Continuous indoor rutting test device and asphalt anti-rutting ability evaluation method

Abstract

The invention discloses a continuous indoor rutting test device and an asphalt material anti-rutting ability evaluation method, comprising a constant temperature box, a loading frame, a loading mechanism, a test rubber wheel, an annular test bench and a total control unit; the loading frame is fixedly arranged in the constant temperature box, the annular test bench is connected to the loading frame, the loading mechanism is arranged on the inner ring of the annular test bench, the loading mechanism comprises a loading support, a plurality of cylinders are arranged on the loading support, the test rubber wheel is rotatably connected to the movable end of the cylinder, the annular test bench surrounds the test rubber wheel, and an arc rutting plate is arranged on the inner ring of the annular test bench; the annular test bench is connected to the rotation drive mechanism, an electromagnetic counter is arranged on the loading frame, a laser displacement sensor is arranged on the cylinder, the laser displacement sensor and the electromagnetic counter are connected to the total control unit, the effect of driving load on the asphalt pavement can be truly simulated, the loading process is continuous, the loading speed and the loading pressure are continuously adjustable, the test efficiency is improved, and a plurality of test pieces can be loaded at the same time.

Description

Technical Field

[0001] The invention belongs to the field of road asphalt mixture testing, and in particular relates to a continuous indoor rutting test device and an asphalt material anti-rutting ability evaluation method. Background Art

[0002] Rutting resistance is an important indicator for evaluating the performance of asphalt pavement. At present, the linear rutting instrument is the main equipment for indoor testing of the high-temperature rutting resistance of asphalt mixtures. Its main principle is to reciprocate and roll the asphalt mixture plate (specimen length 300mm, width 300mm, height 50mm) through the loading wheel (42 times per minute) under the control of test temperature and wheel pressure, and measure the rutting deformation of the specimen after a certain number of rolling times, so as to calculate the dynamic stability. However, this type of equipment has the following main problems: the loading process is discontinuous, and the back-and-forth rolling of the loading wheel does not conform to the actual driving environment; the loading speed is not adjustable and cannot simulate the real high-speed vehicle rolling; the test efficiency is low, and only one plate can be tested at a time and there is only one loading wheel.

[0003] In addition to the above-mentioned traditional rutting test devices, some scholars have also begun to study indoor accelerated loading devices to test the rutting resistance and wear performance of asphalt mixtures in recent years. At present, most indoor continuous accelerated loading rutting test devices adopt a planar ring layout, such as the Chinese invention patent "Indoor small-size ring asphalt pavement structure rutting test device" with the authorized announcement number CN101666727A. Its main feature is that the asphalt mixture to be tested is made into a planar ring specimen, and the loading wheel performs continuous planar circular motion on its surface around its center. It makes up for some shortcomings of traditional devices, but there are still the following problems: (1) The force on the specimen does not match the actual driving load. In addition to the vertical pressure of the loading wheel, it is also affected by the lateral shear force, resulting in the rutting test results being affected by multiple factors; (2) The loading pressure cannot be flexibly adjusted. It uses a counterweight as the load and cannot be continuously adjusted; (3) A special compaction device is required to prepare the specimen, and the existing equipment cannot be used to form the specimen; (4) Limited by the planar ring layout, the equipment occupies a large area and has low longitudinal space utilization.

[0004] At the same time, due to the physical characteristics of current equipment, the indicators for evaluating the high-temperature rutting resistance of asphalt mixtures are usually: (1) absolute deformation at the end of the test; (2) dynamic stability, that is, the ratio of the number of load actions between 45 minutes and 60 minutes to the absolute deformation. However, these evaluation methods all use the absolute deformation at the beginning and end or its difference to characterize the deformation, ignoring the different deformation curve characteristics of the material during the deformation process. The "Highway Engineering Asphalt and Asphalt Mixture Test Procedure" (JTG E20-2011) also states that the rutting deformation curve may be convex, straight, or curved. Therefore, the indicator calculated by only using the absolute deformation at a certain moment cannot fully reflect the rutting resistance of the material throughout the process. For example, the convex deformation curve and the concave deformation curve with the same absolute deformation at the beginning and end are consistent in calculating dynamic stability, but the material with the convex deformation curve will cause obvious deformation of the road surface in the early stage, which seriously affects the use of the road. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a continuous indoor rutting test device and an asphalt material anti-rutting ability evaluation method. The device can truly simulate the effect of vehicle load on asphalt pavement, realize continuous loading process, continuously adjustable loading speed and loading pressure, and significantly improve the test efficiency. Multiple loading wheels can load multiple specimens at the same time, and on this basis, a method of using the rutting equivalent deformation rate under a certain number of load actions to characterize the material's anti-rutting performance is proposed.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is a continuous indoor rutting test device, including a constant temperature box, a loading frame, a loading mechanism, a test rubber wheel, a circular test bench and a general control unit; the loading frame is fixedly arranged in the constant temperature box, the circular test bench is connected to the loading frame, the loading mechanism is arranged on the inner ring of the circular test bench, the loading mechanism includes a loading support, a plurality of cylinders are arranged on the loading support, the test rubber wheel is rotatably connected to the movable end of the cylinder, the circular test bench surrounds the test rubber wheel, the inner ring of the circular test bench is arranged with an arc rutting plate, and the loading support is arranged at the center of the circular test bench; the circular test bench is connected to a rotation drive mechanism, an electromagnetic counter for monitoring the number of circles of the circular test bench is arranged on the loading frame, a laser displacement sensor is arranged on the cylinder, and the laser displacement sensor and the electromagnetic counter are both connected to the signal input end of the general control unit.

[0007] The input end of the cylinder is connected to the air pump, and the control signal input end of the air pump is connected to the output end of the air pressure control unit; the air pressure control unit is connected to the main control unit through an I / O interface, and four cylinders evenly distributed along the circumferential direction are arranged on the loading support, and reinforcing rods are arranged between adjacent cylinders.

[0008] A wheel frame is arranged at the movable end of the loading telescopic rod, and the test rubber wheel is rotatably connected to the wheel frame.

[0009] The outer ring of the annular test bench is gear-shaped, and the outer ring of the annular test bench is provided with a driving gear meshing therewith, the driving gear is arranged on a motor support, the output end of the driving motor is connected to the gear shaft of the driving gear through a belt, the control signal input end of the driving motor is connected to the motor speed control unit, and the motor speed control unit is connected to the general control unit through an I / O interface.

[0010] The thermostat is provided with a heater and a temperature control unit, the heater is connected to the output end of the temperature control unit, an infrared temperature sensor is provided in the middle of the loading support, the infrared temperature sensor is connected to the input end of the temperature control unit, and the temperature control unit and the main control unit are connected through an I / O interface.

[0011] The annular test bench comprises a plurality of arc-shaped baffles and partitions. The arc-shaped baffles are arranged along the circumferential direction of the annular test bench. The partitions are evenly arranged along the inner circle of the annular test bench. The partitions and the arc-shaped baffles form a plurality of rutting plate specimen grooves. The arc-shaped rutting plates are arranged in the rutting plate specimen grooves. Two adjacent arc-shaped baffles are connected and locked by a locker.

[0012] A thermostat door is arranged on the side of the thermostat, an observation window is provided on the thermostat door, a control panel and a display panel are arranged on the thermostat door, the control panel is connected to the I / O interface of the main control unit, and the display panel is connected to the output end of the main control unit.

[0013] A method for evaluating the anti-rutting ability of asphalt materials based on the continuous indoor rutting test device of the present invention comprises the following steps:

[0014] Step 1, fix the rutting plate specimen on the inner side of the annular test platform (14), set the load combination L, set the contact pressure between the test rubber wheel (7) and the rutting plate specimen by adjusting the loading pressure of the loading telescopic rod (4), set the test environment temperature T, heat the inside of the thermostatic box to increase the temperature inside the thermostatic box (1), and when the temperature reaches the set temperature, the driving mechanism drives the annular test platform (14) to start the loading process;

[0015] Step 2: The electromagnetic counter (24) records the number of rotations of the annular test platform (14) in real time, sets the rolling speed of the test piece to V, obtains the cumulative number of rotations n, and the absolute deformation D of each rutting plate test piece. n,i , i = 1…8, the test stops when loading N times;

[0016] Step 3: After the rutting plate specimen is loaded N times with the load L set in step 1 under the test environment temperature T set in step 1 and the loading speed V set in step 2, for the i-th rutting plate specimen, the cumulative number of actions n, n = 0…N and the absolute deformation Dn,i Draw the deformation curve F i,T,V,L (n);

[0017] Step 4: transform the deformation curve F obtained in step 3 i,T,V,L The deformation process of (n) is equivalent to a linear deformation process, and the equivalent deformation eD is calculated n :

[0018]

[0019] Step 5: Calculate the deformation rate within the interval based on the equivalent deformation obtained in step 4, and use the following formula to calculate the equivalent deformation rate eDS between the kNth (0<k<1)th and the Nth times: kN :

[0020]

[0021] When k = 0, the equivalent deformation rate is the equivalent deformation rate of the whole process eDS, which is calculated by the following formula:

[0022]

[0023] In step 1, the load composition L is divided into three types: L1 is a standard load combination, L2 is a heavy load combination, and L3 is an extra-heavy load combination; the test environment temperature T is divided into three types: T=45°C is a low temperature test temperature, T=60°C is a standard test temperature, and T=80°C is an ultra-high temperature test temperature.

[0024] In step 2, the rolling speed V of the rutting plate specimen is divided into three types: V = 24 times / min for low-speed loading, V = 42 times / min for standard speed loading, and V = 420 times / min for high-speed loading; the number of loading times N of the rutting plate specimen is divided into three types: N = 2520 times for standard loading, and N = 7560 times for long-term loading.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The present invention can truly simulate the whole process of rutting of asphalt pavement under driving load. Compared with the prior art, the circular rotation loading test can simulate the straight-line, same-direction and continuous rolling process of wheels; multiple loading wheel pressures can respectively adjust the contact pressure with the asphalt test piece to simulate the damage to the asphalt pavement under various load compositions; the loading speed can be adjusted to simulate the effect of wheel load on the asphalt pavement under different highway driving speed environments, such as expressways, urban roads, and toll stations; the test efficiency is high, multiple loading wheels work at the same time, multiple groups of test pieces can be tested at one time, and large-volume comparison work can be carried out; the structure is compact, the footprint is small, the longitudinal space is fully utilized, and it is suitable for indoor laboratory layout and installation.

[0027] Furthermore, the air pump provides power to the cylinder, and the air pump is connected to an air pressure control unit, which is connected to the main control unit, which helps to realize centralized, automatic and accurate control of the output pressure of the cylinder, thereby improving the accuracy and wide applicability of the test.

[0028] Furthermore, a wheel frame is provided at the movable end of the loading telescopic rod, and the test rubber wheel and the wheel frame are rotatably connected, which can more closely simulate the interaction process between the real wheel and the road surface.

[0029] Furthermore, the outer ring of the annular test bench is gear-shaped, and the outer ring of the annular test bench is provided with a driving gear meshing therewith, the control signal input end of the driving motor is connected to the motor speed control unit, and the motor speed control unit is connected to the main control unit through an I / O interface. The outer ring driving the annular test bench does not require too much torque, the test is easier to conduct, and does not affect the loading process. At the same time, the layout structure is more compact; the speed of the annular test bench can also be centrally and automatically controlled.

[0030] Furthermore, a heater and a temperature control unit are provided in the thermostatic box, so that the thermostatic box can be heated and kept at a constant temperature more conveniently, and the temperature control is also more convenient.

[0031] Furthermore, the rutting plate specimen is fixed in the rutting plate specimen groove, and a more standardized rutting plate specimen is used, which improves efficiency and accuracy, improves the standardization of the test, and facilitates the preparation and installation of the specimen.

[0032] Furthermore, a thermostat door is provided on the side of the thermostat, an observation window is provided on the thermostat door, a control panel and a display panel are provided on the thermostat door, the control panel is connected to the I / O interface of the main control unit, and the display panel is connected to the output end of the main control unit; after the rutting plate specimen is installed, the thermostat door can be closed, and the test device can be operated and controlled on the display panel, the test process is also safer, and the internal loading test process can be visualized through the observation window.

[0033] The evaluation method described in the present invention takes into account the influence of different deformation curve characteristics of asphalt mixtures, and can more comprehensively evaluate the anti-rutting performance of various materials. The evaluation method described in the present invention is combined with the multi-environment simulation of the test equipment, which can evaluate the rutting performance of asphalt mixtures in multiple dimensions and enhance the characterization of engineering performance by indoor tests.

[0034] Furthermore, by setting different load combinations and different rolling speeds to simulate more realistic pavement service conditions, it will help to improve the research level and obtain more realistic data, more accurately evaluate the high-temperature rutting resistance of asphalt mixtures, and thus help provide a reference for improving the high-temperature rutting resistance of green mixtures. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the present invention;

[0036] Figure 2 It is a structural schematic diagram of the annular test bench in the present invention;

[0037] Figure 3 It is a structural schematic diagram of the rutting plate forming mold in the present invention;

[0038] Figure 4 It is a calculation principle diagram of equivalent deformation in the anti-rutting ability evaluation method of the present invention;

[0039] Figure 5 It is a calculation principle diagram of the equivalent deformation rate in the anti-rutting ability evaluation method of the present invention;

[0040] Among them, 1 is a constant temperature box, 2 is a loading frame, 3 is a loading support, 4 is a cylinder, 5 is a reinforcing rod, 6 is a wheel frame, 7 is a test rubber wheel, 8 is an air distribution pipe, 9 is an air pipe protection cover, 10 is an infrared temperature sensor, 11 is a laser displacement sensor, 12 is a bearing, 13 is a connecting arm, 14 is a ring test bench, 15 is a gear, 16 is a rutting plate specimen groove, 17 is a partition, 18 is a baffle, 19 is a locker, 20 is a motor support, 21 is a driving motor, 22 is a belt, 23 is a driving gear, 24 is an electromagnetic counter, 25 is a heater, 26 is a temperature control unit, 27 is an air pump, 28 is an air pressure control unit, 29 is a motor speed control unit, 30 is a power manager, 31 is a main control unit, 32 is a communication bus, 33 is a constant temperature box door, 34 is an observation window, 35 is a control panel, 36 is a display panel, 37 is a rutting plate forming mold, 38 is a bracket, and 39 is a scale. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0042] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is a continuous indoor rutting test device, including a constant temperature box 1, a loading frame 2, a loading mechanism, a test rubber wheel 7, a circular test bench 14 and a general control unit; the loading frame 2 is fixedly arranged in the constant temperature box 1, the circular test bench 14 is connected to the loading frame 2, the loading mechanism is arranged on the inner ring of the circular test bench 14, the loading mechanism includes a loading support 3, a plurality of cylinders 4 are arranged on the loading support 3, the test rubber wheel 7 is rotatably connected to the movable end of the cylinder 4, the circular test bench 14 surrounds the test rubber wheel 7, the inner ring of the circular test bench 14 is provided with an arc rutting plate, and the loading support 3 is arranged at the center of the circular test bench 14; the circular test bench 14 is connected to a rotation drive mechanism, an electromagnetic counter 24 for monitoring the number of turns of the circular test bench 14 is arranged on the loading frame 2, a laser displacement sensor 11 is arranged on the cylinder 4, and the laser displacement sensor 11 and the electromagnetic counter 24 are both connected to the signal input end of the general control unit 31.

[0043] The input end of the cylinder 4 is connected to the air pump, and the control signal input end of the air pump is connected to the output end of the air pressure control unit; the air pressure control unit is connected to the main control unit through an I / O interface, and four cylinders 4 evenly distributed along the circumferential direction are arranged on the loading support 3, and reinforcing rods 5 are arranged between adjacent cylinders 4.

[0044] A wheel frame 6 is provided at the movable end of the loading telescopic rod 4, and the test rubber wheel 7 is rotatably connected to the wheel frame 6.

[0045] The outer ring of the annular test bench 14 is gear-shaped, and the outer ring of the annular test bench 14 is provided with a driving gear 23 meshing therewith, the driving gear 23 is arranged on the motor support 20, the output end of the driving motor 21 is connected to the gear shaft of the driving gear 23 through a belt 22, the control signal input end of the driving motor 21 is connected to the motor speed control unit 29, and the motor speed control unit 29 is connected to the main control unit 31 through an I / O interface.

[0046] The thermostat 1 is provided with a heater 25 and a temperature control unit, the heater 25 is connected to the output end of the temperature control unit 26, an infrared temperature sensor 10 is provided in the middle of the loading support 3, the infrared temperature sensor 10 is connected to the input end of the temperature control unit 26, and the temperature control unit 26 and the main control unit 31 are connected through an I / O interface.

[0047] The annular test bench 14 includes a plurality of arc-shaped baffles 18 and partitions 17. The arc-shaped baffles 18 are arranged along the circumferential direction of the annular test bench 14. The partitions 17 are evenly arranged along the inner circle of the annular test bench. The partitions 17 and the arc-shaped baffles 18 form a plurality of rutting plate specimen grooves 16. The arc-shaped rutting plates are arranged in the rutting plate specimen grooves 16. Two adjacent arc-shaped baffles 18 are connected and locked by a locker 19.

[0048] A thermostat door 33 is provided on the side of the thermostat 1, and an observation window 34 is provided on the thermostat door 33. A control panel 35 and a display panel 36 are provided on the thermostat door 33. The control panel 35 is connected to the I / O interface of the main control unit, and the display panel 36 is connected to the output end of the main control unit 31.

[0049] A method for evaluating the anti-rutting ability of asphalt materials based on the continuous indoor rutting test device of the present invention comprises the following steps:

[0050] Step 1, fix the rutting plate specimen on the inner side of the annular test platform 14, set the load combination L, set the contact pressure between the test rubber wheel 7 and the rutting plate specimen by adjusting the loading pressure of the loading telescopic rod 4, set the test environment temperature T, heat the inside of the thermostatic box to increase the temperature inside the thermostatic box 1, and when the temperature reaches the set temperature, the driving mechanism drives the annular test platform 14 to start the loading process;

[0051] Step 2: The electromagnetic counter 24 records the number of rotations of the annular test platform 14 in real time, sets the rolling speed of the test piece to V, obtains the cumulative number of rotations n, and the absolute deformation D of each rutting plate test piece. n,i , i = 1…8, the test stops when loading N times;

[0052] Step 3: After the rutting plate specimen is loaded N times with the load L set in step 1 under the test environment temperature T set in step 1 and the loading speed V set in step 2, for the i-th rutting plate specimen, the cumulative number of actions n, n = 0…N and the absolute deformation D n,i Draw the deformation curve F i,T,V,L (n);

[0053] Step 4: transform the deformation curve F obtained in step 3 i,T,V,L The deformation process of (n) is equivalent to a linear deformation process, and the equivalent deformation is calculated;

[0054] Step 5: Calculate the deformation rate within the interval according to the equivalent deformation obtained in step 4.

[0055] In step 1, the load composition L is divided into three types: L1 is a standard load combination, L2 is a heavy load combination, and L3 is an extra-heavy load combination; the test environment temperature T is divided into three types: T=45°C is a low temperature test temperature, T=60°C is a standard test temperature, and T=80°C is an ultra-high temperature test temperature.

[0056] In step 2, the rolling speed V of the rutting plate specimen is divided into three types: V = 24 times / min for low-speed loading, V = 42 times / min for standard speed loading, and V = 420 times / min for high-speed loading; the number of loading times N of the rutting plate specimen is divided into three types: N = 2520 times for standard loading, and N = 7560 times for long-term loading.

[0057] Optionally, the annular test bench 14 is disposed on an annular bracket, a rotating shaft is disposed at the center of the annular bracket, the rotating shaft is coaxially installed with an output shaft of a central driving motor, and the central driving motor directly drives the annular test bench 14 to rotate.

[0058] Example 1

[0059] refer to Figure 1 The present invention provides a continuous indoor rutting test device, comprising a thermostatic box 1 and a loading frame 2 fixed on the thermostatic box. A heater 25 and a motor support 20 are installed at the bottom of the thermostatic box 1. The heater 25 heats the thermostatic box 1 and is controlled by a temperature control unit 26. A driving motor 21 is installed on the motor support 20, and the driving motor 21 drives a driving gear 23 through a belt 22, and the driving motor is controlled by a motor speed control unit 29. The loading frame 2 is an X-shaped structure, and a loading support 3 is fixed at the end of the central axis, and a bearing 12 is nested in the central axis, and an electromagnetic counter 24 is installed on the loading frame 2. Cylinders 4 are fixed around the loading support 3, and an infrared temperature sensor 10 and a laser displacement sensor 11 are fixed between the cylinders 4. The cylinders 4 are connected to each other by reinforcing rods 5 to increase rigidity, and the test rubber wheel 7 is fixed to the bottom of the cylinder 4 through a wheel frame 6, and the air pump 27 is connected to the air distribution pipe 8 through the air pressure control unit to supply air to each cylinder 4, and the pressure of each cylinder 4 can be adjusted separately. The bearing 12 is connected to the annular test bench 14 through the connecting arm 13, and the gear 15 is circumferentially arranged outside the annular test bench 14. The gear 15 is meshed with the driving gear 23 to rotate the annular test bench 14. The electromagnetic counter 24 senses the magnetic block on the back of the connecting arm 13, and counts when the annular test bench 14 and the connecting arm 13 rotate. The total control unit 31 manages the temperature control unit 26, the air pressure control unit 28, the motor speed control unit 29, and the power manager 30 through the communication bus 32, and it can be connected to an external computer. The power manager 30 supplies power to all electrical appliances.

[0060] refer to Figure 2 The annular test bench 14 is connected to the bearing 12 through the connecting arm 13, and the interior of the annular test bench 14 is divided into a plurality of rutting plate test piece grooves 16 by the partition 17. The rutting plate test piece grooves 16 can be used to place arc-shaped rutting plates, and the baffles 18 are fixed by tightening the lockers 19, so as to fix the rutting plates in the rutting plate test piece grooves 16.

[0061] refer to Figure 3 A rutting plate forming mold 37 is used to form an arc rutting plate. A bracket 38 is installed at the lower part of the rutting plate forming mold, and a scale 39 is arranged inside to measure the thickness of the test piece. The arc rutting plate is formed by a wheel rolling forming machine according to the T0703-2011 specification.

[0062] refer to Figure 4, the measured deformation points of the rutting plate specimens were obtained by testing with a continuous indoor rutting test device, and a scatter plot was drawn. The deformation curve F was obtained by fitting the measured deformation points with an S-type function. i,T,V,L (n) = a0 / (exp(a1·(a2-n))+1). Calculate the equivalent deformation eD after 500 cumulative loadings. 500 :

[0063]

[0064] refer to Figure 5 , calculate the equivalent deformation eD after loading N / 2 times by the above calculation method of equivalent deformation N / 2 and the equivalent deformation eD after loading to the Nth time N , calculate the equivalent deformation rate eDS between loading N / 2 times to N times N / 2 :

[0065]

[0066] Example 2

[0067] The wheel rolling forming machine is used to form the rutting plates based on the rutting plate forming mold 37, and the eight rutting plates are respectively fixed in the corresponding rutting plate specimen grooves 16, and the locker 19 is tightened. The pressure of the two cylinders 4 is set so that the contact pressure of the two test rubber wheels 7 is 0.7 MPa, and the pressure of the other two cylinders 4 is set so that the contact pressure of the other two test rubber wheels 7 is 1.1 MPa, forming a heavy load combination L2.

[0068] Close the thermostat door 33, and the heater 25 starts heating under the control of the temperature control unit 26. When the infrared temperature sensor 10 detects that the surface temperature T of the rutting plate specimen is stable at 60°C, start the drive motor 21 to drive the drive gear 23 through the belt 22, thereby driving the annular test bench 14 to rotate. The electromagnetic counter 24 feeds back the speed data in real time, and controls the speed of the drive motor 21 through the motor speed control unit 29, so that the rolling speed V of each specimen is 42 times per minute, that is, the annular test bench 14 rotates 10.5 times / min. At the same time, the laser displacement sensor 11 records the deformation of the rutting plates in the grooves 16 of the 8 rutting plate specimens in real time. When the number of rolling times N of each rutting plate reaches 2520 times, stop the test.

[0069] The deformation data D recorded by the laser displacement sensor 11 n,i , draw the deformation curve of the rutting plate specimen in each plate specimen slot 16. The equivalent deformation eD at the 2520th time is calculated 2520 , and by the formula The equivalent deformation rate eDS of the whole process was calculated; the equivalent deformation rates of the whole process of each rutting plate specimen were compared, and then the high temperature anti-rutting performance of each asphalt mixture was evaluated.

Claims

1. A continuous indoor rutting test device, characterized in that: The invention comprises a constant temperature box (1), a loading frame (2), a loading mechanism, a test rubber wheel (7), an annular test bench (14) and a general control unit; the loading frame (2) is fixedly arranged in the constant temperature box (1); the annular test bench (14) is connected to the loading frame (2); the loading mechanism is arranged on the inner ring of the annular test bench (14); the loading mechanism comprises a loading support (3); a plurality of cylinders (4) are arranged on the loading support (3); the test rubber wheel (7) is rotatably connected to the movable ends of the cylinders (4); the annular test bench (14) surrounds the test rubber wheel (7); an arc-shaped rutting plate is arranged on the inner ring of the annular test bench (14); the loading support (3) is arranged at the center of the annular test bench (14); the annular test bench (14) is connected to the rotation drive mechanism; a device for monitoring the annular test bench (14) is arranged on the loading frame (2); 14) an electromagnetic counter (24) for measuring the number of revolutions; a laser displacement sensor (11) is arranged on the cylinder (4); the laser displacement sensor (11) and the electromagnetic counter (24) are both connected to the signal input end of the general control unit (31); a wheel frame (6) is arranged at the movable end of the cylinder (4); the test rubber wheel (7) and the wheel frame (6) are rotatably connected; the annular test bench (14) comprises a plurality of arc-shaped baffles (18) and a partition (17); the arc-shaped baffles (18) are arranged along the circumferential direction of the annular test bench (14); the partitions (17) are evenly arranged along the inner circle of the annular test bench; the partitions (17) and the arc-shaped baffles (18) form a plurality of rutting plate test piece grooves (16); the arc-shaped rutting plates are arranged in the rutting plate test piece grooves (16); two adjacent arc-shaped baffles (18) are connected and locked by a locker (19).

2. The continuous indoor rutting test device according to claim 1, characterized in that: The input end of the air cylinder (4) is connected to the air pump (27), and the control signal input end of the air pump (27) is connected to the output end of the air pressure control unit; the air pressure control unit (28) is connected to the main control unit (31) via an I / O interface, and four air cylinders (4) are evenly distributed along the circumferential direction on the loading support (3), and reinforcing rods (5) are provided between adjacent air cylinders (4).

3. The continuous indoor rutting test device according to claim 1, characterized in that: The outer ring of the annular test bench (14) is gear-shaped, and the outer ring of the annular test bench (14) is provided with a driving gear (23) meshing therewith, the driving gear (23) is arranged on a motor support (20), the output end of the driving motor (21) is connected to the gear shaft of the driving gear (23) via a belt (22), the control signal input end of the driving motor (21) is connected to a motor speed control unit (29), and the motor speed control unit (29) is connected to a general control unit (31) via an I / O interface.

4. The continuous indoor rutting test device according to claim 1, characterized in that: A heater (25) and a temperature control unit are provided in the constant temperature box (1), the heater (25) is connected to the output end of the temperature control unit (26), an infrared temperature sensor (10) is provided in the middle of the loading support (3), the infrared temperature sensor (10) is connected to the input end of the temperature control unit (26), and the temperature control unit (26) and the main control unit (31) are connected via an I / O interface.

5. The continuous indoor rutting test device according to claim 1, characterized in that: A thermostat door (33) is provided on the side of the thermostat (1), an observation window (34) is provided on the thermostat door (33), and a control panel (35) and a display panel (36) are also provided on the thermostat door (33). The control panel (35) is connected to an I / O interface of the main control unit (31), and the display panel (36) is connected to an output end of the main control unit (31).

6. A method for evaluating the anti-rutting ability of asphalt based on the continuous indoor rutting test device of claim 1, characterized in that: The following steps are involved: Step 1: Fix the rutting plate specimen on the inner side of the annular test bench (14) and set the load combination L The contact pressure between the test rubber wheel (7) and the rutting plate specimen is set by adjusting the loading pressure of the cylinder (4) and setting the test environment temperature. T , heating the interior of the thermostatic box to increase the temperature inside the thermostatic box (1), and when the temperature reaches a set temperature, the driving mechanism drives the annular test bench (14) to start the loading process; Step 2: The electromagnetic counter (24) records the number of rotations of the annular test bench (14) in real time, and sets the rolling speed of the test piece to V , get the cumulative number of rotations n , the absolute deformation of each rutting plate specimen , ,load N Stop the test when Step 3: The test environment temperature set in step 1 T and the loading speed set in step 2 V In the following example, the rutting plate specimen is loaded in step 1. Loading N After that, for the i The rutting plate specimens are tested by accumulating the number of actions. n, and absolute deformation Draw deformation curve ; Step 4: The deformation curve obtained in step 3 The deformation process is equivalent to a linear deformation process, and the equivalent deformation is calculated : (1) Step 5: Calculate the deformation rate within the interval according to the equivalent deformation obtained in step 4, and use the following formula to calculate the deformation rate within the interval. kN ( ) and N The equivalent deformation rate between : (2) when When the equivalent deformation rate is the equivalent deformation rate of the whole process , calculated using the following formula: (3)。 7. The method for evaluating the anti-rutting ability of asphalt according to claim 6, characterized in that: In step 1, the load consists of L There are three types: is the standard load combination, For heavy load combinations, For super heavy load combination; test environment temperature T There are three types: is the low temperature test temperature, is the standard test temperature, It is the ultra-high temperature test temperature.

8. The method for evaluating the anti-rutting ability of asphalt according to claim 6, characterized in that: In step 2, the rolling speed of the rutting plate specimen is V There are three types: For slow loading, Loading at standard speed, High-speed loading; the number of loading times of the rutting plate specimen N There are three types: is the standard loading amount, Long-term loading.

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