Method for constructing interface bond-slip constitutive model of closed profiled steel sheet-geopolymer brick aggregate recycled concrete composite slab

Abstract

This invention proposes a method for constructing a constitutive model of the bond-slip interface of a closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab. The method includes the following steps: constructing a theoretical analysis model of the bond stress-relative slip at the interface between the closed-type profiled steel sheet and the polymer brick aggregate recycled concrete slab; determining the performance characteristic points of the bond stress-relative slip of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab and their corresponding mechanical indices; establishing the quantitative relationship between the mechanical indices and design parameters at the performance characteristic points; and establishing the expression for the bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab interface. The constitutive model established by this invention has a simple calculation process and relatively reliable calculation results, providing a reasonable and reliable constitutive model for the study of the interfacial bonding performance of closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slabs.

Description

Technical Field

[0001] This invention belongs to the field of composite structure technology, and particularly relates to a method for constructing an interfacial bond-slip constitutive model for a closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite panel. Background Technology

[0002] The longitudinal shear resistance of the composite slab determines its failure mode to a certain extent, while the bonding performance at the interface of the composite slab is a key factor affecting its longitudinal shear resistance. Among these factors, the mechanical properties of the concrete, the friction coefficient of the profiled steel sheet surface, and the profiled steel sheet type all affect the interfacial bonding performance between the profiled steel sheet and the concrete.

[0003] With the maturation of concrete recycling technology, recycled concrete has been widely used in construction projects, effectively alleviating problems such as the scarcity of sand and gravel resources and the accumulation of construction waste, while realizing the recycling of waste concrete. Compared with beam-column structures, floor slabs use a larger amount of concrete and have lower strength requirements, showing good application prospects. Given that profiled steel sheet-concrete composite slabs have advantages such as high rigidity, high load-bearing capacity, and saving formwork, replacing ordinary concrete in composite slabs with recycled concrete can leverage the performance advantages of the composite structure to compensate for the adverse effects of the mechanical property defects of recycled concrete itself, ensuring that normal use requirements are met, and also having good environmental benefits.

[0004] Currently, there is relatively little research on the interfacial performance of composite panels made of profiled steel sheet and recycled concrete aggregate, and the longitudinal shear force transfer mechanism between the profiled steel sheet and the recycled concrete aggregate in the composite panel is quite complex and difficult to simulate and predict using mathematical methods. There is no interfacial bond-slip constitutive model applicable to the analysis of the interfacial bonding performance of this type of composite panel.

[0005] In view of this, the present invention proposes a method for constructing an interfacial bond-slip constitutive model for a closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite panel. Summary of the Invention

[0006] The purpose of this invention is to address the current lack of research on the interfacial performance of profiled steel sheet-recycled brick aggregate concrete composite slabs by providing a method for establishing a closed-type bond-slip constitutive model for the interfacial bonding of profiled steel sheet-polymer brick aggregate recycled concrete composite slabs. This method establishes an interfacial bond-slip constitutive model that can effectively simulate the bonding performance between the widely used galvanized profiled steel sheet and the polymer brick aggregate recycled concrete slab, while also considering the influence of the strength of the polymer brick aggregate recycled concrete and the thickness of the profiled steel sheet on the interfacial bonding performance, resulting in more accurate calculation results.

[0007] To achieve the above objectives, the technical solution of the present invention is: a method for constructing an interfacial bond-slip constitutive model for a closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab, specifically including the following steps:

[0008] Step 1: Based on the bond stress-relative slip curve of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab, establish a theoretical analysis model of bond stress-relative slip at the interface between the closed-type profiled steel sheet and the polymer brick aggregate recycled concrete slab.

[0009] Step 2: Based on the established theoretical analysis model, determine the performance characteristics of the bond stress-relative slip of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab and their corresponding mechanical indices; the performance characteristics are selected according to the inflection point of the bond stress-relative slip curve in Step 1, including the critical point A(0, τ0) where relative slip begins to occur at the interface, and the point B(s) where the interfacial bond stress reaches its maximum value. u , τ u ), and the starting point C(s) of the interfacial bonding stress entering the smooth segment. s , τ s The mechanical properties include initial bond stress τ0 and peak bond stress τ0. u Peak end slip s corresponding to peak bond stress u Frictional bonding stress τ s And the friction end slip s corresponding to the frictional bonding stress. s ;

[0010] Step 3: Establish the quantitative relationship between the design parameters and the mechanical properties of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab. The design parameters include the strength f of the polymer brick aggregate recycled concrete. c and the thickness t of the profiled steel sheet;

[0011] Step 4: Based on the segmented form of the established theoretical analysis model, the determined performance characteristic points and their corresponding mechanical indices, and the quantitative relationship between the mechanical indices and design parameters, establish an interfacial bond-slip constitutive model for the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab.

[0012] Preferably, the expression for the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite panel in step 4 is as follows:

[0013]

[0014]

[0015] Where τ is the bonding stress, s eFor relative slip, k is the distribution coefficient of the descending segment of the curve.

[0016] Preferably, the bond stress-relative slip curve of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab in step 1 is obtained by the push-out test of the scaled specimen, and the design parameters of the scaled specimen include the strength of the polymer brick aggregate recycled concrete and the thickness of the profiled steel sheet.

[0017] Preferably, the segmented form of the bond stress-relative slip theoretical analysis model is that the bond stress-relative slip curve is divided sequentially by performance characteristic points into a no-slip segment (OA segment), a linearly rising segment (AB segment), a nonlinearly falling segment (BC segment), and a smooth segment (after point C); the OA segment is a vertically rising segment, the AB segment is a slopingly rising segment, the BC segment is a falling segment, and the CD segment is a smooth segment; wherein:

[0018] Section OA is a non-slip section. The longitudinal stress applied by the external load is less than the chemical bonding force at the interface of the composite panel. No relative slippage occurs at the interface of the composite panel. The bonding stress is entirely borne by the chemical bonding force alone. The profiled steel sheet and concrete work together well.

[0019] In the non-linear rising section AB, as the load increases, the chemical bonding force at the interface begins to be lost locally. Small relative slippage begins to occur at the interface between the profiled steel sheet and the concrete of the composite slab. In the area where the chemical bonding force is lost, the longitudinal stress at the interface is borne by frictional resistance and mechanical interlocking force. During this stage, the bonding stress and relative slippage at the interface are approximately linearly related.

[0020] Section BC is the descending section. When the stress at the interface reaches the peak bond stress, it drops sharply. The chemical bonding force at the interface is completely lost, and local separation occurs at the interface between the profiled steel sheet and the concrete. On the curve, this is represented by a sharp drop in bond stress and a tendency to level off. The relative slip at the interface increases significantly. During this stage, the external load changes from being partially borne by the chemical bonding force to being entirely borne by friction and mechanical interlocking force.

[0021] After point C, the interfacial bond stress-relative slip curve becomes a smooth segment, indicating that the bond stress at the interface remains balanced while the relative slip continues to increase. At this stage, all chemical bonding force is lost, and the applied load is entirely borne by friction and ultimate interlocking force. Since the friction and mechanical interlocking forces remain constant throughout the relative slip process and will never disappear before the slip process terminates, the bond stress change at this stage is not significant and can be considered constant.

[0022] Preferably, based on the analysis of existing experimental results regarding the bond stress-relative slip curve, the strength f of recycled concrete with geopolymer brick aggregate is... c And the thickness t of the profiled steel sheet in relation to τ0, τ u τs s u s s A linear influence relationship exists. Based on this, a multiple regression analysis is performed to obtain the quantitative relationship between the design parameters and the mechanical properties of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab, expressed as: , , , , ,in, These are the quantitative functional relationships determined through multiple regression analysis.

[0023] Preferably, the strength f of the recycled concrete made from the geopolymer brick aggregate is... c The value range is 25MPa~40MPa, and the thickness of the profiled steel sheet ranges from 0.9mm to 1.2mm. The coefficient of determination R of the regression model corresponding to each quantitative relationship is... 2 All are greater than 0.5. The quantitative relationship between the design parameters and the mechanical properties of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab is expressed as follows:

[0024]

[0025]

[0026]

[0027]

[0028] .

[0029] Preferably, the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite panel is used for the interfacial bond performance analysis of the composite structure.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The constitutive model established in this invention has a simple calculation process and relatively reliable calculation results. It can provide a reasonable and reliable constitutive model for the study of the interfacial bonding performance of closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slabs. Attached Figure Description

[0032] Figure 1 The bond stress (τ) and relative slip (s) tested in this invention are used to develop the experimental results. e )curve;

[0033] Figure 2 This is the bonding stress-relative slip theory analysis model of the present invention;

[0034] Figure 3 This is a multiple linear regression analysis graph of the various feature values ​​of this invention;

[0035] Figure 4 This is a comparison chart of the theoretical fitting curve and the measured curve of this invention. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-4 The technical solution of the present invention will be described in detail below.

[0037] This invention proposes a method for constructing an interfacial bond-slip constitutive model for a closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab, comprising the following steps, specifically:

[0038] Step 1: Conduct push-out tests on scaled-down specimens of closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slabs to obtain the bond stress (τ) and relative slip (s) of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slabs. e () curve. Specimen parameters include the strength of recycled concrete with polymer brick aggregate and the thickness of the profiled steel sheet, where the strength f of recycled concrete with polymer brick aggregate is... c The values ​​are 25MPa, 32MPa and 40MPa, corresponding to brick aggregate replacement rates of 100%, 50% and 0%, and profiled steel sheet thickness t is 0.9mm, 1mm and 1.2mm.

[0039] Step 2: Establish the bond stress (τ) and relative slip (s) at the interface between the closed-type profiled steel sheet and the recycled concrete slab with polymer brick aggregate. e Theoretical analysis models, such as Figure 2 As shown;

[0040] Step 3: Determine the bond stress (τ) and relative slip (s) for each bond stress (τ). e The performance characteristic points and corresponding mechanical properties in the curve. Using (0, τ0), (s... u , τ u ), (s s , τ s Using ) as the characteristic point, the bond stress (τ) - relative slip (s) e The curve is divided into a no-slip segment (OA segment), a linear rising segment (AB segment), a non-linear falling segment (BC segment), and a smooth segment (after point C). Among them, the OA segment is a vertical rising segment, the AB segment is a sloping rising segment, the BC segment is a falling segment, and the CD segment is a smooth segment.

[0041] Step 3: Based on the test data obtained from the rollout test, determine the strength f of the recycled concrete using polymer brick aggregate. c With the thickness t of the profiled steel sheet as the design parameter, for τ0, τ u τs s u s s Regression analysis was performed to quantify the correlation between the mechanical properties of the bond and the design parameters. The calculation formulas for the mechanical properties at each performance characteristic point are as follows:

[0042] (3)

[0043] (4)

[0044] (5)

[0045] (6)

[0046] (7)

[0047] Step 4: The expression for the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab is as follows:

[0048] (1)

[0049] (2)

[0050] The constitutive model established in this invention has a simple calculation process and relatively reliable calculation results, providing a reasonable and reliable constitutive model for the study of interfacial bonding performance of closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slabs.

[0051] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for constructing an interfacial bond-slip constitutive model for a closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab, characterized in that: Specifically, the following steps are included: Step 1: Based on the bond stress-relative slip curve of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab, establish a theoretical analysis model of bond stress-relative slip at the interface between the closed-type profiled steel sheet and the polymer brick aggregate recycled concrete slab. Step 2: Based on the established theoretical analysis model, determine the performance characteristics of bond stress and relative slip in the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab and their corresponding mechanical indices; the performance characteristics include the critical point A(0, τ0) where relative slip begins to occur at the interface, and the point B(s) where the interfacial bond stress reaches its maximum value. u , τ u ), and the starting point C(s) of the interfacial bonding stress entering the smooth segment. s , τ s The mechanical properties include initial bond stress τ0 and peak bond stress τ0. u Peak end slip s corresponding to peak bond stress u Frictional bonding stress τ s And the friction end slip s corresponding to the frictional bonding stress. s ; Step 3: Establish the quantitative relationship between the design parameters and the mechanical properties of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab. The design parameters include the strength f of the polymer brick aggregate recycled concrete. c and the thickness t of the profiled steel sheet; Step 4: Based on the segmented form of the established theoretical analysis model, the determined performance characteristic points and their corresponding mechanical indices, and the quantitative relationship between the mechanical indices and design parameters, establish an interfacial bond-slip constitutive model for the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab.

2. The method for constructing the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab according to claim 1, characterized in that: The specific expression for the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab mentioned in step 4 is as follows: Where τ is the bonding stress, s e For relative slip, k is the distribution coefficient of the descending segment of the curve.

3. The method for constructing the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab according to claim 1, characterized in that: The bond stress-relative slip curve of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab in step 1 was obtained by the push-out test of scaled specimens. The design parameters of the scaled specimens include the strength of the polymer brick aggregate recycled concrete and the thickness of the profiled steel sheet.

4. The method for constructing the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab according to claim 1, characterized in that: The segmented form of the bond stress-relative slip theoretical analysis model is that the bond stress-relative slip curve is divided into a no-slip segment, a linear rising segment, a nonlinear falling segment, and a smooth segment by performance characteristic points.

5. The method for constructing the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab according to claim 1, characterized in that: The quantitative relationship between the design parameters and the mechanical properties of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab was obtained through multiple regression analysis of the experimental results, and is expressed as follows: , , , , ,in, These are the quantitative functional relationships determined through multiple regression analysis.

6. The method for constructing the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab according to claim 5, characterized in that: The strength f of the recycled concrete with polymer brick aggregate c The value range is 25MPa~40MPa, and the thickness of the profiled steel sheet ranges from 0.9mm to 1.2mm. The coefficient of determination R of the regression model corresponding to each quantitative relationship is... 2 All are greater than 0.

5. The quantitative relationship between the design parameters and the mechanical properties of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab is expressed as follows: 。 7. The method for constructing the interfacial bond-slip constitutive model of the closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite slab according to claim 1, characterized in that: The closed-type profiled steel sheet-polymer brick aggregate recycled concrete composite panel interface bond-slip constitutive model is used for the interface bond performance analysis of the composite structure.

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