Retractable pull-out test steel bar displacement measuring clamp

Abstract

The utility model discloses a telescopic steel bar displacement measuring clamp for a pull-out test, and relates to the field of test and research on the bonding performance of reinforced concrete. Comprising a measuring clamp arranged on a reaction frame, the measuring clamp comprises a first clamping device, a first telescopic rod connected with the first clamping device, a position fixing device connected with the first telescopic rod, a second telescopic rod connected with the position fixing device and a second clamping device connected with the second telescopic rod, and a limiting piece is clamped on the second clamping device; a horizontal pipe is arranged on the side, close to the second clamping device, of the second telescopic rod. By adopting the telescopic pull-out test steel bar displacement measuring clamp with the structure, the problems that a traditional steel bar clamp in a pull-out test is not telescopic, the test adaptability is poor, and errors are generated in measured slippage are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of steel bar concrete bonding performance test research, in particular to a retractile steel bar displacement measuring fixture for a pulling test. Background Art

[0002] In recent years, with reinforced concrete as the most widely used material in the construction industry, railways, bridges, civil buildings and underground structures are inseparable from reinforced concrete. The bonding performance between steel bars and concrete is the most basic mechanical property, and the anchoring capacity between the two is the key factor to ensure the bearing capacity of reinforced concrete structures. Therefore, it is particularly important to study the bonding performance of reinforced concrete. At present, in the process of exploring the bonding mechanism between steel bars and concrete, the pull-out test is widely used in research due to its simplicity and intuitive characteristics. Most of the fixtures for measuring the slippage of steel bars are customized for specific reinforced concrete sizes. They are not scalable, cannot have good test adaptability, and often cannot be reused, resulting in a waste of test resources. At the same time, the displacement meter is usually fixed on the concrete test block. Since discontinuous vibrations will be generated during the test, especially when the specimen is damaged, the vibration is particularly severe, which can easily cause the displacement meter to vibrate, resulting in errors in the tested slippage. Therefore, it is necessary to provide a retractable pull-out test steel bar displacement measurement fixture. In addition, unlike the traditional pull-out test, the fixture also has good applicability for pull-out tests such as uniaxial, biaxial, and combined stress. Utility Model Content

[0003] The utility model aims to provide a retractable steel bar displacement measuring fixture for a pulling test, so as to solve the problems in the pulling test that the traditional steel bar fixture has no retractability, poor steel bar fixing stability, poor test adaptability and errors in the measured slip amount.

[0004] To achieve the above-mentioned purpose, the utility model provides a retractable tension test steel bar displacement measuring fixture, and the technical solution adopted is: it includes a measuring fixture arranged on a reaction frame, the measuring fixture includes a first clamp, a first telescopic rod connected to the first clamp, a position fixer connected to the first telescopic rod, a second telescopic rod connected to the position fixer, and a second clamp connected to the second telescopic rod, and a limit piece is clamped on the second clamp; a horizontal tube is arranged on the side of the second telescopic rod close to the second clamp.

[0005] Preferably, the first clamp and the second clamp each include two clamping plates and a limiting support provided on one of the clamping plates, and the limiting support is connected to one of the clamping plates via a limiting bolt.

[0006] Preferably, the two clamping plates are connected by locking bolts at both ends, and one end of the locking bolt is sleeved with a locking nut for adjusting the tightness.

[0007] Preferably, the limiting member comprises a thin-walled circular tube and a displacement test steel sheet, and the displacement test steel sheet is welded to one end of the thin-walled circular tube.

[0008] Preferably, the reaction frame includes an upper base plate and a lower base plate, and the upper base plate and the lower base plate are fixedly connected by four connecting parts with double-head threads and nuts. An upper chuck is provided on the upper base plate, and a magnetic clamp is provided on the lower wall of the upper base plate. A displacement meter is clamped on the magnetic clamp, and a specimen support is provided on the lower base plate.

[0009] Preferably, a reinforced concrete test block is arranged on the specimen support, a steel bar body is inserted into the reinforced concrete test block, and the steel bar body passes through the specimen support and the lower base plate.

[0010] Preferably, the clamp, telescopic rod, limit piece and position fixer are all made of high-strength metal material aluminum alloy, which has good wear resistance and corrosion resistance.

[0011] Preferably, the telescopic rod has a telescopic length of 0-10 cm, is telescopic in the horizontal direction of the rod, and is fixed by a position fixer.

[0012] Preferably, the limiting member comprises a thin-walled circular tube with a length of 20 cm and a steel sheet of 5×5 cm, and the two are fixedly connected by welding.

[0013] Beneficial effects of the utility model:

[0014] (1) The utility model can conveniently adapt to reinforced concrete specimens of different sizes by adjusting the length of the telescopic rod;

[0015] (2) The utility model can improve the clamping force and stability of the clamping plate through the design of the locking bolt and the limit bolt, so as to better adapt to steel bars of different diameters;

[0016] (3) The utility model prevents the clamped object from shaking by arranging a limit support in the clamping piece and rotating the limit bolt;

[0017] (4) The utility model ensures that the installation position of the fixture is in a horizontal or vertical state by setting a horizontal tube, thereby further ensuring the accuracy of the test;

[0018] (5) The clamp of the utility model is made of aluminum alloy as a whole, which has good wear resistance and corrosion resistance.

[0019] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional structural schematic diagram of a retractable steel bar displacement measuring fixture for a pulling test according to the utility model;

[0021] Figure 2 It is a schematic diagram of a retractable steel bar displacement measuring fixture for pull-out test in a pull-out test according to the utility model;

[0022] Among them, 1. a first clamp; 2. a first telescopic rod; 3. a position fixer; 4. a second telescopic rod; 5. a horizontal tube; 6. a second clamp; 7. a limiter; 8. an upper clamp; 9. a magnetic clamp; 10. a reaction frame; 11. a retractable clamp for measuring the displacement of steel bars in a pull-out test; 12. a displacement meter; 13. a reinforced concrete specimen; 14. a specimen support; 15. a steel bar body; 16. a locking nut; 17. a locking bolt; 18. a limiter support; 19 a limiter bolt; 20. a clamping piece; 21. an upper base plate; 22. a connecting piece; 23. a lower base plate; 24. a nut. DETAILED DESCRIPTION

[0023] The technical solution of the utility model is further described below through the accompanying drawings and embodiments.

[0024] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] Example

[0026] The utility model provides a retractable steel bar displacement measuring fixture for a pulling test, such as Figure 1As shown, it includes a measuring fixture 11 arranged on a reaction frame, and the measuring fixture 11 includes a first clamp 1, a first telescopic rod 2 connected to the first clamp 1, a position fixer 3 connected to the first telescopic rod 2, a second telescopic rod 4 connected to the position fixer 3, and a second clamp 6 connected to the second telescopic rod 4, and a limit piece 7 is clamped on the second clamp 6; a horizontal tube 5 is arranged on the side of the second telescopic rod 4 close to the second clamp 6; the first clamp 1 and the second clamp 6 each include two clamping plates 20 and a limit support 18 arranged on one of the clamping plates 20, and the limit support 18 is connected to one of the clamping plates 20 through a limit bolt 19; the two clamping plates 20 are connected by locking bolts 17 at both ends, and the locking bolts 17 are A locking nut 16 for adjusting tightness is sleeved on one end; the limit member 7 includes a thin-walled circular tube 701 and a displacement test steel sheet 702, and the displacement test steel sheet 702 is welded to one end of the thin-walled circular tube 701; the reaction frame 10 includes an upper base plate 21 and a lower base plate 23, and the upper base plate 21 and the lower base plate 23 are fixedly connected by four connecting members 22 with double-headed threads and nuts 24, an upper clamp 8 is arranged on the upper base plate 21, a magnetic clamp 9 is arranged on the lower wall of the upper base plate 21, a displacement meter 12 is clamped on the magnetic clamp 9, and a specimen support 14 is arranged on the lower base plate 23; a reinforced concrete test block 13 is arranged on the specimen support 14, a steel bar body 15 is inserted into the reinforced concrete test block 13, and the steel bar body 15 passes through the specimen support 14 and the lower base plate 23.

[0027] Figure 1The present invention is a three-dimensional structural diagram of a retractable pull-out test steel bar displacement measurement fixture. As shown in the figure, the clamp is composed of multiple components, including a locking bolt 17, a locking nut 16, a limiting bolt 19, a limiting support 18 and a clamping piece 20. These components work together to achieve a stable fixation of the steel bar body 15. In actual operation, the steel bar body 15 in the pull-out test is firstly fixed by the cooperation of the locking bolt 17 and the locking nut 16. At the same time, by adjusting the limiting bolt 19, the clamp 1 can adapt to steel bar bodies 15 of different diameters and the limiting support 18 can better fix the steel bar body 15 to avoid shaking during the test. In addition, the telescopic rods 2 and 4 can adapt to reinforced concrete specimens 13 of different sizes through the adjustability of their lengths and the use of the position fixer 3. At the same time, by adjusting the bubble position in the horizontal tube 5, it is ensured that the installation position of the clamp is in a horizontal or vertical state, further ensuring the accuracy of the test. The clamp 6 is used to fix the limiting piece. By adjusting the locking bolt 17 and the locking nut 16, the limiter 7 is firmly clamped. At the same time, adjusting the limiter bolt 19 can ensure that the limiter support 18 can better enhance the stability of the limiter 7 and prevent it from shaking or displacement during the test. A displacement test steel sheet 702 is welded to one end of the thin-walled circular tube 701. During the test, by measuring the displacement of the displacement test steel sheet 702, the slippage of the steel bar body 15 can be accurately measured.

[0028] Figure 2 The present invention is a schematic diagram of a retractable pull-out test steel bar body displacement measuring fixture in a pull-out test. As shown in the figure, in actual operation, when the device is used, the reinforced concrete test block 13 is placed in the middle of the test piece support 14 on the lower bottom plate 23, one end of the steel bar body 15 passes through the test piece support 14 and the lower bottom plate 23, and the other end is clamped by the clamp 1. At this time, the magnetic clamp 9 fixes the displacement meter 12 in a position flush with the displacement test steel sheet 702. The upper clamp of the universal testing machine clamps the upper clamp 8, and the lower clamp clamps the steel bar body 15. Then the universal testing machine performs a pull-out test. The reaction frame 10 moves upward under the influence of the pull-out force of the upper clamp 8, and the retractable pull-out test steel bar body displacement measuring fixture 11 in the reaction frame 10 also moves upward. During the test, the displacement of the displacement test steel sheet 702 is measured by the displacement meter 12, and the slippage of the steel bar body 15 can be accurately measured.

[0029] Therefore, the utility model adopts a retractable pull-out test steel bar displacement measuring fixture of the above structure to solve the problems of traditional steel bar fixtures in pull-out tests having no retractability, poor steel bar fixing stability, poor test adaptability, and errors in measured slippage.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the utility model with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the utility model.

Claims

1. A flexible steel bar displacement measuring fixture for pull-out tests, characterized in that: The measuring fixture comprises a measuring fixture arranged on a reaction frame, the measuring fixture comprises a first clamp, a first telescopic rod connected to the first clamp, a position fixer connected to the first telescopic rod, a second telescopic rod connected to the position fixer, and a second clamp connected to the second telescopic rod, wherein a limiting member is clamped on the second clamp; A horizontal tube is arranged on one side of the second telescopic rod close to the second clamp.

2. The retractable steel bar displacement measuring fixture for pull-out test according to claim 1, characterized in that: The first clamp and the second clamp each include two clamping plates and a limiting support provided on one of the clamping plates, wherein the limiting support is connected to one of the clamping plates via a limiting bolt.

3. The retractable steel bar displacement measuring fixture for pull-out test according to claim 2, characterized in that: The two clamping plates are connected by locking bolts at both ends, and one end of the locking bolt is sleeved with a locking nut for adjusting tightness.

4. The retractable steel bar displacement measuring fixture for pull-out test according to claim 1, characterized in that: The limiting member comprises a thin-walled circular tube and a displacement test steel sheet, and the displacement test steel sheet is welded to one end of the thin-walled circular tube.

5. The retractable steel bar displacement measuring fixture for pull-out test according to claim 1, characterized in that: The reaction frame includes an upper base plate and a lower base plate, and the upper base plate and the lower base plate are fixedly connected by four connecting pieces with double-head threads and nuts. An upper chuck is arranged on the upper base plate, and a magnetic clamp is arranged on the lower wall of the upper base plate. A displacement meter is clamped on the magnetic clamp, and a specimen support is arranged on the lower base plate.

6. The retractable steel bar displacement measuring fixture for pull-out test according to claim 5, characterized in that: A reinforced concrete test block is arranged on the test piece support, a steel bar body is inserted into the reinforced concrete test block, and the steel bar body passes through the test piece support and the lower bottom plate.

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