Counter-force frame for double-rib opposite-pulling test

Abstract

The invention relates to a reaction frame, in particular to a reaction frame for a double-rib opposite-pulling test. The invention aims to solve the problems that the lap joint steel bars in the concrete test piece are not coaxial, and eccentric bending moment exists during opposite-pull loading. The device is simple in structure, the adjusting screws are screwed before a double-rib opposite-pulling test is carried out, the positions of the moving plate and the attaching unit on the supporting frame are adjusted until the moving plate moves to the position matched with a test piece, and it is ensured that the position of the contact plate can be completely attached to the vertical face of the test piece; and then the lead screw is screwed, so that the movable plate is close to the side vertical surface of the test piece until the movable plate tightly abuts against the surface of the test block. Therefore, in the test process, as the two symmetrical side vertical surfaces of the test block are limited by the contact plates, the contact plates can balance the eccentric bending moment when the load is applied, the influence of the eccentric bending moment on the test result is avoided, and the accuracy of the test result is improved. The invention belongs to the technical field of concrete double-rib opposite-pulling tests.

Description

Technical Field

[0001] This invention relates to a reaction frame, specifically a reaction frame for double-reinforced tension tests, belonging to the technical field of double-reinforced tension tests for concrete. Background Technology

[0002] To study and analyze the effects of the diameter, anchorage length, and surface form of lapped reinforcing bars on the bond strength of concrete, it is necessary to conduct double-reinforced tensile tests on reinforced concrete specimens.

[0003] However, in actual operation, since the two lapped steel bars in the reinforced concrete specimen are not coaxial, an eccentric bending moment is inevitable when tension is applied. Therefore, it is necessary to consider how to overcome the eccentric bending moment during the test to reduce the adverse effects on the test results. Thus, how to propose a new reaction frame to address the above technical problems has become an urgent problem for those skilled in the art. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention provides a reaction frame for a double-ribbed tension test.

[0005] The technical solution of the present invention is: a reaction frame for a double-rib tension test, comprising two parallel support plates and two parallel support frames, wherein the two support plates and the two support frames are arranged in a rectangular shape.

[0006] The support plate has through holes for the reinforcing bars to pass through, and several threaded rods are fixed to the support frame, with the threaded rods slidably connected to the support plate.

[0007] Two adjusting nuts are installed on the threaded rod, and the two adjusting nuts are respectively arranged on both sides of the support plate.

[0008] The support frame includes a movable plate, adjusting screws, and a fastening unit.

[0009] The movable plate is slidably connected to the support frame, the threaded part of the adjusting screw is threadedly connected to the support frame, and the end of the adjusting screw is rotatably connected to the movable plate.

[0010] The contact unit includes a lead screw, a contact plate, and several guide posts.

[0011] The contact plate and the moving plate are arranged in parallel, the lead screw is arranged perpendicular to the moving plate, and the threaded part of the lead screw is threadedly connected to the moving plate, and the end of the lead screw abuts against the contact plate.

[0012] The guide column is arranged parallel to the lead screw, the guide column is slidably connected to the moving plate, and the end of the guide column is connected to the contact plate.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] The present invention has a simple structure. Before conducting the double-rib tension test, the adjusting screw 603 is turned to adjust the position of the moving plate 602 and the contacting unit 7 on the support frame 4 until the moving plate 602 moves to a position that matches the specimen 2, ensuring that the position of the contact plate 703 can be completely in contact with the side surface of the specimen 2; then the screw 701 is turned to make the moving plate 602 close to the side surface of the specimen 2 until it is in tight contact with the surface of the specimen 2.

[0015] Therefore, during the test, since the two symmetrical sides of the test block 2 are limited by the contact plate 703, the contact plate 703 can balance the eccentric bending moment when the load is applied, thus avoiding the influence of the eccentric bending moment on the test results and improving the accuracy of the test results. Attached Figure Description

[0016] Figure 1 This is the front view of the present invention;

[0017] Figure 2 This is a schematic diagram showing the connection between the support frame 4, the movable plate 602, and the adjusting screw 603 in this invention;

[0018] Figure 3 yes Figure 1 A sectional view along direction A.

[0019] In the diagram: 1. Support plate; 2. Test block; 3. Threaded rod; 301. Adjusting nut; 4. Support frame; 602. Moving plate; 603. Adjusting screw; 7. Fitting unit; 701. Lead screw; 702. Guide column; 703. Contact plate; 704. Ball joint. Detailed Implementation

[0020] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments.

[0021] Specific implementation method one: Combining Figures 1 to 3 This embodiment describes a reaction frame for a double-ribbed tension test, comprising two parallel-arranged support plates 1 and two parallel-arranged support frames 4, wherein the two support plates 1 and the two support frames are arranged in a rectangular shape.

[0022] The support plate 1 has through holes for passing through the reinforcing bars, and several threaded rods 3 are fixedly connected to the support frame 4. The threaded rods 3 are slidably connected to the support plate 1.

[0023] Two adjusting nuts 301 are installed on the threaded rod 3, and the two adjusting nuts 301 are respectively arranged on both sides of the support plate 1. This arrangement makes it easy to adjust the position of the support plate 1 on the threaded rod 3.

[0024] The support frame 4 includes a movable plate 602, an adjusting screw 603, and a fastening unit 7.

[0025] The movable plate 602 is slidably connected to the support frame 4, the threaded part of the adjusting screw 603 is threadedly connected to the support frame 4, and the end of the adjusting screw 603 is rotatably connected to the movable plate 602.

[0026] The fastening unit 7 includes a lead screw 701, a contact plate 703, and several guide posts 702.

[0027] The contact plate 703 is arranged parallel to the moving plate 602, the lead screw 701 is arranged perpendicular to the moving plate 602, and the threaded part of the lead screw 701 is threadedly connected to the moving plate 602, and the end of the lead screw 701 abuts against the contact plate 703.

[0028] The guide post 702 is arranged in parallel with the lead screw 701. The guide post 702 is slidably connected to the moving plate 602, and the end of the guide post 702 is connected to the contact plate 703. With the above arrangement, when the adjusting screw 603 is turned, the position of the moving plate 602 and the sticking unit 7 on the support frame 4 can be adjusted by rotating the thread.

[0029] Specific Implementation Method Two: Combining Figures 1 to 3 This embodiment describes a detachable rectangular frame for support. Other components and connections are the same as in specific embodiment one.

[0030] Specific implementation method three: Combining Figures 1 to 3 This embodiment describes a method where the support frame 4 has a sliding groove, and the side of the movable plate 602 is slidably connected to the sliding groove. Other components and connections are the same as in specific embodiments one or two.

[0031] Specific implementation method four: Combination Figures 1 to 3 This embodiment describes a system where there are two guide posts 702, each positioned on either side of the axis of the lead screw 701. Other components and connections are the same as in embodiments one, two, or three.

[0032] Specific Implementation Method Five: Combining Figures 1 to 3 In this embodiment, the end of the guide post 702 is connected to the contact plate 703 via a ball joint 704. This arrangement is because the concrete mold used to prepare the test block 2 has a draft angle, so the symmetrical side faces of the test block 2 are not parallel. Therefore, the ball joint 704 allows the contact plate 703 to swing slightly relative to the axis of the guide post 702, making the contact plate 703 fit more tightly against the surface of the test block 2. Other components and connections are the same as in specific embodiments one, two, three, or four.

[0033] Working principle

[0034] Combination Figures 1 to 3 To explain the working principle of this invention, when using this invention to conduct a double-rib tension test, follow these steps:

[0035] Step 1: The two lapped steel bars of specimen 2 pass through the through holes on support plate 1 respectively.

[0036] Step 2: Tighten the adjusting screw 603 to adjust the position of the moving plate 602 and the fastening unit 7 on the support frame 4 until the moving plate 602 moves to a position that matches the specimen 2, ensuring that the position of the contact plate 703 can be completely attached to the side surface of the specimen 2.

[0037] Step 3: Tighten screw 701 to bring moving plate 602 close to the side of specimen 2 until it is in close contact with the surface of specimen 2.

[0038] Step 4: Apply tension load to the reinforcing bars. Since the two symmetrical sides of the test block 2 are limited by the contact plate 703, the contact plate 703 can balance the eccentric bending moment when the load is applied during the test, thus avoiding the eccentric bending moment from affecting the test results.

[0039] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any simple modifications, equivalent changes and alterations made by those skilled in the art to the above embodiments without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A reaction frame for a double-ribbed tension test, characterized in that: It includes two parallel support plates (1) and two parallel support frames (4), and the two support plates (1) and the two support frames are arranged in a rectangular shape; The support plate (1) has through holes for passing through the reinforcing bars, and several threaded rods (3) are fixedly connected to the support frame (4). The threaded rods (3) are slidably connected to the support plate (1). Two adjusting nuts (301) are installed on the threaded rod (3), and the two adjusting nuts (301) are respectively arranged on both sides of the support plate (1); The support frame (4) includes a movable plate (602), an adjusting screw (603), and a fastening unit (7); The movable plate (602) is slidably connected to the support frame (4), the threaded part of the adjusting screw (603) is threadedly connected to the support frame (4), and the end of the adjusting screw (603) is rotatably connected to the movable plate (602). The fastening unit (7) includes a lead screw (701), a contact plate (703), and several guide posts (702); The contact plate (703) and the moving plate (602) are arranged in parallel, the lead screw (701) and the moving plate (602) are arranged perpendicularly, and the threaded part of the lead screw (701) is threadedly connected to the moving plate (602), and the end of the lead screw (701) abuts against the contact plate (703). The guide post (702) is arranged in parallel with the lead screw (701), the guide post (702) is slidably connected to the moving plate (602), and the end of the guide post (702) is connected to the contact plate (703).

2. The reaction frame for a double-ribbed tension test according to claim 1, characterized in that: The support frame (4) is a detachable rectangular frame.

3. A reaction frame for a double-ribbed tension test according to claim 2, characterized in that: The support frame (4) has a sliding groove, and the side of the movable plate (602) is slidably connected to the sliding groove.

4. A reaction frame for a double-ribbed tension test according to claim 1, characterized in that: There are two guide posts (702), and the two guide posts (702) are respectively arranged on both sides of the axis of the lead screw (701).

5. A reaction frame for a double-ribbed tension test according to claim 4, characterized in that: The end of the guide post (702) is connected to the contact plate (703) via a ball joint (704).

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