Asphalt pavement structure stress strain sensor calibration device and method

Abstract

The invention provides an asphalt pavement structure stress-strain sensor calibration device, which comprises a mounting rack, and further comprises a comparison sample internally provided with a stress-strain sensor; the movable chassis is mounted at the bottom of the mounting frame and used for being matched with an external power source to drive the device to move; the pressurizing mechanism is mounted on the inner side of the movable chassis and is used for applying pressure to the road surface and the contrast sample; the protection mechanism is mounted on the outer side of the pressurizing mechanism and is in sliding connection with the pressurizing mechanism; and the counterweight mechanism is mounted at the top of the movable chassis. Through the arrangement of the movable chassis and the pressurizing mechanism, the movable chassis can be matched with a vehicle to move the pressurizing mechanism to an asphalt pavement during use, and the stress-strain sensor pre-embedded in an asphalt layer is calibrated through the pressurizing mechanism and the data acquisition mechanism, so that the application is more flexible and convenient; and calibration personnel can conveniently carry out calibration work at different positions of the road surface.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor calibration equipment, and in particular to a device and method for calibrating a stress and strain sensor of an asphalt pavement structure. Background Art

[0002] The principle of pavement stress strain sensor is mainly based on the strain effect, that is, the mechanical deformation of the material under the action of external force will cause its resistance to change. This phenomenon is called strain effect. When external force acts on the sensor, the structure of the sensor will deform, causing the strain gauge attached to it to undergo corresponding strain. This strain will cause the resistance value of the strain gauge to change. The resistance change is converted into a voltage signal through the measuring circuit, thereby indirectly measuring the magnitude of the external force. In the actual pavement construction process, the sensor is usually embedded in the asphalt mixture. The strain sensor pre-buried in the asphalt layer will have data errors during long-term vehicle rolling.

[0003] After searching, the Chinese patent application number 202123152748.8 discloses a strain gauge calibration device, including a force standard machine, a test sample and a strain measurement system for fixing and pasting the strain gauge to be tested, wherein the test sample is connected between the upper and lower chucks of the force standard machine; the strain measurement system includes a laser interferometer, a steering mirror, an interferometer and a measuring mirror; the interferometer and the measuring mirror are vertically distributed on the test sample; the output laser of the laser interferometer is directed toward the steering mirror, and the output light of the steering mirror can reach the interferometer and the measuring mirror in sequence vertically upward; and also includes a measuring instrument for detecting the relative resistance change on the strain gauge to be tested. The utility model has the advantages of being able to fully trace the metrological standard instrument to the metrological reference and being able to calibrate the surface strain gauge.

[0004] The above patent has the following deficiencies: it can only measure and calibrate unused strain sensors, but cannot calibrate strain sensors embedded in asphalt layers. It is not flexible and convenient to use. Different temperature environments cannot be provided during the calibration process. The data is less rich and the calibration results are prone to errors. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that in the prior art, only unused strain sensors can be measured and calibrated, but strain sensors pre-buried in asphalt layers cannot be calibrated, the use is not flexible and convenient, different temperature environments cannot be provided during the calibration process, the data is less rich, and the calibration results are prone to errors.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] Asphalt pavement structure stress and strain sensor calibration device is used to improve the above problems.

[0008] The specific application is as follows:

[0009] Includes mounting bracket, also includes:

[0010] A comparison specimen with a stress and strain sensor installed inside;

[0011] A mobile chassis, mounted at the bottom of the mounting frame, for driving the device to move in coordination with an external power source;

[0012] A pressurizing mechanism, installed on the inner side of the mobile chassis, for applying pressure to the road surface and the comparison sample;

[0013] A protection mechanism, installed on the outside of the pressurizing mechanism and slidably connected to the pressurizing mechanism;

[0014] A counterweight mechanism is mounted on the top of the mobile chassis and symmetrically arranged on both sides of the mounting frame;

[0015] A reciprocating mechanism, installed inside the protection mechanism and located below the pressurizing mechanism;

[0016] A heating mechanism, disposed inside the reciprocating mechanism, for heating the road surface and the comparison sample;

[0017] A cooling mechanism, installed inside the reciprocating mechanism and located below the heating mechanism, for cooling the road surface and the comparison sample;

[0018] The data acquisition mechanism is installed on one side of the mounting frame and is used to collect data detected by the stress and strain sensors in the road surface and the stress and strain sensors in the comparison sample.

[0019] As a preferred technical solution of the present application, the mobile chassis includes a first support frame and a second support frame, a support frame for supporting the mounting frame is fixedly connected between the first support frame and the second support frame, a connecting frame is connected to one side of the second support frame, and multiple rollers are installed at the bottom of the first support frame and the second support frame.

[0020] As a preferred technical solution of the present application, the pressurizing mechanism includes a hydraulic cylinder installed on the top of the inner wall of the mounting frame, the movable end of the hydraulic cylinder is connected to a mounting plate, two adjustable extrusion wheels are installed on the mounting plate, the adjustable extrusion wheel includes a threaded rod passing through the mounting plate, the mounting plate is provided with a hole that cooperates with the threaded rod, the threaded rod is threaded with a first adjusting nut and a second adjusting nut, the bottom end of the threaded rod is connected to an extrusion rod, and the outer side of the extrusion rod is provided with a cylindrical rubber sleeve.

[0021] As a preferred technical solution of the present application, the protective mechanism includes a box body which is sleeved on the outside of the pressurizing mechanism, a through hole is opened at the top center of the box body, a plurality of limit seats which cooperate with the cross bar on the mounting frame are installed on the top of the box body, a limit pin is slidably installed on the limit seat, and a through groove which cooperates with the reciprocating mechanism is opened on the back of the box body.

[0022] As a preferred technical solution of the present application, the counterweight mechanism includes two water tanks installed on the top of the mobile chassis, the two water tanks are respectively located on both sides of the mounting frame, a water filling pipe is installed on the top of the water tank, a drain pipe is installed through the side wall of the water tank, and a first valve located on the outside of the water tank is installed on the drain pipe.

[0023] As a preferred technical solution of the present application, the reciprocating mechanism includes two sliding rails symmetrically installed on the inner wall of the box body, the sliding rails penetrate the box body through the through slot, an installation box is slidably installed on the inner side of the two sliding rails, a handle penetrating the box body through the through slot is installed on the back of the installation box, and a groove for installing the heating mechanism and the cooling mechanism is provided at the bottom end of the installation box.

[0024] As a preferred technical solution of the present application, the heating mechanism includes two groups of electric heating tubes symmetrically installed in the grooves at the bottom end of the installation box.

[0025] As a preferred technical solution of the present application, the cooling mechanism includes a gas cylinder installed on the top of the protective mechanism, a second valve is installed on the air outlet pipe of the gas cylinder, a connecting hose is connected to the end of the air outlet pipe away from the gas cylinder, the connecting hose is connected to two annular jet pipes through a three-way joint, a plurality of evenly distributed nozzles are installed on the inner side of the jet pipe, the jet pipe is installed in a groove at the bottom end of the installation box, and the jet pipe is located below the electric heating pipe.

[0026] As a preferred technical solution of the present application, the data acquisition mechanism includes a data collector and two temperature sensors cooperating with the data collector. The data collector is installed on one side of the mounting frame through a connecting rod, and a touch screen is installed on the front of the data collector.

[0027] The present application also discloses a calibration method for an asphalt pavement structure stress and strain sensor calibration device, comprising the following steps:

[0028] S1: Before calibration: Move the device to the road to be tested by using a vehicle and a mobile chassis, align one of the adjustable extrusion wheels with the stress-strain sensor embedded in the asphalt pavement, and then place a comparison sample under the other adjustable extrusion wheel. Then adjust the positions of the two adjustable extrusion wheels so that their bottoms touch the pavement and the top of the comparison sample respectively, and fill water into the data acquisition mechanism to increase the overall weight of the device.

[0029] S2: Normal temperature calibration: Start the hydraulic cylinder to drive the mounting plate to move downward, and pressurize the road surface and the comparison sample through two adjustable extrusion wheels. The data detected by the stress and strain sensors in the road surface and the comparison sample are collected through the data acquisition mechanism, and then the two sets of collected data are compared;

[0030] S3: Temperature rise calibration: insert two temperature sensors into the comparison sample and the ground respectively, slide the box so that the bottom of the box is against the top of the road surface, and then drive the heating mechanism to move to the top of the road surface and the comparison sample through the reciprocating mechanism to heat the road surface and the comparison sample at the same time. When the road surface and the comparison sample are heated to the temperature to be simulated, the temperature sensor will transmit the temperature data to the data acquisition mechanism. At this time, turn off the heating mechanism and move it away from the top of the road surface and the comparison sample through the reciprocating mechanism, and then start the pressurizing mechanism to pressurize the road surface and the comparison sample. The data detected by the stress and strain sensors in the road surface and the comparison sample are collected by the data acquisition mechanism, and then the two sets of collected data are compared;

[0031] S4: Cooling calibration: The cooling mechanism is driven by the reciprocating mechanism to move to the top of the road surface and the comparison sample to cool the road surface and the comparison sample simultaneously. When the road surface and the comparison sample are cooled to the required simulation temperature, the temperature sensor transmits the temperature data to the data acquisition mechanism. At this time, the cooling mechanism is turned off and moved away from the top of the road surface and the comparison sample by the reciprocating mechanism. Then, the pressurizing mechanism is started to pressurize the road surface and the comparison sample. The data detected by the stress and strain sensors in the road surface and the comparison sample are collected by the data acquisition mechanism, and then the two sets of collected data are compared.

[0032] S5: After calibration: start the hydraulic cylinder to drive the two adjustable extrusion wheels to rise above the installation box through the mounting plate, then push the installation box and the handle into the box through the handle, move the box upward so that the limit seat is sleeved on the outside of the cross bar at the top of the mounting frame, then insert the limit pin into the limit seat, and limit the box by clamping the cross bar inside the limit seat with the limit pin, then open the first valve to drain the water inside the water tank through the drain pipe, and then connect it to the vehicle through the connecting frame.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] In the scheme of this application:

[0035] 1. The asphalt pavement structure stress and strain sensor calibration device, through the setting of the mobile chassis and the pressure mechanism, when in use, the mobile chassis can cooperate with the vehicle to move the pressure mechanism to the asphalt pavement, and the stress and strain sensor embedded in the asphalt layer is calibrated through the pressure mechanism and the data acquisition mechanism. It is more flexible and convenient to use, and can facilitate the calibration personnel to perform calibration work at different positions on the road surface;

[0036] 2. The asphalt pavement structure stress and strain sensor calibration device can heat and cool the pavement by setting a heating mechanism and a cooling mechanism, so as to facilitate the acquisition of data detected by the stress and strain sensors buried in the asphalt pavement at different temperatures, enrich the data source, reduce data errors as much as possible, and improve the accuracy of calibration. The reciprocating mechanism can conveniently drive the heating mechanism and the cooling mechanism to move;

[0037] 3. The asphalt pavement structure stress and strain sensor calibration device, by setting up a data acquisition mechanism and a comparison sample, can make the same comparison sample according to the thickness of the asphalt layer of the asphalt pavement when in use. At the same time, the stress and strain sensor in the comparison sample is of the same model as the one pre-buried in the pavement. During calibration, the data obtained by the two stress and strain sensors can be directly compared through the data acquisition mechanism, and the calibration result is more intuitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The overall structural diagram of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0039] Figure 2 A schematic diagram of the use of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0040] Figure 3 A schematic diagram of the bottom structure of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0041] Figure 4 A schematic diagram of the box structure of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0042] Figure 5 A schematic diagram of the structure of the first support frame of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0043] Figure 6 A schematic diagram of the mounting plate structure of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0044] Figure 7A schematic diagram of the structure of the installation box of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0045] Figure 8 A schematic diagram of the jet pipe structure of the asphalt pavement structure stress and strain sensor calibration device provided in this application;

[0046] Fig. 9 Schematic diagram of the mounting frame structure of the asphalt pavement structure stress and strain sensor calibration device provided in this application.

[0047] Indicated in the figure:

[0048] 1. Mobile chassis; 2. Mounting frame; 3. Pressurizing mechanism; 4. Protective mechanism; 5. Counterweight mechanism; 6. Data acquisition mechanism; 7. Reciprocating mechanism; 8. Comparative sample; 9. Temperature sensor; 10. Cooling mechanism; 11. Electric heating tube; 101. First support frame; 102. Support frame; 103. Second support frame; 104. Connecting frame; 105. Roller; 301. Hydraulic cylinder; 302. Mounting plate; 303. Threaded rod; 304. Extrusion rod; 305. Rubber sleeve; 306. First adjusting nut; 30 7. Second adjusting nut; 401. Box body; 402. Limit seat; 403. Limit pin; 404. Through hole; 405. Through slot; 501. Water tank; 502. Water filling pipe; 503. Drain pipe; 504. First valve; 601. Connecting rod; 602. Data collector; 603. Touch screen; 701. Sliding track; 702. Installation box; 703. Handle; 111. Gas cylinder; 112. Jet pipe; 113. Nozzle; 114. Connecting hose; 115. Three-way connector; 116. Second valve. DETAILED DESCRIPTION

[0049] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0050] like Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a calibration device for an asphalt pavement structure stress and strain sensor, including a mounting frame 2, and also including:

[0051] A comparison sample 8 is provided with a stress-strain sensor inside, wherein the stress-strain sensor in the comparison sample 8 is located at the same position as the stress-strain sensor in the asphalt layer of the road surface and is of the same model;

[0052] The mobile chassis 1 is installed at the bottom of the mounting frame 2 and is used to cooperate with an external power source to drive the device to move. The pressure mechanism 3 is installed on the inner side of the mobile chassis 1 and is used to apply pressure to the road surface and the comparison sample 8. The asphalt pavement structure stress and strain sensor calibration device, through the arrangement of the mobile chassis 1 and the pressure mechanism 3, when in use, the mobile chassis 1 can cooperate with the vehicle to move the pressure mechanism 3 to the asphalt pavement, and the stress and strain sensor embedded in the asphalt layer is calibrated through the pressure mechanism 3 and the data acquisition mechanism 6. It is more flexible and convenient to use, and can facilitate the calibration personnel to perform calibration work at different positions on the road surface;

[0053] The protection mechanism 4 is installed on the outside of the pressurizing mechanism 3 and is slidably connected to the pressurizing mechanism 3. The counterweight mechanism 5 is installed on the top of the mobile chassis 1 and is symmetrically arranged on both sides of the mounting frame 2. Through the setting of the protection mechanism 4, it can cover the comparison sample 8 and the road surface during heating and cooling, reduce the heat dissipation of temperature, and improve the efficiency of heating or cooling. Through the setting of the counterweight mechanism 5, the device can be counterweighted, which is convenient for use with the pressurizing mechanism 3;

[0054] The reciprocating mechanism 7 is installed inside the protection mechanism 4 and is located below the pressurizing mechanism 3. The heating mechanism is arranged inside the reciprocating mechanism 7 and is used to heat the road surface and the comparison sample 8. The cooling mechanism 10 is installed inside the reciprocating mechanism 7 and is located below the heating mechanism and is used to cool the road surface and the comparison sample 8. By arranging the heating mechanism and the cooling mechanism 10, the road surface can be heated and cooled, so as to facilitate the acquisition of data detected by the stress strain sensor buried in the asphalt road surface at different temperatures, enrich the data source, reduce the data error as much as possible, and improve the accuracy of calibration. By arranging the reciprocating mechanism 7, the heating mechanism and the cooling mechanism 10 can be conveniently driven to move;

[0055] The data acquisition mechanism 6 is installed on one side of the mounting frame 2, and is used to collect data detected by the stress and strain sensors in the road surface and the stress and strain sensors in the comparison sample 8. By setting the data acquisition mechanism 6 and the comparison sample 8, the same comparison sample 8 can be made according to the thickness of the asphalt layer of the asphalt road surface during use. At the same time, the stress and strain sensor in the comparison sample 8 is of the same model as the one pre-buried in the road surface. During calibration, the data obtained by the two stress and strain sensors can be directly compared through the data acquisition mechanism 6, and the calibration result is more intuitive.

[0056] like Figure 1 and Figure 5As shown, as a preferred embodiment, on the basis of the above-mentioned manner, further, the mobile chassis 1 includes a first support frame 101 and a second support frame 103, a support frame 102 for supporting the mounting frame 2 is fixedly connected between the first support frame 101 and the second support frame 103, a connecting frame 104 is connected to one side of the second support frame 103, and a plurality of rollers 105 are installed at the bottom of the first support frame 101 and the second support frame 103. It should be noted that by setting the first support frame 101 and the second support frame 103, it is convenient to support the two water tanks 501, by setting the support frame 102, it is convenient to install the mounting frame 2, by setting the connecting frame 104, it can be connected to the trailer hook on the vehicle through the towing connecting arm installed thereon, and by setting the rollers 105, it is convenient to move the mobile chassis 1.

[0057] like Figure 1 , Figure 2 and Figure 6 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the pressurizing mechanism 3 includes a hydraulic cylinder 301 installed on the top of the inner wall of the mounting frame 2, the movable end of the hydraulic cylinder 301 is connected to the mounting plate 302, and two adjustable extrusion wheels are installed on the mounting plate 302, the adjustable extrusion wheel includes a threaded rod 303 passing through the mounting plate 302, the mounting plate 302 is provided with a hole that cooperates with the threaded rod 303, the threaded rod 303 is threadedly connected with a first adjusting nut 306 and a second adjusting nut 307, the bottom end of the threaded rod 303 is connected to the extrusion rod 304, and the outer side of the extrusion rod 304 is provided with a cylindrical rubber sleeve 305. It should be noted that, by loosening the first adjusting nut 306 and the second adjusting nut 307 during use, the threaded rod 303 can be moved up and down through the holes on the mounting plate 302, thereby adjusting the position of the extrusion rod 304. After the adjustment is completed, the first adjusting nut 306 and the second adjusting nut 307 can be tightened to clamp the mounting plate 302 to fix the extrusion rod 304. By setting the rubber sleeve 305, it can be covered on the outside of the extrusion rod 304 to reduce the damage of the extrusion rod 304 to the road surface and the comparison sample 8.

[0058] like Figure 1 and Figure 4As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the protective mechanism 4 includes a box body 401 which is sleeved on the outside of the pressurizing mechanism 3, a through hole 404 is opened at the top center of the box body 401, a plurality of limit seats 402 which cooperate with the cross bars on the mounting frame 2 are installed on the top of the box body 401, and limit pins 403 are slidably installed on the limit seats 402, and a through groove 405 which cooperates with the reciprocating mechanism 7 is opened on the back of the box body 401. It should be noted that when in use, the box body 401 made of heat-insulating material can be covered above the comparison sample 8 and the road surface during heating and cooling, so as to reduce temperature loss and increase the heating or cooling speed. The setting of the through groove 405 can facilitate the reciprocating movement of the reciprocating mechanism 7. The limit seat 402 can be sleeved on the outer side of the top cross bar of the mounting frame 2, and then the limit pin 403 is inserted into the limit seat 402. The limit pin 403 clamps the cross bar inside the limit seat 402 to fix the box body 401. The setting of the through hole 404 can facilitate the use in conjunction with the hydraulic cylinder 301, so that the box body 401 can slide up and down on the outer side of the hydraulic cylinder 301.

[0059] like Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, as a preferred embodiment, on the basis of the above-mentioned manner, further, the counterweight mechanism 5 includes two water tanks 501 mounted on the top of the mobile chassis 1, the two water tanks 501 are respectively located on both sides of the mounting frame 2, a water supply pipe 502 is installed on the top of the water tank 501, a drain pipe 503 is installed through the side wall of the water tank 501, and a first valve 504 located outside the water tank 501 is installed on the drain pipe 503. It should be noted that water can be added to the inside of the water tank 501 through the water supply pipe 502 to increase the weight of the entire device, and the water inside the water tank 501 can be discharged through the drain pipe 503 by opening the first valve 504.

[0060] like Figure 1 , Figure 2 , Figure 3 and Figure 7As shown, as a preferred embodiment, on the basis of the above-mentioned manner, further, the reciprocating mechanism 7 includes two sliding rails 701 symmetrically installed on the inner wall of the box body 401, the sliding rails 701 penetrate the box body 401 through the through slots 405, and the inner sides of the two sliding rails 701 are slidably installed with installation boxes 702, and the back of the installation box 702 is installed with a handle 703 penetrating the box body 401 through the through slots 405, and the bottom end of the installation box 702 is provided with a groove for installing the heating mechanism and the cooling mechanism 10. It should be noted that, through the setting of the sliding rails 701, it is convenient to slide the installation box 702, through the setting of the handle 703, it is convenient to pull the installation box 702 to move, and through the setting of the grooves, it is convenient to install the electric heating tube 11 and the jet tube 112.

[0061] like Figure 1 , Figure 2 , Figure 3 and Figure 7 As shown, as a preferred embodiment, based on the above method, the heating mechanism further includes two sets of electric heating tubes 11 symmetrically installed in the groove at the bottom of the installation box 702. It should be noted that the arrangement of the electric heating tubes 11 can facilitate heating of the road surface and the comparison sample 8.

[0062] like Figure 1 , Figure 2 , Figure 3 and Figure 8 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the cooling mechanism 10 includes a gas cylinder 111 installed on the top of the protective mechanism 4, a second valve 116 is installed on the gas outlet pipe of the gas cylinder 111, and a connecting hose 114 is connected to one end of the gas outlet pipe away from the gas cylinder 111, and the connecting hose 114 is connected to two annular jet pipes 112 through a three-way joint 115, and a plurality of uniformly distributed nozzles 113 are installed on the inner side of the jet pipe 112, and the jet pipe 112 is installed in the groove at the bottom end of the installation box 702, and the jet pipe 112 is located below the electric heating pipe 11. It should be noted that when in use, the second valve 116 is opened to allow the nitrogen inside the gas cylinder 111 to be transported to the inside of the two jet pipes 112 through the connecting hose 114 and the three-way joint 115, and then sprayed out through the plurality of nozzles 113 to cool the road surface and the comparison sample 8 simultaneously.

[0063] like Figure 1 , Figure 2 , Figure 3 and Fig. 9As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the data acquisition mechanism 6 includes a data acquisition device 602 and two temperature sensors 9 that cooperate with the data acquisition device 602. The data acquisition device 602 is installed on one side of the mounting frame 2 through a connecting rod 601, and a touch screen 603 is installed on the front of the data acquisition device 602. It should be noted that, through the setting of the temperature sensor 9, the collected temperature data can be transmitted to the data acquisition device 602, and through the setting of the data acquisition device 602 and the touch screen 603, the collected data can be easily compared and viewed.

[0064] Specifically, the working principle of the asphalt pavement structure stress and strain sensor calibration device is as follows: before calibration, the device is moved to the road to be tested by means of a vehicle and a mobile chassis 1, one of the adjustable extrusion wheels is aligned with the stress and strain sensor embedded in the asphalt pavement, and then a comparison sample 8 is placed under the other adjustable extrusion wheel. Then, the positions of the two adjustable extrusion wheels are adjusted so that their bottoms contact the road surface and the top of the comparison sample 8 respectively, and water is added to the interior of the water tank 501 through the water filling pipe 502 to increase the overall weight of the device. When performing normal temperature calibration, the hydraulic cylinder 301 is started to drive the mounting plate 302 to move downward, and the road surface and the comparison sample 8 are pressurized by the downward movement of the two adjustable extrusion wheels. The data acquisition mechanism 6 collects the data detected by the stress and strain sensors in the road surface and the comparison sample 8, and then compares the two sets of collected data; when performing temperature rise calibration, the two temperature sensors 9 are respectively inserted into the comparison sample 8 and the ground, and then the installation box 702 is pushed to move by the handle 703, so that the two sets of electric heating tubes 11 in the installation box 702 are respectively located above the road surface and the comparison sample 8, and the box body 401 is slid so that the bottom of the box body 401 is against the top of the road surface, and the electric heating tubes 11 are started to heat the road surface and the comparison sample 8 at the same time. When the road surface and the comparison sample 8 are heated to the temperature required to be simulated, the temperature sensor 9 will transmit the temperature data to the data acquisition mechanism 6, and the electric heating is turned off at this time. The pipe 11 moves the installation box 702 and the electric heating pipe 11 away from the road surface and the comparison sample 8 through the handle 703, and then starts the hydraulic cylinder 301 to drive the two adjustable extrusion wheels to move downward through the installation plate 302 to pressurize the road surface and the comparison sample 8, and collects the data detected by the stress and strain sensors in the road surface and the comparison sample 8 through the data acquisition mechanism 6, and then compares the two sets of collected data; when performing temperature reduction calibration, the installation box 702 is pushed to move by the handle 703, so that the two jet pipes 112 in the installation box 702 are respectively located above the road surface and the comparison sample 8, and then the second valve 116 is opened to allow the nitrogen in the gas cylinder 111 to pass through the connecting hose 114 and the three-way joint. 115 is transported to the inside of the two jet pipes 112, and then sprayed out through multiple nozzles 113 to cool the road surface and the comparison sample 8 simultaneously. When the road surface and the comparison sample 8 are reduced to the required simulation temperature, the temperature sensor 9 will transmit the temperature data to the data acquisition mechanism 6. At this time, the second valve 116 is closed, and the mounting box 702 and the jet pipe 112 are moved away from the road surface and the comparison sample 8 through the handle 703. Then, the hydraulic cylinder 301 is started to drive the two adjustable extrusion wheels to move downward through the mounting plate 302 to pressurize the road surface and the comparison sample 8. The data detected by the stress and strain sensors in the road surface and the comparison sample 8 are collected by the data acquisition mechanism 6, and then the two sets of collected data are compared;After the calibration is completed, the hydraulic cylinder 301 is started to drive the two adjustable extrusion wheels to rise through the mounting plate 302, so that they rise to the top of the mounting box 702, and then the mounting box 702 and the handle 703 are pushed into the box body 401, and the box body 401 is moved upward so that the limit seat 402 is sleeved on the outer side of the top cross bar of the mounting frame 2, and then the limit pin 403 is inserted into the limit seat 402, and the limit pin 403 is clamped on the cross bar inside the limit seat 402 to limit the box body 401, and then the first valve 504 is opened to drain the water inside the water tank 501 through the drain pipe 503, and then it is connected to the vehicle through the connecting frame 104. ;

[0065] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A device for calibrating stress and strain sensors for asphalt pavement structures, comprising a mounting frame (2), characterized in that: Also includes: A comparison sample (8) having a stress and strain sensor disposed therein; A mobile chassis (1) is mounted on the bottom of the mounting frame (2) and is used to cooperate with an external power source to drive the device to move; A pressure mechanism (3) installed on the inner side of the mobile chassis (1) and used to apply pressure to the road surface and the comparison sample (8); A protection mechanism (4) is installed on the outside of the pressurizing mechanism (3) and is slidably connected to the pressurizing mechanism (3); A counterweight mechanism (5) is mounted on the top of the mobile chassis (1) and is symmetrically arranged on both sides of the mounting frame (2); A reciprocating mechanism (7) is installed inside the protection mechanism (4) and is located below the pressurizing mechanism (3); A heating mechanism, arranged inside the reciprocating mechanism (7), for heating the road surface and the comparison sample (8); A cooling mechanism (10) is installed inside the reciprocating mechanism (7) and below the heating mechanism, and is used to cool the road surface and the comparison sample (8); The data acquisition mechanism (6) is installed on one side of the mounting frame (2) and is used to collect data detected by the stress and strain sensor in the road surface and the stress and strain sensor in the comparison sample (8).

2. The asphalt pavement structure stress strain sensor calibration device according to claim 1, characterized in that: The mobile chassis (1) comprises a first support frame (101) and a second support frame (103); a support frame (102) for supporting the mounting frame (2) is fixedly connected between the first support frame (101) and the second support frame (103); a connecting frame (104) is connected to one side of the second support frame (103); and a plurality of rollers (105) are installed at the bottom of each of the first support frame (101) and the second support frame (103).

3. The asphalt pavement structure stress and strain sensor calibration device according to claim 1 is characterized in that: The pressurizing mechanism (3) comprises a hydraulic cylinder (301) mounted on the top of the inner wall of the mounting frame (2); the movable end of the hydraulic cylinder (301) is connected to a mounting plate (302); two adjustable extrusion wheels are mounted on the mounting plate (302); the adjustable extrusion wheels comprise a threaded rod (303) penetrating the mounting plate (302); a hole is provided on the mounting plate (302) and is matched with the threaded rod (303); a first adjusting nut (306) and a second adjusting nut (307) are threadedly connected to the threaded rod (303); the bottom end of the threaded rod (303) is connected to an extrusion rod (304); and a cylindrical rubber sleeve (305) is sleeved on the outer side of the extrusion rod (304).

4. The asphalt pavement structure stress and strain sensor calibration device according to claim 1, characterized in that: The protection mechanism (4) comprises a box body (401) sleeved on the outside of the pressurizing mechanism (3), a through hole (404) is provided at the center of the top of the box body (401), a plurality of limit seats (402) cooperating with the upper cross bar of the mounting frame (2) are installed on the top of the box body (401), a limit pin (403) is slidably installed on the limit seat (402), and a through groove (405) cooperating with the reciprocating mechanism (7) is provided on the back of the box body (401).

5. The asphalt pavement structure stress strain sensor calibration device according to claim 1, characterized in that: The counterweight mechanism (5) comprises two water tanks (501) mounted on the top of the mobile chassis (1), the two water tanks (501) being located on both sides of the mounting frame (2), a water supply pipe (502) being installed on the top of the water tank (501), a drainage pipe (503) being installed through the side wall of the water tank (501), and a first valve (504) being installed on the drainage pipe (503) and located on the outside of the water tank (501).

6. The asphalt pavement structure stress strain sensor calibration device according to claim 4, characterized in that: The reciprocating mechanism (7) comprises two sliding rails (701) symmetrically mounted on the inner wall of the box body (401), the sliding rails (701) passing through the box body (401) through the through slot (405), a mounting box (702) is slidably mounted on the inner side of the two sliding rails (701), a handle (703) passing through the box body (401) through the through slot (405) is mounted on the back side of the mounting box (702), and a groove for mounting the heating mechanism and the cooling mechanism (10) is provided at the bottom end of the mounting box (702).

7. The asphalt pavement structure stress strain sensor calibration device according to claim 6, characterized in that: The heating mechanism comprises two groups of electric heating tubes (11) symmetrically installed in grooves at the bottom end of the installation box (702).

8. The asphalt pavement structure stress strain sensor calibration device according to claim 7, characterized in that: The cooling mechanism (10) comprises a gas cylinder (111) mounted on the top of the protective mechanism (4); a second valve (116) is mounted on the gas outlet pipe of the gas cylinder (111); a connecting hose (114) is connected to one end of the gas outlet pipe away from the gas cylinder (111); the connecting hose (114) is connected to two annular jet pipes (112) via a three-way joint (115); a plurality of evenly distributed nozzles (113) are mounted on the inner side of the jet pipe (112); the jet pipe (112) is mounted in a groove at the bottom end of the mounting box (702), and the jet pipe (112) is located below the electric heating pipe (11).

9. The asphalt pavement structure stress strain sensor calibration device according to claim 1, characterized in that: The data acquisition mechanism (6) comprises a data acquisition device (602) and two temperature sensors (9) that cooperate with the data acquisition device (602); the data acquisition device (602) is mounted on one side of the mounting frame (2) via a connecting rod (601); and a touch screen (603) is mounted on the front of the data acquisition device (602).

10. A calibration method for an asphalt pavement structure stress and strain sensor calibration device according to any one of claims 1 to 9, characterized in that: The steps include: S1: Mobile chassis (1): Before calibration: Use the vehicle and the mobile chassis (1) to move the device to the road to be tested, align one of the adjustable extrusion wheels with the stress-strain sensor embedded in the asphalt pavement, and then place the comparison sample (8) under the other adjustable extrusion wheel. Then adjust the positions of the two adjustable extrusion wheels so that their bottoms contact the pavement and the top of the comparison sample (8) respectively, and fill water into the data acquisition mechanism (6) to increase the overall weight of the device; S2: Mounting frame (2): Normal temperature calibration: Start the hydraulic cylinder (301) to drive the mounting plate (302) to move downwards, and pressurize the road surface and the comparison sample (8) by moving downwards with two adjustable extrusion wheels, collect data detected by stress and strain sensors in the road surface and the comparison sample (8) through the data acquisition mechanism (6), and then compare the two sets of collected data; S3: Temperature calibration: insert two temperature sensors (9) into the comparison sample (8) and the ground respectively, slide the box (401) so that the bottom of the box (401) is against the top of the road surface, and then drive the heating mechanism to move to the top of the road surface and the comparison sample (8) through the reciprocating mechanism (7) to heat the road surface and the comparison sample (8) simultaneously. When the road surface and the comparison sample (8) are heated to the temperature required to be simulated, the temperature sensor (9) will transmit the temperature data to the data acquisition mechanism (6). At this time, the heating mechanism is turned off and moved away from the road surface and the comparison sample (8) through the reciprocating mechanism (7). Then, the pressurizing mechanism (3) is started to pressurize the road surface and the comparison sample (8). The data detected by the stress and strain sensors in the road surface and the comparison sample (8) are collected through the data acquisition mechanism (6), and then the two sets of collected data are compared. S4: temperature reduction calibration: the reciprocating mechanism (7) drives the cooling mechanism (10) to move to the top of the road surface and the comparison sample (8) to cool the road surface and the comparison sample (8) simultaneously. When the road surface and the comparison sample (8) are cooled to the required simulation temperature, the temperature sensor (9) transmits the temperature data to the data acquisition mechanism (6). At this time, the cooling mechanism (10) is turned off and the cooling mechanism (10) is moved away from the top of the road surface and the comparison sample (8) by the reciprocating mechanism (7). Then, the pressurizing mechanism (3) is started to pressurize the road surface and the comparison sample (8). The data detected by the stress and strain sensors in the road surface and the comparison sample (8) are collected by the data acquisition mechanism (6), and then the two sets of collected data are compared. S5: After calibration: start the hydraulic cylinder (301) to drive the two adjustable extrusion wheels to rise through the mounting plate (302) to the top of the mounting box (702), then push the mounting box (702) and the handle (703) into the box body (401) through the handle (703), move the box body (401) upward so that the limit seat (402) is sleeved on the outer side of the top cross bar of the mounting frame (2), then insert the limit pin (403) into the limit seat (402), and limit the box body (401) by clamping the cross bar inside the limit seat (402) with the limit pin (403), then open the first valve (504) to drain the water inside the water tank (501) through the drain pipe (503), and then connect it to the vehicle through the connecting frame (104).

Images