Method and device for calculating the bond-slip of lightweight ultra-high performance concrete and steel reinforcement

Abstract

The application provides a lightweight super high-performance concrete and steel bar bonding slip calculation method and device, comprising: determining a preset number of pull-out test pieces according to test piece parameters; respectively performing pull-out tests on each pull-out test piece, obtaining a target bonding slip curve of the lightweight super high-performance concrete and the steel bar according to all pull-out test results; and setting a bonding slip curve model and a preset number of function relationship formulas according to the target bonding slip curve, and calculating a bonding slip curve of a to-be-tested pull-out test piece. Through the pull-out tests on the preset number of pull-out test pieces, the bonding slip curve model and the function relationship formulas are set, so that when the to-be-tested pull-out test piece is used subsequently, the bonding slip curve of the pull-out test piece is obtained through the bonding slip curve model and the function relationship formulas, the bonding performance is obtained, and the pull-out test piece does not need to be tested again, the processing process of the pull-out test piece is reduced, and the promotion and application of the concrete structure are improved.

Description

Technical Field

[0001] This invention relates to the technical field of calculating bond slip between concrete and reinforcing steel, and specifically to a method and apparatus for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel. Background Technology

[0002] The type of concrete has a significant impact on the bond performance between steel reinforcement and concrete. Domestic and international scholars have conducted extensive experimental research and theoretical analysis on the bond performance between steel reinforcement and different types of concrete, indicating that the composition of raw materials in concrete affects the bond performance between steel reinforcement and concrete. However, in current technology, the bond performance between lightweight ultra-high performance concrete (LUHPC) and steel reinforcement remains unclear, hindering its widespread application in concrete structures in civil engineering.

[0003] Therefore, there is an urgent need to propose a method and apparatus for calculating the bond slip between lightweight ultra-high performance concrete and steel reinforcement, in order to solve the technical problem that the bond performance between ultra-high performance concrete and steel reinforcement is not yet clear in the existing technology, which prevents its widespread application in concrete structures. Summary of the Invention

[0004] In view of this, it is necessary to provide a method and apparatus for calculating the bond slip of lightweight ultra-high performance concrete and steel reinforcement, so as to solve the technical problem that the bond performance between ultra-high performance concrete and steel reinforcement is not clear in the prior art, which makes it impossible to promote its application in concrete structures.

[0005] On one hand, this invention provides a method for calculating the bond-slip between lightweight ultra-high performance concrete and reinforcing steel, including:

[0006] The specimen parameters of lightweight ultra-high performance concrete and steel bars are set according to preset standards, and a preset number of pull-out specimens are determined according to the specimen parameters.

[0007] Pull-out tests were performed on each pull-out specimen to obtain the pull-out test results for each specimen. Based on all the pull-out test results, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel was obtained.

[0008] Based on the target bond-slip curve, a bond-slip curve model and a preset quantitative function relationship are set, and the bond-slip curve of the pull-out specimen to be tested is calculated based on the bond-slip curve model and the preset quantitative function relationship.

[0009] In some possible implementations, the specimen parameters corresponding to each pull-out specimen include the maximum pull-out force of the testing machine, the volumetric fiber content, the pre-set number of steel bar bond lengths, the steel bar diameter, and the protective layer thickness;

[0010] The step of performing pull-out tests on each pull-out specimen to obtain the pull-out test results for each specimen includes:

[0011] Based on the maximum pull-out force corresponding to each pull-out specimen, the preset number of rebar bonding lengths, and the rebar diameter, the bonding stress corresponding to each rebar bonding length of each pull-out specimen is obtained;

[0012] Based on the preset number of rebar bonding lengths, the rebar diameter, and the steel fiber volume fraction, the rebar slippage corresponding to each rebar bonding length of each pull-out specimen is obtained;

[0013] Based on all bond stresses and all steel bar slippage corresponding to each pull-out specimen, the pull-out test results corresponding to each pull-out specimen are obtained.

[0014] In some possible implementations, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel is obtained based on all pull-out test results, including...

[0015] Based on the pull-out test results of each pull-out specimen, the bond slip curve corresponding to each pull-out specimen is obtained;

[0016] By analyzing all bond-slip curves, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel is obtained.

[0017] In some possible implementations, setting the bond-slip curve model based on the target bond-slip curve includes:

[0018] The target bond-slip curve is represented by a four-segment broken line model to obtain the bond-slip curve model.

[0019] In some possible implementations, setting a preset quantitative function relationship based on the target adhesion slip curve includes:

[0020] Based on the target bonding slip curve, a preset number of key parameters are obtained;

[0021] Based on the specimen parameters, set the functional relationship corresponding to each key parameter.

[0022] In some possible implementations, calculating the bond-slip curve of the pull-out specimen based on the bond-slip curve model and the preset quantitative function relationship includes:

[0023] Based on the pull-out specimen to be tested, determine the parameters of the specimen;

[0024] The parameters of the test piece are calculated according to the preset quantitative function relationship to obtain the key parameters to be tested;

[0025] By substituting the key parameters to be tested into the bond-slip curve model, the bond-slip curve corresponding to the pull-out specimen to be tested is obtained.

[0026] In some possible implementations, the specimen parameters include a preset quantity of steel fiber volume content;

[0027] The step of determining a preset number of pull-out specimens based on the specimen parameters includes:

[0028] Based on the preset quantity of steel fiber volume content, set the mix proportion corresponding to each steel fiber volume content in the lightweight ultra-high performance concrete;

[0029] A predetermined number of pull-out specimens are prepared based on the specimen parameters and the mixing ratio.

[0030] In some possible implementations, the bond slip curve model is as follows:

[0031]

[0032] In the formula, τ0 is the initial bond strength; τ u τ is the ultimate bond strength; r Residual bond strength; s u s is the slip value corresponding to the ultimate bond strength; s is the slip value; s r k1 and k2 are the slip values ​​corresponding to the residual bond strength and the slopes of the broken line.

[0033] In some possible implementations, the preset quantitative function relationship includes an initial bond strength function expression, an ultimate bond strength function expression, a residual bond strength function expression, a slip amount function expression corresponding to the ultimate bond strength, and a slip amount function expression corresponding to the residual bond strength.

[0034] On the other hand, the present invention also provides a bond-slip calculation device for lightweight ultra-high performance concrete and reinforcing steel, comprising:

[0035] The specimen determination module is used to set the specimen parameters of lightweight ultra-high performance concrete and steel bars according to preset standards, and to determine a preset number of pull-out specimens based on the specimen parameters.

[0036] The test module is used to perform pull-out tests on each pull-out specimen separately, obtain the pull-out test results for each pull-out specimen, and obtain the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel based on all the pull-out test results;

[0037] The model determination module is used to set a bond slip curve model and a preset quantitative function relationship based on the target bond slip curve, and to calculate the bond slip curve of the pull-out specimen to be tested based on the bond slip curve model and the preset quantitative function relationship.

[0038] The beneficial effects of the above embodiments are as follows: The bond-slip calculation method for lightweight ultra-high performance concrete and reinforcing steel provided by the present invention can obtain the bond-slip curve model and preset quantitative function relationship by conducting pull-out tests on a predetermined number of pull-out specimens. This eliminates the need for repeated experiments on the pull-out specimens, reducing the experimental process and saving processing time. Furthermore, the bond-slip curve of the pull-out specimen can be obtained through the bond-slip curve model and preset quantitative function relationship, thus improving the promotion and application of concrete structures. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A schematic flowchart of an embodiment of the bond-slip calculation method for lightweight ultra-high performance concrete and reinforcing steel provided by the present invention;

[0041] Figure 2 A schematic diagram of an embodiment of the construction of the pull-out specimen provided by the present invention;

[0042] Figure 3 This is a schematic diagram of the bond slip curve of an embodiment of the pull-out specimen test group provided by the present invention;

[0043] Figure 4 A schematic diagram of an embodiment of the target bond slip curve provided by the present invention;

[0044] Figure 5 A schematic diagram of an embodiment of the bond-slip calculation device for lightweight ultra-high performance concrete and reinforcing steel provided by the present invention;

[0045] Figure 6 A schematic diagram of an embodiment of the electronic device provided by the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] This invention provides a method and apparatus for calculating the bond slip between lightweight ultra-high performance concrete and reinforcing steel, which will be described below.

[0050] Figure 1 A schematic flowchart of an embodiment of the bond-slip calculation method between lightweight ultra-high performance concrete and reinforcing steel provided by the present invention is shown below. Figure 1 As shown, the calculation method for bond slip between lightweight ultra-high performance concrete and steel reinforcement includes:

[0051] S101. Set the specimen parameters of lightweight ultra-high performance concrete and steel bars according to the preset standards, and determine the preset number of pull-out specimens according to the specimen parameters;

[0052] S102. Perform pull-out tests on each pull-out specimen to obtain the pull-out test results for each pull-out specimen, and obtain the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel based on all the pull-out test results.

[0053] S103. Based on the target bond-slip curve, set a bond-slip curve model and a preset quantitative function relationship, and calculate the bond-slip curve of the pull-out specimen to be tested based on the bond-slip curve model and the preset quantitative function relationship.

[0054] Compared with existing technologies, the bond-slip calculation method for lightweight ultra-high performance concrete and reinforcing steel provided in this invention allows for the calculation of bond-slip curves by conducting pull-out tests on a predetermined number of pull-out specimens and establishing a bond-slip curve model and a predetermined functional relationship. This enables the subsequent use of the pull-out specimens to obtain their bond-slip curves using the model and the pre-defined functional relationship, eliminating the need for repeated experiments and reducing processing time. Furthermore, the bond-slip curves of the pull-out specimens can be obtained through the model and the pre-defined functional relationship, thus revealing the bond performance and improving the promotion and application of concrete structures.

[0055] It should be understood that the preset standard can be the "Standard for Test Methods of Concrete Structures", and the specimen parameters can include all the parameters required in concrete structure tests, such as steel grade, yield strength, ultimate strength, steel diameter, steel fiber volume, steel bond length, and protective layer thickness.

[0056] It should be noted that, in order to obtain a predetermined number of pull-out specimens, in some embodiments of the present invention, the specimen parameters include a predetermined number of steel fiber volume fractions; step S101 includes:

[0057] Based on the preset quantity of steel fiber volume content, set the mix proportion corresponding to each steel fiber volume content in the lightweight ultra-high performance concrete;

[0058] A predetermined number of pull-out specimens are prepared based on the specimen parameters and the mixing ratio.

[0059] It should be understood that different mix proportions can be obtained by varying the volumetric content of steel fibers.

[0060] In specific embodiments of the present invention, the configuration of LUHPC is shown in Table 1:

[0061]

[0062] The compressive strength and splitting tensile strength of LUHPC material were measured using cubic specimens with a side length of 100 mm. The compressive strengths of LUHPC cubes with steel fiber volume fractions of 1.5%, 2.0%, and 2.5% were 103.6 MPa, 108.5 MPa, and 117.0 MPa, respectively, and the splitting tensile strengths were 16.8 MPa, 17.9 MPa, and 19.5 MPa, respectively. The mechanical properties of the reinforcing steel used in the tests were obtained according to relevant specifications, and the specific mechanical properties are as follows:

[0063] As shown in Table 2:

[0064]

[0065] During the experiment, the required pull-out specimens can be determined based on the mix ratio corresponding to different steel fiber volume fractions and the mechanical properties of the reinforcing bars. The steel fiber volume fraction and the contents in the mix ratio can be set according to the actual situation, and this embodiment of the invention does not impose any limitations on them.

[0066] In a specific embodiment of the present invention, the pull-out specimen is constructed as follows: Figure 2 As shown, a cubic eccentric pull-out specimen with sides of 150mm × 150mm × 150mm can be prepared according to the relevant provisions of the "Standard for Test Methods of Concrete Structures". The free end length of the pull-out specimen is 20mm, and the loaded end length is 300mm. The non-anchored areas at both ends are isolated with PVC sleeves, and the bond length of the reinforcing steel is changed by changing the length of the PVC sleeves at both ends. The variable parameters in the specimen parameters of the pull-out specimen may include the diameter of the reinforcing steel d and the volumetric fiber content V. f The parameters include the rebar bond length *l* and the protective layer thickness *c*. The rebar diameter can include two types: 16mm and 18mm; the steel fiber volume fraction can include three types: 1.5%, 2.0%, and 2.5%; the protective layer thickness can include three types: 15mm, 20mm, and 25mm; and the rebar bond length can include four types: 3d (d is the rebar diameter), 4d, 5d, and 6d. Three specimens are prepared for each identical parameter, resulting in a total number of pull-out specimens: 2 (rebar diameter) × 3 (steel fiber volume fraction) × 3 (protective layer thickness) × 4 (rebar bond length) × 3 (three identical specimens) = 216 specimens. The values ​​of the varying parameters in the pull-out specimen parameters and the algorithm for calculating the preset number of pull-out specimens can be set according to actual conditions, and this embodiment of the invention does not impose any limitations.

[0067] In some embodiments of the present invention, the specimen parameters corresponding to each pull-out specimen include the maximum pull-out force of the testing machine, the volumetric fiber content, the pre-set number of rebar bond lengths, the rebar diameter, and the protective layer thickness; step S102 includes:

[0068] Based on the maximum pull-out force corresponding to each pull-out specimen, the preset number of rebar bonding lengths, and the rebar diameter, the bonding stress corresponding to each rebar bonding length of each pull-out specimen is obtained;

[0069] Based on the preset number of rebar bonding lengths, the rebar diameter, and the steel fiber volume fraction, the rebar slippage corresponding to each rebar bonding length of each pull-out specimen is obtained;

[0070] Based on all bond stresses and all steel bar slippage corresponding to each pull-out specimen, the pull-out test results corresponding to each pull-out specimen are obtained.

[0071] It should be noted that the specimen parameters of each pull-out specimen can be calculated to obtain the corresponding bond stress for each pull-out specimen. The bond stress calculation is shown in Formula 1.

[0072]

[0073] In the formula, F is the maximum pull-out force of the testing machine; l is the bond length; and d is the diameter of the reinforcing bar.

[0074] When the bond length of the pull-out specimen is a variable, the bond stress corresponding to each bond length can be obtained. Furthermore, based on a preset number of rebar bond lengths, a preset number of rebar diameters, and a preset number of steel fiber volume fractions, the rebar slippage corresponding to each bond length can be obtained. Thus, all bond stresses and all rebar slippages corresponding to each pull-out specimen can be obtained, yielding the pull-out test results for each specimen.

[0075] In some embodiments of the present invention, step S102 includes:

[0076] Based on the pull-out test results of each pull-out specimen, the bond slip curve corresponding to each pull-out specimen is obtained;

[0077] By analyzing all bond-slip curves, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel is obtained.

[0078] In a specific embodiment of the present invention, after obtaining the pull-out test results for each pull-out specimen, a bond-slip curve can be plotted based on the pull-out test results, with the steel bar slippage as the abscissa and the bond stress as the ordinate. This allows the acquisition of the bond-slip curve for each pull-out specimen. Figure 3 As shown, the bond-slip curves are plotted based on the pull-out test results of test groups P-18-3d-C15-2.0, P-18-3d-C15-2.5, P-18-4d-C15-2.0 and P-18-4d-C15-2.5 out of 216 pull-out specimens.

[0079] In some embodiments of the present invention, step S103 includes:

[0080] The target bond-slip curve is represented by a four-segment broken line model to obtain the bond-slip curve model.

[0081] In a specific embodiment of the present invention, the experimenter can analyze the characteristics of the bond-slip curves of a preset number of pull-out specimens to determine the target bond-slip curve, such as... Figure 4 As shown, the basic shape and preset number of key parameters of the target bond slip curve can be determined, where τ0 is the initial bond strength; τ u τ is the ultimate bond strength; r s is the residual bond strength; s is the slip; s u The slip amount corresponding to the ultimate bond strength; s r k1 and k2 are the slip values ​​corresponding to the residual bond strength and the slopes of the broken line.

[0082] In some embodiments of the present invention, the bond slip curve model is as shown in Formula 2:

[0083]

[0084] It should be noted that the values ​​of preset key parameters can be determined based on the target bond-slip curve, thereby setting the bond-slip curve model. The slopes k1 and k2 of the broken line can be calculated using Formula 2, and Formula 3 is shown below:

[0085]

[0086] In some embodiments of the present invention, step S103 includes:

[0087] Based on the target bonding slip curve, a preset number of key parameters are obtained;

[0088] Based on the specimen parameters, set the functional relationship corresponding to each key parameter.

[0089] In a specific embodiment of the present invention, since the bonding slip curve model needs to be calculated based on a preset number of key parameters, it is necessary to set a function expression for the preset number of key parameters.

[0090] In some embodiments of the present invention, the preset quantitative function relationship includes an initial bond strength function expression, an ultimate bond strength function expression, a residual bond strength function expression, a slip amount function expression corresponding to the ultimate bond strength, and a slip amount function expression corresponding to the residual bond strength.

[0091] In a specific embodiment of the present invention, the expression for the initial bond strength function is shown in Formula 4:

[0092]

[0093] The expression for the ultimate bond strength function is shown in Equation 5:

[0094]

[0095] The expression for the residual bond strength function is shown in Equation 6:

[0096]

[0097] The slip function expression corresponding to the ultimate bond strength is shown in Equation 7:

[0098] s u =(-5.35+0.02l)(-8.44+0.31d)(0.06-0.8V f (7)

[0099] The slip function expression corresponding to the residual bond strength is shown in Equation 8:

[0100] s r = (2.76 + 0.17d)(1.21 - 19.62V) f (8)

[0101] In some embodiments of the present invention, step S103 includes:

[0102] Based on the pull-out specimen to be tested, determine the parameters of the specimen;

[0103] The parameters of the test piece are calculated according to the preset quantitative function relationship to obtain the key parameters to be tested;

[0104] By substituting the key parameters to be tested into the bond-slip curve model, the bond-slip curve corresponding to the pull-out specimen to be tested is obtained.

[0105] It should be noted that after obtaining the bond-slip curve model and the preset quantitative function relationship, when it is necessary to determine the bond-slip capacity of other lightweight ultra-high performance concrete and steel bars to be tested, the preset quantitative key parameters in the bond-slip curve model can be determined by the preset quantitative function relationship. Then, by substituting the preset quantitative key parameters into the bond-slip curve model, the bond-slip curve of the pull-out specimen to be tested with the corresponding parameters can be obtained. Thus, the bond-slip capacity can be obtained from the bond-slip curve without having to conduct another test on the pull-out specimen to be tested, reducing the process of testing pull-out specimens and saving processing time.

[0106] To better implement the bond-slip calculation method for lightweight ultra-high performance concrete and reinforcing steel in the embodiments of the present invention, the embodiments of the present invention also provide a bond-slip calculation device for lightweight ultra-high performance concrete and reinforcing steel, such as... Figure 5 As shown, the bond-slip calculation device for lightweight ultra-high performance concrete and reinforcing steel includes:

[0107] The specimen determination module 501 is used to set the specimen parameters of lightweight ultra-high performance concrete and steel bars according to preset standards, and to determine a preset number of pull-out specimens according to the specimen parameters.

[0108] The test module 502 is used to perform pull-out tests on each pull-out specimen, obtain the pull-out test results corresponding to each pull-out specimen, and obtain the target bond-slip curve between the lightweight ultra-high performance concrete and the steel reinforcement based on all the pull-out test results;

[0109] The model determination module 503 is used to set a bond slip curve model and a preset quantitative function relationship based on the target bond slip curve, and to calculate the bond slip curve of the pull-out specimen to be tested based on the bond slip curve model and the preset quantitative function relationship.

[0110] The bond-slip calculation device for lightweight ultra-high performance concrete and reinforcing steel provided in the above embodiments can realize the technical solutions described in the above embodiments of the bond-slip calculation method for lightweight ultra-high performance concrete and reinforcing steel. The specific implementation principles of each module or unit can be found in the corresponding content in the above embodiments of the bond-slip calculation method for lightweight ultra-high performance concrete and reinforcing steel, and will not be repeated here.

[0111] like Figure 6 As shown, the present invention also provides an electronic device 600. The electronic device 600 includes a processor 601, a memory 602, and a display 603. Figure 6 Only some components of the electronic device 600 are shown, but it should be understood that it is not required to implement all the components shown, and more or fewer components may be implemented instead.

[0112] In some embodiments, memory 602 may be an internal storage unit of electronic device 600, such as a hard disk or memory of electronic device 600. In other embodiments, memory 602 may also be an external storage device of electronic device 600, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on electronic device 600.

[0113] Furthermore, the memory 602 may include both internal storage units of the electronic device 600 and external storage devices. The memory 602 is used to store application software and various types of data installed on the electronic device 600.

[0114] In some embodiments, processor 601 may be a central processing unit (CPU), microprocessor, or other data processing chip, used to run program code stored in memory 602 or process data, such as the bond slip calculation method for lightweight ultra-high performance concrete and steel reinforcement in this invention.

[0115] In some embodiments, display 603 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 603 is used to display information from electronic device 600 and to display a visual user interface. Components 601-603 of electronic device 600 communicate with each other via a system bus.

[0116] In some embodiments of the present invention, when the processor 601 executes the bond-slip calculation program for lightweight ultra-high performance concrete and reinforcing steel in the memory 602, the following steps can be implemented:

[0117] The specimen parameters of lightweight ultra-high performance concrete and steel bars are set according to preset standards, and a preset number of pull-out specimens are determined according to the specimen parameters.

[0118] Pull-out tests were performed on each pull-out specimen to obtain the pull-out test results for each specimen. Based on all the pull-out test results, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel was obtained.

[0119] Based on the target bond-slip curve, a bond-slip curve model and a preset quantitative function relationship are set, and the bond-slip curve of the pull-out specimen to be tested is calculated based on the bond-slip curve model and the preset quantitative function relationship.

[0120] It should be understood that when the processor 601 executes the bond slip calculation program for lightweight ultra-high performance concrete and steel reinforcement in the memory 602, in addition to the functions mentioned above, it can also perform other functions, as can be found in the description of the corresponding method embodiments above.

[0121] Furthermore, this embodiment of the invention does not specifically limit the type of electronic device 600 mentioned. Electronic device 600 can be a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, laptop computer, or other portable electronic device. Exemplary embodiments of portable electronic devices include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic device can also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the invention, electronic device 600 may not be a portable electronic device, but rather a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0122] Accordingly, this application also provides a computer-readable storage medium for storing computer-readable programs or instructions. When the programs or instructions are executed by a processor, they can implement the steps or functions of the bond slip calculation method for lightweight ultra-high performance concrete and steel reinforcement provided in the above-described method embodiments.

[0123] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0124] The above provides a detailed description of the method and apparatus for calculating the bond slip between lightweight ultra-high performance concrete and reinforcing steel provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for calculating the bond-slip between lightweight ultra-high performance concrete and reinforcing steel, characterized in that, include: The specimen parameters of lightweight ultra-high performance concrete and steel bars are set according to preset standards, and a preset number of pull-out specimens are determined according to the specimen parameters. Pull-out tests were performed on each pull-out specimen to obtain the pull-out test results for each specimen. Based on all the pull-out test results, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel was obtained. Based on the target bond-slip curve, a bond-slip curve model and a preset quantitative function relationship are set, and the bond-slip curve of the pull-out specimen to be tested is calculated based on the bond-slip curve model and the preset quantitative function relationship. The preset quantitative function relationship includes the initial bond strength function expression, the ultimate bond strength function expression, the residual bond strength function expression, the slip amount function expression corresponding to the ultimate bond strength, and the slip amount function expression corresponding to the residual bond strength; The initial bond strength function expression is: The expression for the ultimate bond strength function is: The expression for the residual bond strength function is: The slip function expression corresponding to the ultimate bond strength is: The slip function expression corresponding to the residual bond strength is: ； In the formula, τ 0 represents the initial bond strength; τ u This is the ultimate bond strength; τ r Residual bond strength; s u This represents the slip amount corresponding to the ultimate bond strength. s r This represents the slip amount corresponding to the residual bond strength. l This refers to the bonding length; d Rebar diameter, V f This refers to the volumetric content of steel fibers. c This refers to the thickness of the protective layer.

2. The method for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, The specimen parameters corresponding to each pull-out specimen include the maximum pull-out force of the testing machine, the volumetric content of steel fiber, the pre-set number of steel bar bond lengths, the steel bar diameter, and the protective layer thickness. The step of performing pull-out tests on each pull-out specimen to obtain the pull-out test results for each specimen includes: Based on the maximum pull-out force corresponding to each pull-out specimen, the preset number of rebar bonding lengths, and the rebar diameter, the bonding stress corresponding to each rebar bonding length of each pull-out specimen is obtained; Based on the preset number of rebar bonding lengths, the rebar diameter, and the steel fiber volume fraction, the rebar slippage corresponding to each rebar bonding length of each pull-out specimen is obtained; Based on all bond stresses and all steel bar slippage corresponding to each pull-out specimen, the pull-out test results corresponding to each pull-out specimen are obtained.

3. The method for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, Based on all pull-out test results, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel was obtained, including... Based on the pull-out test results of each pull-out specimen, the bond slip curve corresponding to each pull-out specimen is obtained; By analyzing all bond-slip curves, the target bond-slip curve between the lightweight ultra-high performance concrete and the reinforcing steel is obtained.

4. The method for calculating the bond-slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, The step of setting a bond-slip curve model based on the target bond-slip curve includes: The target bond-slip curve is represented by a four-segment broken line model to obtain the bond-slip curve model.

5. The method for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, The step of setting a preset quantity function relationship based on the target bonding slip curve includes: Based on the target bonding slip curve, a preset number of key parameters are obtained; Based on the specimen parameters, set the functional relationship corresponding to each key parameter.

6. The method for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, The calculation of the bond-slip curve of the pull-out specimen based on the bond-slip curve model and the preset quantitative function relationship includes: Based on the pull-out specimen to be tested, determine the parameters of the specimen; The parameters of the test piece are calculated according to the preset quantitative function relationship to obtain the key parameters to be tested; By substituting the key parameters to be tested into the bond-slip curve model, the bond-slip curve corresponding to the pull-out specimen to be tested is obtained.

7. The method for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, The specimen parameters include a preset quantity of steel fiber volume content; The step of determining a preset number of pull-out specimens based on the specimen parameters includes: Based on the preset quantity of steel fiber volume content, set the mix proportion corresponding to each steel fiber volume content in the lightweight ultra-high performance concrete; A predetermined number of pull-out specimens are prepared based on the specimen parameters and the mixing ratio.

8. The method for calculating bond slip between lightweight ultra-high performance concrete and reinforcing steel according to claim 1, characterized in that, The bond slip curve model is as follows: In the formula, τ0 is the initial bond strength; τ u τ is the ultimate bond strength; r Residual bond strength; s u s is the slip value corresponding to the ultimate bond strength; s is the slip value; s r k1 and k2 are the slip values ​​corresponding to the residual bond strength and the slopes of the broken line.

9. A device for calculating the bond slip between lightweight ultra-high performance concrete and reinforcing steel, characterized in that, The method for calculating the bond slip between lightweight ultra-high performance concrete and reinforcing steel as described in any one of claims 1 to 8 includes: The specimen determination module is used to set the specimen parameters of lightweight ultra-high performance concrete and steel bars according to preset standards, and to determine a preset number of pull-out specimens based on the specimen parameters. The test module is used to perform pull-out tests on each pull-out specimen separately, obtain the pull-out test results corresponding to each pull-out specimen, and obtain the target bond-slip curve between the lightweight ultra-high performance concrete and the steel reinforcement based on all the pull-out test results; The model determination module is used to set a bond slip curve model and a preset quantitative function relationship based on the target bond slip curve, and to calculate the bond slip curve of the pull-out specimen to be tested based on the bond slip curve model and the preset quantitative function relationship.

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