Damage detection and analysis method for ultra-high ductility concrete pavement

Abstract

This invention provides a method for damage detection and analysis of ultra-high ductility concrete pavement, belonging to the technical field of damage detection and analysis of ultra-high ductility concrete pavement. The method includes the steps of preparing ultra-high ductility solid waste specimens, setting damage states, statistical law analysis, obtaining vulnerability curves, and acquiring damage states. Multiple ultra-high ductility concrete test specimens are tested separately to obtain the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress, and maximum residual energy material parameters of the ultra-high ductility concrete test specimens. This allows for the establishment of a finite element model of the ultra-high ductility solid waste pavement under bending, and the deflection value at the center point of each damage state is statistically analyzed to obtain the vulnerability curves for each damage state. Actual pavement measurements are taken and compared with each damage state to determine the specific damage state and its probability of occurrence. The damage detection and analysis method for ultra-high ductility concrete pavement provided by this invention ensures the acquisition of all mechanical formation parameters, has low testing costs, and combines numerical simulation with experimental techniques to guarantee testing effectiveness.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultra-high ductility concrete pavement damage detection and analysis, and specifically relates to an ultra-high ductility concrete pavement damage detection and analysis method. Background Art

[0002] With the popularity of hardened roads, asphalt and cement roads account for more than 90%, but as the service time of hardened roads increases, the road surface will inevitably be damaged and destroyed. Compared with the design service life of asphalt pavements, the design service life of cement pavements is longer, so the development of ultra-high ductility and high durability pavements has important economic and social significance. Ultra-high ductility concrete pavements have many advantages over traditional pavements, such as increasing the service life of the pavement, enhancing pavement safety, reducing maintenance costs, increasing bearing capacity, reducing maintenance frequency, and strong adaptability. For this reason, it is necessary to develop methods for damage identification, detection and analysis of ultra-high ductility concrete pavements.

[0003] In the prior art, the following methods are usually used for the identification, detection and analysis of damage in ultra-high ductility concrete pavement:

[0004] 1. Observation and numerical recording method, which is the most common evaluation method. Its basic steps are as follows:

[0005] Field observation: Conduct on-site surveys of roads and conduct detailed inspections of road surface damage, potholes, etc.

[0006] Classification records: Classification records and numerical records are made according to the type (such as cracks, settlement, rutting, bulging, etc.) and degree of observed pavement damage.

[0007] Comprehensive assessment: Comprehensively assess the damage status of the road surface based on the type, quantity, area and severity of the damage.

[0008] 2. Video measurement method: using video equipment to take photos or videos of road damage, and then using image processing technology to measure and analyze road damage. The basic steps are as follows:

[0009] Take photos or videos: Use high-definition cameras to capture the road surface and make sure that the details of the road damage are clearly captured.

[0010] Image processing: Use image processing software to process the captured photos or videos, including steps such as enhancing contrast and sharpening images, so as to more accurately measure the size and depth of road damage.

[0011] Measurement and analysis: Measure and analyze road damage based on processed images to obtain relevant data on the degree of damage; or use artificial intelligence tools such as convolutional neural networks, target recognition networks, etc. for intelligent identification.

[0012] 3. The laser structural depth meter method mainly uses the infrared light generated by semiconductor lasers to project it onto the surface of the road, and measures the structural depth of the road surface in this way. This method has the advantages of convenient transportation, fast operation and reliable results.

[0013] 4. Comprehensive evaluation method: This method uses the above-mentioned observation and numerical recording method, video measurement method and other methods to comprehensively evaluate the pavement damage status in combination with other factors (such as traffic volume, road grade, climatic conditions, etc.). The basic steps are as follows:

[0014] Data collection: Collect pavement damage data measured by various methods and data on other related factors.

[0015] Data Analysis: Conduct statistical analysis on the collected data to find out the main types and causes of pavement damage.

[0016] Comprehensive evaluation: Combined with data analysis results and other factors, a comprehensive evaluation is conducted on the damage status of the road surface to determine the overall damage level of the road surface and the maintenance measures that need to be taken.

[0017] 5. Other methods include using a pavement deflection meter to measure the pavement deflection value to reflect the overall strength of the pavement; using crack rate or crack ratio to reflect the degree of damage to the pavement due to tensile cracking of the structural layer or low-temperature shrinkage cracking under repeated loads; and using the rutting depth index (RDI) to evaluate the degree of damage to the pavement due to accumulated deformation under repeated loads.

[0018] The above methods are all based on the detection of existing paved roads. The detection process is relatively cumbersome, and it is impossible to remove the road surface for sampling. This kind of actual measurement method cannot obtain all mechanical performance parameters, so it has certain limitations for the final test results. Moreover, the test process cannot achieve the simulation of the test value, and thus it is impossible to combine numerical simulation with experimental technology, and the test effect is not good. The purchase, manufacture, transportation, use and maintenance of the actual measurement equipment are involved, and the cost of detection and analysis is high. Summary of the invention

[0019] The embodiment of the present invention provides a super-high ductility concrete pavement damage detection and analysis method, aiming to solve the problem of poor practicality of the existing super-high ductility concrete pavement detection and analysis method due to poor detection and analysis effect.

[0020] To achieve the above object, the technical solution adopted by the present invention is: to provide a method for detecting and analyzing damage of ultra-high ductility concrete pavement, comprising the following steps:

[0021] Prepare ultra-high ductility solid waste specimens and prepare multiple ultra-high ductility concrete test specimens;

[0022] Set the damage state, set f 1. f 2. f 3. f 4. f 5. f 6 and f 7 Seven damage states, the crack width of each damage state increases in sequence;

[0023] Statistical law analysis: by testing a plurality of the ultra-high ductility concrete test specimens respectively, the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters of the ultra-high ductility concrete test specimens are obtained to establish a finite element model of ultra-high ductility solid waste pavement under bending; run no less than 50 sets of finite element analysis, and count no less than 50 center point deflection values ​​corresponding to each damage state;

[0024] Acquiring a fragility curve, statistically analyzing the distribution law of the deflection value of the center point corresponding to each damage state, and calculating the distribution parameters to obtain a fragility curve under each damage state;

[0025] Damage status acquisition, measured elevation difference between the center line of the road surface and the edge of the road surface, recorded as f ,Will f Compare with each of the damage states to determine f The specific damage state; and according to the corresponding vulnerability curve under the damage state, the probability of occurrence of the damage state is obtained.

[0026] In a possible implementation, the ultra-high ductility concrete pavement damage detection and analysis method also includes a bending mechanical properties testing step, placing any complete ultra-high ductility concrete test specimen on a mechanical properties testing device, and adopting three-point loading, and installing multiple acoustic emission sensors on the ultra-high ductility concrete test specimen; after turning on the mechanical properties testing device, each of the damage states corresponding to the ultra-high ductility concrete test specimen is monitored by each of the acoustic emission sensors and a magnifying glass, and the deflection value under each of the damage states is determined by the mechanical properties testing device.

[0027] In a possible implementation, the mechanical property testing equipment includes:

[0028] A press having a load-bearing platform, wherein a vertically movable press end is provided above the load-bearing platform;

[0029] A support seat, fixedly mounted on the bearing platform, the support seat having two overlapping ends spaced apart in the horizontal direction and for the bottom end of the ultra-high ductility concrete test specimen to be overlapped;

[0030] A displacement meter is arranged on the support seat and is located between the two overlapped ends, and the displacement meter abuts against the bottom end of the ultra-high ductility concrete test specimen;

[0031] A lower pressure head is fixedly connected to the pressure end, and the bottom end of the lower pressure head has two loading ends abutting against the top end of the ultra-high ductility concrete test specimen, and the two loading ends are arranged at intervals along the spacing direction of the two lap ends; the distance from any one of the loading ends to the adjacent lap end in the horizontal direction is equal to the spacing distance between the two loading ends.

[0032] In a possible implementation, in the statistical law analysis step, the method of obtaining each material parameter is as follows:

[0033] The matrix fracture toughness material parameters are obtained by setting a notch in the middle of the bottom of the selected ultra-high ductility concrete test specimen, then placing the ultra-high ductility concrete test specimen on a three-point bending strength testing machine, and calculating the matrix fracture toughness according to the load-displacement curve of the ultra-high ductility concrete test specimen and the geometric parameters of the ultra-high ductility concrete test specimen;

[0034] The Young's modulus material parameter is obtained by installing the selected ultra-high ductility concrete test specimen on a tensile testing machine, and at the same time pasting a strain gauge on the surface of the ultra-high ductility concrete test specimen, stretching the ultra-high ductility concrete test specimen in the length direction by the tensile testing machine, and drawing a stress-strain curve according to the numerical value, wherein the slope of the stress-strain curve near the origin is the Young's modulus;

[0035] The fiber bridge bearing capacity material parameters are obtained by installing the selected ultra-high ductility concrete test specimen on a tensile testing machine, stretching the ultra-high ductility concrete test specimen in the length direction by the tensile testing machine, and obtaining the fiber bridge bearing capacity by the tensile force value when the fiber is pulled out and the cross section of the ultra-high ductility concrete test specimen;

[0036] The matrix cracking stress material parameters are obtained, the selected ultra-high ductility concrete test specimen is placed on a three-point bending strength testing machine, and the matrix cracking stress is calculated according to the load-displacement curve of the ultra-high ductility concrete test specimen and the geometric parameters of the ultra-high ductility concrete test specimen;

[0037] The maximum residual energy material parameters are obtained by setting a notch in the middle of the bottom of the selected ultra-high ductility concrete test specimen, then placing the ultra-high ductility concrete test specimen on a three-point bending strength testing machine, and drawing a stress-cracking displacement curve according to the numerical values ​​to obtain the maximum residual energy.

[0038] In a possible implementation, in the statistical law analysis step, each obtained material parameter varies within 10%.

[0039] In a possible implementation, in the step of setting the damage state, each of the damage states is:

[0040] f 1—Microscopic cracking of the pavement material matrix, f 2—Fiber-matrix debonding, f 3—Fiber extraction, f 4—The crack width of the matrix reaches 0.1mm, f 5—The crack width of the matrix reaches 0.2mm, f 6—The crack width of the matrix reaches 0.5mm, f 7—The crack width of the matrix reaches 1.0mm.

[0041] In a possible implementation, in the vulnerability curve acquisition step, a distribution histogram is drawn according to the obtained center point deflection values ​​of each damage state, and the distribution histogram is compared with eight typical distribution types, namely normal distribution, lognormal distribution, Poisson distribution, χ distribution, gamma distribution, Student (t) distribution, Rayleigh distribution, and Rice distribution, and the closest one is selected; then the mean and variance of the center point deflection values ​​of each damage state are calculated, and the distribution function is calculated according to the formula corresponding to the closest distribution type to make a vulnerability curve.

[0042] In a possible implementation, in the damage status acquisition step, when f n < f <f n+1 When f The damage status is f n or f n+1 .

[0043] In this implementation, by preparing ultra-high ductility solid waste specimens and testing the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters of the prepared ultra-high ductility solid waste specimens in the laboratory, the tediousness of actual measurement on the road surface can be avoided, while saving costs and being highly flexible, and all mechanical parameters of ultra-high ductility concrete test specimens can be obtained. In addition, the final actual measurement steps are relatively simple, and the ultra-high ductility solid waste pavement bending finite element model is established based on the material parameters, which can ensure the combination of numerical simulation and experimental technology and the test effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A flow chart of a method for detecting and analyzing damage of an ultra-high ductility concrete pavement provided in an embodiment of the present invention;

[0045] Figure 2 A schematic diagram of a bending mechanical performance testing step and a mechanical forming testing equipment structure used in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0046] Figure 3 A schematic diagram of an operation for obtaining matrix fracture toughness material parameters in a statistical law analysis in a method for detecting and analyzing damage of an ultra-high ductility concrete pavement provided in an embodiment of the present invention;

[0047] Figure 4 A schematic diagram of a stress-strain curve obtained by obtaining the Young's modulus material parameter in the statistical law analysis in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of the operation of obtaining the material parameters of the fiber bridge bearing capacity in the statistical law analysis in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0049] Figure 6 A schematic diagram of the operation of obtaining matrix cracking stress material parameters in the statistical law analysis in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0050] Figure 7 A schematic diagram of a stress-crack displacement curve obtained by obtaining the maximum complementary energy material parameter in the statistical law analysis in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0051] Figure 8 A schematic diagram of a finite element model of ultra-high ductility solid waste pavement subjected to bending established in the statistical law analysis in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0052] Fig. 9 A center point deflection distribution histogram obtained in a specific implementation manner of the fragility curve acquisition step in the ultra-high ductility concrete pavement damage detection and analysis method provided in an embodiment of the present invention;

[0053] Fig.10 for Fig. 9 The fragility curve corresponding to the center point deflection distribution histogram obtained in .

[0054] Description of reference numerals:

[0055] 10. Ultra-high ductility concrete test specimen; 20. Mechanical properties testing equipment; 21. Press; 22. Support seat; 23. Displacement meter; 24. Down pressure head; 25. Pressure end; 26. Overlap end; 27. Loading end; 30. Acoustic emission sensor; 40. Three-point bending strength testing machine; 50. Tensile machine. DETAILED DESCRIPTION

[0056] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0057] See also Figure 1 The ultra-high ductility concrete pavement damage detection and analysis method provided by the present invention is now described. The ultra-high ductility concrete pavement damage detection and analysis method comprises the following steps:

[0058] S100 prepares ultra-high ductility solid waste specimens and prepares multiple ultra-high ductility concrete test specimens 10.

[0059] S200 sets the damage status, setting f 1. f 2. f 3. f 4. f 5. f 6 and f 7 There are seven damage states, and the crack width of each damage state increases in turn.

[0060] S300 statistical law analysis, by testing multiple ultra-high ductility concrete test specimens 10 respectively, obtain the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters of the ultra-high ductility concrete test specimens 10, so as to establish a finite element model of ultra-high ductility solid waste pavement under bending. Run no less than 50 sets of finite element analysis, and count no less than 50 center point deflection values ​​corresponding to each damage state.

[0061] The S400 fragility curve is obtained, the distribution law of the deflection value of the center point corresponding to each damage state is statistically analyzed, and the distribution parameters are calculated to obtain the fragility curve under each damage state.

[0062] S500 damage status acquisition, measured elevation difference between the center line of the road surface and the edge of the road surface, recorded as f ,Will f Compare with each damage state and determine f Specific damage state. At the same time, according to the vulnerability curve under the corresponding damage state, the probability of occurrence of this damage state is obtained.

[0063] Compared with the prior art, the ultra-high ductility concrete pavement damage detection and analysis method provided in this embodiment can avoid the tediousness of actual measurement on the pavement by preparing ultra-high ductility solid waste specimens and testing the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters of the prepared ultra-high ductility solid waste specimens in the laboratory, and can save costs and have high flexibility, and can obtain all mechanical parameters of the ultra-high ductility concrete test specimen 10. In addition, the final actual measurement step is relatively simple, and the ultra-high ductility solid waste pavement bending finite element model is established according to the material parameters, which can ensure the combination of numerical simulation and experimental technology and the test effect.

[0064] In some embodiments, in the step of preparing the ultra-high ductility solid waste test specimen, the size of the ultra-high ductility concrete test specimen 10 can be 100 mm×100 mm×400 mm, and the specific raw material mix ratio can be 0.6 cement, 1.4 slag powder, 2 steel slag powder, 0.55 water, 0.04 water reducer, and 2% PVA fiber by volume. In addition, after preparation, standard curing for 28 days is required to ensure the final detection and analysis effect.

[0065] In some embodiments, see Figure 1 The ultra-high ductility concrete pavement damage detection and analysis method also includes a bending mechanical performance test step S600, placing any complete ultra-high ductility concrete test specimen 10 on a mechanical performance test device 20, and adopting three-equal point loading, and installing multiple acoustic emission sensors 30 on the ultra-high ductility concrete test specimen 10. After the mechanical performance test device 20 is turned on, each damage state corresponding to the ultra-high ductility concrete test specimen 10 is monitored by each acoustic emission sensor 30 and a magnifying glass, and the deflection value under each damage state is determined by the mechanical performance test device 20.

[0066] In the statistical law analysis step, the ultra-high ductility solid waste pavement bending finite element model established based on the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters can calculate the center point deflection value under each damage state. At this time, the deflection value under each damage state obtained in the bending mechanical properties test step of this embodiment can be compared and corrected with the deflection value of each center point, further ensuring the combination of numerical simulation and experimental technology and ensuring the test effect.

[0067] It should be noted that the bending mechanics test step can be performed after the damage state setting step and before the statistical law analysis step, or it can be performed simultaneously with the statistical law analysis step if there are sufficient experimental equipment and staff.

[0068] In some embodiments, the mechanical properties testing device can be used as follows: Figure 3 See the structure shown. Figure 3 The mechanical property testing equipment includes a press 21, a support seat 22, a displacement meter 23 and a lower pressure head 24. The press 21 has a bearing platform, and a vertically movable pressure end 25 is provided above the bearing platform. The support seat 22 is fixed on the bearing platform, and has two overlapping ends 26 arranged at intervals along the horizontal direction and provided for the bottom end of the ultra-high ductility concrete test specimen 10. The displacement meter 23 is arranged on the support seat 22 and is located between the two overlapping ends 26, and the displacement meter 23 abuts against the bottom end of the ultra-high ductility concrete test specimen 10. The lower pressure head 24 is fixedly connected to the pressure end 25, and the bottom end of the lower pressure head 24 has two loading ends 27 abutting against the top end of the ultra-high ductility concrete test specimen 10, and the two loading ends 27 are arranged at intervals along the spacing direction of the two overlapping ends 26. The distance from any loading end 27 to the adjacent overlapping end 26 in the horizontal direction is equal to the spacing distance between the two loading ends 27.

[0069] The press 21, the support 22, the displacement meter 23 and the lower pressure head 24 are arranged to ensure accurate measurement of the deflection of the ultra-high ductility concrete test specimen 10 in the laboratory, and the structure is simple and the cost is low. It is also convenient for the subsequent statistical law analysis steps, and at the same time ensures the combination of numerical simulation and experimental technology to ensure the test effect.

[0070] The press 21 may be a hydraulic press with a large loading capacity.

[0071] Regarding the explanation of the three-point loading, in the horizontal direction, the spacing distance between the two loading ends 27 is equal to the spacing distance from any lap end 26 to its adjacent loading end 27 in the horizontal direction, that is, the two lap ends 26 and the two loading ends 27 divide the ultra-high ductility concrete test specimen 10 into three equal parts in the horizontal direction.

[0072] Regarding the arrangement of the acoustic emission sensors 30 , they can be evenly distributed on the surface of the ultra-high ductility concrete test specimen 10 , and a preamplifier can be electrically connected between each acoustic emission sensor 30 and the acoustic emission recorder to enhance the detection effect.

[0073] In some embodiments, the statistical law analysis step may be performed as follows: Figures 3 to 8 See the structure shown. Figures 3 to 8 , in the statistical law analysis step, the parameters of each material are obtained as follows:

[0074] See also Figure 3 , the matrix fracture toughness material parameters are obtained, a notch is set in the middle of the bottom of the selected ultra-high ductility concrete test specimen 10, and then the ultra-high ductility concrete test specimen 10 is placed on a three-point bending strength testing machine 40, and the matrix fracture toughness is calculated according to the load-displacement curve of the ultra-high ductility concrete test specimen 10 and the geometric parameters of the ultra-high ductility concrete test specimen 10.

[0075] Fracture toughness (Unit: MPa∙m 0.5 ) is calculated as follows:

[0076]

[0077] in is the cracking load, i.e., the maximum value of the ordinate of the linear segment on the load-displacement curve (in kilonewtons); G is the weight of the specimen (in newtons); S is the distance between the specimen supports (in meters); b is the width of the specimen section (in meters); h is the height of the specimen section (in meters). is the relative height of the crack, i.e. the effective crack length The ratio of (approximately 0.67 times the crack length) to h.

[0078] Regarding setting a notch in the middle of the bottom of the test piece, a cutter can be used to open the notch in the middle of the bottom of the test piece. The three-point bending strength tester 40 is a prior art and will not be described in detail here.

[0079] See also Figure 4 , Young's modulus material parameters are obtained, the selected ultra-high ductility concrete test specimen 10 is installed on the tensile testing machine 50, and strain gauges are pasted on the surface of the ultra-high ductility concrete test specimen 10. The ultra-high ductility concrete test specimen 10 is stretched in the length direction by the tensile testing machine 50, and the stress-strain curve is drawn according to the numerical value. The slope of the stress-strain curve near the origin (the slope of the auxiliary straight line) is the Young's modulus.

[0080] See also Figure 5, to obtain the material parameters of the fiber bridging bearing capacity, the selected ultra-high ductility concrete test specimen 10 is installed on the tensile testing machine 50, and the ultra-high ductility concrete test specimen 10 is stretched in the length direction by the tensile testing machine 50, and the fiber bridging bearing capacity is obtained by dividing the tensile force value when the fiber is pulled out by the cross-section of the ultra-high ductility concrete test specimen 10.

[0081] See also Figure 6 , the matrix cracking stress material parameters are obtained, the selected ultra-high ductility concrete test specimen 10 is placed on the three-point bending strength testing machine 40, and the matrix cracking stress is calculated according to the load-displacement curve of the ultra-high ductility concrete test specimen 10 and the geometric parameters of the ultra-high ductility concrete test specimen 10.

[0082] The calculation steps are as follows: the maximum load of the linear segment of the load-displacement curve is multiplied by one quarter of the span and then divided by the elastic resistance moment of the ultra-high ductility concrete test specimen 10.

[0083] See also Figure 7 , the maximum complementary energy material parameters are obtained, a notch is set in the middle of the bottom of the selected ultra-high ductility concrete test specimen 10, and then the ultra-high ductility concrete test specimen 10 is placed on a three-point bending strength testing machine 40, and a stress-cracking displacement curve is plotted according to the numerical value to obtain the maximum complementary energy.

[0084] Specifically, the crack displacement is the X-axis, the stress is the Y-axis, the highest point corresponding to the stress is A, and the area of ​​the curved triangle formed by point A, the projection point B of point A on the Y-axis, and the origin is the maximum complementary energy.

[0085] The above-mentioned methods for obtaining the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters are relatively simple in terms of both the acquisition steps and the operations involved, and can be easily obtained, thereby effectively reducing the difficulty of detecting and analyzing ultra-high ductility concrete pavements, and can comprehensively obtain the mechanical parameters of ultra-high ductility concrete pavements to ensure the detection and analysis results.

[0086] In some embodiments, in the statistical law analysis step, each material parameter obtained is varied within 10%. This is because in the actual use of the road surface, errors in road paving and the distribution of loads are uncertain factors. Therefore, varying the material parameters by 10% can further ensure the accuracy of the simulation.

[0087] Specifically, the load application position and material parameters were randomly varied by ±10% and then entered into the software.

[0088] In some embodiments, in the step of setting the damage state, each damage state is:

[0089] f1—Microscopic cracking of the pavement material matrix, f 2—Fiber-matrix debonding, f 3—Fiber extraction, f 4—The crack width of the matrix reaches 0.1mm, f 5—The crack width of the matrix reaches 0.2mm, f 6—The crack width of the matrix reaches 0.5mm, f 7—The crack width of the matrix reaches 1.0mm.

[0090] By dividing the damage status, the subsequent detection and analysis work can be effectively guaranteed.

[0091] Specifically, about f 1. f 2. f 3 occurs inside the ultra-high ductility concrete test specimen 10 and cannot be detected by surface observation, so an acoustic emission sensor 30 is used. f 4. f 5. f 6. f 7 These four damage states have an important impact on the road surface's ability to resist the intrusion of moisture or foreign substances, and can be measured using a magnifying glass or an electronic crack observation instrument.

[0092] In some embodiments, the above vulnerability curve acquisition step can be performed as follows: Fig. 9 and Fig.10 See the structure shown. Figure 8 and Fig. 9 In the fragility curve acquisition step, a distribution histogram is drawn based on the center point deflection values ​​of each damage state, and the distribution histogram is compared with eight typical distribution types: normal distribution, lognormal distribution, Poisson distribution, χ distribution, gamma distribution, Student (t) distribution, Rayleigh distribution, and Rice distribution, and the closest one is selected. Then the mean and variance of the center point deflection values ​​of each damage state are calculated, and the distribution function is calculated according to the formula corresponding to the closest distribution type to make a fragility curve.

[0093] As a specific implementation of this embodiment, for example, a distribution histogram of the central deflection value corresponding to a certain damage state is obtained, such as Fig. 9 As shown. Comparing the distribution histogram with the eight typical distribution types mentioned above, it just conforms to the lognormal distribution, so the lognormal distribution is selected as the distribution type. Then the mean m and variance v of each central deflection value are calculated;

[0094]

[0095] According to the relationship between the distribution parameters (μ, σ) of the lognormal distribution and the mean and variance of the metadata:

[0096]

[0097] After obtaining the distribution parameters of the lognormal distribution, the vulnerability curve can be drawn according to the following formula (see Fig.10 ):

[0098]

[0099] Of course, in order to avoid numerical integration, the logncdf function of MATLAB software can be used for calculation.

[0100] In some embodiments, the above vulnerability curve acquisition step can be performed as follows: Fig. 9 and Fig.10 See the structure shown. Figure 2 , in the damage state acquisition step, f is the ratio of the elevation difference (deflection) to the span. f n < f <f n+1 When f The damage status is f n or f n+1 By querying the vulnerability curve of the nth or n+1th damage state, the probability of the damage state occurring in this case can be obtained.

[0101] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting and analyzing damage of ultra-high ductility concrete pavement, characterized in that: The steps include: Prepare ultra-high ductility solid waste specimens and prepare multiple ultra-high ductility concrete test specimens; Set the damage state, set f 1. f 2. f 3. f 4. f 5. f 6 and f 7 Seven damage states, the crack width of each damage state increases in sequence; Statistical law analysis: by testing a plurality of the ultra-high ductility concrete test specimens respectively, the matrix fracture toughness, Young's modulus, fiber bridging bearing capacity, matrix cracking stress and maximum residual energy material parameters of the ultra-high ductility concrete test specimens are obtained to establish a finite element model of ultra-high ductility solid waste pavement under bending; run no less than 50 sets of finite element analysis, and count no less than 50 center point deflection values ​​corresponding to each damage state; Acquiring a fragility curve, statistically analyzing the distribution law of the deflection value of the center point corresponding to each damage state, and calculating the distribution parameter, to obtain a fragility curve under each damage state; the abscissa of the fragility curve is expressed as the ratio of the deflection to the span, and the ordinate is expressed as the cumulative distribution function; The damage status is obtained by measuring the elevation difference or deflection between the center line of the pavement and the edge of the pavement and recording it as d ,Will d Compare with the deflection value corresponding to each damage state, when d n < d <d n+1 When d The damage status is f n or f n+1 ， Determine d The specific damage state; and according to the corresponding vulnerability curve under the damage state, the probability of occurrence of the damage state is obtained.

2. The ultra-high ductility concrete pavement damage detection and analysis method according to claim 1, characterized in that: The ultra-high ductility concrete pavement damage detection and analysis method also includes a bending mechanical properties testing step, placing any complete ultra-high ductility concrete test specimen on a mechanical properties testing device, and adopting three-equal point loading, and installing multiple acoustic emission sensors on the ultra-high ductility concrete test specimen; after turning on the mechanical properties testing device, each of the damage states corresponding to the ultra-high ductility concrete test specimen is monitored by each of the acoustic emission sensors and a magnifying glass, and the deflection value under each of the damage states is determined by the mechanical properties testing device.

3. The ultra-high ductility concrete pavement damage detection and analysis method according to claim 2, characterized in that: The mechanical properties testing equipment comprises: A press having a load-bearing platform, wherein a vertically movable press end is provided above the load-bearing platform; A support seat, fixedly mounted on the bearing platform, the support seat having two overlapping ends spaced apart in the horizontal direction and for the bottom end of the ultra-high ductility concrete test specimen to be overlapped; A displacement meter is arranged on the support seat and is located between the two overlapped ends, and the displacement meter abuts against the bottom end of the ultra-high ductility concrete test specimen; A lower pressure head is fixedly connected to the pressure end, and the bottom end of the lower pressure head has two loading ends abutting against the top end of the ultra-high ductility concrete test specimen, and the two loading ends are arranged at intervals along the spacing direction of the two lap ends; the distance from any one of the loading ends to the adjacent lap end in the horizontal direction is equal to the spacing distance between the two loading ends.

4. The ultra-high ductility concrete pavement damage detection and analysis method according to any one of claims 1 to 3, characterized in that: In the statistical law analysis step, the method of obtaining each material parameter is as follows: The matrix fracture toughness material parameters are obtained by setting a notch in the middle of the bottom of the selected ultra-high ductility concrete test specimen, then placing the ultra-high ductility concrete test specimen on a three-point bending strength testing machine, and calculating the matrix fracture toughness according to the load-displacement curve of the ultra-high ductility concrete test specimen and the geometric parameters of the ultra-high ductility concrete test specimen; The Young's modulus material parameter is obtained by installing the selected ultra-high ductility concrete test specimen on a tensile testing machine, and at the same time pasting a strain gauge on the surface of the ultra-high ductility concrete test specimen, stretching the ultra-high ductility concrete test specimen in the length direction by the tensile testing machine, and drawing a stress-strain curve according to the numerical value, wherein the slope of the stress-strain curve near the origin is the Young's modulus; The fiber bridge bearing capacity material parameters are obtained by installing the selected ultra-high ductility concrete test specimen on a tensile testing machine, stretching the ultra-high ductility concrete test specimen in the length direction by the tensile testing machine, and obtaining the fiber bridge bearing capacity by the tensile force value when the fiber is pulled out and the cross section of the ultra-high ductility concrete test specimen; The matrix cracking stress material parameters are obtained, the selected ultra-high ductility concrete test specimen is placed on a three-point bending strength testing machine, and the matrix cracking stress is calculated according to the load-displacement curve of the ultra-high ductility concrete test specimen and the geometric parameters of the ultra-high ductility concrete test specimen; The maximum residual energy material parameters are obtained by setting a notch in the middle of the bottom of the selected ultra-high ductility concrete test specimen, then placing the ultra-high ductility concrete test specimen on a three-point bending strength testing machine, and drawing a stress-cracking displacement curve according to the numerical values ​​to obtain the maximum residual energy.

5. The ultra-high ductility concrete pavement damage detection and analysis method according to claim 4, characterized in that: In the statistical law analysis step, each material parameter obtained is varied within 10%.

6. The ultra-high ductility concrete pavement damage detection and analysis method according to any one of claims 1 to 3, characterized in that: In the step of setting the damage state, each of the damage states is: f 1—Microscopic cracking of the pavement material matrix, f 2—Fiber-matrix debonding, f 3—Fiber extraction, f 4—The crack width of the matrix reaches 0.1mm, f 5—The crack width of the matrix reaches 0.2mm, f 6—The crack width of the matrix reaches 0.5mm, f 7—The crack width of the matrix reaches 1.0mm.

7. The ultra-high ductility concrete pavement damage detection and analysis method according to any one of claims 1 to 3, characterized in that: In the vulnerability curve acquisition step, a distribution histogram is drawn according to the obtained center point deflection values ​​of each damage state, and the distribution histogram is compared with eight typical distribution types, namely normal distribution, lognormal distribution, Poisson distribution, χ distribution, gamma distribution, Student (t) distribution, Rayleigh distribution, and Rice distribution, and the closest one is selected; then the mean and variance of the center point deflection values ​​of each damage state are calculated, and the distribution function is calculated according to the formula corresponding to the closest distribution type to make a vulnerability curve.

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