Test device and evaluation method for shear resistance of concrete-corrugated steel plate-steel bar coupling bonding interface

Abstract

A shear resistance testing device for a concrete-corrugated steel plate-reinforcing steel bar coupling bonding interface comprises a self-balancing concrete pier, outer side concrete piers are vertically arranged at the left end and the right end of the self-balancing concrete pier, and corrugated steel plates are arranged on the opposite sides of the two outer side concrete piers; a core concrete pier is connected between the two corrugated steel plates, the core concrete pier is parallel to the self-balancing concrete pier, a gap is reserved between the core concrete pier and the self-balancing concrete pier, the upper end of the core concrete pier is higher than the outer side concrete pier, the upper ends of the corrugated steel plates are flush with the core concrete pier, and the lower ends of the corrugated steel plates are flush with the outer side concrete pier. A steel tie penetrating through the left end and the right end of the core concrete pier is arranged in the core concrete pier, and the two ends of the steel tie vertically penetrate through the corresponding corrugated steel plates correspondingly and are located in the two outer side concrete piers correspondingly; the shear resistance of the concrete, the corrugated steel plate and the tie bar interface can be accurately measured and analyzed.

Description

Technical Field

[0001] The invention relates to the technical field of shear performance test of coupled bonding interfaces of different materials, and in particular to a shear performance test device and an evaluation method for a coupled bonding interface of concrete-corrugated steel plate-rebar. Background Art

[0002] As modern construction projects have increasingly higher requirements for structural safety, durability and economy, the combination of concrete and composite materials such as steel has been widely used in many projects. In engineering practice, the concrete-corrugated steel plate-rebar coupling structure is widely used to achieve lightweight prefabricated structures, especially bridge piers and other structures.

[0003] In these composite structures, the coupling interface performance between concrete and steel bars, corrugated steel plates and other materials has an important impact on the shear resistance, durability and safety of the structure. Especially during the stress process, the bonding interface between concrete and steel bars and steel plates is subjected to a complex stress state. How to accurately evaluate the shear resistance of this interface is an important issue to ensure the safety and durability of the structure.

[0004] At present, many studies have shown that the bonding performance of concrete with steel bars, corrugated steel plates, etc. has a significant impact on its overall shear capacity and mechanical behavior. However, due to the uneven distribution of interfacial bonding force, the complexity of the interface state, and the nonlinear characteristics of the material, traditional test methods often cannot fully and accurately evaluate the performance of these materials under complex load conditions in actual engineering. Existing test devices are mostly focused on single materials or simple interface structures, and lack a comprehensive evaluation method for the coupling interface between concrete and steel plates and steel bars under complex shear loads. Therefore, there is an urgent need for a new type of test device that can more accurately simulate the real mechanical behavior of the coupling interface between concrete and corrugated steel plates, steel bars, etc., especially the bonding performance under shear. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a shear performance test device and evaluation method for the concrete-corrugated steel plate-rebar coupled bonding interface, which is used to solve the technical problem that the shear performance of the concrete and steel plate, steel bar coupled interface cannot be fully and accurately evaluated.

[0006] To achieve the above-mentioned purpose, the present invention provides a shear performance test device for a coupled bonding interface of concrete-corrugated steel plate-rebar, comprising a self-balancing concrete pier, wherein both left and right ends of the self-balancing concrete pier are vertically provided with outer concrete piers, the two outer concrete piers are parallel to each other, and corrugated steel plates are provided on opposite sides thereof, and the axial direction of the corrugated steel plates is perpendicular to the self-balancing concrete pier; a core concrete pier is connected between the two corrugated steel plates, the core concrete pier is parallel to the self-balancing concrete pier and a spacing L is left, the upper end of the core concrete pier is higher than the outer concrete pier, the upper end of the corrugated steel plate is flush with the core concrete pier, and the lower end is flush with the outer concrete pier, and the left and right side walls of the core concrete pier match the shape of the corrugated steel plate; a tie steel bar is provided in the core concrete pier passing through its left and right ends, and the two ends of the tie steel bar respectively vertically pass through the corresponding corrugated steel plates, and the two ends are respectively located in the two outer concrete piers.

[0007] Optionally, there are multiple tie bars, which respectively correspond to the crests and troughs of the corrugated steel plate.

[0008] Optionally, there are 8 tie steel bars, and the 8 tie steel bars are distributed in three columns, the first column has 3 tie steels, the second column has 2 tie steels, and the third column has 3 tie steels. The tie steel bars in each column are connected to be parallel to the tie steel bars in the remaining columns, and the tie steel bars in adjacent columns are staggered in the horizontal direction.

[0009] Optionally, the spacing L is greater than 15 times the diameter of the tie steel bar and less than 20 times the diameter of the tie steel bar.

[0010] Optionally, a self-balancing pier steel bar is provided in the self-balancing concrete pier, and the self-balancing pier steel bar extends from the self-balancing concrete pier to the lower end of the outer concrete pier; the self-balancing concrete pier and the outer concrete pier are formed integrally.

[0011] Optionally, the angle between the top plane of the core concrete pier and the horizontal plane is less than 3°.

[0012] The present invention also provides a method for evaluating the shear performance of a concrete-corrugated steel plate-rebar coupled bonding interface, comprising:

[0013] Step 1: According to the coupled bonding interface in the design of the corrugated steel plate-concrete-steel composite structure to be tested, a test device as described above is prepared, and a test is performed based on the test device to obtain the value of the test shear resistance of the coupled bonding interface;

[0014] Step 2, calculating the value of theoretical shear resistance;

[0015] Step three, compare the value of the test shear resistance with the value of the theoretical shear resistance. If the error is less than 10%, it is considered that the test measurement result is accurate and there is no test error. If the error is greater than 10%, it is recommended to repeat the test. If the result of the repeated test is still greater than 10%, the test result shall prevail.

[0016] Furthermore, the expression for calculating the theoretical shear resistance is:

[0017]

[0018] Among them, F 抗 is the shear resistance of the concrete-corrugated steel plate-rebar coupled bonding interface theory; α is the safety factor; f c is the compressive strength of concrete; f y b is the tensile strength of the tie steel bar; n is the width of the nth cleavage interface, u is the number of cleavage interfaces, h n is the height of the nth cleavage interface; A s,i is the area of ​​the ith tie steel bar, and m is the total number of tie steel bars.

[0019] Further, the process of testing the test device includes:

[0020] Place the test device on the pressure testing machine, place a steel pad on the top of the test device, place a pressure sensor on the top of the steel pad, and the upper end of the pressure sensor is in contact with the working end of the pressure testing machine;

[0021] Spread fine sand between the contact gaps between the steel plate, the test device, the pressure sensor and the pressure testing machine;

[0022] Start the pressure testing machine;

[0023] Record the reading of the pressure sensor and take the maximum reading of the pressure sensor as the value of the test shear resistance.

[0024] The beneficial effects of the present invention are as follows: the outer concrete pier and the self-balancing concrete pier of the present invention jointly support the core concrete pier, and the connection method of the outer concrete pier, tie steel bars and corrugated steel plates of the present invention can simulate the stress conditions of the coupled bonding interface of three different materials, and is used to test the shear resistance of the coupled bonding interface. The test device of the present invention can accurately measure and analyze the shear resistance of the interface between concrete and corrugated steel plates and tie steel bars under the action of actual shear force by improving the test layout and loading method, especially the mechanical response in terms of interface bonding strength, slippage, peeling, etc. Compared with traditional test methods, this device has higher accuracy and applicability, can simulate more complex interface behaviors, and provide important experimental data support for the design and optimization of concrete and steel composite structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of one viewing angle of an embodiment of the present invention;

[0026] Figure 2 A schematic structural diagram of another perspective of an embodiment of the present invention;

[0027] Figure 3 A schematic diagram showing a tie steel bar and a self-balancing pier steel bar and their related structures as viewed from the front side in an embodiment of the present invention (red represents the tie steel bar, and blue represents the self-balancing pier steel bar);

[0028] Figure 4 A schematic diagram showing a tie steel bar and a self-balancing pier steel bar and their related structures as viewed from the left side in accordance with an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the structure of an embodiment of the present invention in a test state;

[0030] Figure 6 A schematic diagram partially showing cracks in an outer concrete pier according to an embodiment of the present invention;

[0031] Description of reference numerals:

[0032] 1. Self-balancing concrete pier, 2. Outer concrete pier, 3. Corrugated steel plate, 4. Core concrete pier, 5. Tie steel bars, 6. Self-balancing pier steel bars, 7. YHD displacement meter, 8. Steel pad, 9. Pressure testing machine, 10. Pressure sensor, 11. Crack. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] It should be noted that the diagram provided in the present embodiment only illustrates the basic concept of the present invention in a schematic manner, so the diagram only shows the units related to the present invention rather than drawing according to the number, shape and size of the units during actual implementation. The pattern, quantity and ratio of each unit during actual implementation can be a random change, and its unit layout pattern may also be more complicated. The structure, ratio, size, etc. illustrated by the drawings in the present specification are only used to match the content disclosed in the specification, so that people familiar with this technology can understand and read, and are not used to limit the limiting conditions that the present invention can implement, so they have no technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that the present invention can produce and the purpose that can be achieved, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of narration, and are not used to limit the scope of the present invention. The change or adjustment of its relative relationship should also be regarded as the scope of the present invention without substantially changing the technical content.

[0035] Embodiment 1

[0036] like Figure 1-4 As shown, this embodiment provides a shear performance test device for a concrete-corrugated steel plate-rebar coupled bonding interface, comprising a self-balancing concrete pier 1, wherein both left and right ends of the self-balancing concrete pier 1 are vertically provided with outer concrete piers 2, the two outer concrete piers 2 are parallel to each other, and the opposite sides thereof are provided with corrugated steel plates 3, the axial direction of the corrugated steel plates 3 is perpendicular to the self-balancing concrete pier 1, the corrugated steel plates 3 are laid on the two opposite sides of the two outer concrete piers 2, and the corrugated steel plates 3 are tightly connected to the outer concrete piers 2, and the opposite sides of the two outer concrete piers 2 match the shape of the corrugated steel plates 3; the two corrugated steel plates 3 are connected A core concrete pier 4 is connected, the core concrete pier 4 is parallel to the self-balancing concrete pier 1 and there is a spacing L between them, the upper end of the core concrete pier 4 is higher than the outer concrete pier 2, the upper end of the corrugated steel plate 3 is flush with the core concrete pier 4, and the lower end is flush with the outer concrete pier 2, and the left and right side walls of the core concrete pier 4 match the shape of the corrugated steel plate 3; the core concrete pier 4 is provided with tie steel bars 5 passing through its left and right ends, the two ends of the tie steel bars 5 respectively vertically pass through the corresponding corrugated steel plates 3, and the two ends are distributed in the two outer concrete piers 2 to ensure the coupling effect between different material structures.

[0037] Before the test of the device of this embodiment is carried out, first, the test device as described above is cast and placed on the base of the pressure testing machine 9, as shown in FIG. Figure 5As shown, a steel pad 8 is placed on the top of the test device, and the steel pad 8 is used to convert the load of the pressure test machine 9 into a uniformly distributed load; a pressure sensor 10 is placed above the steel pad 8, and the upper end of the pressure sensor 10 contacts the working end of the pressure test machine 9. Fine sand is laid between the gaps between the steel pad 8, the test device, the pressure sensor 10 and the pressure test machine 9 to fill the gaps. Then, YHD displacement meters 7 are respectively installed on the front and rear sides of the core concrete pier 4 to detect the vertical displacement of the core concrete pier 4 and whether the top surface of the core concrete pier 4 maintains vertical displacement on a horizontal plane. Next, the pressure test machine 9 is used to load the test device. During this process, the bottom surface of the core concrete pier 4 is pressed down to the top surface of the self-balancing concrete pier 1 by the pressure test machine 9, and the readings of the pressure sensor 10 and the YHD displacement meter 7 are recorded. The readings of the double YHD displacement meters 7 are controlled to ensure that the core pier is evenly pressed down to the top surface of the self-balancing bottom pier. The pressure test machine 9 in this example is a hydraulic jack. After the pressure tester 9 is pressed down, cracks 11 will appear at each row of the tie bars 5 in the outer concrete pier 2. Figure 6 shown.

[0038] The outer concrete pier 2 and the self-balancing concrete pier 1 described in the present invention jointly support the core concrete pier 4. The connection method of the outer concrete pier 2, the tie steel bars 5 and the corrugated steel plate 3 described in the present invention can simulate the stress conditions of the coupled bonding interface of three different materials, and is used to test the shear resistance of the coupled bonding interface.

[0039] By improving the test layout and loading method, the test device of the present invention can accurately measure and analyze the shear resistance of the interface between concrete and the corrugated steel plate 3 and the tie steel bar 5 under the action of actual shear force, especially the mechanical response in terms of interface bonding strength, slippage, peeling, etc. Compared with traditional test methods, the device has higher accuracy and applicability, can simulate more complex interface behaviors, and provide important experimental data support for the design and optimization of concrete and steel composite structures.

[0040] Furthermore, the reserved spacing L between the core concrete pier 4 and the self-balancing concrete pier 1 varies according to the diameter of the tie steel bar, and the spacing L is greater than 15 times the diameter of the tie steel bar 5 and less than 20 times the diameter of the tie steel bar 5 .

[0041] like Figure 3 and 4As shown, there are multiple tie bars 5, which correspond to the crests and troughs of the corrugated steel plate 3 respectively, and the tie bars 5 penetrate the continuous corrugations in the middle of the corrugated steel plate 3 respectively. The corrugated steel plate 3 is a generally trapezoidal wave structure. In this example, there are 8 tie bars 5, and the 8 tie bars 5 are distributed in three rows, the first row has 3 tie bars 5, the second row has 2 tie bars 5, and the third row has 3 tie bars 5. The tie bars 5 in each row are connected and parallel to the tie bars 5 in the remaining rows, and the tie bars 5 in adjacent rows are staggered in the horizontal direction. The tie bars 5 in each row penetrate different corrugations on the corrugated steel plate 3, that is, the tie bars 5 in the same row penetrate the same corrugation on the corrugated steel plate 3, and the tie bars 5 in different rows penetrate another corrugation on the corrugated steel plate 3.

[0042] In order to stabilize the supporting function of the self-balancing concrete pier 1, a self-balancing pier steel bar 6 is provided in the self-balancing concrete pier 1, and the self-balancing pier steel bar 6 extends from the self-balancing concrete pier 1 to the lower end of the outer concrete pier 2; the self-balancing concrete pier 1 and the outer concrete pier 2 are formed integrally.

[0043] Furthermore, the angle between the top plane of the core concrete pier 4 and the horizontal plane is less than 3°, which ensures the accuracy and reliability of the test process and results.

[0044] Embodiment 2

[0045] This embodiment provides a method for evaluating the shear performance of a concrete-corrugated steel plate-rebar coupled bonding interface, including:

[0046] Step 1: According to the coupled bonding interface in the design of the corrugated steel plate-concrete-steel composite structure to be tested, the test device described in Example 1 is prepared, and the test is performed based on the test device to obtain the test shear resistance value of the coupled bonding interface; the schematic diagram of the test device for testing is shown in Figure 5 As shown;

[0047] The testing process of the test device includes:

[0048] Place the test device on the pressure testing machine 9, place a steel pad 8 on the top of the test device, place a pressure sensor 10 above the steel pad 8, and the upper end of the pressure sensor 10 contacts the working end of the pressure testing machine 9;

[0049] Fine sand is laid between the contact gaps between the steel backing plate 8, the test device, the pressure sensor 10 and the pressure testing machine 9;

[0050] Start the pressure testing machine 9;

[0051] The reading of the pressure sensor 10 is recorded, and the maximum reading of the pressure sensor 10 is taken as the value of the test shear resistance.

[0052] Step 2, calculating the value of theoretical shear resistance;

[0053] First, according to the geometric structure of the test device, such as Figure 1-4 As shown in FIG6 , by measuring the geometric parameters at the crack 11, the splitting cross-sectional area S of the outer concrete pier 2 is determined. 混 , S 混 The calculation expression is:

[0054]

[0055] Among them, b n is the width of the nth cleavage interface, u is the number of cleavage interfaces, h n is the height of the nth cleavage interface.

[0056] The number of split interfaces is determined by the number of columns of tie bars 5. In the first embodiment, there are three columns of tie bars 5, that is, after the downward pressure is completed, three cracks 11 will be generated in the outer concrete pier 2, that is, u=3. Figure 6 shown.

[0057] Then, according to the configuration of the tie bars 5 on the test device, the cross-sectional area of ​​the tie bars 5 at the concrete-corrugated steel plate 3-tie bars 5 coupling bonding interface is determined to evaluate the contribution of the tie bars 5 to the shear performance. Here, it is considered that all tie bars 5 are fully bent during the shear process and provide resistance. The total cross-sectional area S of all tie bars 5 is 钢 The expression is:

[0058]

[0059] Among them, A s,i is the area of ​​the i-th tie steel bar 5, and m is the total number of the tie steel bars 5.

[0060] Next, based on the shear failure mode of the coupled bonding interface, a theoretical model of shear resistance is established. The relevant parameters of concrete, corrugated steel plate 3 and the tie steel bar 5 are substituted into the model, and a simplified calculation of shear resistance is performed based on the following formula:

[0061] F 抗 =α(F 混 +F 钢 )

[0062] F 混 =0.1f c S 混

[0063] F钢 =0.7f y S 钢

[0064] Combining the above formulas, we get:

[0065]

[0066] Among them, F 抗 F is the shear resistance of the coupled bonding interface theory of concrete-corrugated steel plate 3-tie steel bar 5; 混 F is the shear resistance provided by the self-balancing concrete pier 1 and the core concrete pier 4 for the coupling interface; 钢 is the shear resistance provided by the tie bar 5 for the coupling interface; α is the safety factor, and the recommended value is 0.95; f c is the compressive strength of concrete, using the value specified in the national standard; f y For the tensile strength of tie steel bars, the value specified in the national standard is adopted.

[0067] Step three, compare the shear resistance value measured by the test results with the value of the theoretical shear resistance. If the error is less than 10%, it is considered that the test measurement result is accurate and there is no test error. If the error is greater than 10%, it is recommended to repeat the test a certain number of times. If the result of the repeated test is still greater than 10%, the test result shall prevail.

[0068] This evaluation method is based on the shear failure mode of the coupled bonding interface, constructs a mechanical model and calculates it, and evaluates the reliability of the test results by combining numerical simulation with experimental data, that is, by comparing the errors between the test results and the theoretical results. Among them, the theoretical model of shear resistance established is suitable for calculating the shear performance of different types of concrete-steel coupled interfaces, has high accuracy and applicability, and can accurately measure and analyze the shear performance of the coupled interface of concrete, corrugated steel plate 3 and tie steel bar 5, especially in terms of mechanical responses such as interface bonding strength, slip, and peeling.

[0069] In addition, this method provides a basis for verifying the accuracy of the test results and provides a theoretical basis and calculation tools for further optimizing the design and construction. This innovation not only has important theoretical significance, but also provides an effective means for structural safety and reliability assessment in practical engineering applications.

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A shear performance test device for concrete-corrugated steel plate-rebar coupled bonding interface, characterized in that: It comprises a self-balancing concrete pier, wherein both left and right ends of the self-balancing concrete pier are vertically provided with outer concrete piers, the two outer concrete piers are parallel to each other, and the opposite sides thereof are provided with corrugated steel plates, and the axial direction of the corrugated steel plates is perpendicular to the self-balancing concrete pier; a core concrete pier is connected between the two corrugated steel plates, the core concrete pier is parallel to the self-balancing concrete pier and a spacing L is left, the upper end of the core concrete pier is higher than the outer concrete pier, the upper end of the corrugated steel plate is flush with the core concrete pier, and the lower end is flush with the outer concrete pier, and the left and right side walls of the core concrete pier match the shape of the corrugated steel plate; the core concrete pier is provided with tie steel bars passing through its left and right ends, and the two ends of the tie steel bars respectively pass through the corresponding corrugated steel plates vertically, and the two ends are respectively located in the two outer concrete piers.

2. The device according to claim 1, characterized in that There are a plurality of tie steel bars, which respectively correspond to the crests and troughs of the corrugated steel plate.

3. The device according to claim 2, characterized in that There are 8 tie steel bars, which are distributed in three columns. The first column has 3 tie steel bars, the second column has 2 tie steel bars, and the third column has 3 tie steel bars. The tie steel bars in each column are connected and are parallel to the tie steel bars in the remaining columns. The tie steel bars in adjacent columns are staggered in the horizontal direction.

4. The device according to claim 1, characterized in that The spacing L is greater than 15 times the diameter of the tie steel bar and less than 20 times the diameter of the tie steel bar.

5. The device according to claim 1, characterized in that The self-balancing concrete pier is provided with self-balancing pier steel bars, which extend from the self-balancing concrete pier to the lower end of the outer concrete pier; the self-balancing concrete pier and the outer concrete pier are formed in one piece.

6. The device according to claim 1, characterized in that The angle between the top plane of the core concrete pier and the horizontal plane is less than 3°.

7. A method for evaluating the shear performance of a concrete-corrugated steel plate-rebar coupled bonding interface, characterized in that: include: Step 1: According to the coupled bonding interface in the design of the corrugated steel plate-concrete-steel composite structure to be tested, a test device as described in any one of claims 1 to 6 is prepared, and a test is performed based on the test device to obtain the test shear resistance value of the coupled bonding interface; Step 2, calculating the value of theoretical shear resistance; Step three, compare the value of the test shear resistance with the value of the theoretical shear resistance. If the error is less than 10%, it is considered that the test measurement result is accurate and there is no test error. If the error is greater than 10%, it is recommended to repeat the test. If the result of the repeated test is still greater than 10%, the test result shall prevail.

8. The method according to claim 7, characterized in that The expression for calculating the theoretical shear resistance is: Among them, F 抗 is the shear resistance of the concrete-corrugated steel plate-rebar coupled bonding interface theory; α is the safety factor; f c is the compressive strength of concrete; f y b is the tensile strength of the tie steel bar; n is the width of the nth cleavage interface, u is the number of cleavage interfaces, h n is the height of the nth cleavage interface; A s,i is the area of ​​the ith tie steel bar, and m is the total number of tie steel bars.

9. The method according to claim 7, characterized in that: The process of testing the test device includes: Place the test device on the pressure testing machine, place a steel pad on the top of the test device, place a pressure sensor on the top of the steel pad, and the upper end of the pressure sensor is in contact with the working end of the pressure testing machine; Spread fine sand between the contact gaps between the steel plate, the test device, the pressure sensor and the pressure testing machine; Start the pressure testing machine; Record the reading of the pressure sensor and take the maximum reading of the pressure sensor as the value of the test shear resistance.

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