outer surface of the outer sleeve 29. The outer ring plate 25 is fixed to the three web plates 23 with the fixed axis 22 in a circular shape, thus forming a stable wheel carrier 9. An inner ring plate 24 is fixed to the frame 1 above the wheel carrier 9, and the annular water pipe 14 is fixed to the inner ring plate 24. Three removable counterweights 33 are fixed to the outer ring plate 25. By changing the weight of the counterweights 33, the pressure applied by the wheel 10 on the asphalt pavement 41 can be adjusted.

[0044] The wheel 10 shown is arranged at the outer end of the web 23 via an inverted U-shaped wheel frame 35 and a connecting rod 36. The wheel 10 is rotatably arranged on the inverted U-shaped wheel frame 35 via the wheel axle. The inverted U-shaped wheel frame 35 is connected to the web 23 via the connecting rod 36. A support spring 34 is arranged on the periphery of the connecting rod 36. The support spring 34 is used to reduce the vibration of the wheel 10 during the rolling process on the asphalt pavement 41.

[0045] If the rutting test is conducted in a laboratory, a circular asphalt pavement 41 can be laid on the test foundation 40. If the test needs to be conducted on an actual asphalt road, the entire tester must be moved to the road. To facilitate the movement of the entire tester, screws 37 are provided at the four corners of the frame 1 shown. Screws 37 are connected to the frame 1 via threads. The lower ends of the screws 37 are fixed to running wheels 38, and the upper ends are fixed to handwheels 39. By turning handwheels 39, the frame 1 can be driven to rise and fall relative to the screws 37. When the tester needs to be transported, the frame 1 is raised to a position where only the running wheels 38 are in contact with the ground, and the entire tester can be moved.

[0046] like Figure 11 The control schematic diagram of the long-term pavement performance tester of the present invention is shown in FIG. A control circuit comprising a PLC controller 42 and a frequency converter 43 is housed within a control box 6. The PLC controller 42 performs signal acquisition, data calculations, and output control. Four laser rangefinders 18 are shown communicating with the PLC controller 42 via an RS485 bus to measure the depth of the rut at four different locations. The pavement temperature sensor 20 and the air temperature sensor 19 are connected to different analog input ports of the PLC controller 42; the photoelectric switch 21 is connected to a switching input port of the PLC controller 42. The different output ports of the PLC controller 42 control the heating tube 8, the spray pump 12, and the solenoid valve 13 via relays. For remote monitoring and operation, a switch, a monitoring computer, and an all-in-one machine can also be provided. The monitoring computer and all-in-one machine communicate with the PLC controller via the switch.

[0047] like Figure 12 The figure shows a circuit diagram of the connection between the PLC controller and peripheral relays in the present invention. The power supply circuits for heating lamp #1, heating lamp #2, spray water pump 12, and solenoid valve 13 are connected in series with the normally open terminals of relays K1, K2, K3, and K4, respectively. The coils of relays K1, K2, K3, and K4 are connected to different switching output terminals of the PLC controller 42. Thus, the PLC controller 42 can control the on / off states of the heating lamp, spray water pump 12, and solenoid valve 13 by controlling the states of the switching output terminals.

[0048] like Figure 13 As shown in FIG, a schematic diagram of the connection between the temperature sensor and the control circuit of the present invention is given. The outputs of the air temperature sensor 19 and the pavement temperature sensor 20 are connected to the analog input port of the PLC controller 42 after being isolated by the isolator, and the output of the photoelectric switch 21 is connected to the switch input terminal of the PLC controller 42. Figure 14 As shown, a wiring schematic diagram of the frequency converter of the present invention is given. The forward control terminal and the reverse control terminal of the frequency converter are respectively connected in series with the normally open point of relay K5 and the normally open point of relay K6. The coil of relay K5 and the coil of relay K6 are respectively connected to different switching value output terminals of the PLC controller.

[0049] The pavement long-term performance tester with a simulated high temperature and precipitation environment of the present invention can perform rutting test control according to the following steps:

[0050] Step 1: Set the pavement temperature value to a;

[0051] Step 2: Set the rotation speed value to b;

[0052] Step 3: Set the rotation direction to c;

[0053] Step 4: Set the single spray duration to d;

[0054] Step 5: Set the spray cycle duration value to e;

[0055] Step 6: Set the total number of rotations f;

[0056] Step 7: Set the rutting depth measurement period g

[0057] Step 8: Click the one-key start button;

[0058] Step 9: Determine whether the real-time detected pavement temperature g is greater than the set pavement temperature value a. If yes, proceed to step 11; otherwise, proceed to step 10.

[0059] Step 10: Turn on the heating lamp to heat and go to step 9;

[0060] Step 11: Turn off the heating lamp, turn on the rotation motor, start the spray cycle timer and the rutting depth measurement cycle timer, and go to step 12;

[0061] Step 12: Determine whether the actual number of rotations is greater than or equal to the set number of rotations. If so, proceed to step 20; otherwise, proceed to steps 13 and 17.

[0062] Step 13: Determine whether the timing time of the spray cycle timer is equal to the set spray cycle duration value e. If so, go to step 14, otherwise go to step .

[0063] Step 14: Turn on the pressurized water pump and solenoid valve, turn on the single spray duration timer, and go to step 15;

[0064] Step 15: Determine whether the single spray duration timer is greater than or equal to the set single spray duration value d. If so, proceed to step 16, otherwise proceed to step 9;

[0065] Step 16: Turn off the pressurized water pump and solenoid valve, turn off the single spray timer and reset it to zero, and go to step 9;

[0066] Step 17: Determine whether the timing time of the rutting depth measurement cycle timer is equal to the set rutting depth measurement cycle value g. If yes, go to step 18; otherwise, go to step 9.

[0067] Step 18: Send the polling rutting depth measurement command, analyze the feedback data and record it, and go to step 9;

[0068] Step 19: Turn off the rotating motor, turn off the heating lamp, turn off the spray cycle timer and the rutting depth measurement cycle timer and reset them to zero, turn off the pressurized water pump and solenoid valve, and end.

Claims

1. A pavement long-term performance tester capable of simulating high temperature and precipitation environments, comprising a frame (1), a motor (4), a control box (6), a wheel frame (9) and a wheel (10), wherein a housing (2) is fixed to the outer surface of the frame, and a test chamber (3) with an open lower end is formed inside the housing; the motor and the control box are fixed to the frame, the wheel frame and the wheel are located in the test chamber, the wheel is arranged on the wheel frame, and the wheel applies pressure to an asphalt pavement (41) to be tested; the motor drives the wheel frame to rotate via a transmission mechanism, and the wheel rotates following the wheel frame to achieve rolling of the asphalt pavement; the characteristics are: The invention comprises a spraying system and a heating device, wherein the spraying system comprises a water tank (7), a spraying water pump (12), a solenoid valve (13), an annular water pipe (14) and a spray head (15), wherein the water tank is fixed on the outer shell, the annular water pipe is fixed on the wheel frame (9), and a plurality of spray heads for spraying water onto the asphalt pavement in the test chamber are evenly arranged on the annular water pipe, the water inlet of the spraying water pump is connected to the bottom of the water tank through the water outlet pipe (11), and the water outlet of the spraying water pump is connected to the annular water pipe through the solenoid valve; the heating device comprises a heating pipe (8) arranged in the test chamber, and the heating pipe is connected to a heating power supply in the control box; A plurality of laser rangefinders (18) for measuring rutting depth are evenly arranged on the housing (2) above the asphalt pavement (41); a pavement temperature sensor (20) for measuring the temperature of the asphalt pavement is fixed on the housing above the asphalt pavement; an air temperature sensor (19) for measuring the ambient temperature of the air in the test chamber is arranged on the housing; and a photoelectric switch (21) for measuring the number of rotations of the wheel frame (9) is arranged on the housing; The transmission mechanism is composed of a fixed shaft (22), a driving bevel gear (26), a driven bevel gear (27), an inner sleeve (28) and an outer sleeve (29). A bracket (5) is fixed above the frame (1). The fixed shaft is fixed on the bracket. The lower end of the fixed shaft extends into the test cavity (3). The inner sleeve (28) is rotatably arranged on the periphery of the lower end of the fixed shaft. A bolt (30) supporting the inner sleeve is fixed on the lower end of the fixed shaft. The driven bevel gear is fixed to the upper end of the inner sleeve. The driving bevel gear meshes with the driven bevel gear. The driving bevel gear is fixed to the output shaft of the motor. The outer sleeve is located on the periphery of the inner sleeve. Key grooves (31) are provided on the outer surface of the inner sleeve and the inner surface of the outer sleeve along the length direction thereof. The inner sleeve and the outer sleeve are connected via a key (32) located in the key groove. The wheel frame (9) is composed of an outer ring plate (25) and three webs (23), the three webs are in a horizontal state, the angle between two adjacent webs is 120 degrees, the inner ends of the webs are fixed to the outer sleeve (29), the outer ring plate is fixed to the three webs with the fixed axis as the center, and the wheel (10) is fixed to the webs.

2. The pavement long-term performance tester with a simulated high temperature and precipitation environment according to claim 1 is characterized in that: The control box (6) is provided with a control circuit consisting of a PLC controller (42) and a frequency converter (43); the outputs of the air temperature sensor (19) and the pavement temperature sensor (20) are connected to the analog input port of the PLC controller after being isolated by an isolator, and the output of the photoelectric switch (21) is connected to the switch input end of the PLC controller; the laser rangefinder is connected to the PLC controller via the RS485 bus; the heating tube (8) includes a 1# heating lamp and a 2# heating lamp; the power supply circuits of the 1# heating lamp, the 2# heating lamp, the spray water pump (12) and the solenoid valve (13) are respectively connected in series with the normally open points of the relay K1, the relay K2, the relay K3 and the relay K4; the coils of the relay K1, the relay K2, the relay K3 and the relay K4 are connected to different switch output ends of the PLC controller; The power supply is connected to the power input terminal of the motor through the frequency converter, and the control terminal of the frequency converter is connected to the signal output terminal of the PLC logic controller; the forward control terminal and the reverse control terminal of the frequency converter are respectively connected in series with the normally open point of relay K5 and the normally open point of relay K6, and the coil of relay K5 and the coil of relay K6 are respectively connected to different switching output terminals of the PLC controller.

3. The pavement long-term performance tester with a simulated high temperature and precipitation environment according to claim 1 is characterized in that: A detachable counterweight (33) is fixed on the outer ring plate (25).

4. The pavement long-term performance tester with a simulated high temperature and precipitation environment according to claim 1 is characterized in that: The wheel (10) is rotatably fixed to an inverted U-shaped wheel frame (35) via a wheel axle. The inverted U-shaped wheel frame is connected to the web (23) via a connecting rod (36). A support spring (34) for shock absorption is provided on the periphery of the connecting rod.

5. The pavement long-term performance tester with a simulated high temperature and precipitation environment according to claim 1 is characterized in that: The frame (1) is provided with screw rods (37) at the four corners. The screw rods are connected to the frame in the form of threaded connections. A walking wheel (38) is fixed to the lower end of the screw rods, and a hand wheel (39) for rotating the screw rods (37) is fixed to the upper end of the screw rods.

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