CN201402236Y - Main drive wheel pavement material testing device - Google Patents

Abstract

The utility model discloses a main drive wheel type pavement material testing device, which comprises a console, a PLC control box, an electric box, a hydraulic device, a motor, a brake, a transmission chain and a sprocket wheel, a driving wheel, a driven wheel, a water bath, a circulation Air inlet duct, constant temperature room, test cabinet and circulating air outlet duct, the console is located outside the test cabinet, the hydraulic device is connected to the driven wheel, the motor is connected to the driving wheel through the transmission chain and the sprocket, and the driving wheel is fixed on the bracket Above, the driven wheel is placed in the guide groove, and the water bath is set directly below the driven wheel; the laser range finder is located on one side of the driven wheel; one end of the driving wheel is provided with a microphone, and its bottom is provided with a torque sensor. A pressure sensor is arranged on the contact surface of the specimen, and two tachometers are fixed on the bracket, and are respectively located outside the driving wheel and the driven wheel. The utility model has the advantages of simple structure, low price, flexible use and good reliability.

Description

Main drive wheel pavement material testing device

technical field

The utility model relates to a main driving wheel type pavement material testing device, which belongs to the field of material testing.

Background technique

The main modes of action of the wheel load on the asphalt pavement are: the vertical pressure transmitted to the road surface by the wheels, resulting in permanent deformation or rutting of the road surface; the horizontal force exerted on the road surface due to braking, speed change, steering and overcoming various resistances in the process of advancing, making the road surface Shear damage such as pushing deformation occurs, and the surface of the aggregate is gradually polished, resulting in a decline in the anti-skid performance of the asphalt pavement surface; due to the unevenness of the road surface, the bumping of the car and the vibration of the car parts, the impact force and vibration force applied to the road surface, With the friction between the tires and the road surface, noise is generated; due to the vacuum suction generated by the temporary vacuum formed between the rear of the wheel and the road surface, due to the presence of rainwater, hydrodynamic pressure is generated, resulting in water damage to the road surface.

The accelerated loading test device for indoor pavement materials currently mainly includes a rutting tester, which has a relatively single purpose. In the course of its development, represented by the United Kingdom and Japan, a solid wheel with a diameter of 200mm is used for a plate of 300mm×3000mm×50mm The specimens were subjected to repeated load driving test; represented by the United Kingdom, a cylindrical specimen with a diameter of 195-205 mm was used to carry out repeated load driving tests with a solid wheel with a diameter of 20 cm; represented by the French LCPC and the Australian ARRB, a diameter of 400mm or 380mm inflatable test wheel-to-beam specimens for repeated load driving tests; and asphalt concrete surface analyzer (APA) represented by Georgia, USA. The test wheels of the above-mentioned types of rutting testers are all drag-type and cannot be driven to rotate by themselves. They can only apply vertical force to the test piece, but cannot apply horizontal force, which is inconsistent with the actual road surface stress and cannot evaluate the surface function of the road surface. Wang Suiyuan, Xiong Feng, Tan Wei. Summary of the development level of rutting instrument technology. Highway Traffic Technology, 2007 (3): 32-35. Through the analysis of the types and characteristics of various rutting instruments, it is proposed that the development direction of rutting instruments should be wheel For the adjustability of driving speed, load and wheel pressure, Xie Junwei proposed improvement and improvement measures for the rutting test equipment and test methods in China, such as controlling the vertical displacement of the test mold, pressure adjustment, increasing the loading wheel and the number of loading, etc. , the loading method also has an impact on the test results. Li Zhi, Wu Wenliang, Wang Mingyu, etc. respectively used digital image processing technology to obtain the arrangement law of the mixture aggregate after wheel milling, and at the same time explained that different loading modes may have different effects on the test results. Influence.

For the anti-skid performance of the pavement, the pendulum instrument and the manual sanding method are generally used in China to measure the friction coefficient and structural depth of the pavement. These two methods are greatly affected by human factors, time-consuming and labor-intensive, and the detection is extremely unsafe when open to traffic. The sampling frequency is limited, and the representativeness of the test results is low. There are single-wheel and double-wheel lateral force coefficient test systems in foreign countries. Due to the complexity of the test method and the limitation of load pressure and other conditions, the equipment is expensive and its application has great limitations; there is also a dynamic rotary friction coefficient Testers, such as Japan's Dynamic Friction Tester and the tire rubber friction tester developed by Jilin University, are easy to operate and have good stability in test results. However, due to the use of rubber blocks, the applicability is greatly limited. In the on-site test and detection, the Grip Tester friction coefficient instrument produced by Scotland's Findlay Irvine Company uses tires as the driving wheel and test wheel, and the American AASHTO and American Society for Testing and Materials (ASTM) road surface anti-slip test method E274 uses full-scale tires for testing. And fully consider the road humidity, driving speed, temperature, tire type and other related factors. These results provide a good reference for the reasonable indoor determination of the skid resistance of asphalt mixtures.

For noise, there are on-site measurements and indoor measurements. There are two on-site measurement methods, one is the far-field method, which is specified in ISO standard 11819-1 and FHWA manual, and the other is the near-field method, which has been written in ISO standard 11819-2. Among the above-mentioned noise measurement methods, the far-field passing method is time-consuming, and the test is easily affected by different vehicle models, and has strict environmental requirements, such as the road surface must be straight, the vehicle speed must be relatively consistent, and the vehicle must pass alone and should be separated from other traffic noises. Better isolation and more. The near-field method is inevitably affected by vehicle transmission and aerodynamics, and is also affected by other traffic noises like the far-field method; indoor measurement is mainly based on the principle of sound wave absorption, and the impedance tube or standing wave method is used to evaluate the performance of materials. Noise-absorbing properties, used to determine the sound-reducing properties of pavement materials. Impedance tube method already has two standards ISO10534-2:1998 and ASTM E1050-98. The impedance tube method is an indirect measurement method, and the test results are greatly affected by the frequency of the incident wave, so it is difficult to accurately control the test temperature. Another potential problem is how to confine sound to only travel through porous surfaces to avoid energy loss.

Utility model content

The purpose of the utility model is to overcome the defects and deficiencies of the prior art, and provide a main drive wheel type pavement material testing device with simple structure, low price, flexible use and good reliability.

The purpose of this utility model can be achieved by adopting the following technical solutions:

Main drive wheel pavement material testing device, including console, PLC control box, electric box, hydraulic device, motor, brake, transmission chain and sprocket, driving wheel, driven wheel, water bath, circulating air inlet pipe, constant temperature room , test cabinet and circulating air outlet duct, the console is located outside the test cabinet, the driving wheel, driven wheel and water bath are placed in the constant temperature room of the test cabinet; the hydraulic device is connected with the driven wheel, and the motor passes through the transmission chain and the chain The driving wheel is connected with the driving wheel, the driving wheel is fixed on the bracket, and is located directly above the driven wheel, and the test piece is arranged between the driving wheel and the driven wheel; directly below the driven wheel; the laser rangefinder is located on one side of the driven wheel; a microphone is set on one side of the driving wheel, a torque sensor is set on the bottom of the drive wheel, and a pressure sensor is set on the contact surface between the drive wheel and the test piece. Two tachometers are fixed on the bracket, and are respectively located on the outside of the driving wheel and the driven wheel; the brake is connected with the driving wheel; the circulating air inlet duct and the circulating air outlet duct are placed in the thermostatic chamber;

The console includes a temperature control panel, a motor control panel, an electric box panel, a hydraulic control panel, a brake control panel, a track recorder, a sound intensity display, a torque recorder, a PLC panel, a pressure display and a wheel speedometer. The temperature control panel is connected to the constant temperature room through the PID temperature control system, the motor control panel is connected to the motor, the hydraulic control panel is connected to the hydraulic device through the PLC control box, the brake control panel is connected to the brake through the PLC control box, and the rut recorder is connected to the laser distance measurer. The sound intensity display is connected with the microphone through the sound intensity test device, the wheel speedometer is connected with the tachometer, the torque recorder is connected with the torque sensor through the signal conversion system, the pressure display is connected with the pressure sensor, and the electric box panel is connected with the electric box .

On the basis of the above, the axle of the driven wheel is placed in the guide groove, and the two ends of the axle are connected with the hydraulic cylinder. The centerlines of the axle of the driving wheel and the axle of the driven wheel are respectively parallel to the horizontal plane and located in the same vertical plane.

The PLC control box and electric box are placed in the control console; the hydraulic device, motor and brake are placed in the driving room of the test cabinet; the motor is controlled by variable frequency, and the brake adopts an electromagnetic brake combination structure.

The driving wheel, the driven wheel and the water bath are placed in the constant temperature chamber of the test cabinet; the driving wheel is a pneumatic tire, and the driven wheel is a grooved steel wheel.

The sound intensity testing device described in the utility model is composed of a microphone, an amplifier, an anti-aliasing filter, a sampling/holding device, an A/D converter, a calculation processing system and a D/A converter; the microphone will come from the driving wheel and the test piece After the friction noise generated between is amplified by the amplifier and the anti-aliasing filter eliminates the signal aliasing, the data is collected by the sample/hold device and converted by the A/D converter, and then sent to the computing processing system for processing, and then passed through the D/A converter Displayed on the sound intensity display.

The temperature control system described in the utility model is composed of a temperature control panel, a temperature sensor, a transmitter, a PID controller, a voltage regulator and a constant temperature room. The temperature sensor displays the detected temperature signal on the temperature display of the control panel. It is transmitted to the PID controller through the transmitter and compared with the constant value device of the control panel. After processing, the pressure regulator is driven to control the circulation air inlet pipe to adjust the temperature of the constant temperature room.

In order to achieve a better test effect, the utility model adopts a standard asphalt mixture specimen, the specification is 300mm long × 300mm wide × 50mm thick; the driving wheel adopts 4.00-8 tires, the diameter is 415mm, and the rotating speed is 0-300r/min; The outer diameter of the moving wheel is 1100mm, the groove depth is 100mm, and the width is 315mm, so as to reserve enough space for the lateral deformation of the test piece. The speed is 0-121r/min; the rated power of the motor is 3KW, and the frequency control is controlled; the pressure range of the hydraulic device is 0 ~1.0MPa, connected with PLC controller, can set different peak modes to automatically adjust the pressure during the working process, and automatically calibrate the CE mark; the temperature range of the constant temperature room is from room temperature to 80°C, using advanced PID control technology, with automatic control, Over-temperature detection, short-circuit detection and other functions.

In order to make the test operation more convenient, there is a side door on the side of the test cabinet, which can be opened freely.

Compared with the prior art, the utility model has the following advantages:

One, the method of the present utility model is by carrying out the simulation test of the effect of automobile and asphalt pavement, can test every index such as the surface noise of asphalt mixture, coefficient of friction, rutting, anti-fatigue strength, wear and tear and water damage resistance ability, for this aspect The experiments provided good guidance.

2. The utility model can simulate the long-term use effect of the pavement in a short period of time, and belongs to a comprehensive accelerated loading test device for pavement materials. It has strong applicability, wide application range, relatively simple structure and low price.

3. Under the condition that the temperature control system of the utility model controls the temperature of the constant temperature room at room temperature to 80°C, the maximum pressure between the real pneumatic tire and the test piece can reach 1.0MPa, and the driving wheel is driven by the engine to rotate, which is more energy-efficient. Simulate the actual driving conditions of the car on the asphalt road, and improve the defects of the existing pavement material accelerated loading test equipment tow-type test wheel; at the same time, by starting the engine controller to control the engine speed and start the sound intensity test system to monitor the noise , you can observe the change law of the surface friction coefficient and noise intensity of the asphalt mixture specimen when the tire speed is different.

4. The test device of the utility model can carry out parallel test on 6 test pieces at most at the same time, which eliminates the error caused by the inhomogeneity of the test. The side door of the test cabinet can be opened freely, and the driven wheel has a fixed fixture, so the test operation is convenient.

Description of drawings

Fig. 1 is a structural schematic diagram of the main driving wheel type pavement material testing device of the present invention.

Fig. 2 is a schematic diagram of the interior structure of the thermostatic chamber in Fig. 1 .

Fig. 3 is a side view of the brake, driving wheel and driven wheel in Fig. 1 .

Fig. 4 is a schematic structural diagram of the console in Fig. 1 .

Fig. 5 is a schematic diagram of the position of the microphone of the present invention.

Fig. 6 is a schematic diagram of the temperature control principle.

Fig. 7 is a schematic diagram of the sound intensity measurement system.

Figure 8 is a schematic diagram of friction coefficient measurement.

Fig. 9 is a principle diagram of laser measurement of rut deformation.

FIG. 10 is a schematic diagram of the positions of the measuring elements in FIG. 9 .

Detailed ways

The specific embodiment of the utility model is described in detail below in conjunction with accompanying drawing.

The specification of the asphalt concrete specimen of the present utility model is 300mm long × 300mm wide × 50mm thick; the driving wheel adopts 4.00-8 tires, and the rotating speed is 0-300r/min; the outer diameter of the driven wheel is 1100mm, the groove depth is 100mm, and the width is 315mm, so Sufficient space is reserved for the lateral deformation of the specimen, the speed is 0-121r/min; the pressure range of the hydraulic device is 0-1.0MPa; the temperature range of the constant temperature chamber is 25-70°C.

As shown in Figures 1 to 5, the main drive wheel type pavement material testing device of the present invention includes a console 1, a PLC control box 2, an electric box 3, a hydraulic device 4, an electric motor 5, a brake 6, a transmission chain and a chain Wheel 7, driving wheel 8, driven wheel 10, water bath 11, circulating air inlet duct 12, constant temperature room 13, test cabinet 14 and circulating air outlet duct 15; console 1 is located outside test cabinet 14, driving wheel 8 and The driven wheel 10 is located in the constant temperature chamber 13; the constant temperature chamber 13 is located in the test cabinet 14; the hydraulic device 4 is connected with the driven wheel 10, the motor 5 is connected with the driving wheel 8 through the transmission chain and the sprocket 7, and the driving wheel 8 is fixed on the bracket 17 , located directly above the driven wheel 10, a test piece 9 is provided between the driving wheel 8 and the driven wheel 10; Directly below, when the test piece 9 moves to the bottom, it can be immersed in water; the laser range finder 26 is located on one side of the driven wheel 10; the side of the driving wheel 8 is provided with a microphone 23 for detecting the distance between the driving wheel and the test piece. frictional sound, the bottom of which is provided with a torque sensor, which is used to detect the magnitude of the friction torque produced by the driving wheel on the test piece, and a pressure sensor 24 is set on the contact surface between it and the test piece 9, which is used to detect the pressure on the contact surface Two tachometers 22 are fixed on the support 17, and are respectively positioned at the outside of driving wheel 8 and driven wheel 10, are used to measure the rotating speed size of wheel; Brake 6 is connected with driving wheel 8; The air outlet duct 15 is placed in the thermostatic chamber 13; the console 1 includes a temperature control panel 27, a motor control panel 28, an electric box panel 29, a hydraulic control panel 30, a brake control panel 31, a rut recorder 32, a sound intensity display 33, Torque recorder 34, PLC panel 35, pressure indicator 36, wheel speedometer 37, temperature control panel 27 is connected with constant temperature room 13 through PID temperature control system, the constant temperature room can guarantee the temperature required for the test, and requires good sound insulation effect , to prevent the motor noise from affecting the test; the motor control panel 28 is connected to the motor 5, the hydraulic control panel 30 is connected to the hydraulic device 4 through the PLC control box 2, the brake control panel 31 is connected to the brake 6 through the PLC control box 2, and the PLC The control box accepts command signals from the hydraulic pressure, motor and brake control panel, and automatically controls each power and brake device; the motor speed is adjustable, the maximum speed is 750r/min, and the driving wheel 8 is a chain drive, and the motor is connected to the power supply. box; the hydraulic device 4 acts on the axle of the driven wheel 10, pressurizes from bottom to top, and gradually makes the pressure between the tire and the test piece reach a specified value; The sound intensity testing device is connected with the microphone 23, the wheel speedometer 37 is connected with the tachometer 22, the torque recorder 34 is connected with the torque sensor through the signal conversion system, the pressure indicator 36 is connected with the pressure sensor 24, and all the electrical instruments required for the test are connected with the The equipment is connected to the electric box 24, Electric box panel 29 links to each other with electric box 3, and electric box panel 29 is provided with power switch and power indicator light, and electric box 24 is used for the power source of system, has automatic circuit breaker function when emergency occurs, to ensure the safety of system.

On the above basis, the wheel shaft 18 of the driven wheel 10 is placed in the guide groove 19, and the two ends of the shaft are connected with the hydraulic cylinder 16 and can move up and down with the hydraulic cylinder. The centerlines of the driving wheel shaft 21 and the driven wheel shaft 18 are respectively parallel to the horizontal plane. , and located in the same vertical plane; the PLC control box 2 and the electric box 3 are placed in the console 1; the hydraulic device 4, the motor 5 and the brake 6 are placed in the driving chamber 25 of the test cabinet 14; the motor 5 is controlled by frequency conversion, The brake 6 adopts an electromagnetic brake combination structure; the driving wheel 8, the driven wheel 10 and the water bath 11 are placed in the constant temperature chamber 13 of the test cabinet 14; the driving wheel 8 adopts a pneumatic tire, and the driven wheel 10 is a grooved steel wheel.

The sound intensity testing device described in the utility model is made of microphone 23, amplifier 45, anti-aliasing filter 46, sampling/holding device 47, A/D converter 48, calculation processing system 49 and D/A converter 50; Microphone 23 After the friction noise generated between the driving wheel 8 and the test piece 9 is amplified by the amplifier 45 and the anti-aliasing filter 46 eliminates signal aliasing, the data is collected by the sample/hold device 47 and converted by the A/D converter 48 After being transmitted to the calculation processing system 49 for processing, it is displayed on the sound intensity display 33 through the D/A converter 50 .

The temperature control system of the present utility model is composed of a temperature control panel 27, a temperature sensor 40, a transmitter 41, a PID controller 42, a voltage regulator 43 and a thermostatic chamber 13. The temperature sensor 40 displays the detected temperature signal on the control panel. On the temperature display 39 of the panel 27, it is transmitted to the PID controller 42 by the transmitter 41 to compare with the constant value device 38 of the control panel 27. After processing, the pressure regulator 43 is driven to control the circulating air inlet pipe 12 to regulate the temperature of the thermostatic chamber 13.

The hydraulic device 4 has an electronic pressure gauge that can display the pressure value when the driven wheel 10 is pressed up. The hydraulic cylinder 16 has a bore diameter of 80mm and a stroke of 100mm, one on each side; Speed change; the brake 6 adopts a YS-B1-101 single-plate electromagnetic brake combination structure for braking and holding; the motor 5 drives the active Wheel 8 rotates.

The test cabinet 14, as the shell of the main device, is made of 50mm thick color steel composite library board, which plays the role of temperature insulation, sound insulation and protection.

The driving wheel 8 is an actual tire, driven by a motor, and the driven wheel moves in a circle through friction transmission; the driven wheel 10 is a grooved steel wheel, which requires sufficient strength, and has a clamp and a reinforcing ring to place and fix it. Asphalt mixture test piece 9; the test piece is in direct contact with the tire, and the driven wheel acts as a test platform for support and bearing; the side door of the control cabinet can be opened to facilitate the installation and removal of the test piece.

The working process of the present utility model is as follows:

Test noise, rutting, coefficient of friction, wear, fatigue and water damage: fix the asphalt mixture specimen 9 in the wheel groove of the driven wheel 10 through the fixing clip and the reinforcing steel ring; drive the hydraulic device 4 through the hydraulic control panel 30, so that The hydraulic cylinder 16 lifts the driven wheel 10 to move freely up and down in the guide groove 19. Slowly adjust so that the test piece 9 is in positive contact with the driving wheel 8 and produces pressure. The pressure between the driving wheel and the test piece reaches 0-1.0 MPa, and the pressure The sensor 24 is placed between the driving wheel 8 and the asphalt mixture test piece 9 to measure the pressure, and the result is displayed by the pressure indicator 36;

As shown in Figure 6, the temperature control panel 27 includes a constant value device 38 and a temperature display 39, a temperature regulator 43 is connected to a power supply 44, and supplies heat to the thermostatic chamber 13, and the temperature sensor 40 is located in the thermostatic chamber 13, and the detected temperature In addition to sending the signal to the temperature display 39, the signal is converted into a unified signal by the transmitter 41 and sent to the PID controller 42, and compared with the set value of the constant value device 38, if there is a deviation, the voltage regulator 43 is driven to automatically adjust The heating power sent into the constant temperature chamber 13 reaches the purpose of automatic temperature control;

The motor control panel 28 controls the start, stop and frequency conversion of the motor 5; the motor 5 drives the driving wheel 8 to rotate through the transmission chain and the sprocket 7, and adjusts the engine speed so that the driving wheel speed reaches 0-300r/min. Under the action of friction, The asphalt mixture sample 9 makes a circular motion together with the driven wheel 10; two tachometers 22 are fixed on the support 17 to measure the speed of the driving wheel 8 and the driven wheel 10; the brake 6 adopts slow brake braking, so that Drive wheel 8 slows down and stops rotating, so as not to suffer big damage to protection tire.

As shown in Figure 7, the noise test: turn on the sound level meter power supply, start the noise test system, the condenser microphone 23 mainly receives the frictional noise from the driving wheel 8 and the asphalt mixture test piece 9, and the amplifier 45 receives the tiny noise The signal is amplified, the anti-aliasing filter 46 is used to eliminate the influence of the signal aliasing phenomenon on the data acquisition, the sample/hold device 47 performs data acquisition, and converts it into a digital quantity through the A/D converter 48, and the computer processing system 49. Perform high-speed processing on the obtained data according to the set function, then the D/A converter 50 converts the digital signal into an analog signal, and displays the waveform through the sound intensity display 33;

As shown in Figures 9 and 10, the rutting deformation test: there are six magnets 56, which are evenly placed on the outside of the driven wheel 10, corresponding to the central area of the asphalt mixture test piece 9, and the Hall switch 57 is parallel to the laser range finder and is close to it. On the outside of the driven wheel, when the magnet is equal to the Hall switch, the Hall switch is "on", the laser rangefinder works, and the distance Li from the rangefinder to the surface of the test piece is measured. After the magnet deflects away, the Hall switch is "on". "off", the laser rangefinder stops working until the next magnet turns to be level with the Hall switch, and the laser rangefinder starts to work again; the portable computer 58 is responsible for collecting and processing the data, and the deformation of the single test piece ABCD rut δi=Li-L, L is the initial distance between the laser rangefinder and the test piece, which can be set according to the actual situation, then the average value of the rutting of the test piece after one cycle δ=∑δi/6(i=1, 2,… , 6), the rutting recorder 32 accepts the processed data and draws the rutting deformation curve, and stops when the maximum deformation of the cyclic rolling test piece reaches 25mm;

As shown in Figure 8, the friction coefficient is measured: after the device works stably for about 30 minutes, start the brake, the driving wheel 8 stops rotating, and the driven wheel 10 is decelerated under the action of friction and gradually stops rotating. For the friction torque M produced by the asphalt mixture specimen, or the measured rotational speed change of the driven wheel, the friction torque M can be obtained by the kinetic energy theorem, and the friction force F=M/R and the friction coefficient μ=F/N can be calculated, R is the radius of the driven wheel, and N is the positive pressure between the driving wheel and the test piece; in the measurement process, the measuring point 51 is the contact surface between the tire and the test piece, and the torque sensor 52 converts the received signal into an electric quantity, and the amplifier 53 amplifies the weak electrical signal, then converts it into a digital quantity through the A/D converter 54, then processes the data at high speed through the microcomputer 55, and the torque recorder 34 displays the torque measurement result;

Abrasion and fatigue test: After rolling for about 1 hour, observe the occurrence and development of cracks and surface wear of the test piece, and evaluate the wear resistance of the test piece by the mass loss rate according to the change of the total mass of the test piece before and after the test and the shedding of surface particles , mass loss rate=(1-test piece mass/test piece mass before test)%, for different asphalt mixtures, the smaller the mass loss rate, the better its anti-wear performance. Collect; add low-modulus materials, such as rubber blocks, between the asphalt mixture specimen and the bottom of the wheel groove of the driven wheel, so that the bottom of the specimen produces bending and tensile stress during the rolling process, and use a displacement sensor to measure the time of different loading times. The deflection curve at the bottom of the piece was obtained to obtain the deflection curve, and the fatigue resistance of the specimen was evaluated by the number of loading times when the specimen was damaged. For different asphalt mixtures, the more times of loading when the failure occurred, the better the fatigue resistance.

Water damage and water stability test: set up a water bath device so that the driven wheel and the test piece can be immersed in water, and conduct a water rutting test. The temperature of the water tank is 40 ° C, and the rolling cycle is 4000 times. The spalling rate of the test piece is used to evaluate the water resistance of the asphalt mixture. Stability, for different asphalt mixtures, the smaller the spalling rate, the better its water stability, where spalling rate = (1- mass of test piece after test/ mass of test piece before test)%, all test pieces are in the drying state down to weigh.

The electric box 3 is connected to an external power supply, and is opened manually through the electric box panel 29 during the test; the pressure sensor 24 and the torque sensor can be placed manually when doing corresponding tests without interfering with each other; Clean water; the side door of the constant temperature chamber 13 can be opened freely, and it is tightly closed during the test, and the door is sealed with a high-temperature resistant silicon rubber strip to ensure that the heat does not overflow; the circulating air inlet pipe 12 and the air outlet pipe 15 keep the indoor temperature uniform.

When the asphalt mixture test piece 9 adopts a standard test piece, it should be placed and fixed in a heated state so that it can be more easily attached to the bottom of the wheel groove of the driven wheel 10; the test piece can also be formed by a special test mold, and the bottom of the test mold is a circle Arc, the arc corresponds to a central angle of 60° and a radius of 550mm.

Claims (7)

1, main drive wheel type pavement materials proving installation is characterized in that comprising operation bench (1), PLC control box (2), electronic box (3), hydraulic means (4), motor (5), detent (6), driving-chain and sprocket wheel (7), driving wheel (8), engaged wheel (10), sea water bath (11), recirculating air intake stack (12), constant temperature enclosure (13), experiment cabinet (14) and recirculating air wind pipe (15); Described operation bench (1) is positioned at experiment cabinet (14) outside, and described driving wheel (8), engaged wheel (10) and sea water bath (11) place in the constant temperature enclosure (13) of experiment cabinet (14); Hydraulic means (4) links to each other with engaged wheel (10), motor (5) links to each other with driving wheel (8) by driving-chain and sprocket wheel (7), driving wheel (8) is fixed on the support (17), is positioned at directly over the engaged wheel (10), is provided with test specimen (9) between driving wheel (8) and the engaged wheel (10); The wheel shaft (18) of engaged wheel (10) places and can make in its guide groove that moves up and down (19), sea water bath (11) be arranged at engaged wheel (10) under; Laser range finder (26) is positioned at a side of engaged wheel (10); One side of described driving wheel (8) is provided with microphone (23), its bottom is provided with torque sensor, the surface of contact of itself and test specimen (9) is provided with pressure transducer (24), and two velocity gauges (22) are fixed on the support (17), and lay respectively at the outside of driving wheel (8) and engaged wheel (10); Detent (6) is connected with driving wheel (8); Described recirculating air intake stack (12) and recirculating air wind pipe (15) place in the constant temperature enclosure (13);

Described operation bench (1) comprises temperature control panel (27), Motor Control panel (28), electronic box panel (29), hydrostatic control panel (30), detent control panel (31), rut registering instrument (32), sound intensity display (33), moment registering instrument (34), PLC panel (35), pressure display instrument (36) and wheel speed table (37); Described temperature control panel (27) links to each other with constant temperature enclosure (13) by the PID temperature control system, Motor Control panel (28) links to each other with motor (5), hydrostatic control panel (30) links to each other with hydraulic means (4) by PLC control box (2), detent control panel (31) links to each other with detent (6) by PLC control box (2), rut registering instrument (32) links to each other with laser range finder (26), sound intensity display (33) links to each other with microphone (23) by the sound intensity testing device, wheel speed table (37) links to each other with velocity gauge (22), moment registering instrument (34) links to each other with torque sensor by signal changing system, pressure display instrument (36) links to each other with pressure transducer (24), and electronic box panel (29) links to each other with electronic box (3); PLC panel (35) links to each other with PLC control box (2).

2, main drive wheel type pavement materials proving installation according to claim 1, wheel shaft (18) two ends that it is characterized in that described engaged wheel (10) link to each other with hydraulic cylinder (16), driving wheel wheel shaft (21) is parallel with surface level respectively with engaged wheel wheel shaft (18) center line, and is positioned at same perpendicular.

3, main drive wheel type pavement materials proving installation according to claim 1 is characterized in that described PLC control box (2) and electronic box (3) place in the operation bench (1).

4, main drive wheel type pavement materials proving installation according to claim 1 is characterized in that described hydraulic means (4), motor (5) and detent (6) place in the drive chamber (25) of experiment cabinet (14); Motor (5) is a variable frequency control, and detent (6) adopts electromagnetic type braking unitized construction.

5, main drive wheel type pavement materials proving installation according to claim 1 is characterized in that described driving wheel (8) adopts pneumatic tyre, and engaged wheel (10) is annular groove shaped steel wheel.

6, main drive wheel type pavement materials proving installation according to claim 1 is characterized in that described sound intensity testing device is made of microphone (23), amplifier (45), frequency overlapped-resistable filter (46), sampling/retainer (47), A/D converter (48), computing system (49) and D/A transducer (50); Microphone (23) will be sent to computing system (49) processing back and be presented on the sound intensity display (33) by D/A transducer (50) from the friction noise that produces between driving wheel (8) and test specimen (9) behind amplifier (45) amplification and frequency overlapped-resistable filter (46) erasure signal aliasing again after sampling/retainer (47) carries out data acquisition and A/D transducer (48) conversion.

7, main drive wheel type pavement materials proving installation according to claim 1, it is characterized in that described temperature control system is by temperature control panel (27), temperature sensor (40), transmitter (41), PID controller (42), pressure regulator (43) and constant temperature enclosure (13) constitute, temperature sensor (40) is presented at detected temperature signal on the temperature indicator (39) of control panel (27), and is sent to the temperature of valuator (38) comparison process rear drive pressure regulator (43) Control Circulation blast pipe (12) the adjusting constant temperature enclosure (13) of PID controller (42) and control panel (27) by transmitter (41).

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