A test device and method for evaluating the impact resistance of an airport pavement in a laboratory

Abstract

The application provides a test device and method for indoor evaluation of airport pavement impact toughness, and belongs to the technical field of pavement performance testing, which comprises a moving runner, a power system, a fixing support, a moving impact device, a test base and a control module, the test base is connected with the power system through the fixing support, the power output end of the power system is connected with the moving runner, one end of the moving impact device is connected with the moving runner, the test base is used for placing a test sample, and the other end of the moving impact device is arranged above the test sample; and the control module is electrically connected with the moving impact device and the power system respectively. The application can simulate the real impact load action environment of pavement materials in the process of soft landing of an airplane, ensures that the impact load action effect is scientific and reasonable, improves the accuracy of the test result of the impact toughness of the airport pavement materials, guarantees the continuity of the impact load action, and greatly improves the impact action efficiency on the test sample.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of road surface performance testing, and relates to a test device and method for indoor evaluation of the impact toughness of an airport runway. BACKGROUND

[0002] An airport runway is the most critical facility for ensuring the safe take-off and landing of an airplane, and the structural integrity and use function of the runway itself directly determine the safety performance of the airplane take-off and landing. The main stress characteristics of the airport runway are to repeatedly bear the load brought by the acceleration or deceleration of airplanes of various tonnages, and especially for the runway slabs in the airplane take-off and landing area, which need to repeatedly bear huge impact loads. These special slabs bearing repeated impact loads have high requirements for the dynamic load fatigue characteristics of the runway material. The dynamic load fatigue process of the runway material actually undergoes a cyclic process of crack initiation, expansion, recovery, re-initiation, re-expansion and re-recovery under the action of repeated impact wheel loads. In each cyclic process, the runway material with different properties will show different degrees of damage, and the cumulative damage will eventually lead to the overall destruction of the runway structure. The damage degree caused by single impact and the total number of impact loads that the structure as a whole can bear mainly depend on the structural characteristics of the runway material, that is, the ability of the runway material to prevent crack expansion under repeated impact loads, that is, the impact toughness of the runway structure. In other words, the impact toughness represents the maximum energy that the material can accumulate before fracture under impact load, which is equal to the minimum energy required for the material to produce a new surface due to fracture. The greater the impact toughness value, the stronger the material's resistance to cracking. Therefore, to some extent, the cracking damage of the airport runway slab is mainly caused by the brittleness of the material, especially for the brittle and easy-to-crack cement concrete runway, the higher the compressive strength, the higher the brittleness, which leads to the brittle fracture of the runway structure under a lower tensile stress. At the same time, with the use of large-load aircraft models, the load level of the runway has gradually increased, especially the impact load generated during airplane landing, which has brought great challenges to the performance and service life of the airport runway. In view of the special load environment of the airport runway, the runway material should have good strength performance and extremely high impact toughness to reduce the cracking, slab corner fracture or slab fracture of the airport runway surface caused by wheel load, so as to ensure the use performance of the airport runway and the flight safety of the airplane.

[0003] At present, there is no uniform provision and standard for the evaluation method of pavement material impact resistance at home and abroad. Most scholars are based on the drop hammer impact test method recommended by American Concrete Institute Committee 544, and then design the corresponding test method and device according to their own research needs. Drop hammer impact test is to drop a ball or a steel hammer of a specified mass from different heights, or to drop a ball (hammer) of different mass at a specified height, in order to measure the energy required for the sample to produce cracks under the impact of the falling ball (hammer). Due to the advantages of simple equipment, easy operation and low cost, the drop hammer impact method has been widely used in engineering. However, through long-term engineering practice, it is found that because the impact devices and test specimens used by researchers are different, it is difficult to directly quantify the test results obtained by different test methods. On the one hand, the transmission mode between the steel ball and the test specimen is point contact, and the material composition at the point of action of the steel ball on the test specimen will have an important influence on the test results, resulting in a large error in repeated tests. On the other hand, after the impact hammer impacts the steel ball, a secondary rebound phenomenon will occur on the surface of the test specimen. This irregular impact will also have an uncertain influence on the test results, resulting in inaccurate final test results. In the actual wheel load environment, the landing process of the aircraft belongs to a soft landing, which is quite different from the impact generated by the steel ball. At the same time, the contact between the aircraft tire and the pavement is a surface contact, not a point contact as in the impact test. Importantly, the drop hammer impact method often uses the impact times corresponding to the initial cracking or fracture failure to evaluate the impact toughness of the pavement material. Due to the small range of action, the micro-cracks and fracture failure surfaces caused by the impact load are limited, resulting in artificial differences in the determination of the test termination condition by the researchers, and finally leading to an inaccurate evaluation of the test results. At the same time, this evaluation index is also difficult to reflect the changes in stress and strain response of the pavement material due to the generation of micro-cracks or internal damage under the impact of the load.

[0004] In summary, the existing drop hammer impact test cannot objectively, accurately and scientifically evaluate the impact toughness of the airport pavement material. The main reason is that the existing test method has many uncertain factors, the test error is large, and the test simulation scene is quite different from the actual landing process of the aircraft. Therefore, it is urgent to develop a new type of pavement impact resistance indoor simulation test device according to the actual needs, to study a reasonable and reliable impact load action mode, to improve the scientificity and rationality of the impact toughness test evaluation, to better serve the pavement material design and performance evaluation work, to improve the service support level of the airport pavement, and to meet the support task requirements of the "four-type airport" in the new period. SUMMARY

[0005] In view of the problems that the existing drop hammer impact test cannot objectively, accurately and scientifically evaluate the impact toughness of airport pavement materials, the test error is large, and the test simulation scene is quite different from the actual scene during the take-off and landing of the aircraft, the application provides a test device and method for indoor evaluation of the impact toughness of airport pavement.

[0006] The test device for indoor evaluation of the impact toughness of airport pavement of the application can accurately simulate the state of the aircraft wheel impact load under indoor conditions, is more reasonable in design, improves the accuracy and scientificity of the test results of the impact toughness of airport pavement materials, and provides a quantitative impact toughness evaluation index, so that the evaluation results of the impact performance of pavement materials and structures are more accurate and reliable, and the device can better serve the design and performance evaluation of airport pavement materials. The device structure is simple, scientific and reasonable, easy to implement, and can be standardized for production and use, and has extremely important practical engineering significance for studying the impact performance of airport pavement materials and structures.

[0007] The test device for indoor evaluation of the impact toughness of airport pavement comprises a moving wheel, a power system, a fixed support, a moving impact device, a test base and a control module.

[0008] Further limited, the moving impact device comprises a rectangular telescopic sleeve, a cylinder type dynamometer, a force spring, a telescopic shaft and a test wheel.

[0009] Further limited, one end of the force spring is connected with the cylinder type dynamometer through a sliding top plate sleeved on the outside of the telescopic shaft, and the other end of the force spring is connected with the telescopic shaft through an adjustable bottom plate sleeved on the outside of the telescopic shaft.

[0010] Further defined, the telescopic central shaft includes an enlarged central shaft end, an upper rectangular rod, and a lower round rod. The enlarged central shaft end is placed within the telescopic cavity. The upper rectangular rod extends through the telescopic throat to the telescopic cavity and connects with the enlarged central shaft end. The lateral dimension of the enlarged central shaft end is larger than the radial dimension of the telescopic throat. The enlarged central shaft end is slidably connected to the telescopic cavity. The upper rectangular rod is slidably connected to the telescopic throat. The lower round rod is connected to the upper rectangular rod. The cylindrical measuring... A force gauge is installed at the connection between the upper rectangular rod and the rectangular telescopic sleeve of the central shaft. The cylindrical force gauge has a channel in the middle, and the upper rectangular rod of the central shaft extends through the channel of the cylindrical force gauge to the telescopic throat. The sliding top plate is sleeved on the outside of the upper rectangular rod of the central shaft, and the adjustable bottom plate is sleeved on the outside of the lower round rod of the central shaft. The bottom of the lower round rod of the central shaft is rotatably connected to the test wheel. A laser counter for measuring the number of rotations of the moving wheel is installed on the moving wheel, and the laser counter is electrically connected to the control module.

[0011] Furthermore, a portal frame is provided at the bottom of the lower circular rod of the central shaft, and the test wheel is rotatably connected to the portal frame.

[0012] Further specified, the test base has a sample holding slot for placing test specimens, and the test wheel is placed above the test specimens; a laser emitter and a laser receiver are arranged side by side on the wall of the sample holding slot, and both the laser emitter and the laser receiver are electrically connected to the control module; the fixed bracket is located on the outside of the sample holding slot, and the fixed bracket, the laser emitter and the laser receiver are all arranged side by side.

[0013] Further specified, the bottom end face of the test specimen is fixedly connected to the bottom wall of the sample holding tank through a fixed support, the side end face of the test specimen is fixedly connected to the side wall of the sample holding tank through fasteners, and a limiting rubber plate is provided at the connection between the fasteners and the test specimen.

[0014] Furthermore, the power output end of the power system is connected to the moving wheel via a rotating shaft, and the rotating shaft is rotatably connected to a fixed bracket via a fixed bearing.

[0015] A test method for evaluating the impact toughness of airport pavements indoors includes the following steps:

[0016] 1) Fabricate the above-mentioned testing device for indoor evaluation of the impact toughness of airport pavement;

[0017] 2) Adjust the test wheel so that it is within the wheel track area of ​​the test specimen under maximum impact force;

[0018] 3) through the control module to start the power system and control the running speed of the power system, so that the power system rotates, drives the rotating runner to rotate, the rotating runner drives the rectangular telescopic sleeve to rotate along the circumference of the rotating runner through the sleeve, the telescopic shaft slides along the telescopic cavity and the telescopic throat, so that the test wheel experiences the processes of initial contact, compression, unloading and load application away from the surface of the test specimen;

[0019] 4) during the process of the test wheel applying load to the test specimen, the cylinder type dynamometer monitors the rebound force of the force spring as the instantaneous impact load force applied by the test wheel to the test specimen, and transmits the instantaneous impact load force value to the control module; the laser counter measures the number of revolutions of the rotating runner and transmits it to the control module; the laser transmitter and the laser receiver jointly measure the vertical deformation of the test specimen and transmit it to the control module;

[0020] The control module receives the instantaneous impact load force of the test specimen, the number of revolutions of the rotating runner and the vertical deformation of the test specimen, records and stores the instantaneous impact load force of the test specimen, the number of revolutions of the rotating runner and the vertical deformation of the test specimen, and calculates the pavement impact resistance index IRI of the test specimen, and the calculation formula of the pavement impact resistance index IRI is:

[0021]

[0022] In the formula, N is the number of revolutions of the rotating runner, that is, the total number of impact load cycles, unit: times; I i is the impact energy generated by the impact load in the i th impact load cycle, unit: J; H is the thickness of the test specimen, unit: cm.

[0023] Further limited, the step 3) is specifically: through the control module to start the power system and control the running speed of the power system, so that the power system rotates, drives the rotating runner to rotate, the rotating runner drives the middle shaft enlarged end, the middle shaft upper part rectangular rod and the middle shaft lower part circular rod to rotate along the circumference of the rotating runner, the test wheel experiences the processes of initial contact, compression, unloading and load application away from the surface of the test specimen, while the middle shaft enlarged end and the middle shaft upper part rectangular rod slide along the telescopic cavity and the telescopic throat respectively, so that the telescopic shaft is stretched to different degrees, and the sliding top plate slides up and down along the axis of the middle shaft upper part rectangular rod to apply different pressures to the force spring, so that the force spring is compressed to different degrees, and the cylinder type dynamometer can measure the instantaneous impact load force of the test specimen by measuring the instantaneous pressure of the force spring.

[0024] Compared with the prior art, the beneficial effects of the present application are:

[0025] 1. The application is a test device for indoor evaluation of the impact toughness of airport pavement, which comprises a moving runner, a power system, a fixed support, a moving impact device, a test base and a control module. The power system drives the moving runner to rotate, and the moving impact device is driven by the moving runner to move along the circumference of the moving runner under centrifugal force. The moving impact device experiences the processes of initial contact, compression, unloading and load application away from the surface of the test specimen on the test base. Through continuous rotation, the surface of the test specimen is subjected to repeated impact loads. During the processes of initial contact, compression, unloading and load application away, the wheel surface of the test wheel is in surface contact with the surface of the test specimen, which is basically consistent with the contact between the aircraft wheel surface and the airport pavement during the actual process of aircraft landing, taxiing and taking off. The simulation is more realistic, and the impact toughness of the airport pavement material is more objectively evaluated. The application realizes the continuous impact of the test wheel on the test specimen through the rotating operation of the moving impact device, expands the range of impact load, can simulate the real impact load environment of the pavement material during the soft landing of the aircraft, ensures the scientific and reasonable effect of the impact load, and improves the accuracy of the impact toughness test results of the airport pavement material. At the same time, the design of the moving impact device can meet the needs of high-speed operation of the equipment, ensure the continuity of the impact load, and greatly improve the impact efficiency of the test specimen. Based on the proposed pavement impact resistance index IRI evaluation index, the scientific characterization and evaluation of the impact resistance of the pavement material and structure can be realized, and the impact toughness research can better serve the airport pavement material design and performance evaluation work. The application has the advantages of simple structure, scientific and reasonable design, easy implementation, and can be used for indoor shaped specimens, also for new or existing airport pavement field sampling specimens. Its popularization and application have extremely important engineering significance for the research of the impact resistance of the airport pavement material and structure.

[0026] 2. The moving impact device comprises a rectangular telescopic sleeve, a cylinder type dynamometer, a force spring, a telescopic shaft and a test wheel. During testing, the moving runner drives the rectangular telescopic sleeve to move along the circumference of the moving runner under centrifugal force. The telescopic shaft experiences the processes of initial contact, compression, unloading and load application away from the surface of the test specimen through the test wheel. At the same time, the load applied to the test specimen by the test wheel is applied to the force spring in the opposite direction through the rectangular telescopic sleeve, so that the force spring is compressed. The cylinder type dynamometer measures the compression force of the force spring, and then measures the load applied to the test specimen by the test wheel.

[0027] 3. One end of the force-measuring spring is connected to the cylindrical force gauge through a sliding top plate sleeved on the outside of the telescopic central shaft. The sliding top plate can slide along the axial direction of the telescopic central shaft. The sliding of the sliding top plate allows the telescopic central shaft to easily apply the load transmitted by the test wheel to the force-measuring spring, compressing the force-measuring spring. This makes it easier to measure the load applied by the test wheel to the test specimen by measuring the amount of compression of the force-measuring spring.

[0028] 4. The lateral dimension of the enlarged end of the central shaft is larger than the radial dimension of the telescopic throat, which prevents the enlarged end of the central shaft from sliding out of the telescopic cavity during sliding, thus affecting the load transmission. A laser counter is installed on the moving wheel to measure the number of rotations of the moving wheel. The number of rotations reflects the number of times the load was applied to the surface of the test specimen.

[0029] 5. A portal frame is provided at the bottom of the lower round rod of the central shaft. The portal frame facilitates the installation of the test wheel and also ensures the stability of the test wheel during rotation.

[0030] 6. A laser emitter and a laser receiver are arranged side by side on the wall of the sample tank. Through the cooperation of the laser emitter and the laser receiver, the vertical deformation of the test specimen under impact load can be easily monitored.

[0031] 7. The bottom end face of the test specimen is fixedly connected to the bottom wall of the sample collection tank through a fixed support, and the side end face of the test specimen is fixedly connected to the side wall of the sample collection tank through fasteners. At the same time, a limit rubber plate is set at the connection between the fastener and the test specimen to ensure that the test specimen is stable in the sample collection tank and to prevent the test specimen from swinging laterally relative to the forward direction when the test wheel applies a load to the test specimen.

[0032] 8. The rotating shaft is rotatably connected to the fixed bracket through a fixed bearing. The fixed bearing can support the rotating shaft and prevent the rotating shaft from oscillating during rotation. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the test device of the present invention for evaluating the impact toughness of airport pavement indoors;

[0034] Figure 2 This is a side view of the testing device of the present invention for evaluating the impact toughness of airport pavement indoors;

[0035] Figure 3 This is a schematic diagram of the structure of the rotating wheel;

[0036] Figure 4 This is a schematic diagram of the motion impact device;

[0037] Figure 5Structure diagram of telescopic middle shaft;

[0038] Figure 6 Structure diagram of test specimen;

[0039] Figure 7 Structure diagram of deformation measurement point layout position of the application;

[0040] Wherein, 1-movement runner, 1.1-sleeve, 1.1.1-fixed screw, 1.2-rotating shaft, 1.3-positioning hole, 1.4-power system, 1.5-fixed bearing, 1.6-laser counter, 2-fixed support, 3-movement impact device, 3.1-rectangular telescopic sleeve, 3.1.1-limiting screw hole, 3.1.2-telescopic cavity, 3.1.3-telescopic throat, 3.2-cylinder type dynamometer, 3.3-force spring, 3.3.1-adjustable bottom plate, 3.3.2-sliding top plate, 3.3.3-thread, 3.4-telescopic middle shaft, 3.4.1-middle shaft enlarged end, 3.4.2-door type support, 3.4.3-middle shaft upper rectangular rod, 3.4.4-middle shaft lower round rod, 3.5-test wheel, 4-test base, 4.1-sample containing groove, 4.2-fixed support, 4.3-stand, 4.4-laser emitter, 4.5-laser receiver, 4.6-fastening screw, 4.7-limiting rubber plate, 4.8-bottom plate, 4.9-end side baffle, 4.9.1-specimen buckle, 4.9.2-buckle screw, 4.10-maximum impact force wheel trace, 4.11-deformation measurement point, 5-test specimen, 6-control module, 6.1-connection line. DETAILED DESCRIPTION

[0041] The technical solutions of the application will be further explained and described below in combination with the drawings and examples, but the application is not limited to the following described embodiments.

[0042] Referring to Figure 1 and Figure 2 , the application is a test device for indoor evaluation of airport pavement impact resistance, which comprises a movement runner 1, a power system 1.4, a fixed support 2, a movement impact device 3, a test base 4 and a control module 6. The test base 4 is connected with the power system 1.4 through the fixed support 2, the power output end of the power system 1.4 is connected with the movement runner 1, one end of the movement impact device 3 is connected with the movement runner 1, the test base 4 is used for placing a test specimen 5, and the other end of the movement impact device 3 is placed above the test specimen 5. The control module 6 is electrically connected with the movement impact device 3 and the power system 1.4 respectively.

[0043] The motion impact device 3 comprises a rectangular telescopic sleeve 3.1, a cylinder dynamometer 3.2, a force spring 3.3, a telescopic shaft 3.4 and a test wheel 3.5, the sleeve 1.1 is fixedly connected to the motion wheel 1, the rectangular telescopic sleeve 3.1 is connected to the sleeve 1.1, the rectangular telescopic sleeve 3.1 is provided with a telescopic cavity 3.1.2 and a telescopic throat 3.1.3, the telescopic cavity 3.1.2 and the telescopic throat 3.1.3 are communicated along the axial direction of the rectangular telescopic sleeve 3.1; one end of the telescopic shaft 3.4 extends into the telescopic cavity 3.1.2 through the telescopic throat 3.1.3 and is slidably connected to the telescopic cavity 3.1.2 and the telescopic throat 3.1.3; the other end of the telescopic shaft 3.4 is fixedly connected to the test wheel 3.5, the force spring 3.3 and the cylinder dynamometer 3.2 are sequentially sleeved on the outside of the telescopic shaft 3.4 from bottom to top along the axial direction of the telescopic shaft 3.4.

[0044] One end of the force spring 3.3 of the embodiment is connected to the cylinder dynamometer 3.2 through the sliding top plate 3.3.2 sleeved on the outside of the telescopic shaft 3.4, the other end of the force spring 3.3 is connected to the telescopic shaft 3.4 through the adjustable bottom plate 3.3.1 sleeved on the outside of the telescopic shaft 3.4, the sliding top plate 3.3.2 is slidably connected to the telescopic shaft 3.4, and the adjustable bottom plate 3.3.1 is fixedly connected to the telescopic shaft 3.4.

[0045] The telescopic shaft 3.4 comprises a shaft enlarged end 3.4.1, a shaft upper rectangular rod 3.4.3 and a shaft lower circular rod 3.4.4, the shaft enlarged end 3.4.1 is arranged in the telescopic cavity 3.1.2, the shaft upper rectangular rod 3.4.3 extends into the telescopic cavity 3.1.2 through the telescopic throat 3.1.3 and is connected to the shaft enlarged end 3.4.1, the transverse dimension of the shaft enlarged end 3.4.1 is greater than the radial dimension of the telescopic throat 3.1.3, the shaft enlarged end 3.4.1 is slidably connected to the telescopic cavity 3.1.2, the shaft upper rectangular rod 3.4.3 is slidably connected to the telescopic throat 3.1.3, the shaft lower circular rod 3.4.4 is connected to the shaft upper rectangular rod 3.4.3, the cylinder dynamometer 3.2 is arranged at the connection between the shaft upper rectangular rod 3.4.3 and the rectangular telescopic sleeve 3.1, a hole is formed in the middle of the cylinder dynamometer 3.2, the shaft upper rectangular rod 3.4.3 extends into the telescopic throat 3.1.3 through the hole of the cylinder dynamometer 3.2; the sliding top plate 3.3.2 is sleeved on the outside of the shaft upper rectangular rod 3.4.3, and the adjustable bottom plate 3.3.1 is sleeved on the outside of the shaft lower circular rod 3.4.4; the bottom of the shaft lower circular rod 3.4.4 is rotationally connected to the test wheel 3.5; the motion wheel 1 is provided with a laser counter 1.6 for measuring the number of rotations of the motion wheel 1, and the laser counter 1.6 is electrically connected to the control module 6.

[0046] The bottom of the middle shaft lower circular rod 3.4.4 is provided with a door-shaped support 3.4.2, and the test wheel 3.5 is rotationally connected with the door-shaped support 3.4.2.

[0047] A sample containing groove 4.1 is formed on the test base 4, and the sample containing groove 4.1 is used for placing a test sample 5, and the test wheel 3.5 is arranged above the test sample 5; the laser emitter 4.4 and the laser receiver 4.5 are arranged side by side on the groove wall of the sample containing groove 4.1, and the laser emitter 4.4 and the laser receiver 4.5 are electrically connected with the control module 6; the fixed support 2 is arranged outside the sample containing groove 4.1, and the fixed support 2, the laser emitter 4.4 and the laser receiver 4.5 are arranged side by side.

[0048] The bottom end surface of the test sample 5 is fixedly connected with the bottom wall of the sample containing groove 4.1 through a fixed support 4.2, and the side end surface of the test sample 5 is fixedly connected with the side wall of the sample containing groove 4.1 through a fastener, and a limiting rubber plate 4.7 is arranged at the connecting position of the fastener and the test sample 5.

[0049] The power output end of the power system 1.4 is connected with the movement runner 1 through a rotating shaft 1.2, and the rotating shaft 1.2 is rotationally connected with the fixed support 2 through a fixed bearing 1.5.

[0050] The application is used for the test method for evaluating the impact toughness of the airport pavement indoors, and comprises the following steps:

[0051] 1) The test device for evaluating the impact toughness of the airport pavement indoors is prepared;

[0052] 2) The test wheel 3.5 is debugged, so that the test wheel 3.5 is in the maximum impact force wheel trace 4.10 area of the test sample 5;

[0053] 3) The power system 1.4 is started and the running speed of the power system 1.4 is controlled through the control module 6, so that the power system 1.4 rotates and drives the movement runner 1 to rotate, the movement runner 1 drives the rectangular telescopic sleeve 3.1 to rotate along the circumference of the movement runner 1 through the sleeve 1.1, the telescopic middle shaft 3.4 slides along the telescopic cavity 3.1.2 and the telescopic throat 3.1.3, so that the test wheel 3.5 experiences the processes of initial contact, compression, unloading and load application away from the surface of the test sample 5;

[0054] 4) In the process that the test wheel 3.5 applies the load to the test sample 5, the cylinder type dynamometer 3.2 monitors the rebound force of the force spring 3.3 as the instantaneous impact load force applied by the test wheel 3.5 to the test sample 5, and transmits the instantaneous impact load force value to the control module 6; the laser emitter 4.4 and the laser receiver 4.5 jointly measure the vertical deformation amount of the test sample 5 and transmit the vertical deformation amount to the control module 6;

[0055] The control module 6 receives the instantaneous impact load force of the test specimen 5, the number of rotations of the moving runner 1 and the vertical deformation of the test specimen 5, records and stores the instantaneous impact load force of the test specimen 5, the number of rotations of the moving runner 1 and the vertical deformation of the test specimen 5, and calculates the pavement impact resistance index IRI of the test specimen 5, and the calculation formula of the pavement impact resistance index IRI is:

[0056]

[0057] N is the number of rotations of the moving runner 1, i.e. the total number of impact load cycles, unit: times; I i is the impact energy generated by the impact load in the i th impact load cycle, unit: J; H is the thickness of the test specimen 5, unit: cm, and i is the number of impact loads applied.

[0058] Step 3) is specifically: start the power system 1.4 by the control module 6 and control the running speed of the power system 1.4, so that the power system 1.4 rotates, drives the moving runner 1 to rotate, and the moving runner 1 drives the middle shaft enlarged end 3.4.1, the middle shaft upper rectangular rod 3.4.3 and the middle shaft lower circular rod 3.4.4 to rotate along the circumference of the moving runner 1, and the test wheel 3.5 experiences the processes of initial contact, compression, unloading and moving away on the surface of the test specimen 5, while the middle shaft enlarged end 3.4.1 and the middle shaft upper rectangular rod 3.4.3 slide along the telescopic cavity 3.1.2 and the telescopic throat 3.1.3 respectively, so that the telescopic middle shaft 3.4 is stretched to different degrees, and the sliding top plate 3.3.2 slides up and down along the axis of the middle shaft upper rectangular rod 3.4.3 to apply different pressures to the force spring 3.3, so that the force spring 3.3 is compressed to different degrees, and the cylinder type force gauge 3.2 can measure the instantaneous impact load force of the test specimen 5 by measuring the instantaneous pressure of the force spring 3.3.

[0059] Example 1

[0060] The embodiment is a test device for indoor evaluation of airport pavement impact toughness, which comprises a moving runner 1, a power system 1.4, a fixed support 2, a moving impact device 3, a test base 4 and a control module 6. The power output end of the power system 1.4 is connected with the moving runner 1, and the moving runner 1 is provided with rotary driving force by the power system 1.4. The bottom of the fixed support 2 is fixedly connected to the upper end surface of the test base 4, and the top of the fixed support 2 is connected with the power system 1.4, which is used for providing support for the power system 1.4. Preferably, the fixed support 2 is in a herringbone structure, which can ensure the stability of the fixed support 2. The top of the moving impact device 3 is connected with the moving runner 1, preferably in a sliding connection. Specifically, the moving impact device 3 slides along the radial direction of the moving runner 1. The other end of the moving impact device 3 is arranged above the test sample 5, which is used for applying impact load to the test sample 5. The test base 4 is used for placing the test sample 5. The control module 6 is electrically connected with the moving impact device 3 and the power system 1.4, respectively. The control module 6 is used for controlling the start-stop and rotating speed of the power system 1.4, and is also used for recording and storing the impact load applied by the moving impact device 3, and calculating the pavement impact toughness index IRI.

[0061] Embodiment 2

[0062] Referring to Figure 3 、 Figure 4 and Figure 5This embodiment describes a testing device for evaluating the impact toughness of airport pavement indoors. It is based on Embodiment 1. The moving impact device 3 includes a rectangular telescopic sleeve 3.1, a cylindrical force gauge 3.2, a force-measuring spring 3.3, a telescopic central shaft 3.4, and a testing wheel 3.5. A sleeve 1.1 is radially arranged on the moving wheel 1. A mounting hole is provided on the sleeve 1.1 along the radial direction of the moving wheel 1. One end of the rectangular telescopic sleeve 3.1 extends into the mounting hole of the sleeve 1.1 and is fixedly connected to the sleeve 1.1. The rectangular telescopic sleeve 3.1 is coaxially arranged with the sleeve 1.1. At the other end of the rectangular telescopic sleeve 3.1, a telescopic cavity 3.1.2 and a telescopic throat 3.1.3 are sequentially arranged from top to bottom along the axial direction of the rectangular telescopic sleeve 3.1. The telescopic cavity 3.1.2 and the telescopic throat 3.1.3 are connected along the axial direction of the rectangular telescopic sleeve 3.1. Preferably, multiple limiting screw holes 3.1.1 are arranged from top to bottom along the radial direction of the sleeve 1.1. Simultaneously, limiting screw holes 3.1.1 are also arranged radially on the rectangular telescopic sleeve 3.1. At the sleeve 1.1... A fixing screw 1.1.1 is inserted into the limiting screw hole 3.1.1 within the sleeve 1.1 and the rectangular telescopic sleeve 3.1. The fixing screw 1.1.1 secures the sleeve 1.1 to the rectangular telescopic sleeve 3.1. During use, the fixing screw 1.1.1 can be inserted into the corresponding limiting screw hole 3.1.1 of the sleeve 1.1 according to the required extension length of the rectangular telescopic sleeve 3.1, facilitating adjustment of the extension length of the rectangular telescopic sleeve 3.1 as needed. One end of the telescopic central shaft 3.4 extends through the telescopic throat 3.1.3 to the telescopic space. The telescopic central shaft 3.4 is located within cavity 3.1.2 and can slide along the telescopic throat 3.1.3 and telescopic cavity 3.1.2. The other end of the telescopic central shaft 3.4 is fixedly connected to the test wheel 3.5. The force-measuring spring 3.3 and the cylindrical force gauge 3.2 are sequentially sleeved on the outside of the telescopic central shaft 3.4 from bottom to top along the axial direction of the telescopic central shaft 3.4, and both the force-measuring spring 3.3 and the cylindrical force gauge 3.2 can slide along the axial direction of the telescopic central shaft 3.4. Preferably, the cylindrical force gauge 3.2 is located at the bottom end of the rectangular telescopic sleeve 3.1. Specifically, the rectangular telescopic sleeve 3.1 is a cuboid component, and both the telescopic cavity 3.1.2 and the telescopic throat 3.1.3 are cuboid holes. The limiting screw hole 3.1.1 of the rectangular telescopic sleeve 3.1 matches the fixing screw 1.1.1 of the rectangular sleeve 1.1, so that the rectangular telescopic sleeve 3.1 can be inserted into the rectangular sleeve 1.1 and fixed.

[0063] Further, one end of the force spring 3.3 is connected with the columnar force gauge 3.2 through the sliding top plate 3.3.2 sleeved outside the telescopic middle shaft 3.4, and the sliding top plate 3.3.2 is in sliding connection with the telescopic middle shaft 3.4; the other end of the force spring 3.3 is connected with the telescopic middle shaft 3.4 through the adjustable bottom plate 3.3.1 sleeved outside the telescopic middle shaft 3.4, and the adjustable bottom plate 3.3.1 is in fixed connection with the telescopic middle shaft 3.4, preferably, a screw thread 3.3.3 is arranged on the telescopic middle shaft 3.4 in the connection area corresponding to the adjustable bottom plate 3.3.1, and a screw thread 3.3.3 is arranged on one side of the adjustable bottom plate 3.3.1 connected with the telescopic middle shaft 3.4, so that the length of the force spring 3.3 can be adjusted through the adjustable bottom plate 3.3.1 according to the length requirement of the telescopic middle shaft 3.4.

[0064] Further, the telescopic middle shaft 3.4 of the embodiment comprises a middle shaft enlarged end 3.4.1, a middle shaft upper rectangular rod 3.4.3 and a middle shaft lower circular rod 3.4.4, the middle shaft enlarged end 3.4.1 is arranged in the telescopic cavity 3.1.2, the middle shaft enlarged end 3.4.1 has a cuboid structure or a square structure, the middle shaft enlarged end 3.4.1 is arranged along the radial direction of the telescopic cavity 3.1.2, the transverse dimension of the middle shaft enlarged end 3.4.1 is greater than the radial dimension of the telescopic throat 3.1.3, the middle shaft upper rectangular rod 3.4.3 extends through the telescopic throat 3.1.3 to the telescopic cavity 3.1.2 and is connected with the middle shaft enlarged end 3.4.1, the middle shaft upper rectangular rod 3.4.3 is driven to slide along the telescopic throat 3.1.3 through the sliding of the middle shaft enlarged end 3.4.1 along the telescopic cavity 3.1.2, that is, the middle shaft enlarged end 3.4.1 is in sliding connection with the telescopic cavity 3.1.2, the middle shaft upper rectangular rod 3.4.3 is in sliding connection with the telescopic throat 3.1.3, the bottom of the middle shaft lower circular rod 3.4.4 is connected with the top of the middle shaft upper rectangular rod 3.4.3, the cylinder type force gauge 3.2 is arranged at the connection position of the telescopic middle shaft 3.4 and the rectangular telescopic sleeve 3.1, a hole is formed in the middle of the cylinder type force gauge 3.2, the middle shaft upper rectangular rod 3.4.3 extends through the hole of the cylinder type force gauge 3.2 to the telescopic throat 3.1.3, the cylinder type force gauge 3.2, the sliding top plate 3.3.2, the force spring 3.3 and the adjustable bottom plate 3.3.1 are all arranged outside the middle shaft lower circular rod 3.4.4 along the axial direction of the middle shaft lower circular rod 3.4.4, the bottom of the middle shaft lower circular rod 3.4.4 is rotationally connected with the test wheel 3.5, preferably, the door-shaped support 3.4.2 is fixedly connected with the bottom of the middle shaft lower circular rod 3.4.4, the test wheel 3.5 is arranged in the door-shaped support 3.4.2 and is rotationally connected with the door-shaped support 3.4.2, the door-shaped support 3.4.2 facilitates the installation of the test wheel 3.5 and the stability of the test wheel 3.5 during rotation; the laser counter 1.6 for measuring the number of rotations of the motion rotating wheel 1 is arranged on the motion rotating wheel 1, the laser counter 1.6 is electrically connected with the control module 6, the number of rotations of the motion rotating wheel 1 is recorded by the laser counter 1.6 and is transmitted to the control module 6, and the control module 6 records and saves the number of rotations.Specifically, the middle shaft upper part rectangular rod 3.4.3 is a cuboid rod, and the middle shaft lower part circular rod 3.4.4 is a cylindrical rod; the cross-sectional area of the middle shaft enlarged end 3.4.1 is larger than that of the telescopic throat 3.1.3, so as to prevent the middle shaft upper part rectangular rod 3.4.3 from sliding out of the telescopic cavity 3.1.2; preferably, the cylinder type dynamometer 3.2 is arranged at the bottom end of the middle shaft upper part rectangular rod 3.4.3, and the middle shaft lower part circular rod 3.4.4 penetrates through the cylinder type dynamometer 3.2 and is fixedly connected with the middle shaft upper part rectangular rod 3.4.3; the sliding top plate 3.3.2 is a hollow metal plate, and the sliding top plate 3.3.2 can freely slide up and down along the middle shaft lower part circular rod 3.4.4; the sliding top plate 3.3.2 can uniformly transmit the force of the force spring 3.3 to the cylinder type dynamometer 3.2; the cylinder type dynamometer 3.2 is connected with the control module 6 through the connecting line 6.1, so as to realize the monitoring and recording of the impact load force; the adjustable bottom plate 3.3.1 is a circular ring structure, and the adjustable bottom plate 3.3.1 can move up and down along the screw thread 3.3.3, so as to realize the setting of the action length of the force spring 3.3. When the moving rotating wheel 1 drives the motion impact device 3 to rotate, the position relationship between the test wheel 3.5 and the surface of the test specimen 5 will experience the change process of initial contact, compression, unloading and moving away, and at the same time, the force spring 3.3 will be compressed to different degrees along with the rotation of the moving rotating wheel 1, so as to realize the impact load action of the test wheel 3.5 on the test specimen 5. The cylinder type dynamometer 3.2 monitors the rebound force of the force spring 3.3 in the whole process, and the rebound force is taken as the instantaneous impact load force value of the test wheel 3.5 on the test specimen 5; the cylinder type dynamometer 3.2 is connected with the control module 6 through the connecting line 6.1, so as to realize the recording and storage of the impact load force in the test process.

[0065] Preferably, the cross-sectional size of the middle shaft enlarged end 3.4.1 should match the cross-sectional size of the telescopic cavity 3.1.2, and the cross-sectional size of the middle shaft upper part rectangular rod 3.4.3 should match the cross-sectional size of the telescopic throat 3.1.3, so as to ensure that the telescopic middle shaft 3.4 does not swing laterally when it moves in the rectangular telescopic sleeve 3.1.

[0066] In the embodiment, the rectangular sleeve 1.1, the rectangular telescopic sleeve 3.1 and the middle shaft upper part rectangular rod 3.4.3 are used to ensure the stability of the running direction of the test wheel 3.5 at the bottom end of the motion impact device 3, and prevent the test wheel 3.5 from swinging laterally compared with the forward direction when rolling on the surface of the test specimen 5.

[0067] The application sets the extension length of the motion impact device 3 through the limiting screw hole 3.1.1, adjusts the initial compression length of the force spring 3.3 through the adjustable bottom plate 3.3.1, and finally can realize the adjustment of the impact load force size of the test wheel 3.5 on the test sample 5 when the test wheel 1 drives the motion impact device 3 to rotate, so as to carry out the test and evaluation research on the impact resistance of the pavement material under different impact force load levels.

[0068] Embodiment 3

[0069] Referring to Figure 6 and Figure 7This embodiment describes a testing device for evaluating the impact toughness of airport pavement indoors. It is based on Embodiment 1 or Embodiment 2. The test base 4 has a sample holding groove 4.1 for placing the test specimen 5. The test wheel 3.5 is placed above the test specimen 5, and the load is applied to the upper surface of the test specimen 5 through the test wheel 3.5. A laser emitter 4.4 and a laser receiver 4.5 are arranged side by side on the groove wall of the sample holding groove 4.1. Preferably, the laser emitter 4.4 and the laser receiver 4.5 are located at the top of the groove wall of the sample holding groove 4.1. Both the laser emitter 4.4 and the laser receiver 4.5 are electrically connected to the control module 6. The fixed bracket 2 is located on the outside of the sample holding groove 4.1, and the fixed bracket 2, the laser emitter 4.4 and the laser receiver 4.5 are arranged side by side. The bottom surface of the test specimen 5 is fixedly connected to the bottom wall of the sample collection tank 4.1 via a fixed support 4.2, and the side surface of the test specimen 5 is fixedly connected to the side wall of the sample collection tank 4.1 via fasteners. A limiting rubber plate 4.7 is provided at the connection between the fastener and the test specimen 5. Preferably, the fastener is a fastening screw 4.6. Specifically, the fixed support 4.2 is arranged perpendicular to the travel direction of the test wheel 3.5. The test specimen 5 is placed in the sample collection tank 4.1 and supported by the fixed support 4.2. The test base 4 consists of a base plate 4.8 and an end baffle 4.9. The end baffle 4.9 is provided with a fastening screw 4.6. The fastening screw 4.6 limits the test specimen 5 via the limiting rubber plate 4.7 to prevent the test specimen 5 from loosening during the impact. Special note: The surface of the fixed support 4.2 in contact with the test specimen 5 should be as smooth as possible to reduce the frictional resistance that would cause the test specimen 5 to bend and deform under load. A column 4.3 is installed on the end baffle 4.9 of the test base 4. A laser emitter 4.4 and a laser receiver 4.5 are respectively mounted on top of the column 4.3. Based on the triangulation principle, the laser emitter 4.4 and laser receiver 4.5 can measure the vertical deformation of the test specimen 5 under impact load. The vertical deformation monitoring results at deformation measurement point 4.11 are obtained through... The connection line 6.1 transmits data to the control module 6 for recording and storage, thereby enabling deformation monitoring of the test specimen 5 under impact load. Preferably, the end side baffle 4.9 of the test base 4 is also provided with a specimen buckle 4.9.1. The specimen buckle 4.9.1 is connected to the end side baffle 4.9 by a buckle screw 4.9.2 and can rotate around the buckle screw 4.9.2. During the installation or removal of the test specimen 5, the specimen buckle 4.9.1 can be opened and closed as needed, and plays a certain role in stabilizing the test specimen 5 during the impact test.

[0070] Example 4

[0071] The test device for indoor evaluation of the impact toughness of the airport pavement is formed on the basis of the embodiment 3, the power output end of the power system 1.4 is connected with the moving runner 1 through the rotating shaft 1.2, the rotating shaft 1.2 is rotatably connected with the fixed support 2 through the fixed bearing 1.5, and the fixed bearing 1.5 is supported through the fixed support 2. Specifically, the laser counter 1.6 is arranged on the fixed bearing 1.5, preferably, the laser counter 1.6 is arranged on the top of the fixed bearing 1.5, the positioning hole 1.3 is arranged on the moving runner 1, the position of the positioning hole 1.3 corresponds to the position of the laser counter 1.6, the laser counter 1.6 is used to record the rotating number of the moving runner 1, and the time point when the test wheel 3.5 is located directly below the moving runner 1 is captured, which represents that the test wheel 3.5 has run to the corresponding position of the deformation measuring point 4.11, further, the rotating number of the moving runner 1 and the time point information are transmitted to the control module 6 through the connecting line 6.1, the control module 6 reads the load force value of the cylinder type dynamometer 3.2 and the vertical deformation value of the deformation measuring point 4.11 according to the time point information, and the calculation of the impact load action energy of the cycle is completed by the control module 6, which is used for the evaluation and analysis of the impact toughness of the test piece 5.

[0072] It is particularly stated that when the test wheel 3.5 is located directly below the moving runner 1, the force spring 3.3 is compressed to the maximum extent, which represents that the test wheel 3.5 exerts the maximum load action force on the test piece 5, at this moment, the action area of the test wheel 3.5 on the surface of the test sample 5 is the maximum impact force wheel trace 4.10, further, the deformation measuring point 4.11 is arranged outside the maximum impact force wheel trace 4.10 and corresponds to the center of the maximum impact force wheel trace 4.10. Since the fixed support 4.2 is arranged vertically to the running direction of the test wheel 3.5, the test piece 5 will be bent and deformed in the plane perpendicular to the fixed support 4.2 under the impact load action of the test wheel 3.5, and the vertical deformation value at the deformation measuring point 4.11 should be consistent with the vertical deformation value at the center of the maximum impact force wheel trace 4.10, so that the device can realize the accurate measurement of the vertical deformation value at the center of the maximum impact force wheel trace 4.10. During each impact load cycle, the vertical deformation value at the deformation measuring point 4.11 is the difference between the deformation value when the test wheel 3.5 is at the maximum impact force wheel trace 4.10 and the minimum deformation value monitored in the load action process of the cycle.

[0073] In the embodiment, the test wheel 3.5 is preferably a rubber inflatable tire, and the rubber hardness is preferably 66-72 IRHD.

[0074] The test specimen 5 in this embodiment can be prepared by indoor molding, or can be cut and processed by sampling on site of a newly built or existing airport pavement. It can be used for impact toughness evaluation of asphalt concrete or cement concrete pavement materials. The test surface of the test specimen 5 should be the upper surface of the molded or sampled sample.

[0075] During the test, first, the position of the limiting screw hole 3.1.1 is selected according to the thickness of the selected test specimen 5, the initial extension length of the motion impact device 3 is determined, then the motion impact device 3 is rotated to be directly below, the test wheel 3.5 is placed at the position of the maximum impact force wheel trace 4.10, further, the position of the adjustable base plate 3.3.1 is adjusted according to the impact load level, and the force value generated by the force spring 3.3 is read by the cylinder type force gauge 3.2, until the reading of the cylinder type force gauge 3.2 reaches the required set impact load force level.

[0076] Embodiment 5

[0077] This embodiment is a test method for indoor evaluation of the impact toughness of airport pavement, which is formed on the basis of the test device for indoor evaluation of the impact toughness of airport pavement in embodiment 4, which includes the following steps:

[0078] 1) The test device for indoor evaluation of the impact toughness of airport pavement described above is made; specifically, the test specimen 5 is a rectangular plate specimen prepared indoors, or a sample taken on site, then the sample is cut into a rectangular plate specimen according to the designed size, the surface of the test specimen 5 is ensured to be flat and free of floating sand; the test specimen 5 is placed in the sample container 4.1 of the test base 4, above the fixed support 4.2, the test specimen 5 is placed with limiting rubber plates 4.7 at both ends, the fastening screws 4.6 are tightened to ensure that the test specimen 5 is fastened, and then the specimen buckle 4.9.1 is locked;

[0079] 2) Adjust the test wheel 3.5 so that the test wheel 3.5 is in the maximum impact force wheel trace 4.10 area of the test specimen 5; specifically, first, the position of the limiting screw hole 3.1.1 is selected according to the thickness of the selected test specimen 5, so that the initial extension length of the motion impact device 3 can tightly press the test wheel 3.5 on the surface of the test specimen 5, then the motion impact device 3 is rotated to be directly below, so that the test wheel 3.5 is placed at the position of the maximum impact force wheel trace 4.10, and the maximum impact force wheel trace 4.10 area range is marked, further, the position of the adjustable base plate 3.3.1 is adjusted, and the force value generated by the force spring 3.3 is read by the cylinder type force gauge 3.2, until the reading of the cylinder type force gauge 3.2 reaches the required set impact load force level F0. Finally, according to the center position of the maximum impact force wheel trace 4.10, the deformation measurement point 4.11 position is marked, and the laser emitter 4.4 and the laser receiver 4.5 are adjusted to point to the deformation measurement point 4.11 so that the deformation measurement position is on the deformation measurement point 4.11;

[0080] 3) The power system 1.4 is started by the control module 6 and the operating speed of the power system 1.4 is controlled, so that the power system 1.4 rotates and drives the motion wheel 1 to rotate. The motion wheel 1 drives the rectangular telescopic sleeve 3.1 to make centrifugal motion along the circumference of the motion wheel 1 through the sleeve 1.1. Under the action of centrifugal force, the rectangular telescopic sleeve 3.1 slides along the telescopic cavity 3.1.2 and the telescopic throat 3.1.3, so that the test wheel 3.5 experiences the load application process of initial contact, compression, unloading and moving away on the surface of the test specimen 5.

[0081] 4) During the process of the test wheel 3.5 applying load to the test specimen 5, the cylindrical force gauge 3.2 measures the instantaneous impact load value of the test specimen 5 and transmits it to the control module 6; the laser counter 1.6 measures the number of revolutions of the moving wheel 1 and transmits it to the control module 6; the laser emitter 4.4 and the laser receiver 4.5 jointly measure the vertical deformation of the test specimen 5 and transmit it to the control module 6.

[0082] The control module 6 receives the instantaneous impact load force of the test specimen 5, the number of rotations of the moving wheel 1, and the vertical deformation of the test specimen 5. It records and stores these parameters and calculates the pavement impact resistance index (IRI) of the test specimen 5. The formula for calculating the pavement impact resistance index (IRI) is as follows:

[0083]

[0084] In the formula, N is the number of revolutions of the moving wheel 1, that is, the total number of cycles of the impact load applied, in units of times; I i denoted as J, where J is the impact energy generated by the impact load during the i-th impact load cycle; H is the thickness of the test specimen (cm).

[0085] Specifically, the control module 6 sets the rotational speed of the moving wheel 1, activates the automatic operating program of the cylindrical force gauge 3.2, laser counter 1.6, laser emitter 4.4, and laser receiver 4.5, starts the equipment, and performs automatic impact operation and real-time information acquisition. The control module 6 records the rotational number i of the moving wheel 1, as well as the magnitude of the impact load force of the test wheel 3.5 and the vertical deformation of the deformation measurement point 4.11 at each moment during the entire impact load process. Finally, based on the time point captured by the laser counter 1.6 when the test wheel 3.5 reaches the maximum impact force wheel track 4.10, the control module 6 reads the load force value F of the cylindrical force gauge 3.2 at that time point. i And the vertical deformation l at deformation measurement point 4.11 i Furthermore, the control module 6 calculates the impact energy I borne by the test specimen 5 under the impact load of this cycle.i = 0.5F i * 1 i The repeated impact load cycle is repeated until the test specimen 5 is broken or the vertical deformation of the deformation measuring point 4.11 reaches the designed maximum deformation value, and the impact energy value I of each impact cycle under the action of the control module 6 is recorded and stored i The impact energy data is summarized and processed to obtain the total load impact energy ∑I required for the test specimen 5 to be damaged i .

[0086] Example 6

[0087] The test method for evaluating the impact toughness of the airport pavement in the room is formed on the basis of example 5, and the step 3) is specifically:

[0088] The power system 1.4 is started and the running speed of the power system 1.4 is controlled by the control module 6, so that the power system 1.4 rotates to drive the rotating wheel 1 to rotate, and the rotating wheel 1 drives the middle shaft enlarged end 3.4.1, the middle shaft upper rectangular rod 3.4.3 and the middle shaft lower circular rod 3.4.4 to make centrifugal motion along the circumference of the rotating wheel 1, under the action of centrifugal force, the middle shaft enlarged end 3.4.1 and the middle shaft upper rectangular rod 3.4.3 slide along the expansion cavity 3.1.2 and the expansion throat 3.1.3 respectively, so that the test wheel 3.5 experiences the processes of initial contact, compression, unloading and moving away on the surface of the test specimen 5 during the load application process, and at the same time, the middle shaft enlarged end 3.4.1 and the middle shaft upper rectangular rod 3.4.3 slide along the expansion cavity 3.1.2 and the expansion throat 3.1.3 respectively, so that the expansion middle shaft 3.4 is stretched to different degrees, and the sliding top plate 3.3.2 slides up and down along the axis of the middle shaft upper rectangular rod 3.4.3 to apply different pressures to the force spring 3.3, so that the force spring 3.3 is compressed to different degrees, and the cylinder type force gauge 3.2 can measure the instantaneous impact load force of the test specimen 5 by measuring the instantaneous pressure of the force spring 3.3.

Claims

1. A test device for indoor evaluation of the impact resistance of an airport pavement, characterized in that, Including motion rotating wheel (1), power system (1.4), fixed support (2), motion impact device (3), test base (4) and control module (6), the motion rotating wheel (1) is fixedly connected with sleeve (1.1), the test base (4) is connected with power system (1.4) through fixed support (2), the power output end of power system (1.4) is connected with motion rotating wheel (1), one end of motion impact device (3) is connected with motion rotating wheel (1), the test base (4) is used to place test test piece (5), the other end of motion impact device (3) is placed above test test piece (5);The control module (6) is electrically connected with motion impact device (3) and power system (1.4) respectively; The motion impact device (3) includes rectangular telescopic sleeve pipe (3.1), and the rectangular telescopic sleeve pipe (3.1) is provided with telescopic cavity (3.1.2) and telescopic throat (3.1.3); By controlling module (6) starts power system (1.4) and controls the running speed of power system (1.4), so that power system (1.4) rotates, drives motion rotating wheel (1) to rotate, motion rotating wheel (1) drives rectangular telescopic sleeve pipe (3.1) to rotate along the circumference of motion rotating wheel (1) through sleeve (1.1), telescopic shaft (3.4) slides along telescopic cavity (3.1.2) and telescopic throat (3.1.3), so that test wheel (3.5) experiences the load application process of preliminary contact, compaction, unloading and away on the surface of test test piece (5);Control module (6) will receive the instantaneous impact load force of test test piece (5), the number of revolutions of motion rotating wheel (1) and the vertical deformation of test test piece (5), record and store the instantaneous impact load force of test test piece (5), the number of revolutions of motion rotating wheel (1) and the vertical deformation of test test piece (5), and calculate the pavement impact resistance index IRI of test test piece (5), and the calculation formula of pavement impact resistance index IRI is: In the formula, N is the number of revolutions of motion rotating wheel (1), that is, the total cycle number of impact load, unit: times; I i H is the thickness of the test specimen (5) in cm.

2. The test apparatus for indoor evaluation of the impact resistance of an airport pavement according to claim 1, characterized in that, The motion impact device (3) further includes cylinder type dynamometer (3.2), force spring (3.3), telescopic shaft (3.4) and test wheel (3.5), the rectangular telescopic sleeve pipe (3.1) is connected with the sleeve (1.1), and the telescopic cavity (3.1.2) and the telescopic throat (3.1.3) are communicated along the axial direction of the rectangular telescopic sleeve pipe (3.1);One end of the telescopic shaft (3.4) extends into the telescopic cavity (3.1.2) through the telescopic throat (3.1.3) and is slidably connected with the telescopic cavity (3.1.2) and the telescopic throat (3.1.3);The other end of the telescopic shaft (3.4) is fixedly connected with the test wheel (3.5), and the force spring (3.3) and the cylinder type dynamometer (3.2) are sequentially arranged on the outside of the telescopic shaft (3.4) from bottom to top along the axial direction of the telescopic shaft (3.4).

3. The test apparatus for indoor evaluation of the impact resistance of an airport pavement according to claim 2, characterized in that, One end of the force spring (3.3) is connected with the cylinder force gauge (3.2) through the sliding top plate (3.3.2) sleeved outside the telescopic shaft (3.4), and the other end of the force spring (3.3) is connected with the telescopic shaft (3.4) through the adjustable bottom plate (3.3.1) sleeved outside the telescopic shaft (3.4), the sliding top plate (3.3.2) is slidingly connected with the telescopic shaft (3.4), and the adjustable bottom plate (3.3.1) is fixedly connected with the telescopic shaft (3.4).

4. The test apparatus for indoor evaluation of the impact resistance of an airport pavement according to claim 3, characterized in that, The telescopic shaft (3.4) comprises a shaft enlarged end (3.4.1), a shaft upper rectangular rod (3.4.3) and a shaft lower circular rod (3.4.4), the shaft enlarged end (3.4.1) is arranged in the telescopic cavity (3.1.2), the shaft upper rectangular rod (3.4.3) extends through the telescopic throat (3.1.3) to the telescopic cavity (3.1.2) and is connected with the shaft enlarged end (3.4.1), the transverse dimension of the shaft enlarged end (3.4.1) is greater than the radial dimension of the telescopic throat (3.1.3), the shaft enlarged end (3.4.1) is slidingly connected with the telescopic cavity (3.1.2), the shaft upper rectangular rod (3.4.3) is slidingly connected with the telescopic throat (3.1.3), the shaft lower circular rod (3.4.4) is connected with the shaft upper rectangular rod (3.4.3), the cylinder force gauge (3.2) is arranged at the connection position of the shaft upper rectangular rod (3.4.3) and the rectangular telescopic sleeve (3.1), a hole is formed in the middle of the cylinder force gauge (3.2), the shaft upper rectangular rod (3.4.3) extends through the hole of the cylinder force gauge (3.2) to the telescopic throat (3.1.3), the sliding top plate (3.3.2) is sleeved outside the shaft upper rectangular rod (3.4.3), and the adjustable bottom plate (3.3.1) is sleeved outside the shaft lower circular rod (3.4.4); the bottom of the shaft lower circular rod (3.4.4) is rotationally connected with the test wheel (3.5); the motion rotating wheel (1) is provided with a laser counter (1.6) for measuring the number of rotations of the motion rotating wheel (1), and the laser counter (1.6) is electrically connected with the control module (6).

5. The test apparatus for indoor evaluation of the impact resistance of an airport pavement according to claim 4, characterized in that, The bottom of the shaft lower circular rod (3.4.4) is provided with a door-shaped support (3.4.2), and the test wheel (3.5) is rotationally connected with the door-shaped support (3.4.2).

6. The test apparatus for indoor evaluation of the impact resistance of an airport pavement according to claim 4, characterized in that, The test base (4) is provided with a sample containing groove (4.1), the sample containing groove (4.1) is used for placing a test sample (5), and the test wheel (3.5) is arranged above the test sample (5); the groove wall of the sample containing groove (4.1) is provided with a laser emitter (4.4) and a laser receiver (4.5) side by side, and the laser emitter (4.4) and the laser receiver (4.5) are electrically connected with the control module (6); the fixed support (2) is arranged outside the sample containing groove (4.1), and the fixed support (2), the laser emitter (4.4) and the laser receiver (4.5) are arranged side by side.

7. The test apparatus for indoor evaluation of the impact resistance of an airport pavement according to claim 6, characterized in that, The bottom end surface of the test sample (5) is fixedly connected with the bottom wall of the sample container (4.1) through a fixed support (4.2), and the side end surface of the test sample (5) is fixedly connected with the side wall of the sample container (4.1) through a fastener, and a limiting rubber plate (4.7) is arranged at the connection between the fastener and the test sample (5).

8. The test device for indoor evaluation of the impact resistance of an airport pavement according to claim 1, characterized in that, The power output end of the power system (1.4) is connected with the moving runner (1) through a rotating shaft (1.2), and the rotating shaft (1.2) is rotatably connected with the fixed support (2) through a fixed bearing (1.5).

9. A test method for evaluating the impact resistance of an airport pavement in a laboratory, characterized in that, The method comprises the following steps: 1) making the test device for indoor evaluation of the impact toughness of the airport pavement as claimed in claim 6; 2) debugging the test wheel (3.5) so that the test wheel (3.5) is in the maximum impact force wheel trace (4.10) area of the test sample (5); 3) starting the power system (1.4) and controlling the running speed of the power system (1.4) through the control module (6), so that the power system (1.4) rotates to drive the moving runner (1) to rotate, the moving runner (1) drives the rectangular telescopic sleeve (3.1) to rotate along the circumference of the moving runner (1) through the sleeve (1.1), and the telescopic shaft (3.4) slides along the telescopic cavity (3.1.2) and the telescopic throat (3.1.3), so that the test wheel (3.5) experiences the processes of initial contact, compression, unloading and load application away from the surface of the test sample (5); 4) during the process of applying load to the test sample (5) by the test wheel (3.5), the columnar force gauge (3.2) monitors the rebound force of the force spring (3.3) as the instantaneous impact load force applied to the test sample (5) by the test wheel (3.5), and transmits the instantaneous impact load force value to the control module (6); the laser counter (1.6) measures the number of revolutions of the moving runner (1) and transmits it to the control module (6); the laser transmitter (4.4) and the laser receiver (4.5) jointly measure the vertical deformation amount of the test sample (5) and transmit it to the control module (6); The control module (6) receives the instantaneous impact load force of the test sample (5), the number of revolutions of the moving runner (1) and the vertical deformation amount of the test sample (5), records and stores the instantaneous impact load force of the test sample (5), the number of revolutions of the moving runner (1) and the vertical deformation amount of the test sample (5), and calculates the pavement impact resistance index IRI of the test sample (5), and the calculation formula of the pavement impact resistance index IRI is: wherein N is the number of revolutions of the moving runner (1), i.e. the total number of impact load cycles, unit: times; I i H is the thickness of the test specimen (5) in cm.

10. The test method for indoor evaluation of the impact resistance of an airport pavement according to claim 9, characterized in that, The step 3) is specifically: starting the power system (1.4) and controlling the running speed of the power system (1.4) through the control module (6), so that the power system (1.4) rotates, drives the motion runner (1) to rotate, and drives the middle shaft enlarged end (3.4.1), the middle shaft upper rectangular rod (3.4.3) and the middle shaft lower circular rod (3.4.4) to rotate along the circumference of the motion runner (1) through the sleeve (1.1), the test wheel (3.5) experiences the processes of initial contact, compression, unloading and load application away from the surface of the test sample (5), at the same time, the middle shaft enlarged end (3.4.1) and the middle shaft upper rectangular rod (3.4.3) slide along the telescopic cavity (3.1.2) and the telescopic throat (3.1.3) respectively, so that the telescopic middle shaft (3.4) is stretched to different degrees, and the sliding top plate (3.3.2) slides up and down along the axis of the middle shaft upper rectangular rod (3.4.3) to apply different pressures to the force measuring spring (3.3), so that the force measuring spring (3.3) is compressed to different degrees, and the cylinder type force gauge (3.2) can measure the instantaneous impact load force of the test sample (5) by measuring the instantaneous pressure of the force measuring spring (3.3).

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