Seawater sea sand concrete beam shear resistance evaluation system based on load and chlorine salt coupling

Abstract

The invention discloses a load and chlorine salt coupling-based seawater and sea sand concrete beam shear resistance evaluation system, which is characterized in that the actual chlorine salt solution concentration is collected and combined with the reference chlorine salt solution concentration to calculate an erosion coefficient; combining the bending strength degradation rate with the coupling effect comprehensive coefficient to calculate the relevancy between the bending strength degradation of the stirrup and the shear bearing capacity degradation of the beam; calculating the residual ultimate shear bearing capacity of the concrete beam body by combining the residual shear bearing capacity of the concrete beam body and the residual shear bearing capacity of the stirrup; the residual shear bearing capacity of the concrete beam body is corrected; constructing a comprehensive evaluation index model, and calculating a comprehensive evaluation index; and constructing a grade division model, and dividing shear resistance grades. According to the system, through a beam body shear resistance calculation and degradation mechanism fusion module, the core component of beam body shear resistance is comprehensively covered, meanwhile, microscopic damage and macroscopic shear resistance are combined, and the limitation that calculation is conducted only through macroscopic parameters is made up.

Description

Technical Field

[0001] This invention relates to the field of concrete beams, and more specifically to a shear resistance assessment system for seawater sand concrete beams based on load-chloride coupling. Background Technology

[0002] The load-chlorine coupling-based shear resistance assessment system for seawater sand concrete beams is a comprehensive technical system for accurately assessing the shear resistance, analyzing degradation mechanisms, and determining safety levels of seawater sand concrete beams under the combined effects of long-term load and chloride erosion. The assessment system typically consists of a data acquisition module, a stirrup bending strength analysis module, a macroscopic shear resistance calculation module, a microscopic degradation mechanism fusion and correction module, and a comprehensive shear resistance assessment module. The assessment system can be widely applied to projects using seawater sand concrete beams, such as coastal bridges, port terminals, and offshore platforms.

[0003] In practical applications, existing technologies have two main drawbacks. First, the evaluation system's objectives are not comprehensive enough. It only evaluates the concrete beam separately, neglecting the core component of stirrups, which reduces the accuracy of the beam's shear performance evaluation. Second, the evaluation system has certain limitations. It usually relies on visual observation of the beam's damage, making it difficult to detect microscopic damage in a timely manner, thus reducing the scientific rigor of the evaluation system. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, the present invention aims to provide a shear strength assessment system for seawater sand concrete beams based on load-chloride coupling, thereby solving the problems of insufficient assessment objectives and limitations of the existing assessment systems. The system of the present invention improves scientific rigor while ensuring accuracy, and meets the requirements of practical application scenarios.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a shear resistance assessment system for seawater sand concrete beams based on load-chloride coupling, the system comprising:

[0007] Module 1: Data Acquisition Module. This module acquires the actual chloride solution concentration and combines it with the baseline chloride solution concentration to calculate the erosion coefficient; it constructs a load action coefficient model and calculates the load action coefficient by combining the load level and the test age; and it calculates the coupling effect comprehensive coefficient by combining the erosion coefficient and the load action coefficient.

[0008] Module 2: Stirrup Bending Strength Calculation Module. This module constructs a bending strength degradation rate model to calculate the bending strength degradation rate of stirrups in the bending region. Based on the bending strength degradation rate, it calculates the remaining bending strength of stirrups in the bending region. Combining the bending strength degradation rate and the coupling effect comprehensive coefficient, it calculates the correlation between stirrup bending strength degradation and beam shear capacity degradation.

[0009] Module 3: Beam Shear Performance Calculation Module. This module constructs a model of the remaining shear capacity of a concrete beam and calculates its remaining shear capacity; it also constructs a model of the remaining shear capacity of stirrups and calculates their remaining shear capacity; finally, by combining the remaining shear capacity of the concrete beam and the remaining shear capacity of the stirrups, the module calculates the ultimate remaining shear capacity of the concrete beam.

[0010] Module 4: Degradation Mechanism Fusion Module. This module uses SEM to observe the number of corroded fibers and the area of ​​peeling damage in the stirrups, calculating the degree of damage and fiber corrosion rate of the stirrups. Based on the degree of damage and fiber corrosion rate of the stirrups, a correction model is constructed to correct the remaining shear capacity of the concrete beam. Based on the corrected remaining shear capacity, a comprehensive degradation mechanism coefficient is calculated.

[0011] Module 5: Comprehensive Shear Performance Evaluation Module. Based on the modified residual shear capacity, the benchmark ultimate shear capacity, the degradation mechanism comprehensive coefficient, the maximum crack width, and the benchmark maximum crack width, a comprehensive evaluation index model is constructed, and comprehensive evaluation indices are calculated. Based on the comprehensive evaluation indices, a safety reserve coefficient is calculated. A grading model is constructed, and shear performance grades are classified by combining the comprehensive evaluation indices and the safety reserve coefficient.

[0012] Furthermore, in module two, the bending strength degradation rate model is as follows:

[0013]

[0014] in, The rate of flexural strength degradation; It is an exponential function; This is the bending strength degradation coefficient of the stirrup; This is the comprehensive coefficient of the coupling effect; The experimental age;

[0015] Construct a correlation calculation model, as shown below:

[0016]

[0017] in, The correlation coefficient; and These are the weighting coefficients; The rate of flexural strength degradation; This is the combined coefficient of the coupling effect.

[0018] Furthermore, in module three, a model for the remaining ultimate shear capacity of the beam is constructed to calculate the remaining ultimate shear capacity of the concrete beam. The model is shown below:

[0019]

[0020] in, for The remaining ultimate shear capacity of the concrete beam at any given moment; for The remaining shear capacity of the concrete beam at any given moment; for The remaining shear capacity of the stirrups at any given time; The correlation coefficient; This is the combined coefficient of the coupling effect.

[0021] Furthermore, in module four, the corrected model is as follows:

[0022]

[0023] in, for Residual shear capacity after time correction; and These are the weighting coefficients; The degree of damage to the stirrups; The fiber corrosion rate of the stirrups; for The remaining ultimate shear capacity of the concrete beam at any given moment;

[0024] The comprehensive coefficient function for calculating the degradation mechanism is shown below:

[0025]

[0026] in, This is the comprehensive coefficient for the degradation mechanism; and These are the weighting coefficients; This represents the baseline ultimate shear capacity of the concrete beam.

[0027] Furthermore, the comprehensive evaluation index model is as follows:

[0028]

[0029] in, For comprehensive evaluation indicators; , and These are the weighting coefficients; for The maximum crack width of the concrete beam at any given moment; This represents the baseline maximum crack width for a concrete beam.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The system of this invention proposes a beam shear performance calculation module, which calculates the remaining shear capacity of the concrete beam and stirrups respectively, comprehensively covering the core components of beam shear resistance. At the same time, it outputs cracking load and maximum crack width index simultaneously, reflecting the degradation state of beam shear performance from multiple dimensions, and meeting the actual evaluation needs of engineering.

[0032] The system of this invention proposes a degradation mechanism fusion module, which obtains the stirrup damage degree and fiber corrosion rate through SEM microscopic observation, combines microscopic damage with macroscopic shear performance to improve the scientific nature of the assessment. At the same time, it corrects the remaining shear bearing capacity of the beam, makes up for the limitations of calculation based solely on macroscopic parameters, and makes the results more consistent with the actual degradation situation. Finally, it quantifies the comprehensive coefficient of degradation mechanism to clearly present the essential reasons for the degradation of beam shear performance. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the system's workflow in this invention;

[0035] Figure 2 This is a schematic diagram of the data acquisition module architecture in the system of this invention;

[0036] Figure 3 This is a schematic diagram of the stirrup bending strength calculation module architecture in the present invention;

[0037] Figure 4 This is a schematic diagram of the beam shear performance calculation module architecture in the system of this invention;

[0038] Figure 5 This is a schematic diagram of the degradation mechanism fusion module architecture in the system of this invention;

[0039] Figure 6 This is a schematic diagram of the comprehensive shear performance evaluation module architecture of the system in this invention. Detailed Implementation

[0040] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0041] Reference Figure 1 As shown, the present invention provides a shear resistance assessment system for seawater sand concrete beams based on load-chloride coupling. The system includes:

[0042] Module 1: Data Acquisition Module. This module collects the actual chloride solution concentration and combines it with the baseline chloride solution concentration to calculate the erosion coefficient; it constructs a load action coefficient model and calculates the load action coefficient by combining the load level and test age; and it calculates the comprehensive coefficient of coupling effect by combining the erosion coefficient and the load action coefficient.

[0043] First, we construct an erosion coefficient function to calculate the erosion coefficient of chloride salts. The function is as follows:

[0044]

[0045] in, The corrosion coefficient of chloride salts; This is the correction factor for chloride salt corrosion; This represents the actual concentration of the chloride solution. The concentration of the reference chloride solution is a fixed value. This represents the number of dry-wet cycles of chloride salts;

[0046] Secondly, combining the load level and test age, a load action coefficient model is constructed, and the load action coefficient is calculated. The model is shown below:

[0047]

[0048] in, This is the load factor; This is the load damage correction factor; For load-bearing level; The experimental age;

[0049] Finally, based on the chloride erosion coefficient and the load coefficient, the comprehensive coefficient of coupling effect is calculated, as shown in the following function:

[0050]

[0051] in, This is the combined coefficient of the coupling effect. The larger the value, the more significant the effect of the coupling effect on the performance degradation of the concrete beam. The chloride erosion coefficient; This is the load factor.

[0052] Module 2: Stirrup Bending Strength Calculation Module. This module constructs a bending strength degradation rate model to calculate the bending strength degradation rate of stirrups in the bending region. Based on the bending strength degradation rate, it calculates the remaining bending strength of stirrups in the bending region. Combining the bending strength degradation rate and the coupling effect comprehensive coefficient, it calculates the correlation between the bending strength degradation of stirrups and the degradation of beam shear capacity.

[0053] First, a bending strength degradation rate model is constructed, and combined with the coupling effect comprehensive coefficient, the bending strength degradation rate of the stirrup in the bending region is calculated. The model is shown below:

[0054]

[0055] in, The rate of flexural strength degradation; It is an exponential function; This is the bending strength degradation coefficient of the stirrup; This is the comprehensive coefficient of the coupling effect; The experimental age;

[0056] Secondly, based on the bending strength degradation rate, the remaining bending strength of the stirrup in the bending region is calculated using the following function:

[0057]

[0058] in, for The remaining bending strength of the stirrup bending zone at any given time; The reference bending strength of the stirrup bending zone can be directly measured from standard parts; The rate of flexural strength degradation;

[0059] Finally, based on the bending strength degradation rate and the combined coefficient of coupling effect, a correlation calculation model is constructed to calculate the correlation coefficient between the bending strength degradation of stirrups and the shear capacity degradation of beams. The model is shown below:

[0060]

[0061] in, The correlation coefficient is... The larger the value, the stronger the correlation between the degradation of the stirrup bending strength and the degradation of the beam's shear capacity; and These are the weighting coefficients; The rate of flexural strength degradation; This is the combined coefficient of the coupling effect.

[0062] Module 3: Beam Shear Performance Calculation Module. This module constructs a model of the remaining shear capacity of a concrete beam and calculates its remaining shear capacity; it also constructs a model of the remaining shear capacity of stirrups and calculates their remaining shear capacity; finally, by combining the remaining shear capacity of the concrete beam and the remaining shear capacity of the stirrups, it calculates the ultimate remaining shear capacity of the concrete beam.

[0063] First, a model of the remaining shear capacity of the concrete beam is constructed, and the remaining shear capacity of the concrete beam is calculated. The model is shown below:

[0064]

[0065] in, for The remaining shear capacity of the concrete beam at any given moment; The reference shear capacity of the concrete beam is directly measured from the reference beam. It is an exponential function; This is the shear degradation coefficient of the concrete beam. This is the comprehensive coefficient of the coupling effect; The experimental age;

[0066] Construct a model for the residual shear capacity of the stirrups and calculate their residual shear capacity. The model is shown below:

[0067]

[0068] in, for The remaining shear capacity of the stirrups at any given time; This is the shear efficiency coefficient of the stirrups; This represents the cross-sectional area of ​​a single stirrup; for The remaining bending strength of the stirrup bending zone at any given time; The effective height of the concrete beam section; The spacing of the stirrups;

[0069] Secondly, based on the remaining shear capacity of the concrete beam and the remaining shear capacity of the stirrups, a model for the remaining ultimate shear capacity of the beam is constructed, and the remaining ultimate shear capacity of the concrete beam is calculated. The model is shown below:

[0070]

[0071] in, for The remaining ultimate shear capacity of the concrete beam at any given moment; for The remaining shear capacity of the concrete beam at any given moment; for The remaining shear capacity of the stirrups at any given time; The correlation coefficient; This is the comprehensive coefficient of the coupling effect;

[0072] Finally, the cracking load and maximum crack width of the concrete beam are calculated using the following function:

[0073]

[0074]

[0075] in, for Cracking load on concrete beams at any given moment; The reference cracking load for the concrete beam is directly measured from the reference beam. for The remaining shear capacity of the concrete beam at any given moment; The reference shear capacity of the concrete beam is directly measured from the reference beam. for The maximum crack width of the concrete beam at any given moment; The reference maximum crack width of the concrete beam is directly measured from the reference beam. The rate of flexural strength degradation; This is the combined coefficient of the coupling effect.

[0076] Module 4: Degradation Mechanism Integration Module. This module uses SEM to observe the number of corroded fibers and the area of ​​peeling damage in the stirrups, calculating the degree of damage and fiber corrosion rate. Based on the degree of damage and fiber corrosion rate, a modified model is constructed to correct the remaining shear capacity of the concrete beam. Based on the corrected remaining shear capacity, a comprehensive coefficient for the degradation mechanism is calculated.

[0077] First, the number of corroded fibers and the area of ​​peeling damage in the stirrups were observed using SEM:

[0078] A damage measurement model is constructed, and the damage degree of the stirrups is calculated by combining the coupling effect comprehensive coefficient. The model is as follows:

[0079]

[0080] in, The degree of damage to the stirrups; The area of ​​the ablation damage was obtained statistically from SEM images; The total observed area is a fixed value. This is the comprehensive coefficient of the coupling effect;

[0081] A quantitative model for fiber corrosion rate is constructed, and the fiber corrosion rate of the stirrups is calculated by combining the bending strength degradation rate. The model is shown below:

[0082]

[0083] in, The fiber corrosion rate of the stirrups; The number of corroded fibers was obtained statistically from SEM images; A fixed value was used to determine the total number of fibers observed. The rate of flexural strength degradation;

[0084] Secondly, based on the damage degree of the stirrups and the fiber corrosion rate, a modified model is constructed to correct the residual shear capacity of the concrete beam, as shown in the following model:

[0085]

[0086] in, for Residual shear capacity after time correction; for The remaining shear capacity of the concrete beam at any given moment; and These are the weighting coefficients; The degree of damage to the stirrups; The fiber corrosion rate of the stirrups;

[0087] Finally, based on the corrected residual shear capacity, the degradation mechanism comprehensive coefficient is calculated, as shown in the following function:

[0088]

[0089] in, This is the comprehensive coefficient for the degradation mechanism; and These are the weighting coefficients; The reference ultimate shear capacity of the concrete beam is directly measured from the reference beam. for Residual shear capacity after time correction; The degree of damage to the stirrups; The fiber corrosion rate of the stirrups.

[0090] Module 5: Comprehensive Shear Performance Assessment Module. Based on the modified residual shear capacity, benchmark ultimate shear capacity, degradation mechanism comprehensive coefficient, maximum crack width, and benchmark maximum crack width, a comprehensive assessment index model is constructed to calculate the comprehensive assessment index; based on the comprehensive assessment index, the safety reserve coefficient is calculated; a grading model is constructed, and the shear performance grades are classified by combining the comprehensive assessment index and the safety reserve coefficient.

[0091] First, a comprehensive evaluation index model is constructed. Combining the modified residual shear capacity, the benchmark ultimate shear capacity, the degradation mechanism comprehensive coefficient, the maximum crack width, and the benchmark maximum crack width, the comprehensive evaluation index is calculated. The model is shown below:

[0092]

[0093] in, For comprehensive evaluation indicators; , and These are the weighting coefficients; for Residual shear capacity after time correction; This represents the baseline ultimate shear capacity of the concrete beam. This is the comprehensive coefficient for the degradation mechanism; for The maximum crack width of the concrete beam at any given moment; The reference maximum crack width of the concrete beam is directly measured from the reference beam.

[0094] Secondly, based on the comprehensive evaluation indicators and combined with the coupling effect comprehensive coefficient, the safety reserve coefficient is calculated using the following function:

[0095]

[0096] in, This is the safety reserve factor; For comprehensive evaluation indicators; This is the comprehensive coefficient of the coupling effect;

[0097] Finally, a grading model is constructed, combining comprehensive evaluation indicators and safety reserve coefficients to classify shear performance levels, as shown in the model below:

[0098]

[0099] in, Shear performance grades include Excellent good, qualified, Warning and Five levels of danger; For comprehensive evaluation indicators; , , , and Thresholds for comprehensive evaluation indicators; This is the safety reserve factor; , , , and This is the threshold for the safety reserve factor.

[0100] In this example,

[0101] Five sets of test conditions were designed, and the data are shown in the table below.

[0102]

[0103] In Module 1, the chloride salt corrosion correction factor is used. Load damage correction factor Actual chloride solution concentration and the concentration of the reference chloride solution Substituting the values ​​into the formula, the data is shown in the table below.

[0104]

[0105] In Module 2, the bending strength degradation coefficient of the stirrups is taken. Reference bending strength of stirrup bending zone and weighting coefficients , Substituting the values ​​into the formula, the data is shown in the table below.

[0106] In Module 3, the shear degradation coefficient of the concrete beam is taken. The shear efficiency coefficient of stirrups and the benchmark shear bearing capacity of concrete beams The benchmark cracking load of concrete beams The reference maximum crack width of concrete beams Cross-sectional area of ​​a single stirrup Effective height of concrete beam section Spacing between stirrups Substituting the values ​​into the formula, the data is shown in the table below.

[0107]

[0108] In Module 4, the total observed area is taken. Total number of observed fibers Weighting coefficient , and , and the benchmark ultimate shear capacity of concrete beams Substituting the values ​​into the formula, the data is shown in the table below.

[0109]

[0110] In simulation five, the weighting coefficients are taken. , and Thresholds of comprehensive evaluation indicators , , and The threshold of the safety reserve factor , , and Substituting the values ​​into the formula, the data is shown in the table below.

[0111]

[0112] This invention has many specific applications. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A shear resistance assessment system for seawater sand concrete beams based on load-chloride coupling, characterized in that, The system includes: Module 1: Data Acquisition Module. This module acquires the actual chloride solution concentration and combines it with the baseline chloride solution concentration to calculate the erosion coefficient; it constructs a load action coefficient model and calculates the load action coefficient by combining the load level and the test age; and it calculates the coupling effect comprehensive coefficient by combining the erosion coefficient and the load action coefficient. Module 2: Stirrup Bending Strength Calculation Module. This module constructs a bending strength degradation rate model to calculate the bending strength degradation rate of stirrups in the bending region. Based on the bending strength degradation rate, it calculates the remaining bending strength of stirrups in the bending region. Combining the bending strength degradation rate and the coupling effect comprehensive coefficient, it calculates the correlation between stirrup bending strength degradation and beam shear capacity degradation. Module 3: Beam Shear Performance Calculation Module. This module constructs a model of the remaining shear capacity of a concrete beam and calculates its remaining shear capacity; it also constructs a model of the remaining shear capacity of stirrups and calculates their remaining shear capacity; finally, by combining the remaining shear capacity of the concrete beam and the remaining shear capacity of the stirrups, the module calculates the ultimate remaining shear capacity of the concrete beam. Module 4: Degradation Mechanism Fusion Module. This module uses SEM to observe the number of corroded fibers and the area of ​​peeling damage in the stirrups, calculating the degree of damage and fiber corrosion rate of the stirrups. Based on the degree of damage and fiber corrosion rate of the stirrups, a correction model is constructed to correct the remaining shear capacity of the concrete beam. Based on the corrected remaining shear capacity, a comprehensive degradation mechanism coefficient is calculated. Module 5: Comprehensive Shear Performance Evaluation Module. Based on the modified residual shear capacity, the benchmark ultimate shear capacity, the degradation mechanism comprehensive coefficient, the maximum crack width, and the benchmark maximum crack width, a comprehensive evaluation index model is constructed, and comprehensive evaluation indices are calculated. Based on the comprehensive evaluation indices, a safety reserve coefficient is calculated. A grading model is constructed, and shear performance grades are classified by combining the comprehensive evaluation indices and the safety reserve coefficient.

2. The system according to claim 1, characterized in that, In module two, the bending strength degradation rate model is as follows: in, The rate of flexural strength degradation; It is an exponential function; This is the bending strength degradation coefficient of the stirrup; This is the comprehensive coefficient of coupling effect; The experimental age; A correlation calculation model is constructed, as shown below: in, The correlation coefficient; and These are the weighting coefficients; The rate of flexural strength degradation; This is the combined coefficient of the coupling effect.

3. The system according to claim 1, characterized in that, In Module 3, a model for the residual ultimate shear capacity of the beam is constructed to calculate the residual ultimate shear capacity of the concrete beam. The model is shown below: in, for The remaining ultimate shear capacity of the concrete beam at any given moment; for The remaining shear capacity of the concrete beam at any given time; for The remaining shear capacity of the stirrups at any given time; The correlation coefficient; This is the combined coefficient of the coupling effect.

4. The system according to claim 1, characterized in that, In module four, the corrected model is as follows: in, for Residual shear capacity after time correction; and These are the weighting coefficients; The degree of damage to the stirrups; The fiber corrosion rate of the stirrups; for The remaining ultimate shear capacity of the concrete beam at any given moment; The comprehensive coefficient function for calculating the degradation mechanism is shown below: in, This is the comprehensive coefficient for the degradation mechanism; and These are the weighting coefficients; This represents the baseline ultimate shear capacity of the concrete beam.

5. The system according to claim 1, characterized in that, In Module 5, the comprehensive evaluation index model is as follows: in, For comprehensive evaluation indicators; , and These are the weighting coefficients; for The maximum crack width of the concrete beam at any given moment; This represents the baseline maximum crack width for a concrete beam.

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