A test device for testing the interface bond slip between trc and concrete flexural members

Abstract

The utility model discloses a TRC and concrete flexural member interface bonding slip test device, including flexural member, slip monitoring device, TRC reinforcing layer and distributed fiber bragg grating sensor, slip monitoring device includes center support, displacement meter fixed support and displacement detection subassembly, displacement detection subassembly is divided into displacement detection subassembly one and displacement detection subassembly two, and displacement detection subassembly one is used for detecting the tensile deformation of flexural member at the bonding interface, and displacement detection subassembly two is used for detecting the tensile deformation of TRC reinforcing layer, TRC reinforcing layer includes cement base and fiber braided net, and distributed fiber bragg grating sensor is connected with fiber braided net, and is used for detecting the strain value of TRC reinforcing layer. The test device of the application can comprehensively consider the interface bonding performance under the joint action of bonding normal stress and bonding shear stress, so that the test data is more accurate.

Description

Technical Field

[0001] This utility model mainly relates to the field of bond-slip performance testing technology for reinforced concrete, specifically to a bond-slip testing device for the interface between TRC and concrete flexural members. Background Technology

[0002] With the increasing service life of buildings, environmental corrosion, material aging, and the effects of natural disasters, the mechanical properties of concrete structures gradually decline. Based on economic and environmental considerations, reinforcement and repair measures are prioritized over reconstruction. Currently, carbon fiber reinforced polymer (FRP) has become the mainstream technology for building structure reinforcement. However, due to the poor high-temperature resistance and corrosion resistance of FRP, its application in complex environments is significantly limited. Textile reinforced concrete (TRC) reinforcement technology, as a new reinforcement method following FRP reinforcement, is receiving widespread attention. Compared to FRP reinforcement, TRC reinforcement technology has stronger corrosion resistance, high-temperature resistance, and environmental adaptability, while also exhibiting good compatibility with concrete materials, making it a promising candidate for engineering reinforcement.

[0003] In the practical application of TRC reinforcement technology, the bond performance between the reinforcement layer and the concrete member directly determines the overall reinforcement effect, and good bond performance is key to ensuring their coordinated stress distribution. Insufficient interfacial bond performance may lead to reinforcement layer delamination failure, not only failing to restore the structural bearing capacity but also potentially causing secondary damage. Therefore, in-depth research on the bond performance between the TRC reinforcement layer and the reinforced member is particularly important. Currently, the main method for testing the bond performance between the TRC reinforcement layer and concrete is the pull-out test, which involves attaching strain gauges to the bonding interface and measuring the slip displacement at the loaded and free ends of the TRC reinforcement layer, plotting the bond-slip curve for analyzing the interfacial bond performance. However, traditional pull-out test methods have some shortcomings that may affect the accuracy of the test results, mainly in the following aspects: (1) Traditional pull-out tests only consider the stress in a single direction and ignore the influence of interfacial bonding normal stress caused by deflection. The bonding performance measured by this simplified test method differs from that in actual engineering.

[0004] (2) The interfacial bond stress in traditional pull-out tests is mainly measured by strain gauges. This method not only causes certain damage to the bond interface, but the strain gauges may also fail during the casting process of the specimen. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a test device for interfacial bond slip of TRC and concrete flexural members, which can comprehensively consider the interfacial bond performance under the combined action of bond normal stress and bond shear stress, so as to make the test data more accurate.

[0006] To solve the above-mentioned technical problems, the technical solution adopted in this application is: A test device for interfacial bond slip between TRC and concrete flexural members includes a test sample, a distributed fiber optic grating sensor, and a slip monitoring device.

[0007] The test sample includes a bending member and a TRC reinforcement layer disposed at the bottom of the bending member; at least one layer of fiber woven mesh is laid inside the TRC reinforcement layer.

[0008] Distributed fiber Bragg grating sensors are connected to a fiber braided mesh to detect the strain value of the TRC reinforcement layer.

[0009] The slip monitoring device includes a central support, a displacement gauge mounting bracket, and a displacement detection assembly.

[0010] The central support is set at the mid-span of the test sample; there are several displacement gauge holders, two of which are symmetrically set at the beginning and end of the test sample, and the remaining displacement gauge holders are symmetrically and evenly arranged on the test sample about the central support, with their arrangement spacing matching the grating spacing of the distributed fiber Bragg grating sensor.

[0011] Each displacement gauge mounting bracket is equipped with a displacement detection component, which is divided into displacement detection component one and displacement detection component two. Displacement detection component one is used to detect the tensile deformation of the bending member at the bonding interface, and displacement detection component two is used to detect the tensile deformation of the TRC reinforcement layer.

[0012] Preferably, the central support and each displacement gauge holder include two vertical rods and two fixing screws, which are connected to form a rectangular frame structure and fitted around the outer periphery of the sample to be tested.

[0013] Preferably, for each displacement gauge mounting frame, two sets of displacement detection components are symmetrically arranged front and back; two sets of displacement detection components are symmetrically arranged front and back.

[0014] Preferably, both displacement detection component one and displacement detection component two include a rope displacement meter and a fixed pulley.

[0015] The pull rope displacement gauge and the fixed pulley are longitudinally mounted on the displacement gauge mounting frame; the pull rope of the pull rope displacement gauge extends vertically, passes around the fixed pulley, and is connected to the adjacent displacement gauge mounting frame in the horizontal direction.

[0016] Preferably, in displacement detection component one, the horizontal height of the pull rope is consistent with the height of the bonding interface; in displacement detection component two, the horizontal height of the pull rope is consistent with the height at 1 / 2 of the thickness of the TRC reinforcement layer.

[0017] Preferably, the fixed pulley is longitudinally slidably mounted on the displacement gauge mounting bracket.

[0018] Preferably, the displacement gauge mounting bracket is provided with a longitudinal slide rail, and a slider is installed inside the slide rail, with one end of the slider connected to a fixed pulley.

[0019] Preferably, the end of the slider opposite to the fixed pulley is provided with a traction fixed end, which is threadedly connected to the threaded traction head of the opposite pull rope displacement meter.

[0020] Preferably, a longitudinal slide rail is provided on the central support, and a second slider is provided inside the slide rail. Traction fixing ends are symmetrically arranged on the left and right sides of the second slider, and the traction fixing ends are threadedly connected to the corresponding pull rope displacement meter threaded traction head.

[0021] Preferably, limit bolts are provided on slider one and slider two to fix the position of the sliders.

[0022] This utility model has the following beneficial effects: 1. This utility model comprehensively considers the interfacial bonding performance under the influence of bonding normal stress. Compared with traditional testing methods that only consider the force in one direction, its test results are more in line with the actual engineering situation. It can provide a reliable basis for the accurate application of TRC reinforcement technology in civil engineering and improve the accuracy of the evaluation of the reinforcement effect of reinforced concrete beams.

[0023] 2. By placing the distributed fiber optic grating sensor within the fiber braided mesh, the problems of damage to the bonding interface and easy failure of strain gauges caused by pasting strain gauges at the bonding interface in traditional testing methods are avoided. This ensures both the stability and reliability of the sensor and the integrity of the bond between the TRC reinforcement layer and the concrete beam specimen, resulting in more accurate test data.

[0024] 3. The cable displacement meter fixing device has a simple structure and is easy to operate. It is evenly arranged along the length of the concrete beam specimen, and the slider can be flexibly moved to the part to be measured and fixed. With the help of the fixed pulley, the traction direction of the cable displacement meter can be changed. It can conveniently and efficiently measure the tensile deformation of concrete beam specimens of different sizes and TRC reinforcement layers, which greatly improves the testing efficiency and flexibility. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the interface bonding and slip test device for TRC and concrete flexural members according to this application.

[0026] Figure 2 This is a schematic diagram of the displacement gauge fixing frame and central support structure of this application.

[0027] Figure 3 This is a schematic diagram of the slider structure of this application.

[0028] Figure 4 This is a schematic diagram of the slider structure of this application.

[0029] Figure 5 This is a schematic diagram of the structure of the drawstring displacement meter in this application.

[0030] Figure 6 This is a schematic diagram of the installation of the rope displacement gauge in this application.

[0031] Figure 7 This is a schematic diagram of the TRC reinforcement layer structure in this application.

[0032] Figure 8 This is a schematic diagram illustrating the measurement principle of this application.

[0033] Figure 9 This is a stress analysis diagram of the bonding interface in this application.

[0034] Figure 10 This is a schematic diagram of the measurement point layout for this application.

[0035] Figure 11 for Figure 1 Enlarged diagram of point A in the middle.

[0036] Figure 12 for Figure 1 Enlarged diagram of point B in the middle.

[0037] Among them are: 1. Bending members; 2. Slip monitoring device; 21. Displacement gauge mounting bracket; 22. Central support; 23. Displacement detection assembly; 24. Cable displacement gauge; 211. Nut; 212. Fixing screw; 213. Vertical rod; 221. Traction fixed end; 222. Sliding block; 223. Fixed pulley; 224. Limit bolt; 231. Threaded traction head; 232. Fixing buckle; 233. Fixing bolt; 3. TRC reinforcement layer; 31. Fiber woven mesh; 32. Cement-based; 4. Distributed fiber Bragg grating sensor. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0039] In the description of this utility model, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the protection scope of this utility model.

[0040] like Figures 1-12 As shown, a test device for interfacial bond slip between TRC and concrete flexural members includes a test sample, a distributed fiber optic grating sensor 4, and a slip monitoring device 2.

[0041] The test sample includes a bending member 1 and a TRC reinforcement layer 3. The TRC reinforcement layer 3 is disposed at the bottom of the bending member 1 to enhance its mechanical properties. The TRC reinforcement layer 3 includes a cement base 32 and an internal fiber woven mesh 31, with at least one layer of fiber woven mesh 31 laid inside the TRC reinforcement layer 3. During fabrication, the TRC reinforcement layer 3 is directly cast into the bottom of the bending member 1 using a cast-in-place method. The bending member 1 and the TRC reinforcement layer 3 have the same width.

[0042] The interface between the bending member 1 and the TRC reinforcement layer 3 is the bonding interface to be tested.

[0043] The distributed fiber Bragg grating sensor 4 is used to detect the strain value of the TRC reinforcement layer 3. The distributed fiber Bragg grating sensor 4 is connected to the fiber braided mesh 31 in the TRC reinforcement layer 3, and is connected to two bundles of fibers in the middle of the fiber braided mesh 31 near the bonding interface. The fibers are encapsulated by a winding molding process to encapsulate the distributed fiber Bragg grating sensor 4.

[0044] The slip monitoring device 2 includes a central support 22, a displacement gauge fixing frame 21, and a displacement detection component 23.

[0045] The central support 22 is set at the mid-span of the test sample; there are several displacement gauge fixing frames 21 (number n≥2), two of which are symmetrically set at the beginning and end of the test sample, and the remaining displacement gauge fixing frames 21 are symmetrically and evenly arranged on the test sample about the central support 22, and their arrangement spacing matches the grating spacing of the distributed fiber optic grating sensor 4.

[0046] The central support 22 and each displacement gauge mounting bracket 21 include two vertical rods 213 and two horizontally arranged fixing screws 212. The two vertical rods 213 and the two fixing screws 212 are connected to form a rectangular frame structure, which is fitted around the outer periphery of the test sample. Specifically, bolt holes are opened at both ends of each vertical rod 213, and the two vertical rods 213 are respectively set on the front and rear sides of the test sample; the fixing screws 212 are double-ended screws, and the two fixing screws 212 are respectively set at the top and bottom of the test sample. Both ends of each fixing screw 212 pass through the bolt holes of the vertical rods 213 and are locked with nuts 211, thereby fixing the displacement gauge mounting bracket 21 and the central support 22 to the test sample.

[0047] The two vertical rods 213 are connected by a fixing screw 212 and a nut 211, and the width can be flexibly adjusted to suit test samples of different sizes.

[0048] Each displacement gauge mounting bracket 21 is equipped with a displacement detection component 23. The displacement detection component 23 is divided into displacement detection component one and displacement detection component two. Displacement detection component one is used to detect the tensile deformation of the bending member 1 at the bonding interface, and displacement detection component two is used to detect the tensile deformation of the TRC reinforcement layer 3.

[0049] For each displacement gauge mounting bracket 21, two sets of displacement detection components are symmetrically arranged front and back, respectively on the front and rear vertical rods 213 of the displacement gauge mounting bracket; two sets of displacement detection components are symmetrically arranged front and back, also respectively on the front and rear vertical rods 213 of the displacement gauge mounting bracket.

[0050] Both displacement detection component one and displacement detection component two include a pull rope displacement meter 24 and a fixed pulley 223; the pull rope displacement meter 24 and the fixed pulley 223 are longitudinally arranged on the vertical rod 213 of the displacement meter fixing frame 21; the pull rope of the pull rope displacement meter 24 extends vertically, passes around the fixed pulley 223, and is connected to the vertical rod 213 of the adjacent displacement meter fixing frame 21 in the horizontal direction.

[0051] The horizontal height of the pull rope of displacement detection component one is consistent with the height of the bonding interface; the horizontal height of the pull rope of displacement detection component two is consistent with the height of the TRC reinforcement layer 3 at 1 / 2 thickness.

[0052] The fixed pulley 223 is longitudinally slidably mounted on the vertical rod 213 of the displacement gauge fixing frame 21. Specifically, each vertical rod 213 has a longitudinal slide rail, and a slider 222 is installed inside the slide rail. The slider 222 can slide freely along the slide rail inside the vertical rod 213. The slide rail is preferably a rectangular slide rail formed by hollowing out the inside of the vertical rod 213. Slide grooves are opened on the four sides of the vertical rod 213 where the slide rail is located. The slider 222 is preferably a cubic structure that matches the shape of the slide rail. The slider 222 is placed inside the slide rail. Slide keys are provided on the four sides of the slider 222, which are slidably connected to the slide grooves. Through the cooperation of the slide grooves and slide keys, the slider 222 can slide smoothly within the slide rail.

[0053] The slider 222 is also provided with a limit bolt 224, which can be used to fix the slider 222 at a specific measurement position.

[0054] Slider 222 can be divided into slider one and slider two according to its installation position. Slider one is set on the displacement gauge fixing frame 21; for the displacement gauge fixing frame 21 located at the starting end and the ending end, one end of slider one is connected to the fixed pulley 223, such as... Figure 3 As shown in Figure a; for the remaining displacement gauge mounting brackets 21, one end of its slider is connected to the fixed pulley 223, and the other end opposite to the fixed pulley 223 is also provided with a traction fixing end 221, which is used to connect with the threaded traction head 231 of the rope displacement gauge 24, as shown in Figure a. Figure 3 As shown in b.

[0055] Figure 11 The arrangement of the two displacement gauge holders 21 from left to right at the starting end of the test sample is shown. For the displacement gauge holder 21 at the starting end, the vertical rod 213 is provided with displacement detection component one and displacement detection component two from top to bottom, specifically, a pull rope displacement gauge 24, a slider one, a slider one and a pull rope displacement gauge 24 in sequence. The pull rope displacement gauge 24 is fixed to the vertical rod 213 by a fixing buckle 232 and a fixing bolt 233.

[0056] The cable displacement meter 24 of the displacement detection component 1 has a threaded traction head 231 that drives the cable to pass through the fixed pulley 223 of the lower slider 1, and then horizontally connects to the slider 1 on the adjacent displacement meter fixing frame 21 on the right. The left side of the slider 1 is provided with a traction fixing end 221, which is threadedly connected to the threaded traction head 231 of the cable displacement meter 24.

[0057] The cable displacement meter 24 of the displacement detection component 2 has a threaded traction head 231 that drives the cable to pass through the fixed pulley 223 of the upper slider 1, and then horizontally connects to the slider 1 on the adjacent displacement meter fixing frame 21 on the right. The left side of the slider 1 is provided with a traction fixing end 221, which is threadedly connected to the threaded traction head 231 of the cable displacement meter 24.

[0058] Figure 12 The specific configuration of the central support 22 is shown. The central support 22 is also provided with a longitudinal slide rail, and a slider 2 is provided inside the slide rail. Traction fixing ends 221 are symmetrically arranged on the left and right sides of the slider 2. The traction fixing ends 221 on the left and right sides are threadedly connected to the threaded traction heads 231 of the pull rope displacement gauges 24 opposite to them.

[0059] The displacement detection components 23 from the starting end of the test sample to the central support 22 are all set as above, and the displacement detection components 23 from the ending end of the test sample to the central support 22 are symmetrically set. The displacement detection components 23 convert the vertical direction of the rope displacement meter 24 to the horizontal direction by setting a fixed pulley 223, so that it can measure the tensile deformation of the bending member 1 and the TRC reinforcement layer 3.

[0060] The method of using this device is as follows: Step 1: Set the measuring points according to the size of the sample to be tested, and set the displacement gauge fixing brackets that match the number of measuring points. Assemble the central bracket 22 and each displacement gauge fixing bracket 21 and fix them on the sample to be tested.

[0061] Figure 10 The illustration shows the measurement point location arrangement of an embodiment of this application, which includes a total of 8 measurement points, 8 displacement gauge holders 21 and 1 central support 22. With the central support 22 as the center of symmetry, 4 measurement points are set on the right side and 4 displacement gauge holders 21 are fixed thereon, and 4 measurement points are set on the left side and 4 displacement gauge holders 21 are fixed thereon, so that the sample to be tested is evenly divided into 8 measurement zones.

[0062] Step 2: Adjust the position of the fixed pulley 223 on the slider 222, and then horizontally connect the threaded traction head 231 of the pull rope displacement meter 24 to the corresponding traction fixed end 221, so that the horizontal height of the pull rope of displacement detection component one is consistent with the height of the bonding interface; the horizontal height of the pull rope of displacement detection component two is consistent with the height of the TRC reinforcement layer 3 at 1 / 2 thickness.

[0063] Step 3: Place the assembled test device and the test sample on the universal testing machine, perform four-point bending loading, collect the readings of the tension rope displacement gauge 24 and the strain demodulator measurement information of the distributed fiber optic grating sensor 4 in real time, and plot the bond-slip constitutive curve.

[0064] The data collected at each measuring point are as follows: (1) Displacement detection component 1 collects the tensile deformation of bending member 1 at the bonding interface. Two sets of displacement detection components are set at the front and back of each displacement gauge fixing frame 21, which can measure two sets of data and take the average value as the final data.

[0065] (2) The displacement detection component 2 collects the tensile deformation of the middle of the TRC reinforcement layer 3. This is approximately equivalent to the tensile deformation of the TRC reinforcement layer 3 at the bonding interface; each displacement gauge fixture 21 is equipped with two sets of displacement detection components, which can measure two sets of data and take the average value as the final data.

[0066] (3) Distributed fiber optic grating sensor 4 collects strain values ​​of TRC reinforcement layer 3. , Let be the strain value at the i-th measuring point.

[0067] The method for determining the bond-slip constitutive curve is as follows: like Figures 8-9 As shown, the deformation measured at the bonding interface is approximately the tensile deformation of the concrete flexural member at the bonding interface, and the deformation measured in the middle of the TRC reinforcement layer is approximately the tensile deformation of the TRC reinforcement layer at the bonding interface. The difference in tensile deformation between the two is approximately the slip value of the bonding interface.

[0068] In the formula: This refers to the localized tensile deformation of the concrete beam specimen. For local tensile deformation of the TRC reinforcement layer, This represents the local slip value.

[0069] Total slip:

[0070]

[0071] In the formula: This represents the local slip value on the right side of the concrete beam specimen. This represents the local slip value on the left side of the concrete beam specimen. This represents the total slip value on the right side of the concrete beam specimen. This represents the total slip value on the left side of the concrete beam specimen.

[0072] like Figure 9 As shown, assuming the cementitious matrix only serves to bond and transfer stress, the interfacial bond stress is transferred to the fiber braided mesh through the cementitious matrix. The strain distribution along the bonding interface of the fiber braided mesh under each load level is measured by a distributed fiber optic grating sensor. The average bond stress is then calculated using the following formula:

[0073] In the formula: For local average bond stress, For fiber modulus, For fiber thickness, Let be the strain value at the i-th monitoring point. Spacing between adjacent monitoring points.

[0074]

[0075]

[0076] In the formula: The average bond stress at the right interface. The average bond stress at the left interface. The average bond stress is located on the right side. The average local bond stress on the left side. For the width of the bonding interface, This represents the area of ​​the bonding interface.

[0077] By plotting the slip value on the x-axis and the average interfacial bond stress on the y-axis, the interfacial bond-slip constitutive curve can be obtained.

[0078] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various equivalent transformations can be made to the technical solution of this application, and all such equivalent transformations fall within the protection scope of this application.

Claims

1. A test device for bond slip at the interface between TRC and concrete flexural members, characterized in that, This includes the test sample, a distributed fiber Bragg grating sensor, and a slip monitoring device; The test samples include bending members and a TRC reinforcement layer located at the bottom of the bending members; At least one layer of fiber woven mesh is laid inside the TRC reinforcement layer; A distributed fiber Bragg grating sensor is connected to a fiber braided mesh to detect the strain value of the TRC reinforcement layer; The slip monitoring device includes a central support, a displacement gauge mounting bracket, and a displacement detection assembly; The central support is set at the mid-span of the test sample; there are several displacement gauge holders, two of which are symmetrically set at the beginning and end of the test sample, and the remaining displacement gauge holders are symmetrically and evenly arranged on the test sample about the central support, with their arrangement spacing matching the grating spacing of the distributed fiber Bragg grating sensor. Each displacement gauge mounting bracket is equipped with a displacement detection component, which is divided into displacement detection component one and displacement detection component two. Displacement detection component one is used to detect the tensile deformation of the bending member at the bonding interface, and displacement detection component two is used to detect the tensile deformation of the TRC reinforcement layer.

2. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 1, characterized in that, The central support and each displacement gauge mounting bracket include two vertical rods and two fixing screws. The two vertical rods and two fixing screws are connected to form a rectangular frame structure, which is fitted around the outer periphery of the sample to be tested.

3. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 1, characterized in that, For each displacement gauge mounting frame, two sets of displacement detection components are symmetrically arranged front and back; two sets of displacement detection components are symmetrically arranged front and back.

4. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 1, characterized in that, Both displacement detection component one and displacement detection component two include a draw rope displacement meter and a fixed pulley; The pull rope displacement gauge and the fixed pulley are longitudinally mounted on the displacement gauge mounting frame; the pull rope of the pull rope displacement gauge extends vertically, passes around the fixed pulley, and is connected to the adjacent displacement gauge mounting frame in the horizontal direction.

5. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 4, characterized in that, The first displacement detection component has a horizontal rope height that matches the height of the bonding interface; the second displacement detection component has a horizontal rope height that matches the height at 1 / 2 the thickness of the TRC reinforcement layer.

6. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 4, characterized in that, The fixed pulley is longitudinally slidably mounted on the displacement gauge mounting bracket.

7. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 6, characterized in that, The displacement gauge mounting bracket is equipped with a longitudinal slide rail, and a slider is installed inside the slide rail. One end of the slider is connected to a fixed pulley.

8. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 7, characterized in that, The slider is provided with a traction fixed end at the end opposite to the fixed pulley, and the traction fixed end is threadedly connected to the threaded traction head of the opposite pull rope displacement gauge.

9. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 8, characterized in that, The central support is equipped with a longitudinal slide rail, and a second slider is installed inside the slide rail. Traction fixing ends are symmetrically arranged on the left and right sides of the second slider, and the traction fixing ends are threadedly connected to the corresponding pull rope displacement meter threaded traction head.

10. The test device for interfacial bond slippage between TRC and concrete flexural members according to claim 9, characterized in that, Limit bolts are provided on slider one and slider two to fix the position of the sliders.

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