Asphalt concrete pull-out test device

Abstract

The utility model discloses an asphalt concrete drawing test device, including test table, the crossbeam of two opposite setting column support above test table, set up between test table and crossbeam's temperature regulation box and set up in the first test fixture and second test fixture of temperature regulation box, temperature regulation box includes the box and the box door of setting in the box front side, first test fixture and second test fixture structure are same, and respectively clamped in two ends of test sample piece, the bottom of crossbeam is equipped with by from top to bottom the connection of electro -hydraulic servo linear actuator, tension sensor and tow chain in proper order, and the bottom end of tow chain extends into the box and is detachably connected with first test fixture, and the support column of extending into the box is equipped on test table, and the top of support column is detachably connected with second test fixture through universal joint.

Description

Technical Field

[0001] This utility model relates to the field of asphalt concrete testing technology, specifically to an asphalt concrete pull-out test device. Background Technology

[0002] As the most important pavement material in modern road engineering, asphalt concrete's various mechanical properties directly determine the pavement's service life and quality. Interlayer bonding performance is a key indicator, referring to the bonding ability between the various structural layers of the asphalt pavement (such as the surface layer and base layer). Insufficient interlayer bonding can easily lead to interlayer slippage, shoving, rutting, and even overall asphalt layer peeling under vehicle loads and temperature changes, seriously endangering driving safety and shortening road life.

[0003] Pull-out testing is an important and direct laboratory testing method for evaluating and improving interlayer bond performance. This method measures the tensile strength (i.e., bond strength) between asphalt concrete test specimens by applying vertical tensile stress under specific conditions.

[0004] However, existing pull-out testing devices for asphalt concrete have several limitations. First, traditional pull-out testing devices cannot guarantee pure axial tension during the application of tensile force. Even slight eccentric forces can introduce bending moments, potentially causing premature damage or stress concentration at the clamping points of the test specimen, rather than failure at the pre-set bond interface, leading to test results that deviate from the material's true bond strength. Second, since asphalt is a typical temperature-sensitive material, its bond strength varies significantly with temperature. Therefore, current pull-out testing devices often incorporate a temperature control chamber, where the loading and unloading of the test fixtures takes place, making the process very inconvenient.

[0005] Therefore, there is an urgent need in the field for an asphalt concrete pull-out test device that can overcome the above-mentioned limitations. Utility Model Content

[0006] The purpose of this invention is to provide an asphalt concrete pull-out test device to solve the problem that existing devices cannot guarantee pure axial tension.

[0007] To solve the above-mentioned technical problems, this utility model provides an asphalt concrete pull-out test device, including a test platform, a crossbeam supported above the test platform by two opposing columns, a temperature regulating box disposed between the test platform and the crossbeam, and a first test fixture and a second test fixture disposed inside the temperature regulating box.

[0008] The temperature control chamber includes a chamber body and a door located on the front side of the chamber body;

[0009] The first and second test fixtures have the same structure and are respectively clamped at both ends of the test specimen;

[0010] The bottom of the crossbeam is equipped with an electro-hydraulic servo linear actuator, a tension sensor and a traction chain connected in sequence from top to bottom. The bottom end of the traction chain extends into the box and is detachably connected to the first test fixture.

[0011] The test bench is equipped with a support column that extends into the chamber. The top of the support column is detachably connected to the second test fixture via a universal joint.

[0012] Furthermore, the traction chain is detachably connected to the first test fixture via the first hook, and the first test fixture is provided with a first hanging ring that cooperates with the first hook.

[0013] Furthermore, the universal joint is detachably connected to the second test fixture via the second hook, and the second test fixture is provided with a second hanging ring that cooperates with the second hook.

[0014] Furthermore, the first test fixture includes a fixture body, which is U-shaped and includes a horizontal part and parallel side plates disposed at both ends of the horizontal part. Each side plate is provided with a limiting plate at the end away from the horizontal part. The limiting plates are arranged parallel to the horizontal part, and the distance between the two limiting plates is less than the distance between the two side plates.

[0015] Furthermore, the limiting plate and the side plate are detachably connected.

[0016] Furthermore, a detachable pad is provided between the side plate of the fixture body and the limiting plate.

[0017] Furthermore, a clamping plate is provided on the side of the side plate facing the test specimen, and a screw is provided in the middle of the side plate that penetrates the side plate and is rotatably connected to the clamping plate.

[0018] Furthermore, the first test fixture includes a fixture body, which is U-shaped and includes a horizontal part and parallel side plates disposed at both ends of the horizontal part. Each side plate is provided with a limiting plate at the end away from the horizontal part. The limiting plates are arranged parallel to the horizontal part, and the distance between the two limiting plates is less than the distance between the two side plates.

[0019] Furthermore, the clamping plate has toothed pins on the side facing the test specimen.

[0020] Furthermore, a side baffle is connected between the two side plates on the same side; the two ends of the side baffle are respectively fixedly connected to the side plate by a second fastener.

[0021] The beneficial effects of this utility model are as follows: by setting up a temperature-controlled environment including a temperature regulating chamber, constant temperature or variable temperature tests can be performed on asphalt concrete test specimens, making the results more consistent with actual road working conditions; by combining the upper electro-hydraulic servo linear actuator with the tension sensor, precise control and real-time measurement of loading force and speed can be achieved; by forming a tension structure with the universal joint and the traction chain, automatic adjustment and compensation can be achieved to ensure pure axial tension of the tension during the tensioning process, avoid bending moment caused by small alignment errors, and ensure the accuracy of test data. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, use the same reference numerals to denote the same or similar parts. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the first test fixture and the second test fixture according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the first test fixture and the second test fixture according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the fixture body according to an embodiment of the present invention.

[0027] The components include: 1. Test bench; 101. Column; 102. Crossbeam; 2. Electro-hydraulic servo linear actuator; 3. Tension sensor; 4. First hook; 401. Traction chain; 5. First hanging ring; 6. Fixture body; 601. First threaded hole; 602. Second threaded hole; 603. Third threaded hole; 604. Fourth threaded hole; 61. Limiting plate; 611. First fastener; 62. Side baffle; 621. Second fastener; 63. Pad; 64. Clamping plate; 641. Screw; 7. Second hook; 701. Universal joint; 8. Support column; 801. Fixture base; 9. Temperature control chamber; 901. Chamber door; 10. Test specimen. Detailed Implementation

[0028] like Figure 1The asphalt concrete pull-out test apparatus shown includes a test bench 1, a crossbeam 102 supported above the test bench 1 by two opposing columns 101, a temperature regulating chamber 9 located between the test bench 1 and the crossbeam 102, and a first test fixture and a second test fixture located inside the temperature regulating chamber 9. The temperature regulating chamber 9 includes a chamber body and a door 901 located on the front side of the chamber body. The first and second test fixtures have the same structure and clamp the two ends of the test specimen 10, respectively. The bottom of the crossbeam 102 is provided with an electro-hydraulic servo linear actuator 2, a tension sensor 3, and a traction chain 401 connected sequentially from top to bottom. The bottom end of the traction chain 401 extends into the chamber and is detachably connected to the first test fixture. The test bench 1 is provided with a support column 8 extending into the chamber, and the top of the support column 8 is detachably connected to the second test fixture via a universal joint 701. The internal temperature of the temperature regulating chamber can be regulated by a dual-purpose fan for both heating and cooling installed inside the temperature regulating chamber.

[0029] This invention, by setting up a temperature-controlled environment including a temperature regulating chamber 9 (the internal temperature of the temperature regulating chamber 9 can be adjusted by a dual-purpose hot and cold fan), can perform constant-temperature or variable-temperature tests on asphalt concrete test specimens 10, making the results more consistent with actual road conditions; by combining the upper electro-hydraulic servo linear actuator 2 with the tension sensor 3, precise control and real-time measurement of loading force and speed can be achieved; by forming a tension structure with the universal joint 701 and the traction chain 401, automatic adjustment and compensation can be achieved to ensure the pure axiality of the tensile load, avoid bending moments caused by small alignment errors, and ensure the accuracy of test data.

[0030] According to one embodiment of this application, the traction chain 401 is detachably connected to the first test fixture via a first hook 4, and the first test fixture is provided with a first hanging ring 5 that cooperates with the first hook 4. This embodiment, through the connection method of the hook and hanging ring, achieves quick and convenient installation and disassembly of the first test fixture and the traction chain 401, improving testing efficiency. Furthermore, this simple connection method ensures that the tensile force can be directly and without interference transmitted from the traction chain 401 to the first test fixture, avoiding internal force loss caused by complex connection structures, and ensuring that the tensile force value measured by the tensile sensor 3 is the actual tensile force applied to the test specimen 10.

[0031] According to one embodiment of this application, the universal joint 701 is detachably connected to the second test fixture via a second hook 7, and the second test fixture is provided with a second hanging ring that cooperates with the second hook 7. Similarly, this embodiment achieves quick and convenient installation and disassembly of the second test fixture and the universal joint 701 through the connection method of the hook and the hanging ring, thereby improving the testing efficiency.

[0032] According to one embodiment of this application, such as Figures 2 to 4As shown, the first test fixture includes a fixture body 6, which is U-shaped and includes a horizontal section and parallel side plates at both ends of the horizontal section. Each side plate has a limiting plate 61 at its end furthest from the horizontal section. The limiting plates 61 are parallel to the horizontal section, and the distance between the two limiting plates 61 is less than the distance between the two side plates. In this embodiment, the fixture body 6 and the limiting plates 61 form a slot structure. The limiting plates 61 can restrict and fix the two ends of the I-shaped test specimen 10 to prevent it from slipping out of the fixture during the tensile process. This fixture does not rely on adhesives to fix the test specimen 10 as in traditional methods, avoiding the problem that the bonding interface often becomes a stress concentration area, leading to frequent interface fractures during testing and seriously affecting the reliability of the test results. A third threaded hole is provided in the middle of the horizontal section of the fixture body 6, and the hanging ring is connected to the test fixture through a stud that engages with the threaded hole 603.

[0033] According to one embodiment of this application, the limiting plate 61 is detachably connected to the side plate. This embodiment, by making the limiting plate 61 detachably connected to the side plate, provides the fixture with good flexibility and maintainability, allowing for easy replacement of limiting plates 61 of different specifications according to different sizes of test specimens 10, thus expanding the applicability of the fixture.

[0034] According to one embodiment of this application, a detachably connected pad 63 is provided between the side plate of the fixture body 6 and the limiting plate 61. The limiting plate 61 and the pad 63 are fixedly mounted on the side plate by a first fastener 611 passing through the limiting plate 61 and the pad 63; the first fastener 611 is a bolt or screw, and the end of the side plate away from the horizontal part is provided with a first threaded hole 601 that is threadedly engaged with the first fastener 611. By adding, removing, or replacing pads 63 of different thicknesses, the effective space between the side plate and the limiting plate 61 can be adjusted, thereby accurately adapting to test specimens 10 of different thicknesses. This allows one set of fixtures to meet the needs of multiple test standards or test specimens 10 with different designs, greatly improving the versatility and economy of the device.

[0035] According to one embodiment of this application, a clamping plate 64 is provided on the side of the side plate facing the test specimen 10. A screw 641 is provided in the middle of the side plate, penetrating the side plate and rotatably connected to the clamping plate 64. A fourth threaded hole 604 is provided in the middle of the side plate, which is threadedly engaged with the screw. By rotating the screw to drive the clamping plate 64, a uniform and stable clamping force can be applied to the test specimen 10. Obviously, at this time, the distance between the two limiting plates 61 is also greater than the distance between the two clamping plates 64.

[0036] According to one embodiment of this application, the clamping plate 64 is provided with toothed spikes on the side facing the test specimen 10. By providing toothed spikes on the clamping plate 64, when a pull-out force is applied, the toothed spikes can embed into the relatively soft surface of the asphalt concrete test specimen 10, forming a reliable mechanical interlock. This greatly enhances the mechanical interlocking force and friction between the clamp and the asphalt concrete test specimen 10, preventing relative sliding between the test specimen 10 and the clamping plate 64. This ensures that the tensile load can be transferred more completely and effectively from the clamp to the body of the test specimen 10, reducing test errors caused by clamping failure.

[0037] According to one embodiment of this application, a side baffle 62 is connected between the two side plates on the same side; both ends of the side baffle 62 are fixedly connected to the side plates by a second fastener 621; the second fastener 621 is a bolt or screw, and both ends of the side plates are provided with second threaded holes 602 that mate with the second fastener 621. The side baffle 62 can restrain the asphalt concrete in the test fixture, prevent the material from excessively detaching from the side, and ensure the standardization of the test process and the reliability of the results.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An asphalt concrete pull-out test apparatus, characterized in that, It includes a test bench, a crossbeam supported above the test bench by two opposing columns, a temperature regulating box disposed between the test bench and the crossbeam, and a first test fixture and a second test fixture disposed inside the temperature regulating box; The temperature control box includes a box body and a door located on the front side of the box body; The first and second test fixtures have the same structure and are respectively clamped at both ends of the test specimen; The bottom of the crossbeam is provided with an electro-hydraulic servo linear actuator, a tension sensor and a traction chain connected in sequence from top to bottom. The bottom end of the traction chain extends into the box and is detachably connected to the first test fixture. The test bench is provided with a support column extending into the box body, and the top of the support column is detachably connected to the second test fixture via a universal joint.

2. The asphalt concrete pull-out test apparatus according to claim 1, characterized in that, The traction chain is detachably connected to the first test fixture via a first hook, and the first test fixture is provided with a first hanging ring that cooperates with the first hook.

3. The asphalt concrete pull-out test apparatus according to claim 1 or 2, characterized in that, The universal joint is detachably connected to the second test fixture via a second hook, and the second test fixture is provided with a second hanging ring that cooperates with the second hook.

4. The asphalt concrete pull-out test apparatus according to claim 1, characterized in that, The first test fixture includes a fixture body, which is U-shaped and includes a horizontal part and parallel side plates disposed at both ends of the horizontal part. Each side plate is provided with a limiting plate at the end away from the horizontal part. The limiting plate is arranged parallel to the horizontal part, and the distance between the two limiting plates is less than the distance between the two side plates.

5. The asphalt concrete pull-out test apparatus according to claim 4, characterized in that, The limiting plate is detachably connected to the side plate.

6. The asphalt concrete pull-out test apparatus according to claim 4 or 5, characterized in that, A detachable pad is provided between the side plate and the limiting plate of the clamp body.

7. The asphalt concrete pull-out test apparatus according to claim 4, characterized in that, A clamping plate is provided on the side of the side plate facing the test specimen, and a screw is provided in the middle of the side plate that penetrates the side plate and is rotatably connected to the clamping plate.

8. The asphalt concrete pull-out test apparatus according to claim 7, characterized in that, The clamping plate has toothed spikes on the side facing the test specimen.

9. The asphalt concrete pull-out test apparatus according to claim 4, characterized in that, A side baffle is connected between the two side plates on the same side; the two ends of the side baffle are respectively fixedly connected to the side plate by a second fastener.

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