Device and method for testing temperature stress of asphalt concrete foundation bed

Abstract

The invention discloses an asphalt concrete foundation bed temperature stress test device and test method, and relates to the technical field of asphalt concrete tests.The asphalt concrete foundation bed temperature stress test device comprises a test box, a box door is installed on the outer wall of the test box, an air inlet pipe and an air outlet pipe are fixedly connected to the outer wall of one side of the test box, and a detection material is tested through a detection mechanism; the detection mechanism comprises a base, a displacement sensor, a fixed frame, a connecting disc, a movable frame, a movable plate, a connecting mechanism and a mounting mechanism. According to the invention, the detection mechanism is arranged, the temperature in the test box is reduced, the detected material shrinks when being cooled, the shrinkage displacement is detected through the displacement sensor, and the shrinkage displacement of the test piece is proportioned by utilizing the cold shrinkage of the movable plate structure; therefore, the superimposed effect of self-generated temperature shrinkage of the asphalt concrete layer and temperature shrinkage warping of the track plate above the asphalt concrete layer under the load-bearing environment of the foundation bed is simulated, and the temperature stress of the asphalt concrete foundation bed is tested.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt concrete testing, and specifically to a temperature stress testing device and test method for an asphalt concrete subgrade. Background Art

[0002] Asphalt concrete is commonly known as asphalt concrete. It is a mixture prepared by artificially selecting mineral materials, crushed stones or crushed gravels, stone chips or sands, mineral powders, etc. with a certain gradation composition, and a certain proportion of road asphalt materials under strictly controlled conditions. When laying track slabs on an asphalt concrete subgrade, there are gaps between the track slabs. When the temperature drops, the asphalt concrete subgrade is affected by the superposition effect of its own thermal shrinkage and the thermal shrinkage warping of the track slabs, and the temperature stress level is high, resulting in cracking at the position between the track slabs. Only by correctly simulating the thermal shrinkage deformation of the asphalt concrete subgrade under this superposition temperature effect can the loading system immediately apply the same displacement load to the asphalt concrete specimen, so as to achieve the purpose of forcing the asphalt concrete specimen not to shrink. Therefore, accurately applying the shrinkage deformation amount of asphalt concrete caused by the superposition temperature effect in the subgrade service environment is the key to realizing the above compensation process. In order to achieve the purpose of compensating the thermal shrinkage deformation amount of the asphalt concrete subgrade under the superposition temperature effect to obtain the temperature stress, a temperature stress testing device and test method for an asphalt concrete subgrade are provided. Summary of the Invention

[0003] The purpose of the present invention is to provide a temperature stress testing device and test method for an asphalt concrete subgrade in order to achieve the purpose of compensating the thermal shrinkage deformation amount of the asphalt concrete subgrade under the superposition temperature effect to obtain the temperature stress.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A temperature stress testing device for an asphalt concrete subgrade, including a test box, a box door is installed on the outer wall of the test box, an air inlet pipe and an air outlet pipe are fixedly connected to one outer wall of the test box, the test material is tested through a detection mechanism, the detection mechanism includes a base and a displacement sensor, the base is arranged at the bottom end of the inner wall of the test box, the displacement sensor is installed at the top end of the inner wall of the test box, a fixing frame is fixedly connected to the top end of the base, the upper and lower ends of the test material are fixedly connected with connecting plates, the two connecting plates are respectively an upper plate and a lower plate, the upper plate is fixedly connected with the fixing frame, a movable frame penetrating through the upper plate is fixedly connected to the outer wall of the lower plate, a movable plate is fixedly connected to the top end of the movable frame, the top end of the movable plate is connected to the output end of the displacement sensor, the test material is connected to the connecting plate through a connecting mechanism, and the lower plate is fixedly connected to the movable frame through an installation mechanism.

[0005] As a further solution of the present invention: The connecting mechanism includes a connecting block, the connecting block is fixedly connected to the top and bottom of the detection material, a fixing groove is formed on the outer wall of the connecting block, a connecting groove is formed on the outer wall of the connecting disk, a fixing block extending to the inner wall of the connecting groove is connected inside the connecting disk, a connecting shaft is fixedly connected to the top of the fixing block, a straight gear is fixedly connected to the top of the connecting shaft, a rotating seat is rotatably connected to the outer wall of the straight gear inside the upper disk, the rotating seat extends to the outer wall of the connecting disk, a positioning groove is formed on the outer wall of the rotating seat, a positioning rod is slidably connected to the outer wall of the connecting disk, a threaded rod penetrating through the positioning rod is rotatably connected inside the connecting disk, and a rotating column is fixedly connected to one end of the threaded rod.

[0006] As a further solution of the present invention: The installation mechanism includes a first vertical groove symmetrically formed on the outer wall of the upper disk, a second vertical groove is symmetrically formed on the outer wall of the lower disk, a displacement groove is formed on the inner wall of the second vertical groove, a clamping block extending into the inner cavity of the displacement groove is slidably connected inside the lower disk, a first spring is connected between the clamping block and the lower disk, a displacement plate extending out of the movable frame is slidably connected inside the movable frame, a rotating block is rotatably connected to the bottom end of the movable frame, a rotating shaft is fixedly connected to the top of the rotating block, a rotating disk is fixedly connected to the top of the rotating shaft, a convex block is fixedly connected to the outer wall of the rotating disk, a slot is formed at the bottom end of the movable frame, an inserting block extending to the top of the rotating block is slidably connected inside the rotating block, a second spring is connected between the bottom end of the inserting block and the rotating block, and a pulling frame is fixedly connected to the bottom end of the inserting block.

[0007] As a further solution of the present invention: The inner wall of the connecting groove fits with the outer wall of the connecting block, and the inner wall of the fixing groove fits with the outer wall of the fixing block.

[0008] As a further solution of the present invention: The outer wall of the rotating seat is provided with teeth, and the teeth mesh with the straight gear.

[0009] As a further solution of the present invention: The inner wall of the positioning groove fits with the outer wall of one end of the positioning rod, and a threaded hole is formed on the outer wall of the positioning rod, and the threaded hole matches the threaded rod.

[0010] As a further solution of the present invention: A groove is formed at the top of the rotating seat, and a vertical plate is fixedly connected to the inner wall of the groove.

[0011] As a further solution of the present invention: The inner walls of the first vertical groove and the second vertical groove fit with the outer wall of the movable frame, and the outer wall of the displacement plate fits with the inner wall of the displacement groove.

[0012] As a further solution of the present invention: a card slot is provided on the outer wall of the displacement plate, one end of the card block is engaged with the card slot, the other end of the card block is engaged with the spur gear, and the inner wall of the slot fits with the outer wall of the plug block.

[0013] A test method for the temperature stress of an asphalt concrete bed, the specific steps are as follows: Step 1: Install the test material between the upper plate and the lower plate through the cooperation of the parts in the connection mechanism, pass the movable frame through the upper plate, and fixedly connect the movable frame and the lower plate through the cooperation of the parts in the installation mechanism, so that the movable plate is in contact with the displacement sensor. Step 2: Lower the temperature in the test chamber through the intake pipe and the exhaust pipe. The test material shrinks when it is cooled. The shrinkage of the test material drives the lower plate to move upward, the upward movement of the lower plate drives the movable frame to move upward, and the upward movement of the movable frame drives the movable plate to move upward. The displacement sensor detects the movement amount of the movable plate, so as to judge the shrinkage amount of the test material. At the same time, a stress opposite to the shrinkage amount is applied to the test material by using a dynamic hydraulic servo multi-functional material testing machine, so that the shrinkage amount is zeroed in real time. Finally, under the preset temperature condition, the amplitude of the displacement load applied by the dynamic hydraulic servo multi-functional material testing machine is determined, so as to obtain the temperature stress of the test material.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. By setting up the detection mechanism, the temperature in the test chamber is lowered. The test material shrinks when it is cooled. The shrinkage of the test material drives the lower plate to move upward, the movement of the lower plate drives the movable frame to move upward, and the upward movement of the movable frame drives the movable plate to move upward. The displacement sensor detects the movement amount of the movable plate, so as to judge the shrinkage deformation amount of the test material, which is convenient for testing the temperature stress of the asphalt concrete bed.

[0015] 2. By setting up the connection mechanism and the installation mechanism, it is convenient to quickly install and fix the connection plate and the test material, fixedly connect the movable frame and the lower plate, and can adapt to the lengths of different test materials. At the same time, when fixedly connecting the movable frame and the lower plate, the connection between the lower plate and the test material is strengthened to prevent loosening. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a structural schematic diagram of the present invention; Figure 2 is an installation schematic diagram of the movable plate of the present invention; Figure 3 is an installation schematic diagram of the upper plate and the lower plate of the present invention; Figure 4 is a structural schematic diagram of the connection block of the present invention; Figure 5 is a cross-sectional view of the upper plate of the present invention; Figure 6 Structural schematic diagram of the rotating seat of the present invention; Figure 7 Connection schematic diagram of the movable frame and the lower plate of the present invention; Figure 8 Cross-sectional view of the lower plate of the present invention; Figure 9 Cross-sectional view of the movable frame of the present invention; Figure 10 Cross-sectional view of the rotating block of the present invention.

[0017] In the figure: 1, test box; 2, box door; 3, intake pipe; 4, exhaust pipe; 5, detection material; 6, detection mechanism; 601, base; 602, fixing frame; 603, connecting plate; 604, movable plate; 605, movable frame; 606, displacement sensor; 7, connecting mechanism; 701, connecting block; 702, fixing groove; 703, connecting groove; 704, fixing block; 705, connecting shaft; 706, spur gear; 707, rotating seat; 708, positioning groove; 709, positioning rod; 710, threaded rod; 711, rotating column; 8, mounting mechanism; 801, first vertical groove; 802, second vertical groove; 803, displacement groove; 804, clamping block; 805, first spring; 806, displacement plate; 807, rotating block; 808, rotating shaft; 809, rotating disk; 810, convex block; 811, slot; 812, plug; 813, second spring; 814, pulling frame; 9, upper plate; 10, lower plate; 11, groove; 12, vertical plate. Detailed implementation manners

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. The following will describe the embodiments according to the overall structure of the present invention.

[0020] Please refer to Figures 1 to 10 , in the embodiment of the present invention, a temperature stress test device for an asphalt concrete bed includes a test box 1. A box door 2 is installed on the outer wall of the test box 1. An air inlet pipe 3 and an air outlet pipe 4 are fixedly connected to one outer wall of the test box 1. The test material 5 is tested through a detection mechanism 6. The detection mechanism 6 includes a base 601 and a displacement sensor 606. The base 601 is arranged at the bottom end of the inner wall of the test box 1, and the displacement sensor 606 is installed at the top end of the inner wall of the test box 1. A fixing frame 602 is fixedly connected to the top end of the base 601. Connecting disks 603 are fixedly connected to the upper and lower ends of the test material 5. The two connecting disks 603 are a upper disk 9 and a lower disk 10 respectively. The upper disk 9 is fixedly connected to the fixing frame 602. A movable frame 605 penetrating through the upper disk 9 is fixedly connected to the outer wall of the lower disk 10. A movable plate 604 is fixedly connected to the top end of the movable frame 605. The top end of the movable plate 604 is connected to the output end of the displacement sensor 606. The test material 5 is connected to the connecting disk 603 through a connecting mechanism 7. The lower disk 10 is fixedly connected to the movable frame 605 through an installation mechanism 8.

[0021] In this embodiment: The test material 5 is installed between the upper plate 9 and the lower plate 10 through the cooperation of the parts in the connecting mechanism 7. The movable frame 605 penetrates through the upper plate 9, and the movable frame 605 and the lower plate 10 are fixedly connected through the cooperation of the parts in the installation mechanism 8, so that the movable plate 604 is in contact with the displacement sensor 606. The temperature in the test chamber 1 is reduced through the intake pipe 3 and the exhaust pipe 4. The test material 5 shrinks when cooled. The shrinkage of the test material 5 drives the lower plate 10 to move upward. The movement of the lower plate 10 drives the movable frame 605 to move upward. The upward movement of the movable frame 605 drives the movable plate 604 to move upward. The displacement sensor 606 detects the movement amount of the movable plate 604, thereby judging the shrinkage amount of the test material 5, which is convenient for testing the temperature stress of the asphalt concrete bed. It should be noted that one end of each of the intake pipe 3 and the exhaust pipe 4 is connected to a cold air device.

[0022] Please refer specifically to Figures 3 to 6 , the connecting mechanism 7 includes a connecting block 701. The connecting block 701 is fixedly connected to the top and bottom of the test material 5. A fixing groove 702 is formed on the outer wall of the connecting block 701. A connecting groove 703 is formed on the outer wall of the connecting disk 603. A fixing block 704 extending to the inner wall of the connecting groove 703 is connected inside the connecting disk 603. A connecting shaft 705 is fixedly connected to the top of the fixing block 704. A spur gear 706 is fixedly connected to the top of the connecting shaft 705. A rotating seat 707 is rotatably connected to the outer wall of the spur gear 706 inside the upper plate 9. The rotating seat 707 extends to the outer wall of the connecting disk 603. A positioning groove 708 is formed on the outer wall of the rotating seat 707. A positioning rod 709 is slidably connected to the outer wall of the connecting disk 603. A threaded rod 710 penetrating through the positioning rod 709 is rotatably connected inside the connecting disk 603. A rotating column 711 is fixedly connected to one end of the threaded rod 710.

[0023] In this embodiment: When connecting the connecting disk 603 and the test material 5, insert the connecting block 701 into the connecting groove 703, and then rotate the rotating seat 707. The rotation of the rotating seat 707 drives the spur gear 706 to rotate. The rotation of the spur gear 706 drives the connecting shaft 705 to rotate. The rotation of the connecting shaft 705 drives the fixing block 704 to rotate. The fixing block 704 rotates into the fixing groove 702 to fix the connecting block 701 in the connecting groove 703. Then rotate the rotating column 711. The rotation of the rotating column 711 drives the threaded rod 710 to rotate. The rotation of the threaded rod 710 drives the positioning rod 709 to displace. The positioning rod 709 displaces and inserts into the positioning groove 708 to fix the rotating seat 707, thereby quickly installing and fixing the connecting disk 603 and the test material 5.

[0024] Please refer specifically to Figures 5 to 10, the installation mechanism 8 includes a first vertical groove 801 symmetrically opened on the outer wall of the upper plate 9, and second vertical grooves 802 are symmetrically opened on the outer wall of the lower plate 10. A displacement groove 803 is opened on the inner wall of the second vertical groove 802. A clamping block 804 extending into the inner cavity of the displacement groove 803 is slidably connected inside the lower plate 10. A first spring 805 is connected between the clamping block 804 and the lower plate 10. A displacement plate 806 extending out of the movable frame 605 is slidably connected inside the movable frame 605. A rotating block 807 is rotatably connected to the bottom end of the movable frame 605. A rotating shaft 808 is fixedly connected to the top end of the rotating block 807. A rotating disk 809 is fixedly connected to the top end of the rotating shaft 808. A convex block 810 is fixedly connected to the outer wall of the rotating disk 809. A slot 811 is opened at the bottom end of the movable frame 605. An inserting block 812 extending to the top end of the rotating block 807 is slidably connected inside the rotating block 807. A second spring 813 is connected between the bottom end of the inserting block 812 and the rotating block 807. A pulling frame 814 is fixedly connected to the bottom end of the inserting block 812.

[0025] In this embodiment: When connecting the movable frame 605 and the lower plate 10, the movable frame 605 is in a state of passing through the first vertical groove 801. When connecting the lower plate 10 with the test material 5, the movable frame 605 is connected into the second vertical groove 802, and the displacement plate 806 slides into the displacement groove 803. After the installation is completed, rotate the rotating block 807. The rotation of the rotating block 807 drives the rotation of the rotating shaft 808. The rotation of the rotating shaft 808 drives the rotation of the rotating disk 809. The rotation of the rotating disk 809 drives the displacement of the convex block 810. The displacement of the convex block 810 contacts the displacement plate 806, pushing the displacement plate 806 to displace. The displacement of the displacement plate 806 contacts the clamping block 804, pushing the clamping block 804 to displace, squeezing the first spring 805. The displacement of the clamping block 804 engages with the spur gear 706, so that both ends of the clamping block 804 are engaged with the spur gear 706 and the displacement plate 806 respectively. At this time, the rotation of the rotating block 807 drives the displacement of the inserting block 812. The inserting block 812 moves to the bottom end of the slot 811, and the inserting block 812 is engaged into the slot 811 under the elastic force of the second spring 813, fixing the rotating block 807, thereby fixing between the movable frame 605 and the lower plate 10, facilitating the quick fixed connection between the movable frame 605 and the lower plate 10, and being adaptable to the lengths of different test materials 5. At the same time, when fixedly connecting the movable frame 605 and the lower plate 10, the connection between the lower plate 10 and the test material 5 is strengthened to prevent loosening.

[0026] Please refer to Figures 3 to 6 , the inner wall of the connection groove 703 fits with the outer wall of the connection block 701, the inner wall of the fixing groove 702 fits with the outer wall of the fixing block 704, and gear teeth are provided on the outer wall of the rotating seat 707, and the gear teeth are engaged with the spur gear 706.

[0027] In this embodiment: Insert the connecting block 701 into the connecting groove 703, and then rotate the rotating seat 707. The rotation of the rotating seat 707 drives the spur gear 706 to rotate. The rotation of the spur gear 706 drives the connecting shaft 705 to rotate. The rotation of the connecting shaft 705 drives the fixing block 704 to rotate. The fixing block 704 rotates into the fixing groove 702 to fix the connecting block 701 in the connecting groove 703.

[0028] Please refer specifically to Figures 3 to 6 , the inner wall of the positioning groove 708 is in contact with the outer wall of one end of the positioning rod 709. A threaded hole is provided on the outer wall of the positioning rod 709, and the threaded hole matches the threaded rod 710.

[0029] In this embodiment: Rotate the rotating column 711. The rotation of the rotating column 711 drives the threaded rod 710 to rotate. The rotation of the threaded rod 710 drives the positioning rod 709 to displace. The positioning rod 709 displaces and inserts into the positioning groove 708 to fix the rotating seat 707.

[0030] Please refer specifically to Figures 3 to 6 , a groove 11 is provided at the top of the rotating seat 707, and a vertical plate 12 is fixedly connected to the inner wall of the groove 11.

[0031] In this embodiment: By rotating the vertical plate 12, the rotating seat 707 is driven to rotate, which facilitates the operation of rotating the rotating seat 707.

[0032] Please refer specifically to Figures 5 to 10 , the inner walls of the first vertical groove 801 and the second vertical groove 802 are in contact with the outer wall of the movable frame 605, and the outer wall of the displacement plate 806 is in contact with the inner wall of the displacement groove 803.

[0033] In this embodiment: When connecting the lower plate 10 with the test material 5, the movable frame 605 is connected and enters the second vertical groove 802, and the displacement plate 806 slides into the displacement groove 803.

[0034] Please refer specifically to Figures 5 to 10 , a clamping groove is provided on the outer wall of the displacement plate 806. One end of the clamping block 804 is engaged with the clamping groove, the other end of the clamping block 804 is engaged with the spur gear 706, and the inner wall of the insertion slot 811 is in contact with the outer wall of the insertion block 812.

[0035] In this embodiment: Rotate the rotating block 807. The rotation of the rotating block 807 drives the rotation of the rotating shaft 808. The rotation of the rotating shaft 808 drives the rotation of the rotating disk 809. The rotation of the rotating disk 809 drives the displacement of the convex block 810. The displacement of the convex block 810 contacts the displacement plate 806 and pushes the displacement plate 806 to displace. The displacement of the displacement plate 806 contacts the latch 804 and pushes the latch 804 to displace, squeezing the first spring 805. The displacement of the latch 804 engages with the spur gear 706, so that both ends of the latch 804 are engaged with the spur gear 706 and the displacement plate 806 respectively.

[0036] A test method for temperature stress of asphalt concrete subgrade is as follows. Step 1: Install the test material 5 between the upper plate 9 and the lower plate 10 through the cooperation of the parts in the connecting mechanism 7. Pass the movable frame 605 through the upper plate 9, and fixedly connect the movable frame 605 and the lower plate 10 through the cooperation of the parts in the installation mechanism 8, so that the movable plate 604 contacts the displacement sensor 606. Step 2: Lower the temperature in the test chamber 1 through the intake pipe 3 and the exhaust pipe 4. The test material 5 shrinks when cooled. The shrinkage of the test material 5 drives the movable frame 605 to move upward through the lower plate 10. The upward movement of the movable frame 605 drives the movable plate 604 to move upward. The displacement sensor 606 detects the movement amount of the movable plate 604, so as to judge the shrinkage amount of the test material 5. At the same time, use a UTM-30 type dynamic hydraulic servo multi-functional material testing machine to apply a stress opposite to the shrinkage amount to the test material 5, making the shrinkage amount zero in real time. Finally, under the preset temperature condition, determine the amplitude of the displacement load applied by the dynamic hydraulic servo multi-functional material testing machine, so as to obtain the temperature stress of the test material 5.

[0037] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An asphalt concrete subgrade temperature stress testing device, comprising a testing box (1), an outer wall of the testing box (1) is provided with a box door (2), and one outer wall of the testing box (1) is fixedly connected with an air inlet pipe (3) and an air outlet pipe (4), characterized in that, The test material (5) is tested by a testing agency (6), and the testing agency (6) includes a base (601) and a displacement sensor (606). The base (601) is arranged at the bottom end of the inner wall of the test chamber (1), and the displacement sensor (606) is installed at the top end of the inner wall of the test chamber (1). A fixing frame (602) is fixedly connected to the top end of the base (601). The upper and lower ends of the test material (5) are fixedly connected with connection disks (603). The two connection disks (603) are respectively an upper disk (9) and a lower disk (10). The upper disk (9) is fixedly connected with the fixing frame (602). An activity frame (605) penetrating through the upper disk (9) is fixedly connected to the outer wall of the lower disk (10). An activity plate (604) is fixedly connected to the top end of the activity frame (605). The top end of the activity plate (604) is connected to the output end of the displacement sensor (606). The test material (5) is connected to the connection disk (603) through a connection mechanism (7). The lower disk (10) is fixedly connected to the activity frame (605) through an installation mechanism (8).

2. The temperature stress testing device for asphalt concrete bed according to claim 1, wherein, The connection mechanism (7) includes a connection block (701). The connection block (701) is fixedly connected to the top and bottom ends of the test material (5). A fixing groove (702) is formed on the outer wall of the connection block (701). A connection groove (703) is formed on the outer wall of the connection disk (603). A fixing block (704) extending to the inner wall of the connection groove (703) is connected inside the connection disk (603). A connection shaft (705) is fixedly connected to the top end of the fixing block (704). A straight gear (706) is fixedly connected to the top end of the connection shaft (705). A rotating seat (707) is rotatably connected to the outer wall of the straight gear (706) inside the upper disk (9). The rotating seat (707) extends to the outer wall of the connection disk (603). A positioning groove (708) is formed on the outer wall of the rotating seat (707). A positioning rod (709) is slidably connected to the outer wall of the connection disk (603). A threaded rod (710) penetrating through the positioning rod (709) is rotatably connected inside the connection disk (603). A rotating column (711) is fixedly connected to one end of the threaded rod (710).

3. The asphalt concrete bed temperature stress testing device according to claim 2, wherein The installation mechanism (8) includes a first vertical groove (801) symmetrically opened on the outer wall of the upper disk (9). Second vertical grooves (802) are symmetrically opened on the outer wall of the lower disk (10). A displacement groove (803) is opened on the inner wall of the second vertical groove (802). A clamping block (804) extending into the inner cavity of the displacement groove (803) is slidably connected inside the lower disk (10). A first spring (805) is connected between the clamping block (804) and the lower disk (10). A displacement plate (806) extending out of the movable frame (605) is slidably connected inside the movable frame (605). A rotating block (807) is rotatably connected to the bottom end of the movable frame (605). A rotating shaft (808) is fixedly connected to the top end of the rotating block (807). A rotating disk (809) is fixedly connected to the top end of the rotating shaft (808). A convex block (810) is fixedly connected to the outer wall of the rotating disk (809). A slot (811) is opened at the bottom end of the movable frame (605). A plug block (812) extending to the top end of the rotating block (807) is slidably connected inside the rotating block (807). A second spring (813) is connected between the bottom end of the plug block (812) and the rotating block (807). A pulling frame (814) is fixedly connected to the bottom end of the plug block (812).

4. The asphalt concrete bed temperature stress testing device according to claim 2, characterized in that, The inner wall of the connecting groove (703) is in contact with the outer wall of the connecting block (701), and the inner wall of the fixing groove (702) is in contact with the outer wall of the fixing block (704).

5. The asphalt concrete bed temperature stress testing device according to claim 2, characterized in that, The outer wall of the rotating seat (707) is provided with gear teeth that mesh with the spur gear (706).

6. The asphalt concrete bed temperature stress testing device according to claim 2, characterized in that, The inner wall of the positioning groove (708) is in contact with one end outer wall of the positioning rod (709). A threaded hole is opened on the outer wall of the positioning rod (709), and the threaded hole matches the threaded rod (710).

7. The asphalt concrete bed temperature stress testing device according to claim 2, characterized in that, A groove (11) is opened at the top end of the rotating seat (707), and a vertical plate (12) is fixedly connected to the inner wall of the groove (11).

8. The asphalt concrete bed temperature stress testing device according to claim 3, characterized in that The inner walls of the first vertical groove (801) and the second vertical groove (802) are in contact with the outer wall of the movable frame (605), and the outer wall of the displacement plate (806) is in contact with the inner wall of the displacement groove (803).

9. The temperature stress testing device for asphalt concrete bed according to claim 3, characterized in that, A clamping groove is opened on the outer wall of the displacement plate (806). One end of the clamping block (804) is clamped with the clamping groove, and the other end of the clamping block (804) is clamped with the spur gear (706). The inner wall of the slot (811) is in contact with the outer wall of the plug block (812).

10. An experimental method for the temperature stress of an asphalt concrete subgrade bed adopting any one of claims 1-9, characterized in that, The specific steps are as follows: Step 1: Install the test material (5) between the upper disk (9) and the lower disk (10) through the cooperation of the parts in the connecting mechanism (7). Pass the movable frame (605) through the upper disk (9). Fix and connect the movable frame (605) and the lower disk (10) through the cooperation of the parts in the installation mechanism (8) so that the movable plate (604) contacts the displacement sensor (606). Step 2: Lower the temperature inside the test chamber (1) through the intake pipe (3) and the outlet pipe (4), detect that the material (5) shrinks when cooled, detect that the shrinkage of the material (5) drives the movable frame (605) to move upward through the lower plate (10), the upward movement of the movable frame (605) drives the movable plate (604) to move upward, and detect the movement amount of the movable plate (604) through the displacement sensor (606), so as to judge the shrinkage amount of the test material (5); at the same time, use a dynamic hydraulic servo multi-functional material testing machine to apply a stress opposite to the shrinkage amount to the test material (5), make the shrinkage amount return to zero in real time, and finally, under the preset temperature condition, determine the amplitude of the displacement load applied by the dynamic hydraulic servo multi-functional material testing machine, so as to obtain the temperature stress of the test material (5).

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