Clamp for detecting tensile strength of steel fiber

Abstract

The utility model relates to a clamp, in particular to a clamp for detecting the tensile strength of steel fibers, which comprises a first clamp and a second clamp which are symmetrically arranged. The first clamp is the same as the second clamp, the first clamp comprises a fixing part and a connecting part, and the fixing part and the connecting part are integrally formed; a connecting hole is formed in the end face of the fixing part, an anti-disengaging line and a fracture interval are arranged on the connecting part, and the anti-disengaging line is located between the connecting hole and the fracture interval. Scales are arranged at the two ends of the connecting part. The length of the anti-falling lines is 30 mm, and the length of the fracture section is 10 mm; the fracture sections of the first clamp and the second clamp are connected. The length of the anti-falling lines is 32 mm, and the length of the fracture section is 8 mm; the fracture sections of the first clamp and the second clamp are connected. According to the utility model, the steel fiber can be more firmly fixed on the clamp through the high-strength glue, so that the pulling-off condition is avoided, and the accuracy and authenticity of an experiment are improved.

Description

Technical Field

[0001] This utility model relates to a clamp, specifically a clamp for testing the tensile strength of steel fibers. Background Technology

[0002] Tensile strength is an important mechanical property of steel fibers used in concrete. The tensile strength test of steel fibers for concrete is a crucial method for assessing the tensile properties of steel fiber materials. Currently, commonly used methods for testing the tensile strength of steel fibers for concrete are divided into the direct clamping pull-out method and the assisted fixing pull-out method. The former involves manually placing the steel fiber into two separate tensile clamps on the testing machine; once the fiber is fixed, the test can begin directly. The latter involves pre-fixing the fiber in the tensile clamps using high-strength adhesive, auxiliary fasteners, etc., and then installing the testing clamps together on the testing machine to begin the test.

[0003] In the direct clamping and pulling method, the clamp ends are typically designed with a conical structure with undulating edges and equipped with a strong spring to firmly lock the steel fiber ends. This structure leads to stress concentration in the steel fiber gripping section, causing the fiber to easily break within the clamp. In the assisted fixing and pulling method, existing clamps generally have a relatively smooth and flat steel fiber bonding surface, making the steel fiber easy to pull off during the test. At the same time, the pre-set fracture zone of the steel fiber in the middle of the opposing clamp is small, making the steel fiber prone to breakage in the assisted fixing section, which cannot guarantee the accuracy of the results. Utility Model Content

[0004] The purpose of this invention is to provide a fixture for testing the tensile strength of steel fibers, which solves the problems of small fracture range and low reliability of experimental results in the fixtures currently used in the auxiliary fixed pull-out method.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A fixture for testing the tensile strength of steel fibers includes a first fixture and a second fixture, which are placed symmetrically. The first fixture and the second fixture are identical. The first fixture includes a fixing part and a connecting part, which are integrally formed. The fixing part has a connecting hole on its end face, and the connecting part has anti-slipping and fracture zones, with the anti-slipping zone located between the connecting hole and the fracture zone. The connecting part has graduations at both ends.

[0007] Furthermore, the anti-slip texture is 30mm long and the fracture section is 10mm long; the fracture sections of the first clamp and the second clamp are connected.

[0008] Furthermore, the anti-slip texture is 32mm long and the fracture section is 8mm long; the fracture sections of the first clamp and the second clamp are connected.

[0009] Furthermore, the anti-slip texture includes multiple serrated stripes, each serrated stripe having a first connecting surface and a second connecting surface. The first connecting surface is perpendicular to the horizontal plane, and the second connecting surface forms an acute angle with the first connecting surface.

[0010] Furthermore, the anti-slip stripe includes multiple W-shaped stripes; the W-shaped stripes include a first fixing surface, a second fixing surface, and a third fixing surface, wherein the third fixing surface is parallel to the horizontal plane, the third fixing surface is perpendicular to the first fixing surface, and the second fixing surface forms an acute angle with the first fixing surface.

[0011] Furthermore, the connecting hole is a bolt hole with a diameter of 10mm, and the connecting hole is used to connect the connector on the testing machine.

[0012] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0013] This invention features anti-detachment textured joints. When high-strength adhesive is applied, it remains within these textures, increasing the area of ​​the adhesive covering the steel fiber and thus securing it more firmly. The joint also includes graduations, allowing for easy determination of fiber symmetry during fixation. This prevents the fiber from breaking off outside the designated fracture zone, which could affect experimental results. Furthermore, the design incorporates fracture zones of varying lengths to accommodate steel fibers of different lengths. Excessively large fracture zones would result in shorter fiber adhesion lengths, weakening the fixation strength and potentially leading to inaccurate results. This invention, using high-strength adhesive, more firmly fixes the steel fiber to the clamp, preventing pull-out and improving the accuracy and reliability of the experiment. Attached Figure Description

[0014] Figure 1 This is a top view of a fixture used for testing the tensile strength of steel fibers, with a fracture interval of 10 mm.

[0015] Figure 2 This is a front view of a fixture used for testing the tensile strength of steel fibers, with a fracture interval of 10 mm.

[0016] Figure 3 This is a top view of a fixture used for testing the tensile strength of steel fibers, with a fracture interval of 8mm.

[0017] Figure 4 This is a front view of a fixture used for testing the tensile strength of steel fibers, with a fracture interval of 8mm.

[0018] Figure 5 This is a top view of a fixture with W-shaped stripes used for testing the tensile strength of steel fibers.

[0019] Figure 6This is a front view of a fixture with W-shaped stripes used for testing the tensile strength of steel fibers. Detailed Implementation

[0020] Example 1

[0021] like Figures 1 to 4 As shown, a fixture for testing the tensile strength of steel fibers includes a first fixture and a second fixture, which are symmetrically placed. The first and second fixtures are identical. The first fixture includes a fixing part 1 and a connecting part 2, which are integrally formed. A connecting hole 3 is provided on the end face of the fixing part 1, and an anti-detachment texture 4 and a fracture zone 5 are provided on the connecting part 2. The anti-detachment texture 4 is located between the connecting hole 3 and the fracture zone 5. Scales 6 are provided at both ends of the connecting part 2. Steel fibers are adhered to the connecting part 2 with high-strength adhesive. By observing the scales 6, the two sides of the steel fiber are made symmetrical, and the center of the steel fiber is located in the fracture zone 5. The connecting part 2 of the first and second fixtures is connected, forming a ring-shaped fracture zone 5. When the high-strength adhesive enters the anti-detachment texture 4, it accumulates within it. When the steel fiber is placed on the anti-detachment texture 4, the accumulated high-strength adhesive comes into contact with the steel fiber. This accumulation of high-strength adhesive within the anti-detachment texture 4 increases the contact area between the adhesive and the steel fiber, firmly adhering the steel fiber to the connecting part 2. Compared to the smooth connecting part 2, the high-strength adhesive has a fixed thickness, resulting in a smaller contact area between the adhesive and the steel fiber. This can lead to pull-out or even breakage of the steel fiber during the experiment, causing inaccurate or unreliable experimental results. After the steel fiber is adhered, the connecting hole 3 is a 10mm diameter bolt hole used to connect a connector on the testing machine. The connector is threaded into the connecting hole 3, and then the connector is fixed to the testing machine. The tensile strength of the steel fiber is measured by the pulling action of the testing machine on the first clamp.

[0022] When bonding steel fibers, the length of the steel fibers is first measured using scale 6. If the steel fiber length is greater than 60mm, a clamp with a 30mm anti-detachment 4 length and a 10mm fracture interval 5 length is required. If the steel fiber length is less than 60mm but greater than 35mm, a clamp with a 32mm anti-detachment 4 length and an 8mm fracture interval 5 length is required. The fracture intervals 5 of the first and second clamps are connected. This prevents the steel fiber from being too short, and the selected clamp fracture interval 5 being too large, resulting in a short bonded portion that is prone to pull-out or fracture at the connection point between the steel fiber and the clamp, leading to unreliable experimental results. After selecting the clamps, the steel fibers are symmetrically bonded to the clamps using scale 6, ensuring the center of the steel fiber is between 3mm from the left end of the fracture interval 5 of the first clamp and 3mm from the right end of the fracture interval 5 of the second clamp, thus improving the reliability of the experiment.

[0023] The anti-detachment texture 4 includes multiple serrated stripes, each comprising a first connecting surface 11 and a second connecting surface 12. The first connecting surface 11 is perpendicular to the horizontal plane, and the second connecting surface 12 forms an acute angle with the first connecting surface 11. After the high-strength adhesive is applied to the connecting part 2, it quickly fills the serrated stripes along the first connecting surface 11, which not only improves the utilization rate of the high-strength adhesive and reduces experimental costs, but also improves the bonding efficiency of the steel fiber.

[0024] Example 2

[0025] like Figure 5 and Figure 6 As shown, this embodiment is a variation of Embodiment 1. The difference between this embodiment and Embodiment 1 is that the anti-detachment texture 4 includes multiple W-shaped stripes; the W-shaped stripes include a first fixing surface 21, a second fixing surface 22, and a third fixing surface 23. The third fixing surface 23 is parallel to the horizontal plane, perpendicular to the first fixing surface 21, and the second fixing surface 22 forms an acute angle with the first fixing surface 21. After the high-strength adhesive is poured onto the connecting part 2, the high-strength adhesive will quickly fill the W-shaped stripes along the first fixing surface 21, and the third fixing surface 23 will increase the contact area between the anti-detachment texture 4 and the steel fiber, preventing the steel fiber from rolling in a direction parallel to the anti-detachment texture 4 during the bonding process, thus increasing bonding time and reducing experimental efficiency.

[0026] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A fixture for testing the tensile strength of steel fibers, characterized in that, It includes a first clamp and a second clamp, which are placed symmetrically. The first clamp and the second clamp are the same. The first clamp includes a fixing part and a connecting part, which are integrally formed. The end face of the fixing part is provided with a connecting hole, and the connecting part is provided with anti-slipping and breakage intervals. The anti-slipping is located between the connecting hole and the breakage interval. The two ends of the connecting part are provided with scales.

2. The fixture for testing the tensile strength of steel fibers according to claim 1, characterized in that, The anti-slip texture is 30mm long and the fracture section is 10mm long; the fracture sections of the first clamp and the second clamp are connected.

3. The fixture for testing the tensile strength of steel fibers according to claim 1, characterized in that, The anti-slip texture is 32mm long and the fracture section is 8mm long; the fracture sections of the first clamp and the second clamp are connected.

4. A fixture for testing the tensile strength of steel fibers according to claim 1, characterized in that, The anti-shedding texture includes multiple serrated stripes, each serrated stripe having a first connecting surface and a second connecting surface. The first connecting surface is perpendicular to the horizontal plane, and the second connecting surface forms an acute angle with the first connecting surface.

5. A fixture for testing the tensile strength of steel fibers according to claim 1, characterized in that, The anti-slip texture includes multiple W-shaped stripes; the W-shaped stripes include a first fixing surface, a second fixing surface, and a third fixing surface, the third fixing surface is parallel to the horizontal plane, the third fixing surface is perpendicular to the first fixing surface, and the second fixing surface forms an acute angle with the first fixing surface.

6. A fixture for testing the tensile strength of steel fibers according to claim 1, characterized in that, The connecting hole is a bolt hole with a diameter of 10mm, and the connecting hole is used to connect the connecting parts on the testing machine.

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