A fiber and bonding material pulling test device and test method

Abstract

A fiber and adhesive material pull-out test device and test method belong to the technical field of building materials. The device includes: a transparent slot is provided on the test bench; the specimen mold box includes: a specimen mold slot composed of five transparent materials, an L-shaped baffle arranged in the specimen mold slot and whose position in the specimen mold slot can be changed, and a fixing clamp for fixing the L-shaped baffle; the L-shaped baffle divides the specimen mold slot into two spaces, wherein a plurality of one-to-one corresponding small holes are arranged on one side of the L-shaped baffle and the corresponding specimen mold slot in the rectangular space; the connection direction of each two corresponding small holes is horizontal; the fiber fixing bracket is used in pairs, one is arranged in a non-rectangular space in the two spaces divided by the L-shaped baffle and the specimen mold slot, and the other is arranged outside the specimen mold slot; the fiber passes through the small holes on the L-shaped baffle and the specimen mold slot, and the two ends are respectively arranged on the fiber fixing bracket. The present invention can measure the pull-out resistance and the holding force between the fiber and the adhesive material.

Description

Technical Field

[0001] The invention belongs to the field of building materials, and in particular relates to a fiber and bonding material pulling test device and a test method. Background Art

[0002] In recent years, fiber reinforcement technology has been widely used in various soil reinforcement projects and concrete reinforcement due to its advantages of simple construction, good mixing uniformity, and no environmental pollution. Studies have shown that fiber reinforcement can effectively improve shear strength, inhibit the formation of tension cracks, and improve permeability. At the same time, it will not form potential weak structural surfaces, so it is an excellent reinforcement technology.

[0003] Cement is the building material with the largest consumption and the widest application range in human society today. Cement-based materials have high compressive strength, but have the disadvantages of low tensile strength, poor crack resistance and high brittleness. These disadvantages are essential and difficult to solve by improving the material itself. Only by adopting the "composite" technical approach, adding fibers to cement-based materials to improve their performance, a series of cement-based composite materials have been developed, such as fiber concrete, high-performance fiber-reinforced cement-based composite materials, etc. In the past two decades, building fibers and geotechnical materials have ushered in a high-performance era. Compared with other fibers, PVA fibers have more outstanding advantages, such as high strength, high modulus, good wear resistance, acid and alkali resistance, good bonding with cement matrix, good weather resistance, good dispersibility, easy mixing, non-toxic and environmentally friendly. At present, the research on fiber in composite materials has not received much attention, and the interface performance between it and cement needs to be further improved, so as to greatly extend the service life of the material. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a fiber and adhesive material pull-out test device and test method. By changing the fiber embedding depth, fiber number, fiber type, adhesive material type, etc., the stress condition between the fiber and the adhesive material is analyzed to understand the pull-out resistance of the fiber material in the adhesive body.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0006] A fiber and bonding material pulling test device, the device comprising:

[0007] The test bench is provided with a through slot;

[0008] A specimen mold box; the specimen mold box comprises: a specimen mold slot made of five transparent materials, an L-shaped baffle disposed in the specimen mold slot and capable of changing its position in the specimen mold slot, and a fixing clip for fixing the L-shaped baffle; the L-shaped baffle divides the specimen mold slot into two spaces, wherein a plurality of small holes corresponding to each other are arranged on one side of the L-shaped baffle and the corresponding specimen mold slot in the rectangular space; the connecting direction of each two corresponding small holes is horizontal;

[0009] Fiber fixing bracket; the fiber fixing bracket is used in pairs, one is arranged in a non-rectangular space in the two spaces divided by the L-shaped baffle plate and the specimen mold groove, and the other is arranged outside the specimen mold groove; the fiber passes through the small holes on the L-shaped baffle plate and the specimen mold groove, and the two ends are respectively arranged on the fiber fixing bracket.

[0010] Preferably, the fiber fixing bracket comprises: a plurality of parallel columns, each column is provided with a fixing device movable up and down, each fixing device is provided with a clip, a crossbeam fixing the plurality of columns and a suction cup arranged under the beam.

[0011] Preferably, the plurality of parallel columns are spaced at equal intervals.

[0012] Preferably, the length of the through slot on the test bench is greater than the length of the fiber fixing bracket.

[0013] Preferably, scale values ​​are provided on the surfaces of the specimen mold groove and the L-shaped baffle in the same direction parallel to the fibers.

[0014] Preferably, the five transparent surfaces of the specimen mold groove are made of glass.

[0015] A test method for a fiber and bonding material pulling test device, the method comprising the following steps:

[0016] Step 1: Place the specimen mold box on the test bench, observe the scales above and below the L-shaped baffle and the specimen mold slot, and adjust the position of the L-shaped baffle in the specimen mold slot; fix the L-shaped baffle with a fixing clip above the L-shaped baffle;

[0017] Step 2: Pass a single fiber or a fiber bundle through the small holes on the specimen mold groove and the L-shaped baffle, leaving a certain length at both ends as required;

[0018] Step 3: Place a pair of fiber fixing brackets on the outside of the specimen mold groove and the L-shaped baffle respectively, and after the suction cups are fixed, adjust the height of the fixing device to straighten the fiber filaments or fiber bundles and keep them in a horizontal state, and fix them with clips;

[0019] Step 4: injecting the cementing material, and after the cementing material fills the rectangular space, curing begins, and after three days, the fiber fixing bracket is removed;

[0020] Step 5: Rotate the specimen mold box counterclockwise by 90 degrees, align the fiber with the through slot, expose it from the through slot, and load a counterweight to implement a test method for a fiber and bonding material pull-out test device.

[0021] Preferably, in step three, the height of each fiber filament in the stretched fiber bundle is the same.

[0022] The beneficial effects of the present invention are: 1. The present invention can measure the pull-out resistance and the bond strength between the fiber and the adhesive material; 2. The mold wall is movable, and the mold thickness can be adjusted to perform pull-out tests on fibers and adhesive materials at different buried depths; 3. The mold with scales can accurately determine the fiber embedding depth; 4. The transparent organic glass material can clearly see the internal density and whether there are bubbles from all directions, and can be processed at any time during the pouring process to ensure the accuracy of the test; 5. The test bench with a notch can better complete the loading; 6. The sample demolding process is eliminated, which can better protect the integrity of the sample and ensure the fiber embedding thickness; 7. Multiple groups of parallel tests can be performed at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a fiber and bonding material pulling test device according to the present invention.

[0024] Figure 2 A stereoscopic diagram of a test bench of a fiber and bonding material pulling test device according to the present invention.

[0025] Figure 3 A stereoscopic diagram of a specimen mold box of a fiber and bonding material pulling test device of the present invention.

[0026] Figure 4 A side view of a test piece mold box of a fiber and bonding material pulling test device of the present invention.

[0027] Figure 5 A side view of a fiber fixing bracket of a fiber and bonding material pulling test device of the present invention.

[0028] Figure 6 A schematic diagram of a fiber fixing bracket of a fiber and bonding material pulling test device of the present invention.

[0029] Figure 7 Application diagram of a fiber and bonding material pulling test device of the present invention.

[0030] In the figure: 1. test bench, 11. through slot, 2. specimen mold box, 21. specimen mold slot, 22. small hole, 23. L-shaped baffle, 24. fixing clip, 3. fiber fixing bracket, 31. suction cup, 32. fixing device, 33. clamp. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 As shown, a fiber and adhesive material pulling test device, the device comprises:

[0033] The test bench 1 is provided with a through slot 11, for loading the fiber can pass through the through slot 11, such as Figure 2 shown.

[0034] The specimen mold box 2; the specimen mold box 2 includes: Figure 3 As shown, the specimen mold groove 21 is composed of five transparent materials, and there is no baffle on the top, which is convenient for adjusting the internal glue material. In this embodiment, the transparent material is glass as a component of the specimen mold groove 21, an L-shaped baffle 23 is arranged in the specimen mold 21 and its position can be changed in the specimen mold groove 21, and a fixing clamp 24 for fixing the L-shaped baffle 23; the L-shaped baffle 23 divides the specimen mold groove 21 into two spaces, a rectangular space and a non-rectangular space; wherein a surface of the L-shaped baffle 23 in the rectangular space and a surface of the specimen mold groove 21 opposite to each other are provided with a plurality of small holes 22 corresponding to each other; the direction of the line connecting each two corresponding small holes 22 is horizontal; each fiber passes through a corresponding group of small holes 22, and each fiber is parallel to the horizontal plane.

[0035] The L-shaped baffle 23 is used to control the thickness of the cementing material. Figure 4 As shown, the upper and lower horizontal directions of the L-shaped baffle 23 are provided with scales, which are used in conjunction with the upper and lower scales of the specimen mold groove 21, and the principle of a vernier caliper is adopted to accurately determine the thickness of the cementing material. The thickness of the cementing material is made uniform by controlling the upper and lower scales; when the L-shaped baffle 23 is moved to the required position, the fixing clamp 24 set on the L-shaped baffle 23 is tightened to lock the L-shaped baffle 23 and the specimen mold groove 21, ensuring that the L-shaped baffle 23 will not slide at will during the process of pouring the cementing material. When the L-shaped baffle 23 needs to be moved, the fixing clamp 24 can be loosened to allow the L-shaped baffle 23 to move at will.

[0036] Fiber fixing bracket 3; the fiber fixing bracket 3 is used in pairs, one is arranged in a non-rectangular space of the two spaces divided by the L-shaped baffle 23 and the specimen mold groove 21, and the other is arranged outside the specimen mold groove 21; the fiber passes through the small holes 22 on the L-shaped baffle 23 and the specimen mold groove 21, and the two ends are respectively arranged on the fiber fixing bracket 3. Figure 5 As shown, the fiber fixing bracket 3 comprises: a plurality of parallel columns, each column is equipped with a fixing device 32 that can move up and down, each fixing device is equipped with a clip 33, a crossbeam for fixing the plurality of columns, and a suction cup 31 arranged under the measurement. Figure 6 As shown, the spacing between the plurality of parallel columns is equal. In this embodiment, the suction cup 31 serves as a fixing bracket to keep the fiber in a horizontal and straight state when the fiber fixing bracket 3 is used; the fixing device 32 can adjust the height of the clip 33 by moving up and down to keep the fiber in a horizontal direction; the clip 33 is used to fix and straighten the fiber. In this embodiment, ten columns are arranged in a row in the horizontal direction, and the horizontal spacing is consistent with the horizontal spacing of the small holes 22 on the specimen mold box 2.

[0037] A test method for a fiber and bonding material pulling test device, the method comprising the following steps:

[0038] Step 1: Place the specimen mold box 2 on the test bench 1, observe the scales above and below the L-shaped baffle 23 and the specimen mold groove 21, and adjust the position of the L-shaped baffle 23 in the specimen mold groove 21; after determining the type and thickness of the injected material, fix the L-shaped baffle 23 with the fixing clamp 24 above the L-shaped baffle 23.

[0039] Step 2: Pass a single fiber or a fiber bundle through the specimen mold groove 21 and the small hole 22 on the L-shaped baffle 23, leaving a certain length at both ends as required to facilitate adding a counterweight at one end of the fiber during subsequent testing.

[0040] Step three: Place a pair of fiber fixing brackets 3 on the outside of the specimen mold groove 21 and the outside of the L-shaped baffle 23, that is, inside the non-rectangular space. After the suction cup 31 of the fiber fixing bracket 3 is fixed, adjust the height of the fixing device 33 to straighten the fiber filaments or fiber bundles and keep them in a horizontal state, and fix them with clips 33. In this embodiment, the heights of the fixing devices 33 of the pair of fiber fixing brackets 3 are consistent.

[0041] Step 4: inject the cementing material. After the cementing material fills the rectangular space, start curing, which can be covered with plastic sheet or watered. After three days, remove the pair of fiber fixing brackets 3.

[0042] Step 5: Rotate the specimen mold box 2 90 degrees counterclockwise. Figure 7As shown, the fiber or fiber bundle is aligned with the through slot 11 on the test bench 1, the fiber or fiber bundle is exposed from the through slot 11, and a counterweight is loaded on the end of the exposed fiber or fiber bundle, thereby realizing a test method of a fiber and adhesive material pulling test device.

Claims

1. A test method based on a fiber and bonding material pull-out test device, characterized in that: The device includes: The test bench is provided with a through slot; A specimen mold box; the specimen mold box comprises: a specimen mold slot made of five transparent materials, an L-shaped baffle disposed in the specimen mold slot and capable of changing its position in the specimen mold slot, and a fixing clamp for fixing the L-shaped baffle; the L-shaped baffle divides the specimen mold slot into two spaces, wherein a plurality of small holes corresponding to each other are arranged on one side of the L-shaped baffle and the corresponding specimen mold slot in the rectangular space; the connecting direction of each two corresponding small holes is horizontal; scale values ​​are arranged on the surfaces of the specimen mold slot and the L-shaped baffle in the same direction parallel to the fiber; Fiber fixing bracket; the fiber fixing bracket is used in pairs, one is arranged in a non-rectangular space of the two spaces divided by the L-shaped baffle plate and the specimen mold groove, and the other is arranged outside the specimen mold groove; the fiber passes through the small holes on the L-shaped baffle plate and the specimen mold groove, and the two ends are respectively arranged on the fiber fixing bracket; the fiber fixing bracket comprises: a plurality of parallel columns, each column is equipped with a fixing device that can move up and down, each fixing device is equipped with a clip, a beam that fixes a plurality of columns, and a suction cup arranged under the beam; The method comprises the following steps: Step 1: Place the specimen mold box on the test bench, observe the scales above and below the L-shaped baffle and the specimen mold slot, and adjust the position of the L-shaped baffle in the specimen mold slot; fix the L-shaped baffle with a fixing clip above the L-shaped baffle; Step 2: Pass a single fiber or a fiber bundle through the small holes on the specimen mold groove and the L-shaped baffle, leaving a certain length at both ends as required; Step 3: Place a pair of fiber fixing brackets on the outside of the specimen mold groove and the L-shaped baffle respectively, and after the suction cups are fixed, adjust the height of the fixing device to straighten the fiber filaments or fiber bundles and keep them in a horizontal state, and fix them with clips; Step 4: injecting the cementing material, and after the cementing material fills the rectangular space, curing begins, and after three days, the fiber fixing bracket is removed; Step 5: Rotate the specimen mold box 90 degrees counterclockwise, align the fiber with the through slot, expose it from the through slot, load a counterweight, and implement a test method for a fiber and bonding material pull-out test device.

2. The test method according to claim 1, characterized in that The spacings between the plurality of parallel columns are equal.

3. The test method according to claim 1, characterized in that: The length of the through slot on the test bench is greater than the length of the fiber fixing bracket.

4. The test method according to claim 1, characterized in that: The five transparent surfaces of the specimen mold groove are made of glass.

5. The test method according to claim 1, characterized in that: In the step 3, the height of each fiber filament in the stretched fiber bundle is the same.

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