Disease assessment method for recent modern historical buildings

Abstract

The invention provides a recent modern historical building disease assessment method which comprises the following steps: 1) determining a historical building assessment part which comprises disease assessment factor grade division and disease assessment factor weight calculation; 2) obtaining disease evaluation indexes; according to the method, the limitation of traditional qualitative analysis is broken through, and quantitative treatment is performed on the diseases, so that the safety performance of the building is reflected more accurately, it is ensured that the historical building is stored for a long time and properly repaired, and the disease state of the whole building or a specific component (such as a single wall or a single column) can be comprehensively reflected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of building structure risk assessment, and particularly relates to a method for evaluating diseases of modern and contemporary historical buildings. BACKGROUND

[0002] The disease evaluation of historical buildings is an important basis for the sustainable maintenance, reinforcement and protection of the buildings. In view of the complexity and uncertainty of the diseases of historical buildings and the natural environmental factors of the regions where the buildings are located, it is necessary to develop a disease evaluation standard for a specific region, such as a coastal region, to objectively evaluate different types and degrees of diseases and provide a reliable reference for the later reinforcement and repair of historical buildings. SUMMARY

[0003] The present application provides a method for evaluating diseases of modern and contemporary historical buildings to objectively evaluate different types and degrees of diseases and provide a reliable reference for the later reinforcement and repair of historical buildings.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is a method for evaluating diseases of modern and contemporary historical buildings, comprising the following steps:

[0005] 1) determining the historical building evaluation part, which includes disease evaluation factor grade division and disease evaluation factor weight calculation, the disease evaluation factor grade division grades include slight, general, relatively heavy, serious, very serious, corresponding to grade values of 1, 2, 3, 4, and 5, respectively;

[0006] 2) obtaining disease evaluation indexes, weighting and comprehensively calculating multiple characteristic values of disease phenomenon area proportion, disease factor grade score, and disease factor weight index to obtain disease evaluation index values;

[0007] 3) grade standard division and comprehensive disease evaluation, dividing the disease grades from small to large according to the obtained disease evaluation index values, including grades 1 to 5, and corresponding the evaluation factors to the overall disease condition of the building, observing and recording the disease related items, evaluating each disease according to the standard of disease factor grade division, and recording the disease area proportion.

[0008] The basis for the disease evaluation factor grade division includes wall stain discoloration, wall finish layer falling off, wall vegetation growth, component crack, wall puffy, concrete damage, steel corrosion and fracture, component decay and insect damage, and component fracture.

[0009] The proportion of the area of the wall body with discoloration and spots is 0-8%, corresponding to the disease assessment factor level of slight; the proportion of the area of the wall body with discoloration and spots is 8-15%, corresponding to the disease assessment factor level of general; the proportion of the area of the wall body with discoloration and spots is 15-25%, corresponding to the disease assessment factor level of relatively heavy; the proportion of the area of the wall body with discoloration and spots is 25-40%, corresponding to the disease assessment factor level of serious; and the proportion of the area of the wall body with discoloration and spots is greater than 40%, corresponding to the disease assessment factor level of very serious.

[0010] The proportion of the area of the wall body with the falling of the decorative layer is 0-5%, and the disease depth is less than 20%, corresponding to the disease assessment factor level of slight; the proportion of the area of the wall body with the falling of the decorative layer is 5%-10%, and the disease depth is 20%-50%, corresponding to the disease assessment factor level of general; the proportion of the area of the wall body with the falling of the decorative layer is 10%-20%, and the disease depth is 50%-80%, corresponding to the disease assessment factor level of relatively heavy; the proportion of the area of the wall body with the falling of the decorative layer is 20%-30%, and the disease depth is 80%-100%, corresponding to the disease assessment factor level of serious; and the proportion of the area of the wall body with the falling of the decorative layer is greater than 30%, and the disease depth is greater than 100%, corresponding to the disease assessment factor level of very serious.

[0011] The proportion of the area of the wall body with the growth of vegetation is 0-40%, corresponding to the disease assessment factor level of slight; the proportion of the area of the wall body with the growth of vegetation is 40%-50%, corresponding to the disease assessment factor level of general; the proportion of the area of the wall body with the growth of vegetation is 50%-60%, corresponding to the disease assessment factor level of relatively heavy; the proportion of the area of the wall body with the growth of vegetation is 60%-70%, corresponding to the disease assessment factor level of serious; and the proportion of the area of the wall body with the growth of vegetation is greater than 70%, corresponding to the disease assessment factor level of very serious.

[0012] The component has no obvious cracks, corresponding to the disease assessment factor level of slight; the maximum crack width of the component is less than 0.1 mm, corresponding to the disease assessment factor level of general; 0.1 mm≤the maximum crack width of the component<0.4 mm, corresponding to the disease assessment factor level of relatively heavy; 0.4 mm≤the maximum crack width of the component<1.0 mm, corresponding to the disease assessment factor level of serious; and the maximum crack width of the component is greater than 1.0 mm, the length of the vertical crack exceeds 1 / 2 of the height of the component, or the component has horizontal cracks due to eccentric compression, corresponding to the disease assessment factor level of very serious.

[0013] The proportion of the area of the wall body with the falling of the decorative layer is 0-5%, and the disease depth is less than 20%, corresponding to the disease assessment factor level of slight; the proportion of the area of the wall body with the falling of the decorative layer is 5%-10%, and the disease depth is 20%-50%, corresponding to the disease assessment factor level of general; the proportion of the area of the wall body with the falling of the decorative layer is 10%-20%, and the disease depth is 50%-80%, corresponding to the disease assessment factor level of relatively heavy; the proportion of the area of the wall body with the falling of the decorative layer is 20%-30%, and the disease depth is 80%-100%, corresponding to the disease assessment factor level of serious; and the proportion of the area of the wall body with the falling of the decorative layer is greater than 30%, and the disease depth is greater than 100%, corresponding to the disease assessment factor level of very serious.

[0014] Steel bar corrosion rate is 0-3%, no rust break corresponding disease assessment factor level is slight, steel bar corrosion rate is 3%-8%, no rust break corresponding disease assessment factor level is general, steel bar corrosion rate is 8%-15%, rust break <3 corresponding disease assessment factor level is heavy, steel bar corrosion rate is 15%-20%, rust break <5 corresponding disease assessment factor level is serious, steel bar corrosion rate >20%, rust break >5 corresponding disease assessment factor level is very serious.

[0015] Use analytic hierarchy process as the weight calculation method of disease factor, including the following steps: constructing hierarchical structure model, constructing each level judgment matrix, hierarchical single ordering and consistency check, hierarchical total ordering and consistency check.

[0016] Disease assessment index value calculation formula is:

[0017]

[0018] Wherein:

[0019] D wb Disease degree index;

[0020] K n The nth disease level (value 1-5) is judged by apparent disease condition;

[0021] W n The weight value of the nth disease is adopted;

[0022] A is the total area of the assessment object

[0023] K max The most serious disease level of the disease is constant 5.

[0024] Compared with the prior art, the present application has the following advantages and positive effects:

[0025] The present application breaks through the limitations of traditional qualitative analysis, quantitatively processes the disease, and thus more accurately reflects the safety performance of the building, ensures the long-term preservation and proper repair of the historical building, and can comprehensively reflect the disease state of the entire building or specific components (such as single wall or column). BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0027] Figure 1 Disease assessment factor map. DETAILED DESCRIPTION

[0028] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as there is no conflict between them.

[0030] 1 Disease factor classification

[0031] According to "Dangerous Building Appraisal Standard" JGJ 125-2016

[106] , "Civil Building Reliability Appraisal Standard" GB50292-2015

[107] and relevant documents such as

[44] , nine kinds of common diseases of historic buildings are classified respectively, each kind of disease is divided into five levels of slight, general, heavy, serious and very serious, and the corresponding disease degree of each level is described.

[0032] 1.1 Stain discoloration

[0033] Stain discoloration is formed by the action of moisture in the air, which is a form of disease from the inside to the outside of the wall. Stain discoloration is often accompanied by wet block, efflorescence and other phenomena. According to the previous disease investigation, it is found that stain discoloration generally occurs near the wall corner and wall foot. If stain discoloration occurs in a large area, measures such as moisture prevention or seepage prevention should be taken. Through investigation and reference to relevant documents, the disease is determined as a dangerous critical value when the wall area reaches 40%, and the specific disease degree classification standard is shown in Table 1.1.

[0034] Table 1.1 Disease degree classification standard of stain discoloration

[0035]

[0036] 1.2 Decorative layer peeling

[0037] The surface layer is mostly painted material, although the surface layer disease has no direct impact on the integrity of historic buildings, but its various disease mechanisms are related to the deterioration mechanism of the internal materials of the building, and to some extent, it can reflect the adverse effects on the interior of the building. The surface layer will fall off, causing the building to lose protection in some areas and be exposed, causing more serious diseases on the surface of the building. Therefore, when assessing the disease of historic buildings, the surface layer separation disease needs to be considered, and the disease degree classification standard is established, as shown in Table 1.2.

[0038] Table 1.2 Surface layer peeling disease degree classification standard

[0039]

[0040] 1.3 Vegetation growth

[0041] Vegetation growth disease occurs more frequently in humid areas. Although vegetation growth does not have a direct impact on historic buildings, when there is too much plant coverage on the wall, it will cause the wall to be cold for a long time, inducing wet patches and other related diseases. In rare cases, shrubs grow on the wall or wall of the building, and the plant roots directly compress the wall and damage its integrity. Therefore, when assessing the disease of historic buildings, the impact of vegetation growth needs to be considered. Based on the statistical analysis of vegetation growth disease, a vegetation growth disease degree classification standard is established, as shown in Table 1.3.

[0042] Table 1.3 Vegetation growth disease degree classification standard

[0043]

[0044] 1.4 Member cracks

[0045] The occurrence of member cracks will directly affect the integrity and safety of the entire building. Wood member cracks will weaken the load-bearing capacity of the member, thereby affecting the stability of the overall structure; brick masonry cracks will reduce the load-bearing capacity of the member, leading to water penetration, accelerating the weathering and corrosion process of the brick masonry, and weakening the structural performance. Concrete cracks will damage the integrity of the concrete, cause stress concentration, lead to steel corrosion, water penetration, and other problems, and have a serious impact on the structural safety and performance of the building. Through research and reference to relevant literature, reference is made to the Hazardous Building Identification Standard JGJ 125-2016

[106] The maximum crack width of the member due to compression is greater than 1.0 mm, the crack length is more than 1 / 2 of the member height, or the horizontal crack of the member due to eccentric compression is determined as a dangerous critical value. The specific content of the member crack disease degree classification standard is shown in Table 1.4.

[0046] Table 1.4 Member crack disease degree classification standard

[0047]

[0048] 1.5 Wall body alkali

[0049] With the influence of moisture, the wall is rich in a large number of soluble salts, which will repeatedly dissolve, crystallize under the influence of temperature and humidity changes, and gradually accumulate on the surface of the wall. Due to the volume change caused by salt crystallization and dissolution, under the action of repeated expansion and contraction, the wall structure is constantly loose, and the surface is continuously eroded to form alkali disease. Refer to the Standard for Identification of Dangerous Buildings JGJ 125-2016

[106] When the effective section is weakened by 20% and the disease depth is greater than 15mm, it is the critical value of danger, and the specific classification standard is shown in Table 1.5.

[0050] Table 1.5 Wall alkali disease degree classification standard

[0051]

[0052] 1.6 Concrete damage

[0053] The damage of concrete will reduce the structural strength and stability of the concrete members of historical buildings, at the same time, the damage may also lead to water intrusion, steel corrosion and fracture, etc., thereby further endangering the structural integrity of the building. Therefore, the influence of concrete damage on historical buildings is very serious, and this disease should also be fully considered in the disease assessment. Refer to the Standard for Identification of Dangerous Buildings JGJ 125-2016

[106] When the effective section of the concrete damage is weakened by 20% and the disease depth is greater than 30mm, it is the critical value of danger, and the specific classification standard is shown in Table 1.6.

[0054] Table 1.6 Concrete damage disease degree classification standard

[0055]

[0056] 1.7 Steel corrosion and fracture

[0057] The steel in the concrete members of historical buildings will be corroded and even fractured due to long-term influence of wet environment. Steel corrosion not only damages the load-carrying capacity of the member, but also causes cracking and spalling of concrete, thereby accelerating the functional loss and even loss of concrete members. When assessing the disease of historical buildings, the steel corrosion and fracture disease should be considered. Refer to the Standard for Identification of Dangerous Buildings JGJ 125-2016

[106] and other relevant literature, when the steel section corrosion rate exceeds 20% and the rust fracture exceeds 5, it is the critical value of danger, and the specific classification standard of this disease is shown in Table 1.7.

[0058] Table 1.7 Steel bar corrosion and fracture disease degree grading standard

[0059]

[0060] 1.8 Woodworm

[0061] Woodworm disease generally only occurs on wooden components, mainly manifested as a decrease in effective cross-section caused by material decay, and growth defects caused by woodworm. Decay and woodworm can significantly reduce the strength and hardness of wood, resulting in a significant decrease in its load-bearing capacity. In addition, woodworm can form cavities and channels inside the wood, further weakening the structural performance of the component, and may become a pathway for water and other harmful substances to enter, accelerating the decay process of the wood and causing serious damage to the structure and function. After investigation and reference to the "Reliability Identification Standard for Civil Buildings" GB50292-2015

[107] , if the area of woodworm decay of the component is greater than 10% of the original cross-sectional area, it is considered to reach the critical value of danger. The specific grading standard is shown in Table 1.8.

[0062] Table 1.8 Woodworm disease degree grading standard

[0063]

[0064] 1.9 Component fracture

[0065] When a component is fractured, it means that the material is separated or damaged, resulting in a visible fracture surface. This will cause a sharp decrease in the performance of the building material, or even complete loss, leading to partial or complete collapse, and seriously affecting the safety of the overall building. Through investigation and reference to relevant literature, it is determined that when the component fracture is greater than 8, it is considered to reach the critical value of danger. The specific grading standard is shown in Table 1.9.

[0066] Table 1.9 Component fracture disease degree grading standard

[0067]

[0068]

[0069] 2 Disease factor weight calculation

[0070] Combining modern evaluation methods and referring to relevant cases of value assessment, the Analytic Hierarchy Process (AHP) is used as the weight calculation method of disease factors. The Analytic Hierarchy Process provides a scientific decision-making method for the importance, influence, and priority of factors that are difficult to quantify

[108]

[109] , which mainly includes the following steps: constructing a hierarchical structure model, constructing a judgment matrix for each level, single ordering and consistency checking, and total ordering and consistency checking

[110]

[111] .

[0071] According to the analytic hierarchy process and Figure 1 , the disease assessment factor model is established, including 1 target layer, 3 criterion layers, and 3 index layers under each criterion layer, as shown in Table 1.10.

[0072] Table 1.10 Disease Assessment Factor Model

[0073]

[0074] 2.1 Constructing the Criterion Layer Judgment Matrix

[0075] The 1-9 ratio scale method is used

[112] to assign values to the judgment matrix, obtaining the A-Bi judgment matrix, as shown in Table 1.12.

[0076] Table 1.11 Risk Factor Comparison Score Value Table

[0077]

[0078]

[0079] Table 1.12 A-Bi Judgment Matrix

[0080]

[0081] The square root method is used to calculate the evaluation factor weight vector W i , as shown in equation (5.1),

[0082]

[0083] ∑W i = 3.3651

[0084] The approximate value of the weight vector W i is normalized to obtain the evaluation factor weight vector ω i , as shown in equation (5.2),

[0085]

[0086] 2.2 Consistency Test of Criterion Layer on Target Layer

[0087] The judgment matrix AW = λW,

[0088]

[0089] The maximum eigenvalue λ max = 3 is calculated, and the consistency index is calculated as shown in equation (5.3),

[0090]

[0091] Substitute C1=0, when n=3, R1=0.58, and the consistency ratio CR=C1 / R1, substitute CR=0<0.1, meet the consistency requirements.

[0092] The matrix has complete consistency.

[0093] 2.3 Constructing the judgment matrix of index layer C1i, weight calculation and consistency test

[0094] The index layer C1i each element of the guideline layer of the surface disease weight calculation, the judgment matrix constructed is shown in Table 1.13.

[0095] Table 1.13 B1-C1i judgment matrix

[0096]

[0097] Similarly, the square root method can be used to obtain the approximate value of the weight:

[0098]

[0099] ∑W i =3.3651

[0100] Through the normalization processing can be obtained:

[0101]

[0102] The judgment matrix AW=λW,

[0103]

[0104] The maximum eigenvalue λ max =3,

[0105] The consistency index C1=0, when n=4, R1=0.58, and the consistency ratio CR=C1 / R1, substitute CR=0<0.1, meet the consistency requirements.

[0106] 2.4 Constructing the judgment matrix of index layer C2i, weight calculation and consistency test

[0107] The index layer C2i each element of the guideline layer of the deep disease weight calculation, the judgment matrix constructed is shown in Table 1.14.

[0108] Table 1.14 B2-C2i judgment matrix

[0109]

[0110] Still using the square root method, the approximate value of the weight can be obtained:

[0111]

[0112] ∑W i = 3.3651

[0113] By normalization processing can be obtained:

[0114]

[0115] Judgment matrix AW = λW,

[0116]

[0117] The maximum eigenvalue λ max = 3,

[0118] The consistency index C1 = 0, when n = 3, R1 = 0.58, the consistency ratio CR = 0 < 0.1, meet the consistency requirements.

[0119] 2.5 Construction of index layer C3i judgment matrix, weight calculation and consistency check

[0120] Index layer C3i each element of the guideline layer weight calculation of the internal disease, the judgment matrix constructed is shown in Table 1.15.

[0121] Table 1.15 B3-C3i judgment matrix

[0122]

[0123] Still using the square root method, the weight approximation value can be obtained:

[0124]

[0125] By normalization processing can be obtained:

[0126]

[0127] Judgment matrix AW = λW,

[0128]

[0129] The maximum eigenvalue λ max = 3,

[0130] The consistency index C1 = 0, when n = 3, R1 = 0.58, the consistency ratio CR = 0 < 0.1, meet the consistency requirements.

[0131] 2.6 Weight calculation results

[0132] Through calculation, the weight proportion of surface disease to disease evaluation factor is 0.06120, 0.06120 and 0.02039, the weight proportion of deep disease to disease evaluation factor is 0.18370, 0.18370 and 0.06120, and the weight proportion of inner disease to disease evaluation factor is 0.25716, 0.08572 and 0.08572, respectively. The weight proportion of each disease evaluation factor is shown in Table 1.16.

[0133] Table 1.16 Weight proportion of each disease evaluation factor

[0134]

[0135] 3 Comprehensive disease degree index and grade standard division

[0136] In the evaluation of the comprehensive disease degree of historical buildings, the evaluation object is first determined, then the type of disease of the evaluated object is determined, the occurrence of the disease phenomenon is observed, the corresponding grade of the disease is judged according to the aforementioned disease degree grading table, and the ratio of the affected area to the total area of the evaluation object is recorded. The disease degree index is represented by D wb , the disease phenomenon area ratio, the disease factor grade score, and the disease factor weight index are weighted and comprehensively calculated to obtain the disease degree index.

[0137] The calculation formula is:

[0138]

[0139] Among them:

[0140] D wb is the disease degree index;

[0141] K n is the disease grade of the nth disease determined by the apparent disease condition (taking the value 1-5);

[0142] W n is the weight value of the nth disease;

[0143] A is the total area of the evaluation object

[0144] K max is the most serious disease grade of the disease, taking the constant 5.

[0145] The obtained disease degree index value is the comprehensive value of the disease degree, and the quantitative value can make the various disease phenomena of the evaluated object more comparable and researchable. Referring to the relevant research and standard, the evaluation results of historical buildings are divided into five grades, different numerical ranges correspond to different disease degrees, the grade standard of the disease degree index of historical buildings is obtained, and treatment suggestions and protection measures are proposed for the corresponding conditions, as shown in Table 1.17.

[0146] Table 1.17 Index of the extent of disease of historical buildings

[0147]

[0148] Finally, it should be noted that the above examples are intended to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for assessing damage to modern and contemporary historical buildings, characterized in that: The steps include: 1) Determine the historical building assessment part, which includes the classification of disease assessment factors and the calculation of disease assessment factor weights. The disease assessment factor classification levels include mild, general, severe, serious, and very serious, corresponding to level values ​​1, 2, 3, 4, and 5 respectively; 2) Obtaining a disease assessment index by weighted comprehensive calculation of multiple characteristic values ​​including the disease phenomenon area ratio, the disease factor grade score, and the disease factor weight index to obtain a disease assessment index value; 3) Classification of grades and comprehensive disease evaluation: Classify the disease grades from small to large according to the obtained disease assessment index values, including grades one to five, and correspond the evaluation factors to the overall disease conditions of the building. Observe and record the disease-related items, evaluate each disease according to the standards for disease factor classification, and record the proportion of the disease area.

2. The method for assessing damage to modern and contemporary historical buildings according to claim 1 is characterized in that: The basis for the classification of the disease assessment factors includes the condition of wall stains and discoloration, the condition of wall finishing layer peeling, the condition of wall vegetation growth, the condition of component cracks, the condition of wall alkali erosion, the condition of concrete damage, the condition of steel bar rust and fracture, the condition of component decay and insect infestation, and the condition of component fracture.

3. The method for assessing damage to modern and contemporary historical buildings according to claim 2, characterized in that: If the wall area with discoloration and scars accounts for 0-8%, the corresponding disease assessment factor level is mild; if the wall area with discoloration and scars accounts for 8-15%, the corresponding disease assessment factor level is general; if the wall area with discoloration and scars accounts for 15-25%, the corresponding disease assessment factor level is severe; if the wall area with discoloration and scars accounts for 25-40%, the corresponding disease assessment factor level is serious; if the wall area with discoloration and scars accounts for more than 40%, the corresponding disease assessment factor level is very serious.

4. The method for assessing damage to modern and contemporary historical buildings according to claim 2, characterized in that: If the area of ​​wall finishing layer falling off accounts for 0-5% and the depth of the disease is less than 20%, the corresponding damage assessment factor level is mild; if the area of ​​wall finishing layer falling off accounts for 5%-10% and the depth of the disease is 20%-50%, the corresponding damage assessment factor level is general; if the area of ​​wall finishing layer falling off accounts for 10%-20% and the depth of the disease is 50%-80%, the corresponding damage assessment factor level is severe; if the area of ​​wall finishing layer falling off accounts for 20%-30% and the depth of the disease is 80%-100%, the corresponding damage assessment factor level is serious; if the area of ​​wall finishing layer falling off accounts for more than 30% and the depth of the disease is more than 100%, the corresponding damage assessment factor level is very serious.

5. The method for assessing damage to modern and contemporary historical buildings according to claim 2, characterized in that: When the wall vegetation growth area accounts for 0-40%, the corresponding disease assessment factor level is mild; when the wall vegetation growth area accounts for 40%-50%, the corresponding disease assessment factor level is general; when the wall vegetation growth area accounts for 50%-60%, the corresponding disease assessment factor level is severe; when the wall vegetation growth area accounts for 60%-70%, the corresponding disease assessment factor level is serious; when the wall vegetation growth area accounts for more than 70%, the corresponding disease assessment factor level is very serious.

6. The method for assessing damage to modern and contemporary historical buildings according to claim 2 is characterized in that: The corresponding disease assessment factor level for components with no obvious cracks is mild, the corresponding disease assessment factor level for components with a maximum crack width of less than 0.1mm is general, the corresponding disease assessment factor level for components with a maximum crack width of 0.1mm≤<0.4mm is severe, the corresponding disease assessment factor level for components with a maximum crack width of 0.4mm≤<1.0mm is serious, and the corresponding disease assessment factor level for components with a maximum crack width greater than 1.0mm and a crack length exceeding 1 / 2 of the height of the component, or horizontal cracks in the component caused by eccentric compression, is very serious.

7. The method for assessing damage to modern and contemporary historical buildings according to claim 2, characterized in that: If the wall efflorescence area accounts for 0-5% and the disease depth is <3mm, the corresponding disease assessment factor level is mild; if the wall efflorescence area accounts for 5%-10% and the disease depth is 3-5mm, the corresponding disease assessment factor level is general; if the wall efflorescence area accounts for 10%-15% and the disease depth is 5-10mm, the corresponding disease assessment factor level is severe; if the wall efflorescence area accounts for 15%-20% and the disease depth is 10-15mm, the corresponding disease assessment factor level is serious; if the wall efflorescence area accounts for 20% and the disease depth is >15mm, the corresponding disease assessment factor level is very serious.

8. The method for assessing damage to modern and contemporary historical buildings according to claim 2 is characterized in that: The corresponding disease assessment factor level for a steel bar corrosion rate of 0-3% and no rust breaks is mild; the corresponding disease assessment factor level for a steel bar corrosion rate of 3%-8% and no rust breaks is general; the corresponding disease assessment factor level for a steel bar corrosion rate of 8%-15% and <3 rust breaks is severe; the corresponding disease assessment factor level for a steel bar corrosion rate of 15%-20% and <5 rust breaks is serious; the corresponding disease assessment factor level for a steel bar corrosion rate of >20% and >5 rust breaks is very serious.

9. The method for assessing damage to modern and contemporary historical buildings according to claim 1, characterized in that: The analytic hierarchy process is used as a weight calculation method for disease factors, which includes the following steps: building a hierarchical structure model, constructing a judgment matrix for each level, hierarchical single sorting and consistency test, hierarchical total sorting and consistency test.

10. The method for assessing damage to modern and contemporary historical buildings according to claim 1, characterized in that: The calculation formula for disease assessment index value is: in: D wb —Disease severity index; K n —Disease grade of the nth disease (range 1-5) determined by the apparent disease condition; W n —The weight value used for the nth disease; A—total area of ​​the assessment object; K max —The most serious disease level of the disease, which is taken as a constant of 5.

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