Angle-adjustable loading clamp for compression-shear test of concrete test piece
By designing a concrete specimen press shear test loading fixture with adjustable angles, the problems of complexity of traditional test devices and inaccurate test results are solved, and the multi-angle press shear test of concrete specimen under uniaxial loading conditions is realized, which improves the accuracy and efficiency of the test.
Patent Information
- Application Number
- CN202421195797.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-05-29
AI Technical Summary
The traditional concrete test piece press shear test device is complex and difficult to operate. The single-axis loading test machine cannot complete multi-angle tests, and the pads are difficult to place in the appropriate position, resulting in inaccurate test results.
A concrete specimen press shear test loading fixture with adjustable angle is designed, including an upper base and a lower base. The horizontal movement and angle adjustment of the fixture are achieved through the slide rail block and the rotary shaft. The concrete specimen is clamped and fixed at the desired angle using the L-shaped clamping part and fixing member.
The compression and shear loads of concrete specimens under uniaxial loading conditions are implemented simultaneously, which simplifies the test device, improves the accuracy and efficiency of the test, and can conduct tests under multi-angle working conditions.
Smart Images
Figure CN222882454U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a concrete specimen compression shear test loading fixture, in particular to an angle-adjustable concrete specimen compression shear test loading fixture. Background Art
[0002] Concrete is an important material for infrastructure construction. Shear strength and compressive strength are both important physical and mechanical performance indicators of concrete, which can reflect the quality of concrete mechanical properties. In recent years, the mechanical behavior of concrete materials under shear load has begun to be valued by many researchers. However, in the actual service process of concrete, it often bears compressive loads and shear loads at the same time. Therefore, the physical and mechanical properties of concrete materials under compression-shear combined loading have become the focus of research.
[0003] The compression-shear test of concrete specimens is a common method used to study the destructive behavior of concrete under compression-shear combined loading. However, there are still some problems with traditional test equipment, which will make the test difficult, complicated to operate, and the results are not accurate. Specifically: 1. Common compression-shear tests often require biaxial loading, and a compressive load needs to be applied in the vertical direction while a shear load is applied in one direction, which makes the test equipment complicated and the uniaxial testing machine cannot complete the test; 2. At present, the angle of the uniaxial loading testing machine is fixed when performing compression-shear tests, and it is impossible to perform multi-angle tests, which makes it difficult to meet some test requirements; 3. When a pad is used on a uniaxial loading testing machine for compression-shear tests, it is difficult to place the pad in a suitable position and requires manual assistance. Summary of the invention
[0004] In order to solve the above technical problems, the utility model proposes a simple, easy-to-use, accurate and reliable concrete compression shear test loading fixture, which makes the compression shear test more efficient and accurate.
[0005] The utility model adopts the following technical solutions:
[0006] An angle-adjustable concrete specimen compression shear test loading fixture is installed on a universal testing machine and is used to fix the concrete specimen for compression shear test, comprising an upper base and a lower base, wherein the lower base is connected to the lower part of the universal testing machine, and the upper base is connected to a slide block, and the upper base can move horizontally along the slide block, and the slide block is connected to the upper part of the universal testing machine;
[0007] The upper base and the lower base are rotatably connected with an L-shaped upper clamping part and a lower clamping part, respectively, which are arranged opposite to each other to clamp the bottom surface, the top surface and the two side surfaces of the concrete specimen. The upper base and the lower base are also provided with fixing parts. When the upper clamping part and the lower clamping part are rotated to the angle required for the experiment, the upper clamping part and the lower clamping part are respectively fixed by the fixing parts and then the test is carried out.
[0008] Preferably, the upper clamping part comprises an upper pressure block and an upper side plate which are vertically connected, the upper pressure block is fixed to the upper base through a rotating shaft, the upper pressure block is in contact with the top surface of the concrete specimen, and the upper side plate is in contact with one side surface of the concrete specimen;
[0009] The lower clamping part includes a lower pressure block and a lower side plate which are vertically connected. The lower pressure block is fixed to the lower base through a rotating shaft. The lower pressure block is in contact with the bottom surface of the concrete specimen, and the lower side plate is in contact with the other side surface of the concrete specimen.
[0010] Fixing members are provided on both sides of the upper base and the lower base, and a plurality of through holes are opened on the fixing members. Through holes are also opened on the upper pressure block and the lower pressure block. The positions of the upper pressure block and the lower pressure block are fixed by the cooperation of angle limiting bolts and the through holes.
[0011] Preferably, the lengths of the upper pressure block and the lower pressure block are both half the length of the concrete specimen.
[0012] Preferably, the fixing piece is in the shape of an arc bar, and through holes are evenly spaced apart on the arc bar.
[0013] Preferably, rollers are provided on the surfaces of the upper side plate and the lower side plate that are in contact with the concrete specimen.
[0014] Compared with the prior art, the utility model has the following beneficial effects:
[0015] 1. This fixture is relatively simple and convenient when placing concrete specimens into the fixture, and does not require much manual assistance.
[0016] 2. This fixture subjects the concrete specimen to both compression load and shear load under uniaxial loading conditions. The test device is simple and easy to use, and has low requirements on loading conditions.
[0017] 3. This fixture adjusts and fixes the angle of the pressure block through the joint work of the rotating shaft, fixing parts and angle limiting bolts, thereby changing the loading angle of the concrete specimen for compression-shear test. The same device can carry out compression-shear test of concrete specimens under multi-angle conditions. By changing different compression-shear angles, the ratio of the compression load and shear load of the concrete specimen also changes, which can improve the test efficiency and research depth. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a three-dimensional structural schematic diagram of the clamp of the utility model;
[0019] Figure 2 This is a front view structural diagram of the clamp of the utility model;
[0020] Figure 3 This is a schematic diagram of the structure of the clamp of the utility model with a pressing and shearing angle of 0°;
[0021] Figure 4 This is a schematic diagram of the structure of the clamping part of the utility model (the clamping part is taken as an example below);
[0022] Figure 5 This is a force analysis diagram of the compression and shear test of the fixture of the utility model;
[0023] In the figure: 1-concrete specimen, 2-upper base, 3-lower base, 4-fixing bolt, 5-slide block, 6-upper pressure block, 7-lower pressure block, 8-rotating shaft, 9-upper side plate, 10-lower side plate, 11-fixing part, 12-angle limiting bolt. DETAILED DESCRIPTION
[0024] The utility model is described in detail below with reference to the accompanying drawings and specific embodiments.
[0025] Example
[0026] like Figure 1-3 As shown, an angle-adjustable concrete specimen compression shear test loading fixture is installed on a universal testing machine and is used to fix a concrete specimen 1 for compression shear test, comprising an upper base 2 and a lower base 3, wherein the lower base 3 is connected to the lower part of the universal testing machine, and the upper base 2 is connected to a slide block 5, wherein the upper base 2 can move horizontally along the slide block 5, and the slide block 5 is connected to the upper part of the universal testing machine; wherein the lower base 3 and the slide block 5 are respectively connected to the universal testing machine through fixing bolts 4. The fixing bolts 4 are hexagon socket bolts with a size of M10*50, and the material of the I-type connecting bolts 6 is 304 steel, which has good comprehensive performance (corrosion resistance and formability).
[0027] The upper base 2 and the lower base 3 are rotatably connected with an L-shaped upper clamping part and a lower clamping part, respectively, which are arranged opposite to each other to clamp the bottom surface, the top surface and the two side surfaces of the concrete specimen 1. The upper base 2 and the lower base 3 are also provided with a fixing block 11.
[0028] When using the above device, use a suitable hexagonal wrench to fix the lower base 3 and the slide block 5 on the universal testing machine, rotate and adjust the angles of the upper clamping part and the lower clamping part, and fix the upper clamping part and the lower clamping part respectively by the fixing part 11 after reaching the angle required for the experiment. Start the universal testing machine, and the upper clamping part and the lower clamping part transfer the load to the concrete specimen to carry out the test. The loading stress during the test loading is relatively large, and the use of steel materials in the device can ensure sufficient rigidity.
[0029] Specifically, the upper and lower clamping parts can be designed as follows: the upper clamping part includes an upper pressure block 6 and an upper side plate 9 which are vertically connected; the upper pressure block 6 is fixed to the upper base 2 through a rotating shaft 8; the upper pressure block 6 is fitted to the top surface of the concrete specimen 1; and the upper side plate 9 is fitted to one side surface of the concrete specimen 1.
[0030] The lower clamping part includes a lower pressure block 7 and a lower side plate 10 which are vertically connected. The lower pressure block 7 is fixed to the lower base 3 through a rotating shaft 8. The lower pressure block 7 is in contact with the bottom surface of the concrete specimen 1, and the lower side plate 10 is in contact with the other side surface of the concrete specimen 1.
[0031] A fixing part 11 is provided on both sides of the upper base 2 and the lower base 3. A plurality of through holes are opened on the fixing part 11. Through holes are also opened on the upper pressure block 6 and the lower pressure block 7. The positions of the upper pressure block 6 and the lower pressure block 7 are fixed by the angle limiting bolts 12 cooperating with the through holes.
[0032] The lengths of the upper pressure block 6 and the lower pressure block 7 are both half of the length of the concrete specimen 1 , and when the concrete specimen 1 is clamped, shear forces are provided in the up and down directions.
[0033] The fixing member 11 may be designed as an arc strip, and through holes are evenly spaced on the arc strip. Figure 1-3 As shown, the arc bar is specifically a quarter arc, one end of which is fixed flush with the upper base 2 and the lower base 3, and the other end is fixed to the base through a vertical bracket. Starting from the horizontal direction, through holes are reserved at the positions of 0°, 15°, 30°, and 45° of the arc bar, and the angle limiting bolts 12 pass through the through holes on the pressure block and the fixing member 11 to limit the displacement of the pressure block, thereby fixing the pressure block to the base at a corresponding angle. The through holes on the upper and lower pressure blocks and the fixing member 11 can be set as threaded holes or smooth holes, corresponding to the use of threaded rods, or connecting rods with threads at both ends and no threads in the middle.
[0034] Of course, the fixing member 11 can also adopt other structures to cooperate with the pressure block. For example, the shape of the fixing member 11 is not limited, but the hole distribution arrangement on it remains unchanged, and the upper and lower pressure blocks may not be provided with through holes, but holes may be provided on both sides to cooperate and fix with the fixing members 11 on both sides.
[0035] Specifically, Figure 4 As shown, rollers are provided on the sides of the upper side plate 9 and the lower side plate 10 that are in contact with the concrete specimen 1, and their function is to reduce the influence of the friction between the concrete side and the side plate during loading.
[0036] In specific experiments:
[0037] First, use the hexagon socket to fix the slide block 5 to the upper part of the universal testing machine, install the upper base 2 to the slide block 5, and fix the lower base 3 to the lower part of the universal testing machine. During installation, ensure that the upper base 2 and the lower base 3 remain level. At this time, the upper pressure block 6, the lower pressure block 7, and the upper and lower side plates have been fixed to the upper base 2 and the lower base 3 through the rotating shaft 8;
[0038] Then, the lower pressure block 7 is rotated to adjust to the desired angle, the angle limiting bolt 12 is inserted into the lower pressure block 7 and the fixing member 11, the lower pressure block 7 is fixed at the desired angle, and the concrete specimen 1 is placed on the lower pressure block 7, and when placing, it is noted that the lower surface of the concrete is in close contact with the lower pressure block 7;
[0039] Then adjust the height of the universal testing machine's boom to adjust the vertical position of the upper pressure block 6, adjust the horizontal position of the upper pressure block 6 through the slide groove of the slide rail block 5, adjust to the appropriate position where the upper pressure block 6 and the upper side plate 9 fit the concrete specimen 1, insert the angle limiting bolt 12 to fix the upper pressure block 6, and the universal testing machine starts working. The concrete specimen is subjected to compression load and shear load at the set angle. Different compression angles correspond to different compression ratios, and the universal testing machine records the test data.
[0040] After the experiment, remove the concrete specimen, remove the angle limiting bolt 12 when the compression-shear angle needs to be switched, and repeat the above operation.
[0041] During loading, the universal testing machine applies a downward force to the upper base 2 and an upward force to the lower base 3, so that the upper base 2 and the lower base 3 tend to move closer to each other in the vertical direction. The force on the base is transmitted to the pressure block and the side plate through the rotating shaft 8, and the upper pressure block 6 and the lower pressure block 7 tend to move closer to each other in the vertical direction. The upper pressure block 6 contacts the upper surface of the concrete specimen at a certain angle, and the lower pressure block 7 contacts the lower surface of the concrete specimen. The upper side plate 9 contacts the right side of the concrete specimen, and the lower side plate 10 contacts the left side of the concrete specimen. The pressure blocks and side plates at a certain angle transmit force to the concrete specimen, and the concrete specimen is subjected to the combined action of compression load and shear load at a specific angle. The stress state of the concrete specimen is as follows: Figure 5 As shown, from the equilibrium equation we can get:
[0042] F=F n cosβ+F s sinβ
[0043] Where F is the pressure obtained by the universal testing machine, F n is the normal shear force acting on the specimen, F s is the compressive load acting on the side of the specimen, and β is the inclination angle of the concrete specimen.
[0044] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make modifications, substitutions and deformations within the technical scope disclosed by the present invention without departing from the spirit and principles of the present invention.
Claims
1. A concrete specimen compression shear test loading fixture with adjustable angle, installed on a universal testing machine, used to fix a concrete specimen (1) for compression shear test, characterized in that: It comprises an upper base (2) and a lower base (3), wherein the lower base (3) is connected to the lower part of the universal testing machine, and the upper base (2) is connected to a slide block (5), and the upper base (2) can move horizontally along the slide block (5), and the slide block (5) is connected to the upper part of the universal testing machine; The upper base (2) and the lower base (3) are rotatably connected with an L-shaped upper clamping part and a lower clamping part, respectively, which are arranged opposite to each other to clamp the bottom surface, the top surface and the two side surfaces of the concrete test piece (1). The upper base (2) and the lower base (3) are also provided with a fixing part (11). When the upper clamping part and the lower clamping part are rotated to the angle required for the experiment, the upper clamping part and the lower clamping part are respectively fixed by the fixing part (11) and then the test is carried out.
2. The angle-adjustable concrete specimen compression shear test loading fixture according to claim 1, characterized in that: The upper clamping portion comprises an upper pressure block (6) and an upper side plate (9) which are vertically connected, the upper pressure block (6) being fixed to the upper base (2) via a rotating shaft (8), the upper pressure block (6) being in contact with the top surface of the concrete specimen (1), and the upper side plate (9) being in contact with one side surface of the concrete specimen (1); The lower clamping part comprises a lower pressure block (7) and a lower side plate (10) which are vertically connected, the lower pressure block (7) is fixed to the lower base (3) via a rotating shaft (8), the lower pressure block (7) is in contact with the bottom surface of the concrete specimen (1), and the lower side plate (10) is in contact with the other side surface of the concrete specimen (1); A fixing member (11) is provided on both sides of the upper base (2) and the lower base (3), and a plurality of through holes are provided on the fixing member (11). Through holes are also provided on the upper pressure block (6) and the lower pressure block (7), and the positions of the upper pressure block (6) and the lower pressure block (7) are fixed by means of angle limiting bolts (12) cooperating with the through holes.
3. The angle-adjustable concrete specimen compression shear test loading fixture according to claim 2, characterized in that: The lengths of the upper pressure block (6) and the lower pressure block (7) are both half the length of the concrete test piece (1).
4. The angle-adjustable concrete specimen compression shear test loading fixture according to claim 2, characterized in that: The fixing member (11) is in the shape of an arc strip, and through holes are evenly spaced apart on the arc strip.
5. The angle-adjustable concrete specimen compression shear test loading fixture according to claim 2, characterized in that: Rollers are provided on the sides of the upper side plate (9) and the lower side plate (10) that are in contact with the concrete test piece (1).