A method for constructing a constitutive relation model of interface bonding and sliding of gutta-percha salt corrosion deterioration
By constructing a constitutive model of bond-slip relationship at the masonry interface that takes into account salt corrosion degradation, the problem of insufficient accuracy in evaluating the stability of masonry structures due to salt corrosion damage was solved, and accurate stability assessment of ancient pagodas and other cultural relics structures was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEFEI UNIV OF TECH
- Filing Date
- 2026-03-31
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies fail to effectively consider the impact of salt corrosion damage on the interface mechanical parameters of masonry structures, resulting in insufficient accuracy of the interface constitutive relationship model and an inability to scientifically evaluate the stability of masonry cultural relics such as ancient pagodas.
By conducting bond-slip tests on un-salted masonry interfaces, combined with aging tests on salt-corroded interfaces, mortar compressive strength tests, and interface double-sided shear tests, a bond-slip constitutive model of masonry interfaces considering salt corrosion deterioration was established. Normal stress, salt corrosion cycle number, and mortar compressive strength were introduced as key parameters to construct an accurate bond-slip coupled constitutive model.
The model's computational accuracy has been improved, enabling a more accurate assessment of the stability of immovable cultural relic masonry structures such as ancient pagodas. It provides more reliable technical support, avoids errors caused by modern materials, and minimizes the error between model predictions and experimental values.
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Figure CN122287350A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of interface deterioration prediction methods and computational mechanics for immovable cultural relics masonry structures, specifically involving a method for constructing a constitutive relationship model of interface bonding and slippage in ancient pagodas affected by salt corrosion. Background Technology
[0002] Ancient pagodas are important cultural heritages in my country and even the world, and masonry structures are a typical structural type of immovable cultural relics. The bond-slip properties of the block-mortar interface determine the overall stability of the masonry structure. Having endured thousands of years of exposure to sunlight, air pollution, and groundwater erosion, ancient pagodas are prone to salt corrosion on their structural surfaces, causing the block-mortar interface properties to gradually degrade.
[0003] Currently, research on the interface durability of masonry structures is limited. Existing techniques often simplify the interface constitutive model to a broken-line type and fail to consider the impact of typical damage such as salt corrosion on the interface mechanical parameters. Determining the key interface mechanical parameters and their bond-slip constitutive models is a crucial foundation for scientifically evaluating the structural stability of masonry cultural relics such as ancient pagodas. Therefore, there is an urgent need to propose a method for constructing a bond-slip constitutive model for ancient pagoda masonry interfaces that considers salt corrosion degradation. Summary of the Invention
[0004] The purpose of this invention is to provide a method for constructing a constitutive model of interface adhesion and slippage in ancient pagodas affected by salt corrosion, so as to solve the problems of existing technologies not considering salt corrosion damage and insufficient model accuracy.
[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for constructing a constitutive relation model of interface adhesion and slippage in ancient pagodas affected by salt erosion includes the following steps: S1. Conduct bond-slip tests on the interface of unsalted masonry to determine the bond-slip constitutive model of the interface of masonry in the unsalted state. The model includes the bond-softening stage and the friction residual stage. S2. Conduct salt corrosion interface aging tests with different number of cycles; S3. Conduct mortar compressive strength tests on specimens after different salt corrosion cycles, analyze the compressive strength degradation law, and construct a mortar compressive strength prediction model. S4. Conduct interfacial double-sided shear tests under different normal stresses to determine the peak bond stress and corresponding slip at the interface under different stress states. S5. Introduce normal stress, salt corrosion cycle number, and mortar compressive strength as key parameters to establish a prediction model for peak bond stress and corresponding slip. S6. Based on the piecewise function characteristics of the bond-softening segment and the friction residual segment, a bond-slip coupling constitutive relationship model of the interface of salt-corroded and deteriorated masonry is obtained by fitting.
[0006] Furthermore, in step S1, the expression for the bond-slip constitutive relation model is: In the formula: , In the formula: It is interfacial bonding stress. It is the amount of slip. The peak stress at the interface, Peak stress The corresponding slip amount, It refers to the number of aging test cycles. It is normal stress. This represents the test value of the mortar compressive strength.
[0007] Furthermore, in step S2, one cycle of the salt corrosion interface aging test is as follows: take a standard specimen, dry it at high temperature to constant weight, cool it and soak it in salt solution for 15 hours, then keep it at 80°C for 6 hours, and then cool it to 20°C and keep it for 2 hours.
[0008] Furthermore, in step S2, the number of cycles selected for the salt corrosion interface aging test includes at least 5, 10, 12, and 18 cycles.
[0009] Furthermore, in step S3, the expression for the mortar compressive strength prediction model is:
[0010]
[0011] In the formula: yes Mortar compressive strength under multiple salt erosion cycles It is the compressive strength of mortar under 0 salt corrosion cycles.
[0012] Furthermore, in step S4, the normal stress selected for the interfacial double-sided shear test includes at least 0.2 MPa, 0.4 MPa, and 0.6 MPa.
[0013] Furthermore, in step S5, the peak bond stress is the inflection point between the bond softening segment and the friction stage of the curve. The formula for calculating bond stress is:
[0014] In the formula: This represents the maximum load value in the double-sided shear test. This represents the area of the shear plane on one side.
[0015] Considering key parameters such as normal stress, number of cycles, and mortar strength, the prediction model for peak bond stress and corresponding slip is as follows:
[0016] .
[0017] Furthermore, in step S6, the constitutive model of the bond-slip coupling at the interface of the salt-corroded and deteriorated masonry is as follows: .
[0018] Furthermore, the bond-slip coupling constitutive model of the salt-eroded masonry interface is used for stability assessment of ancient pagodas or other immovable cultural relic masonry structures.
[0019] Furthermore, in the bond-slip test of the unsalted masonry interface, the selected specimens were standard masonry specimens made from block materials fired using traditional cultural techniques and typical mortar types.
[0020] Beneficial Effects: This invention selects block materials and typical mortar types fired using traditional cultural techniques. The experimental materials have consistent mechanical properties with those of historical masonry buildings such as ancient pagodas, avoiding errors introduced by modern masonry materials. This invention considers key influencing factors such as the number of salt corrosion cycles, normal stress, and mortar strength, overcoming the limitations of existing technologies that simplify interface constitutive relations to a broken-line model. The established constitutive relation model more closely reflects the actual deterioration state of the interface of ancient pagoda masonry. Comparative experimental results show that the absolute and relative errors between the predicted and experimental values of the model of this invention are small, with high calculation accuracy, providing precise mechanical parameter basis for the structural stability assessment of historical buildings such as ancient pagodas. Attached Figure Description
[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart illustrating the method for constructing the interface bonding and slip constitutive relation model of ancient pagoda salt corrosion deterioration according to an embodiment of the present invention; Figure 2 This is a flowchart of the salt corrosion cycle in the method for constructing the interface bonding and slip constitutive relation model of ancient pagoda salt corrosion degradation according to an embodiment of the present invention; Figure 3 This is a comparison diagram between the constitutive model constructed by the method for constructing the interface bonding and slip constitutive relation model of ancient pagoda salt erosion and deterioration described in this embodiment of the invention and existing models. Detailed Implementation
[0022] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.
[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0024] Example 1 See Figure 1-2 A method for constructing a constitutive relation model of interface adhesion and slippage in ancient pagodas due to salt erosion and degradation, comprising the following steps: S1. Conduct bond-slip tests on the interface of unsalted masonry to determine the bond-slip constitutive model of the interface of masonry in the unsalted state. The model includes the bond-softening stage and the friction residual stage. In step S1, the expression for the bond-slip constitutive relation model is: In the formula: , In the formula: It is interfacial bonding stress. It is the amount of slip. The peak stress at the interface, Peak stress The corresponding slip amount, It refers to the number of aging test cycles. It is normal stress. This refers to the test value of the mortar compressive strength. In the specific implementation, a specimen of ancient pagoda brick-lime mortar masonry without salt corrosion was selected, with a size of 240mm×115mm×53mm. Bond-slip test was carried out to obtain the bond-slip curve of the uncorroded interface and determine the mechanical characteristic parameters of its bond-softening section and friction residual section.
[0025] S2. Conduct salt corrosion interface aging tests with different number of cycles; In step S2, one cycle of the salt corrosion interface aging test is as follows: take a standard specimen, dry it at high temperature to constant weight, cool it and soak it in salt solution for 15 hours, then keep it at 80°C for 6 hours, then cool it to 20°C and keep it for 2 hours. In step S2, the number of cycles selected for the salt corrosion interface aging test includes at least 5, 10, 12 and 18 times. In practice, 12 specimens of the above specifications were taken and divided into 4 groups of 3 specimens each. Salt corrosion cycle tests were conducted for 5, 10, 12, and 18 cycles, respectively. The salt solution used was a 5% NaCl solution, and the drying temperature was 105℃. The criterion for determining constant weight was that the mass change rate was less than 0.1% for 2 consecutive hours.
[0026] S3. Conduct mortar compressive strength tests on specimens after different salt corrosion cycles, analyze the compressive strength degradation law, and construct a mortar compressive strength prediction model. In step S3, the expression for the mortar compressive strength prediction model is:
[0027]
[0028] In the formula: yes Mortar compressive strength under multiple salt erosion cycles It is the compressive strength of mortar under 0 salt corrosion cycles.
[0029] In practice, mortar core samples were drilled from the specimens after each salt corrosion cycle to make cubic specimens with a side length of 70.7 mm, and compressive strength tests were carried out. The test results are shown in Table 1 below.
[0030] Table 1 Test values and predicted values of mortar compressive strength
[0031] A mortar compressive strength prediction model was obtained by fitting experimental data.
[0032] S4. Conduct interfacial double-sided shear tests under different normal stresses to determine the peak bond stress and corresponding slip at the interface under different stress states. In step S4, the normal stress selected for the interfacial double-sided shear test includes at least 0.2 MPa, 0.4 MPa, and 0.6 MPa; In the specific implementation, normal stresses of 0.2MPa, 0.4MPa, and 0.6MPa were applied to each group of specimens, and double-sided shear tests were carried out to determine the peak bond stress and the corresponding slip. The comparison results between the test values and the predicted values are shown in Table 2 below.
[0033] Table 2. Test and predicted values of main mechanical parameters of the interface.
[0034] S5. Introduce normal stress, salt corrosion cycle number, and mortar compressive strength as key parameters to establish a prediction model for peak bond stress and corresponding slip. In step S5, the peak bond stress is the inflection point between the bond softening segment and the friction stage of the curve. The formula for calculating bond stress is:
[0035] In the formula: This represents the maximum load value in the double-sided shear test. This represents the area of the shear plane on one side.
[0036] Considering key parameters such as normal stress, number of cycles, and mortar strength, the prediction model for peak bond stress and corresponding slip is as follows:
[0037] .
[0038] S6. Based on the piecewise function characteristics of the bond-softening segment and the friction residual segment, a bond-slip coupling constitutive relationship model of the interface of salt-corroded and deteriorated masonry is obtained by fitting. In step S6, the constitutive model of the bond-slip coupling at the interface of the salt-corroded and deteriorated masonry is as follows: .
[0039] In a specific instance, the bond-slip coupling constitutive model of the salt-eroded masonry interface in this embodiment is used for stability assessment of ancient pagodas or other immovable cultural relic masonry structures.
[0040] In a specific instance, in the bond-slip test of the unsalted masonry interface, the selected specimens were standard masonry specimens made from block materials fired using traditional cultural techniques and typical mortar types.
[0041] See Figure 3 In the figure, 1-the constitutive model of the interface of the present invention, 2-the constitutive model of the combination of adhesion and friction, and 3-the constitutive model considering only the adhesion effect.
[0042] Therefore, Figure 3 The invention demonstrates the comparative effect of its model with existing technology models, showing that the model better reflects the actual bond-slip mechanical behavior of the interface of salt-eroded and deteriorated masonry, and intuitively demonstrates the accuracy advantage of the invention's model. The invention obtains an accurate constitutive relation model by fitting experimental data. Compared with existing technologies, the invention considers the core factors of salt-erosion and deterioration, the experimental materials are consistent with the actual masonry materials of ancient pagodas, the model has higher prediction accuracy, and can provide more reliable technical support for cultural relic protection.
[0043] In summary, the experimental materials used in this embodiment are block materials fired using traditional cultural techniques and typical mortar types, which have significantly different mechanical properties from modern masonry materials. Existing technologies simplify the interface constitutive relationship model to a broken-line type and do not consider the impact of typical damage on interface mechanical parameters. This invention proposes an interface mechanical prediction model under different damage states based on typical salt corrosion. Comparing the experimental results, the technical effect of this invention is quite close to the experimental results of interface mechanical parameters. By considering parameters such as normal stress and cycle number, the main mechanical indices of the interface under different vertical pressures and damage states can be accurately calculated. The calculation results and the interface bond-slip constitutive relationship model can provide accurate assurance for the structural stability assessment of historical buildings such as ancient pagodas.
[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for constructing a constitutive relation model of interface adhesion and slippage in ancient pagodas due to salt erosion and deterioration, characterized in that, Includes the following steps: S1. Conduct bond-slip tests on the interface of unsalted masonry to determine the bond-slip constitutive model of the interface of masonry in the unsalted state. The model includes the bond-softening stage and the friction residual stage. S2. Conduct salt corrosion interface aging tests with different number of cycles; S3. Conduct mortar compressive strength tests on specimens after different salt corrosion cycles, analyze the compressive strength degradation law, and construct a mortar compressive strength prediction model. S4. Conduct interfacial double-sided shear tests under different normal stresses to determine the peak bond stress and corresponding slip at the interface under different stress states. S5. Introduce normal stress, salt corrosion cycle number, and mortar compressive strength as key parameters to establish a prediction model for peak bond stress and corresponding slip. S6. Based on the piecewise function characteristics of the bond-softening segment and the friction residual segment, a bond-slip coupling constitutive relationship model of the interface of salt-corroded and deteriorated masonry is obtained by fitting.
2. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In step S1, the expression for the bond-slip constitutive relation model is: In the formula: , In the formula: It is interfacial bonding stress. It is the amount of slip. The peak stress at the interface, Peak stress The corresponding slip amount, It refers to the number of aging test cycles. It is normal stress. This represents the test value of the mortar compressive strength.
3. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In step S2, one cycle of the salt corrosion interface aging test is as follows: take a standard specimen, dry it at high temperature to constant weight, cool it and soak it in salt solution for 15 hours, then keep it at 80°C for 6 hours, and then cool it to 20°C and keep it for 2 hours.
4. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In step S2, the number of cycles selected for the salt corrosion interface aging test includes at least 5, 10, 12, and 18 cycles.
5. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In step S3, the expression for the mortar compressive strength prediction model is: In the formula: yes Mortar compressive strength under multiple salt erosion cycles It is the compressive strength of mortar under 0 salt corrosion cycles.
6. The method for constructing the interface bonding and slip constitutive relation model of ancient pagoda salt erosion and deterioration according to claim 1, characterized in that, In step S4, the normal stress selected for the interfacial double-sided shear test includes at least 0.2 MPa, 0.4 MPa, and 0.6 MPa.
7. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In step S5, the peak bond stress is the inflection point between the bond softening segment and the friction stage of the curve. The formula for calculating bond stress is: In the formula: This represents the maximum load value in the double-sided shear test. This represents the area of the shear plane on one side. Considering key parameters such as normal stress, number of cycles, and mortar strength, the prediction model for peak bond stress and corresponding slip is as follows: 。 8. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In step S6, the constitutive model of the bond-slip coupling at the interface of the salt-corroded and deteriorated masonry is as follows: 。 9. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, The bond-slip coupling constitutive model of the interface of salt-corroded and deteriorated masonry is used for stability assessment of masonry structures of ancient pagodas or other immovable cultural relics.
10. The method for constructing the constitutive relation model of interface adhesion and slippage in ancient pagoda salt erosion deterioration according to claim 1, characterized in that, In the bond-slip test of the unsalted masonry interface, the selected specimens were standard masonry specimens made of block materials fired using traditional cultural techniques and typical mortar types.