Method and device for determining high-temperature performance development stage of asphalt pavement

Abstract

This invention discloses a method and apparatus for determining the high-temperature performance development stage of asphalt pavement, belonging to the field of road maintenance. The method involves conducting indoor multi-sequence local loading tests on core samples from the wheel track zone and shoulder of the asphalt pavement to obtain strain rate values ​​of different layer materials under multiple stresses. Combined with the axle load spectrum of the cored sections, the average strain rate of different layer materials under light, medium, and heavy traffic is calculated. The ratio of the average strain rate of the wheel track zone to that of the shoulder material is used to ultimately determine the high-temperature performance development stage of the pavement material at different depths. This method allows for a comprehensive and effective determination of the high-temperature performance development trend of actual asphalt pavements based on their traffic characteristics, helping road management units to formulate scientific and refined maintenance strategies for rutting damage and saving maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of road maintenance, and in particular to a method and apparatus for determining the high-temperature performance development stage of asphalt pavement. Background Technology

[0002] Traditional evaluation methods for the rutting resistance of in-service asphalt pavements suffer from two main drawbacks: ① Core samples are typically taken only from the wheel track area, and then subjected to indoor high-temperature performance tests to obtain high-temperature performance evaluation indicators, such as repeated creep tests to determine the material's rheological cycles. Traditional evaluation methods and indicators can only compare the high-temperature performance of the core samples, but cannot determine the current stage of high-temperature performance development of the cored pavement. This is because determining the performance development stage requires anchoring an initial performance point, i.e., the starting point of the high-temperature performance of the cored pavement when it was newly constructed and put into use. As is well known, due to limitations in maintenance management, there is no record of this performance point when the pavement was put into use. Because it is difficult to obtain the true initial performance of the material for comparison, existing studies cannot determine the stage of high-temperature performance development of the cored pavement. ② Traditional high-temperature performance tests can only apply a single stress level of loading to the material. However, the traffic conditions on actual roads are complex, and the impact of heavy loads and overloads on the performance of asphalt pavement materials cannot be ignored. In other words, the strain rate development law of asphalt pavement materials under different traffic levels has significant differences. Therefore, the high-temperature performance development stage of asphalt pavement materials should be distinguished according to the different traffic axle load ranges in which they are located. Summary of the Invention

[0003] In order to at least partially solve one of the technical problems existing in the prior art, the purpose of this invention is to provide a method and apparatus for determining the development stage of high-temperature performance of asphalt pavement.

[0004] The technical solution adopted in this invention is:

[0005] A method for determining the development stage of high-temperature performance of asphalt pavement includes the following steps:

[0006] S1. Conduct multi-sequence local loading tests on pavement core specimens;

[0007] S2. Based on the cumulative strain curve obtained from the experiment, fit the slope of the cumulative strain change with time under each stress sequence, denoted as strain rate, unit: με / s;

[0008] S3. Fit the functional relationship between the strain rate of the road surface material and the stress.

[0009] S4. Divide the traffic axle load spectrum of the core sampling section into three axle load intervals: light, medium, and heavy. Each axle load interval contains several axle load levels. Calculate the percentage of cumulative axle loads for each axle load level in the total cumulative axle loads of its respective axle load interval, denoted as P. i,k ;

[0010] S5. Based on the conversion relationship between axle load and tire pressure, calculate the average ground pressure of the tires under each axle load level;

[0011] S6. Calculate the compressive stress values ​​of the core sample pavement at different depths of the surface layer under various levels of axle load;

[0012] S7. Calculate the strain rate of the pavement material at different depths under various levels of axle load, denoted as ε. i,k ;

[0013] S8. Calculate the average strain rate of the pavement material in different axle load ranges, denoted as...

[0014] S9. Calculate the ratio of the average strain rate of the pavement material in different axle load ranges, denoted as A. i ;

[0015] S10. Based on the magnitude and comparison of the average strain rate ratio of the pavement material in different axle load ranges, determine the high-temperature performance development stage of the pavement material.

[0016] Furthermore, the proportion P in step S4 i,k The calculation formula is as follows:

[0017]

[0018] In the formula, i represents the number of axle load intervals, i = 1, 2, 3, representing the light, medium, and heavy intervals respectively; n i n represents the number of axle weight levels contained within the i-th axle weight interval. i ≥1; N i,k This represents the cumulative number of axle loads under the k-th axle load level within the i-th axle load interval, where 1 ≤ k ≤ n. i ;P i,k This represents the proportion of the cumulative number of axles under the k axle weight levels to the total cumulative number of axles in the i-th axle weight interval.

[0019] Furthermore, the average strain rate in step S8 The calculation formula is as follows:

[0020]

[0021] In the formula, n i n represents the number of axle weight levels contained within the i-th axle weight interval. i ≥1; ε i,kThis represents the strain rate of the material at the k-th axle load level within the i-th axle load range, where 1 ≤ k ≤ n. i Units: με / s; P i,k This represents the proportion of the cumulative number of axles under the k-th axle weight level to the total cumulative number of axles in the ith axle weight interval. This represents the average strain rate of the material in the i-th axial load interval, where i = 1, 2, 3, and the unit is με / s.

[0022] Furthermore, the average strain rate ratio A in step S9 i The calculation formula is as follows:

[0023]

[0024] In the formula, i is the number of axle load intervals, i = 1, 2, 3, representing the light, medium, and heavy intervals respectively; This represents the average strain rate of the material at the wheel track zone within the i-th axle load interval, in με / s; 路肩 This represents the average strain rate of the material at the shoulder within the i-th axle load interval, in με / s; i This represents the ratio of the average strain rate of the material at the wheel track to that at the shoulder within the i-th axle load interval.

[0025] Furthermore, the determination of the high-temperature performance development stage of the road surface material in step S10 includes:

[0026] ① When A3 > 2, the pavement material is in a period of accelerated performance degradation;

[0027] ② When 1≤A3≤2, the pavement material is in the middle stage of performance degradation;

[0028] ③ When 0 < A3 < 1 and A3 > A1 and A3 > A2, the pavement material is in the early stage of performance degradation;

[0029] ④ When 0 < A3 < 1 and A3 < A1 and A3 < A2, the pavement material is in the performance enhancement period;

[0030] ⑤ When 0 < A3 < 1 and the relationship between A3 and A1, A2 does not fall under the conditions listed in ③ and ④, the pavement material is in a period of stable performance.

[0031] Furthermore, the road surface core samples in step S1 include core samples from the wheel track area and the shoulder area, and the core samples from the wheel track area and the shoulder area are taken from the same traffic section of the same highway.

[0032] Further, step S1 includes:

[0033] The road surface core sample was divided into upper, middle and lower layers, and then a multi-sequence local loading test was performed on the sample of each layer.

[0034] Furthermore, the test temperatures of specimens at different layers are maintained at a preset temperature difference;

[0035] The test temperature range for the top layer is 60–65℃, for the middle layer it is 55–60℃, and for the bottom layer it is 50–55℃.

[0036] Furthermore, the multi-sequence local loading described in step S1 includes two loading stages: preloading and multi-stress loading. In the preloading stage, only one stress level and a fixed number of repeated loading sequences are set. In the multi-stress loading stage, at least three different stress magnitudes but with the same number of repeated loading sequences are set.

[0037] Another technical solution adopted in this invention is:

[0038] A device for determining the high-temperature performance development stage of asphalt pavement, comprising:

[0039] At least one processor;

[0040] At least one memory for storing at least one program;

[0041] When the at least one program is executed by the at least one processor, the at least one processor performs the method as described above.

[0042] Another technical solution adopted in this invention is:

[0043] A computer-readable storage medium storing a processor-executable program, which, when executed by a processor, performs the method described above.

[0044] The beneficial effects of this invention are: this invention can comprehensively and effectively determine the high-temperature performance development trend of actual asphalt pavement based on the traffic characteristics, helping road management units to formulate scientific and refined maintenance strategies for pavement rutting and saving maintenance costs. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following description is provided with accompanying drawings of the relevant technical solutions in the embodiments of the present invention or the prior art. It should be understood that the accompanying drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1This is a schematic diagram showing the axle load spectrum and the division of different axle load ranges from the opening of the Yanjiang Expressway to 2016 in an embodiment of the present invention;

[0047] Figure 2 This is a schematic diagram illustrating the determination of the high-temperature performance development stage of asphalt mixture based on the average strain rate ratio in an embodiment of the present invention. Detailed Implementation

[0048] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0049] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0050] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0051] Furthermore, in the description of this invention, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0053] Determining the development stage of high-temperature performance of asphalt pavement is crucial for maintenance decisions regarding pavement rutting resistance, impacting the scientific and rational allocation of millions or even tens of millions of yuan in annual maintenance costs. To more accurately determine the development stage of high-temperature performance of materials, this invention proposes a method for judging the development stage of high-temperature performance of asphalt pavement. This method uses the high-temperature performance of core samples from the shoulder of a core-taken section as the starting point for the performance of that section, effectively solving the first drawback mentioned above and making the evaluation results more targeted. Secondly, the multi-sequence local loading test used in this invention can obtain the strain rate of the material under various stress levels, thus enabling a comprehensive judgment of the high-temperature performance development stage of asphalt pavement under different traffic levels, making the evaluation results more comprehensive, complete, and reliable.

[0054] This embodiment provides a method for determining the high-temperature performance development stage of asphalt pavement, including the following steps:

[0055] 1) Conduct multi-sequence local loading tests on pavement core specimens;

[0056] 2) Based on the cumulative permanent strain curves obtained from the above experiments, the slope of the cumulative strain changing with time under each stress sequence is fitted and denoted as the strain rate, with units of με / s;

[0057] 3) Fit the functional relationship between the strain rate of the material and the stress;

[0058] 4) Divide the traffic axle load spectrum of the core section into three axle load intervals: light, medium, and heavy. Each axle load interval contains several axle load levels. Calculate the percentage of cumulative axle loads for each axle load level in the total cumulative axle loads of its respective axle load interval, denoted as P, according to the following formula. i,k ;

[0059]

[0060] In the formula: i — the number of axle load intervals, i = 1, 2, 3, representing the light, medium, and heavy intervals respectively;

[0061] n i —The number of axle weight levels contained in the i-th axle weight interval, n i ≥1;

[0062] N i,k —The cumulative number of axle loads under the k-th axle load level within the i-th axle load interval, 1≤k≤n i ;

[0063] P i,k —The proportion of cumulative axle loads at the k-th axle load level to the total cumulative axle loads in the i-th axle load interval, 1≤k≤n i ;

[0064] 5) Calculate the average ground contact pressure of the tires under each axle load level based on the conversion relationship between axle load and tire pressure;

[0065] 6) Calculate the compressive stress values ​​of the core sample pavement at different depths of the surface layer under various axle loads;

[0066] 7) Calculate the strain rate of the material at different depths under various levels of axle load, denoted as ε. i,k ;

[0067] 8) Calculate the average strain rate of the material in different axle load ranges according to the following formula, denoted as:

[0068]

[0069] Where: n i —The number of axle weight levels contained in the i-th axle weight interval, n i ≥1;

[0070] ε i,k —The strain rate of the material at the k-th axle load level within the i-th axle load interval, 1≤k≤n i Unit: με / s;

[0071] P i,k —The proportion of cumulative axle loads at the k-th axle load level to the total cumulative axle loads in the i-th axle load interval, 1≤k≤n i ;

[0072] —The average strain rate of the material in the i-th axial load interval, i = 1, 2, 3, unit: με / s;

[0073] 9) Calculate the ratio of the average strain rate of the material in different axle load ranges according to the following formula, denoted as A. i ;

[0074]

[0075] In the formula: i——the i-th axle weight interval, i=1, 2, 3;

[0076] —The average strain rate of the material at the wheel track zone in the i-th axle load interval, in με / s;

[0077] —The average strain rate of the material at the shoulder in the i-th axle load interval, in με / s;

[0078] A i —The ratio of the average strain rate of the material at the wheel track to that at the shoulder within the i-th axle load interval;

[0079] 10) Based on the magnitude and comparison of the average strain rate ratio of the material in different axial load ranges, determine its high-temperature performance development stage according to the following rules:

[0080] ① When A3 > 2, the material is in a period of accelerated performance degradation;

[0081] ② When 1≤A3≤2, the material is in the middle stage of performance degradation;

[0082] ③ When 0 < A3 < 1 and A3 > A1 and A3 > A2, the material is in the early stage of performance degradation;

[0083] ④ When 0 < A3 < 1 and A3 < A1 and A3 < A2, the material is in the performance enhancement period;

[0084] ⑤ When 0 < A3 < 1 and the relationship between A3 and A1, A2 does not fall under the conditions listed in ③ and ④, the material is in a period of stable performance.

[0085] This embodiment of the method involves conducting indoor multi-sequence local loading tests on core samples from the wheel track zone and shoulder of the asphalt pavement. This yields strain rate values ​​for different layer materials under multiple stresses. Combined with the axle load spectrum of the cored sections, the average strain rate of different layer materials under light, medium, and heavy traffic conditions is calculated. By comparing the ratio of the average strain rate of the wheel track zone to that of the shoulder material, the high-temperature performance development stage of the pavement material at different depths is ultimately determined. This method allows for a comprehensive and effective assessment of the high-temperature performance development trend of actual asphalt pavements based on their traffic characteristics. It helps road management units develop scientific and refined maintenance strategies for rutting damage, thereby saving maintenance costs.

[0086] The following uses the results of multi-sequence local loading tests on core samples from the upper, middle, and lower wheel track zones and shoulders of the Yanjiang Expressway as examples, combined with the accompanying drawings and specific embodiments, to further illustrate the present invention.

[0087] This embodiment provides a method for determining the development stage of high-temperature performance of asphalt pavement, specifically including the following steps:

[0088] Step 1: Core samples from the wheel tracks and shoulders of the Yanjiang Expressway were cut according to their layer thickness. The thicknesses of the upper, middle, and lower layer specimens after cutting were 34–40 mm, 54–60 mm, and 52–80 mm, respectively, with a diameter of 150 mm for all specimens. The loading stress sequences set according to the stress characteristics of different layers are shown in Table 1. Then, multi-sequence local loading tests were conducted on the upper, middle, and lower layer specimens. A half-sine wave pulse load was used in the test, with each complete loading cycle including a 0.1 s loading time and a 0.9 s unloading time. The pre-loading was repeated 400 times, and the remaining sequences were repeated 50 times. The test temperatures for the upper, middle, and lower layers were 62℃, 58℃, and 52℃, respectively. The diameter of the indenter used in the test was 50 mm.

[0089] Table 1. Stress settings for multi-sequence local loading tests on specimens at different layers.

[0090]

[0091]

[0092] Step 2: Based on the cumulative permanent strain curves obtained from the above experiments, fit the slope of the cumulative strain versus time for each stress sequence, i.e., the strain rate (unit: με / s). The fitting results are shown in Table 2.

[0093] Table 2. Strain rates of road shoulder and wheel track specimens at different stress sequences.

[0094]

[0095] Step 3: Based on the strain rates obtained in Table 2, fit the power function relationship between the strain rate of the material and the stress. The results are shown in Table 3.

[0096] Table 3. Fitting functions of strain rate and stress magnitude for specimens.

[0097]

[0098] Step 4: Query the traffic axle load spectrum since the opening of the Yanjiang Expressway. Divide the axle load spectrum into three axle load intervals: light, medium, and heavy. Calculate the percentage of cumulative axle load occurrences for each axle load level within the total cumulative axle load interval for that interval. For example... Figure 1 As shown in Table 4, the light traffic zone includes four axle load levels, the medium traffic zone includes five axle load levels, and the heavy traffic zone includes four axle load levels. The cumulative axle load percentage for each level is shown in Table 4.

[0099] Table 4 Distribution ratio of cumulative axle loads at each level

[0100]

[0101]

[0102] Step 5: Referring to existing literature, the vehicle axle load and tire contact pressure can be converted using the following formula:

[0103]

[0104] In the formula: σ i —Axle load is q i Grounding pressure at that time;

[0105] q i —Axle load, in kN;

[0106] q s —Standard axle load, value is 100kN;

[0107] σ s —Standard tire pressure is 0.7 MPa.

[0108] The ground pressure corresponding to the median value of each axle load is taken as the average ground pressure of the axle load in that range. The average ground pressure of the tire under different axle loads after conversion according to the above formula is shown in Table 5.

[0109] Table 5 Average ground pressure of tires under various axle loads

[0110]

[0111] Step 6: Establish a finite element model of the asphalt pavement structure and calculate the vertical compressive stress at different depths of the surface layer under various axle loads. The results are shown in Table 6.

[0112] Table 6 Vertical compressive stress at different depths of the lower layer under various axial loads.

[0113]

[0114] Step 7: Substitute the compressive stresses obtained from Table 6 at different depths into the corresponding strain rate fitting functions in Table 3 to calculate the strain rate values ​​at the top (0, 4 cm, 10 cm) of the upper, middle, and lower layers under various axial loads. The results are shown in Table 7.

[0115] Table 7. Strain rates at different depths of the surface layer under various axial loads (unit: με / s)

[0116]

[0117] Step 8: Based on the strain rates of the material at different depths obtained in Table 7, and combined with the distribution ratio of each axle load in Table 4, calculate the average strain rate of the material in different axle load ranges (light, medium, and heavy). The calculation results are shown in Table 8.

[0118] Table 8. Average strain rate at different depths of the surface layer.

[0119]

[0120] Step 9: Divide the average strain rate at the wheel track area by the average strain rate at the shoulder to obtain the average strain rate ratios at different depths of the surface layer and under different traffic levels (light, medium, and heavy are represented by A1, A2, and A3, respectively). The calculation results are shown in Table 9.

[0121] Table 9. Average strain rate ratios at different depths of the surface layer.

[0122]

[0123]

[0124] Step 10, according to Figure 2 The established criteria determine the high-temperature performance development stages at different depths of the asphalt surface layer. Ultimately, at depths of 0cm, 4cm, and 10cm, the material's high-temperature performance is determined to be in the mid-deterioration, early-deterioration, and strengthening stages, respectively.

[0125] In summary, this embodiment provides a method for determining the development stage of high-temperature performance of asphalt pavement. First, it uses the high-temperature performance results of a core sample from the same location on the shoulder as the core sample taken from the wheel track as the starting point for the high-temperature performance of that road section. This solves the problem that traditional high-temperature performance evaluation cannot anchor the starting value, transforming the evaluation results from qualitative assessment to quantitative assessment. Second, due to the adoption of an innovative high-temperature performance evaluation test, the traditional single traffic axle load is extended to multi-dimensional performance development evaluation under different traffic levels, thus making the evaluation results more comprehensive, complete, and reliable.

[0126] This embodiment also provides a device for determining the high-temperature performance development stage of asphalt pavement, including:

[0127] At least one processor;

[0128] At least one memory for storing at least one program;

[0129] When the at least one program is executed by the at least one processor, the at least one processor performs the method as described above.

[0130] This embodiment of the device for determining the high-temperature performance development stage of asphalt pavement can execute the method for determining the high-temperature performance development stage of asphalt pavement provided in the method embodiment of the present invention. It can execute any combination of the implementation steps of the method embodiment and has the corresponding functions and beneficial effects of the method.

[0131] This embodiment also provides a storage medium storing instructions or programs that can execute the method for determining the high-temperature performance development stage of asphalt pavement provided in the method embodiment of the present invention. When the instructions or programs are run, any combination of implementation steps of the method embodiment can be executed, and the method has the corresponding functions and beneficial effects.

[0132] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is altered and sub-operations described as part of a larger operation are executed independently.

[0133] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the described functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0134] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0135] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0136] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0137] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0138] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0139] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0140] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for determining the development stage of high-temperature performance of asphalt pavement, characterized in that, Includes the following steps: S1. Conduct multi-sequence local loading tests on pavement core specimens; S2. Based on the cumulative strain curve obtained from the experiment, fit the slope of the cumulative strain changing with time under each stress sequence, and denote it as the strain rate; S3. Fit the functional relationship between the strain rate of the road surface material and the stress. S4. Divide the traffic axle load spectrum of the core sampling section into three axle load intervals: light, medium, and heavy. Each axle load interval contains several axle load levels. Calculate the percentage of cumulative axle loads for each axle load level in the total cumulative axle loads of its respective axle load interval, denoted as . ; S5. Based on the conversion relationship between axle load and tire pressure, calculate the average ground pressure of the tires under each axle load level; S6. Calculate the compressive stress values ​​of the core sample pavement at different depths of the surface layer under various levels of axle load; S7. Calculate the strain rate of the pavement material at different depths under various levels of axle load, denoted as... ; S8. Calculate the average strain rate of the pavement material in different axle load ranges, denoted as... ; S9. Calculate the ratio of the average strain rate of the pavement material in different axle load ranges, denoted as: ; S10. Based on the magnitude and comparison of the average strain rate ratio of the pavement material in different axle load ranges, determine the high-temperature performance development stage of the pavement material. The proportion in step S4 The calculation formula is as follows: In the formula, This represents the number of axle load intervals. These represent the light, medium, and heavy weight ranges, respectively. Indicates the first The number of axle load levels included within each axle load range ; Indicates the first Within the first axle load interval Cumulative axle loads at each axle load level ; express The cumulative number of axle load levels accounts for the [percentage missing]. The proportion of total cumulative axle loads within each axle load range; Average strain rate in step S8 The calculation formula is as follows: In the formula, Indicates the first The number of axle load levels included within each axle load range ; Indicates the first Within the first axle load interval Strain rate of material at each axle load level ; Indicates the first The cumulative number of axle load levels accounts for the [percentage missing]. The proportion of total cumulative axle loads within each axle load range; Indicates the material in the first Average strain rate of each axle load range ; The average strain rate ratio in step S9 The calculation formula is as follows: In the formula, This represents the number of axle load intervals. These represent the light, medium, and heavy weight ranges, respectively. Indicates the material at the wheel track in the first... Average strain rate within each axial load range; Indicates the material at the shoulder in the first... Average strain rate within each axial load range; Indicates the first Within each axle load range, the ratio of the average strain rate of the material at the wheel track to that at the shoulder; The step S10, which involves determining the high-temperature performance development stage of the road surface material, includes: ① When A3 > 2, the pavement material is in a period of accelerated performance degradation; ② When 1≤A3≤2, the pavement material is in the middle stage of performance degradation; ③ When 0 < A3 < 1 and A3 > A1 and A3 > A2, the pavement material is in the early stage of performance degradation; ④ When 0 < A3 < 1 and A3 < A1 and A3 < A2, the pavement material is in the performance enhancement period; ⑤ When 0 < A3 < 1 and the relationship between A3 and A1, A2 does not fall under the conditions listed in ③ and ④, the pavement material is in a period of stable performance.

2. The method for determining the high-temperature performance development stage of asphalt pavement according to claim 1, characterized in that, The road surface core samples in step S1 include core samples from the wheel track area and the shoulder area, and the core samples from the wheel track area and the shoulder area are taken from the same traffic section of the same highway.

3. The method for determining the high-temperature performance development stage of asphalt pavement according to claim 1, characterized in that, Step S1 includes: The road surface core sample was divided into upper, middle and lower layers, and then a multi-sequence local loading test was performed on the sample of each layer.

4. The method for determining the high-temperature performance development stage of asphalt pavement according to claim 3, characterized in that, The test temperatures of specimens at different layers are maintained at a preset temperature difference; The test temperature range for the top layer is 60~65℃, for the middle layer it is 55~60℃, and for the bottom layer it is 50~55℃.

5. The method for determining the high-temperature performance development stage of asphalt pavement according to claim 1, characterized in that, The multi-sequence local loading described in step S1 includes two loading stages: preloading and multi-stress loading. The preloading stage sets only one stress level and a fixed number of repeated loading sequences, while the multi-stress loading stage sets at least three different stress magnitudes but with the same number of repeated loading sequences.

6. A device for determining the high-temperature performance development stage of asphalt pavement, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method of any one of claims 1-5.

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