Device for testing bonding characteristic of outer-layer fiber material and wall body interface and use method

Abstract

The invention discloses a device for testing the bonding characteristic of an outer-layer fiber material and a wall interface, which comprises a concentric-square-shaped loading block, the concentric-square-shaped loading block is provided with a T-shaped groove, a T-shaped connecting rod is arranged in the T-shaped groove, a loading rod is fixedly arranged at the bottom of the T-shaped groove, one end of the loading rod extends out of the T-shaped groove, the loading rod is connected with a fiber through a support plate, and the T-shaped connecting rod is connected with the T-shaped groove. The fiber is connected with the wall body, the reserved steel bar is connected to the wall body, the lower clamp of the loading tester clamps the reserved steel bar in the wall body, and the upper clamp clamps the T-shaped connecting rod. According to the device for testing the bonding property of the outer-layer fiber material and the wall interface, the bonding property test in a pure shearing mode and a shearing and stripping mixed mode can be carried out by changing the included angle theta, the testing device is simplified, and the consumption of a wall base material is reduced.

Description

Technical Field

[0001] The invention relates to a device for testing the bonding characteristics of an outer fiber material and a wall interface and a use method thereof, belonging to the field of testing. Background Art

[0002] When fiber materials are attached to wall substrates such as concrete, their different failure modes under external forces determine their bond strength. Common failure modes include shear failure and peeling failure. There is currently no standard experimental test device for evaluating bond strength. The most common ones are single shear, double shear and beam bending tests. However, the single shear test requires a separate loading system, and the double shear test and beam bending test require the processing of specially shaped specimens for loading. In addition, only one mode of loading can be performed, which has a great impact on the simplicity and repeatability of the test. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a device for testing the bonding properties between the outer fiber material and the wall interface. By changing the size of the angle θ, the bonding performance test can be carried out in pure shear mode and shear-peel mixed mode, which simplifies the test device and reduces the amount of wall substrate used.

[0004] Technical solution: In order to solve the above technical problems, the present invention provides a device for testing the bonding properties of the interface between the outer fiber material and the wall, including a circular loading block, the circular loading block is provided with a T-slot, a T-shaped connecting rod is installed in the T-slot, a loading rod is fixedly installed at the bottom of the T-slot, one end of the loading rod extends out of the T-slot, the loading rod is connected to the fiber through a support plate, the fiber is connected to the wall, and reserved steel bars are connected to the wall. The lower clamp of the loading tester clamps the reserved steel bars in the wall, and the upper clamp clamps the T-shaped connecting rod.

[0005] Preferably, the inner dimension of the annular loading block is 1.1-1.2 times the width of the T-shaped connecting rod beam, that is, the cavity width. An opening is provided on the upper part of the annular loading block, and the opening dimension is 1.1-1.2 times the diameter of the vertical rod of the T-shaped connecting rod.

[0006] Preferably, the vertical rod of the T-shaped connecting rod is fixed on the hydraulic servo testing machine, and the lower crossbeam is fixed to the upper part of the circular loading block with bolts.

[0007] Preferably, the loading rod has a rectangular cross-section, is slightly smaller than the inner size of the circular loading block, and is fixed to the lower part of the circular loading block with bolts.

[0008] Preferably, the support plate is a retractable plate.

[0009] Preferably, the support plate includes a fixed plate, a first movable plate and a second movable plate. The fixed plate is fixed on the loading rod, and a guide groove is provided on the fixed plate. Grooves are provided on both sides of the first movable plate and the second movable plate. The grooves move along the guide grooves, and the tops of the guide grooves are flush with the upper surfaces of the first movable plate and the second movable plate.

[0010] Preferably, a pressing plate is provided on the back of the fixed plate. When the first movable plate and the second movable plate are adjusted to appropriate positions, the pressing plate is fixed by bolts, thereby locking the first movable plate and the second movable plate.

[0011] A method for using the above-mentioned device for testing the bonding properties between the outer fiber material and the wall comprises the following steps:

[0012] S1: Prepare prismatic wall blocks and reserve steel bars with a diameter of no less than 16 mm inside the prisms. Grind and decontaminate the wall surface to achieve CP2 roughness grade.

[0013] S2: Use epoxy resin to stick the two ends of the fiber material to the two sides of the prism, leaving 20mm at the end of the prism unbonded with the fiber;

[0014] S3: Paste the linear variable displacement sensor LVDT on the loading end of the fiber surface;

[0015] S4: Assemble the test device and insert it into the U-shaped fiber;

[0016] S5: The lower clamp of the loading test machine clamps the steel bars reserved in the wall, and the upper clamp clamps the vertical rod of the T-shaped connecting rod.

[0017] S6: Adjust the support plate length. When the unbonded portion of the fiber is parallel to the side of the prism, the loading mode is pure shear, and the LVDT measurement indicates the relative slip between the fiber and the prism. When the angle between the unbonded portion and the side of the prism is θ, the loading mode is a combined shear and peel mode, and the displacement reading on the loading tester indicates the relative slip between the fiber and the prism. The relationship between slip and the tester load can be used to determine the bonding performance of the fiber to the wall.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The test device can be used on any servo hydraulic load testing machine, and loading is convenient;

[0020] (2) By changing the angle θ, the bonding performance test can be carried out in pure shear mode and shear-peel mixed mode, which simplifies the test device and reduces the amount of wall base material used;

[0021] (3) The effects of different size ratios of the substrate can be tested by simply adjusting the fiber pasting size, and there is no size restriction on the loaded specimen, which makes it easier to calculate different specimen sizes specified in different standards, specifications and / or codes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention.

[0023] Figure 2 Schematic diagram of the wall.

[0024] Figure 3 For different loading modes.

[0025] Figure 4 Schematic diagram of the structure of the support plate.

[0026] In the figure: 1. circular loading block, 2. T-shaped connecting rod, 3. loading rod, 4. bolt, 5. roller, 6. roller shaft, 7. fiber, 8. wall, 9. reserved steel bar, 11. first movable plate, 12. fixed plate, 13. second movable plate. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] like Figures 1 to 3 As shown, the present invention is a device for testing the bonding properties of the interface between the outer fiber material and the wall, including a circular loading block, the circular loading block is provided with a T-slot, a T-shaped connecting rod is installed in the T-slot, a loading rod is fixedly installed at the bottom of the T-slot, one end of the loading rod extends out of the T-slot, the loading rod is connected to the fiber through a support plate, the fiber is connected to the wall, and reserved steel bars are connected to the wall, the lower clamp of the loading tester clamps the reserved steel bars in the wall, and the upper clamp clamps the T-shaped connecting rod.

[0029] In the present invention, the inner dimension of the circular loading block is 1.1-1.2 times the width of the T-shaped connecting rod beam, and an opening is provided on the upper part of the circular loading block, and the opening dimension is 1.1-1.2 times the diameter of the T-shaped connecting rod vertical rod.

[0030] In the present invention, the vertical rod of the T-shaped connecting rod is fixed on the hydraulic servo testing machine, and the lower crossbeam is fixed to the upper part of the circular loading block with bolts.

[0031] In the present invention, the loading rod has a rectangular cross section, a size slightly smaller than the inner size of the circular loading block, and is fixed to the lower part of the circular loading block with bolts.

[0032] In the present invention, the support plate is a retractable plate.

[0033] In the present invention, the support plate includes a fixed plate, a first movable plate and a second movable plate. The fixed plate is fixed on the loading rod, and a guide groove is provided on the fixed plate. Grooves are provided on both sides of the first movable plate and the second movable plate. The grooves move along the guide grooves, and the tops of the guide grooves are flush with the upper surfaces of the first movable plate and the second movable plate.

[0034] In the present invention, a pressing plate is provided on the back of the fixed plate. When the first movable plate and the second movable plate are adjusted to appropriate positions, the pressing plate is fixed by bolts, thereby locking the first movable plate and the second movable plate.

[0035] A method for using the above-mentioned device for testing the bonding properties between the outer fiber material and the wall comprises the following steps:

[0036] S1: Prepare prismatic wall blocks and reserve steel bars with a diameter of no less than 16 mm inside the prisms. Grind and decontaminate the wall surface to achieve CP2 roughness grade.

[0037] S2: Use epoxy resin to stick the two ends of the fiber material to the two sides of the prism, leaving 20mm at the end of the prism unbonded with the fiber;

[0038] S3: Paste the linear variable displacement sensor LVDT on the loading end of the fiber surface;

[0039] S4: Assemble the test device and insert it into the U-shaped fiber;

[0040] S5: The lower clamp of the loading test machine clamps the steel bars reserved in the wall, and the upper clamp clamps the vertical rod of the T-shaped connecting rod.

[0041] S6: Adjust the support plate length. When the unbonded portion of the fiber is parallel to the side of the prism, the loading mode is pure shear, and the LVDT measurement indicates the relative slip between the fiber and the prism. When the angle between the unbonded portion and the side of the prism is θ, the loading mode is a combined shear and peel mode, and the displacement reading on the loading tester indicates the relative slip between the fiber and the prism. The relationship between slip and the tester load can be used to determine the bonding performance of the fiber to the wall.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for testing the bonding properties between an outer fiber material and a wall, characterized by: It includes a circular loading block, which is provided with a T-shaped slot, a T-shaped connecting rod is installed in the T-shaped slot, a loading rod is fixedly installed at the bottom of the T-shaped slot, one end of the loading rod extends out of the T-shaped slot, the loading rod is connected to the fiber through a support plate, the fiber is connected to the wall, and reserved steel bars are connected to the wall. The lower clamp of the loading tester clamps the reserved steel bars in the wall, and the upper clamp clamps the T-shaped connecting rod.

2. The device for testing the bonding properties between the outer fiber material and the wall according to claim 1, characterized in that: The inner dimension of the circular loading block is 1.1-1.2 times the width of the T-shaped connecting rod beam. An opening is provided on the upper part of the circular loading block, and the opening dimension is 1.1-1.2 times the diameter of the T-shaped connecting rod vertical rod.

3. The device for testing the bonding properties between the outer fiber material and the wall according to claim 1, characterized in that: The vertical rod of the T-shaped connecting rod is fixed on the hydraulic servo testing machine, and the lower crossbeam is fixed to the upper part of the circular loading block with bolts.

4. The device for testing the bonding properties between the outer fiber material and the wall according to claim 1, characterized in that: The loading rod has a rectangular cross section, is slightly smaller than the inner size of the circular loading block, and is fixed to the lower part of the circular loading block with bolts.

5. The device for testing the bonding properties between the outer fiber material and the wall according to claim 1, characterized in that: The support plate is a retractable plate.

6. The device for testing the bonding properties between the outer fiber material and the wall according to claim 1, characterized in that: The support plate includes a fixed plate, a first movable plate and a second movable plate. The fixed plate is fixed on the loading rod. A guide groove is provided on the fixed plate. Grooves are provided on both sides of the first movable plate and the second movable plate. The grooves move along the guide grooves, and the tops of the guide grooves are flush with the upper surfaces of the first movable plate and the second movable plate.

7. The device for testing the bonding properties between the outer fiber material and the wall according to claim 6, characterized in that: A pressing plate is provided on the back of the fixed plate. When the first movable plate and the second movable plate are adjusted to appropriate positions, the pressing plate is fixed by bolts, thereby locking the first movable plate and the second movable plate.

8. A method for using the device for testing the bonding properties of the interface between an outer fiber material and a wall according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: Prepare prismatic wall blocks and reserve steel bars with a diameter of no less than 16 mm inside the prisms. Grind and decontaminate the wall surface to achieve CP2 roughness grade. S2: Use epoxy resin to stick the two ends of the fiber material to the two sides of the prism, leaving 20mm at the end of the prism unbonded with the fiber; S3: Paste the linear variable displacement sensor LVDT on the loading end of the fiber surface; S4: Assemble the test device and insert it into the U-shaped fiber; S5: The lower clamp of the loading test machine clamps the steel bars reserved in the wall, and the upper clamp clamps the vertical rod of the T-shaped connecting rod. S6: Adjust the length of the support plate. When the unbonded portion of the fiber is parallel to the side of the prism, it is a pure shear loading mode, and the LVDT measurement result is the relative slip between the fiber and the prism. When the angle between the unbonded portion of the fiber and the side of the prism is θ, it is a shear and peeling composite loading mode, and the displacement reading of the loading test machine is the relative slip between the fiber and the prism. The bonding performance between the fiber and the wall can be determined based on the relationship between the slip amount and the test machine load.

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