A Dynamic Evaluation Method for the Structural Performance of Asphalt Pavements

Abstract

The present invention discloses a dynamic evaluation method for the structural performance of asphalt pavements, which relates to the technical field of road engineering. According to the annual temperature field and traffic load data in the historical monitoring data since the asphalt pavement was opened to traffic, the invention calculates the moduli of each structural layer by back-calculating the asphalt pavement strength test at multiple temperatures. After correcting the master curves of the moduli of each structural layer, the invention collects the pavement crack and vertical permanent deformation data, calculates the structural damage of the asphalt pavement at the current moment and predicts the structural damage at a future moment by using the structural fatigue damage model of the asphalt pavement. Combining the pavement crack and vertical permanent deformation data, the invention corrects the transverse crack length model and the permanent deformation model, calculates the transverse crack length and rut depth at the current moment and predicts the transverse crack length and rut depth at a future moment, determines the structural performance evaluation parameters of the asphalt pavement at the current moment and a future moment, and proceeds to the next moment to continue the structural performance evaluation of the asphalt pavement until the asphalt pavement ends its service life, thus realizing the accurate evaluation of the structural performance of the asphalt pavement.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, and particularly relates to a method for dynamically evaluating the structural performance of asphalt pavements. Background Art

[0002] The service performance of highway asphalt pavements directly affects the driving safety of vehicles, travel efficiency, and the maintenance investment of asphalt pavements. As the existing roads gradually enter the period mainly focused on maintenance, accurately grasping the performance of the pavement structure in advance is conducive to timely proposing preventive maintenance strategies. However, there are certain deficiencies in the current pavement structure performance detection and evaluation methods. For example, the evaluation results of pavement structure performance do not match the actual situation, destructive detection methods are used, the detection data acquisition efficiency is low, etc. The traditional pavement structure performance detection methods are mainly regular manual detections, which have many limitations, require a large amount of manpower, material resources, and financial resources, have a long detection cycle, and are likely to affect the normal operation of traffic. At the same time, the detection results of traditional pavement structure performance detection methods often depend on the professional knowledge level, experience, and on-site conditions of the detection personnel, resulting in strong subjectivity of the detection results and difficulty in timely detecting the damages that occur to the pavement structure during the inspection interval period.

[0003] In addition, at present, the performance evaluation of asphalt pavement structures mainly analyzes the external detection information of the pavement. This method does not need to consider the mechanical environment inside the pavement structure and only evaluates from the external appearance of the pavement structure. It cannot fundamentally determine the internal causes of pavement structure damage, and the evaluation of pavement structure performance is mostly a post-event evaluation. Only a small part of the pavement damage causes can be determined through external observation, and most of the disease sources are the effects of internal stresses in the pavement structure, that is, the inevitable manifestations when the internal stresses in the pavement structure exceed the critical limit. However, the internal stresses in the pavement structure cannot be directly obtained through observation. Therefore, the existing asphalt pavement structure performance evaluation methods in the prior art cannot accurately evaluate the performance of pavement structures. Summary of the Invention

[0004] The present invention aims to solve the above problems and provides a method for dynamically evaluating the structural performance of asphalt pavements. Based on historical monitoring data and the master curves of the moduli of each structural layer of the asphalt pavement after correction, the pavement structure damage is determined in real time in a manner of dividing by time, axle type, and axle load interval, and combined with the real-time measured pavement crack and vertical permanent deformation data, the pavement structure performance is associated with the asphalt pavement materials and service environment, realizing the accurate evaluation of the asphalt pavement structure performance and providing a basis for the maintenance and repair of the asphalt pavement structure.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for dynamically evaluating the structural performance of asphalt pavements, comprising the following steps:

[0007] Step 1: Obtain the hourly average temperature, traffic volume, and axle load spectrum data of the asphalt pavement based on the annual temperature field and traffic load data in the historical monitoring data since the asphalt pavement was opened to traffic.

[0008] Step 2: Conduct asphalt pavement strength tests at multiple temperatures. By back-calculating the structural layer modulus of the asphalt pavement, determine the dynamic modulus of each structural layer in the asphalt pavement at different temperatures, and correct the modulus master curve of each structural layer of the asphalt pavement based on the least squares method.

[0009] Step 3: Use an integrated inspection vehicle to detect the surface cracks and permanent deformation of the asphalt pavement, measure the pavement crack and vertical permanent deformation data of the asphalt pavement at the current moment, and obtain the measured values of the transverse crack length and rut depth of the asphalt pavement at the current moment.

[0010] Step 4: According to the hourly average temperature, traffic volume, and axle load spectrum data obtained in Step 1, combined with the corrected modulus master curve of each structural layer of the asphalt pavement, use the asphalt pavement structural fatigue damage model to calculate the structural damage of the asphalt pavement at the current moment and predict the structural damage of the asphalt pavement at a specified future moment.

[0011] Step 5: Use the transverse crack length model and permanent deformation model to calculate the calculated values of the transverse crack length and rut depth of the asphalt pavement at the current moment. Combine the measured values of the transverse crack length and rut depth of the asphalt pavement at the current moment to correct the transverse crack length model and permanent deformation model of the asphalt pavement.

[0012] Step 6: According to the corrected modulus master curve of each structural layer of the asphalt pavement, use the corrected transverse crack length model and permanent deformation model to predict the transverse crack length and rut depth of the asphalt pavement at a specified future moment. Then, combined with the asphalt pavement structural damage, calculate the structural damage rate, transverse crack length growth rate, and permanent deformation rate of the asphalt pavement at the current moment and predict the values at a specified future moment to complete the performance evaluation of the asphalt pavement structure at the current moment.

[0013] Step 7: Move to the next moment, and repeat Steps 1 to 6 to continue the dynamic evaluation of the asphalt pavement structure until the asphalt pavement ends its service life and stop the dynamic evaluation of the asphalt pavement structure performance.

[0014] Preferably, the asphalt pavement strength test is carried out using a falling weight deflectometer, and the strength of the asphalt pavement structure is tested in the high temperature range, medium temperature range, and low temperature range respectively, where 35°C ≤ high temperature range < 50°C, 15°C ≤ medium temperature range < 35°C, and 0°C ≤ low temperature range < 15°C.

[0015] Preferably, the fatigue damage model of the asphalt pavement structure adopts a calculation method that divides by time, axle type, and axle load interval, and is based on the fatigue damage caused by various axle loads in each axle load interval at each moment from the opening of the asphalt pavement to the current moment, as shown in formula (1):

[0016]

[0017] Among them,

[0018]

[0019] In the formula, D is the damage of the asphalt pavement structure; t is the time serial number, T is the total duration; i is the axle type serial number; j is the axle load interval serial number; D ijt is the fatigue damage generated when the i-th axle type passes through the asphalt pavement in the j-th axle load interval within the t-th hour; NA ijt is the total number of loadings of the i-th axle type in the j-th axle load interval within the t-th hour; is the fatigue life of the asphalt pavement when the i-th axle type passes through in the j-th axle load interval within the t-th hour; β is the target reliability; k a is the adjustment coefficient for the seasonal frozen soil area; k b is the fatigue loading mode coefficient; is the temperature adjustment coefficient; is the bottom tensile strain of the asphalt layer generated when the i-th axle type passes through in the j-th axle load interval within the t-th hour; is the dynamic modulus of the asphalt mixture when the i-th axle type passes through in the j-th axle load interval within the t-th hour; VFA is the asphalt saturation of the asphalt mixture; h a is the layer thickness of the asphalt mixture.

[0020] Preferably, the transverse crack length model is:

[0021]

[0022] Among them,

[0023]

[0024] In the formula, l′ is the calculated value of the transverse crack length of the asphalt pavement structure; β2 is the crack length calculation coefficient; N(·) is the standard normal distribution function; SD is the standard deviation parameter of the transverse crack depth of the asphalt pavement structure; H a is the asphalt layer thickness of the asphalt pavement structure; t is the time serial number, T is the total duration; C is the crack depth value of the asphalt pavement structure; C2 is the crack depth value of the asphalt pavement structure at the end of the 2nd hour; C t-1 is the crack depth value of the asphalt pavement structure at the end of the (t - 1)-th hour; C t-2is the crack depth value of the asphalt pavement structure at the end of the (t - 2)-th hour; Δk t is the change in the stress intensity factor within the t-th hour; k t is the stress intensity factor at the t-th hour; k t-1 is the stress intensity factor at the (t - 1)-th hour; σ t is the internal force acting on the crack tip within the t-th hour; σ t-1 is the internal force acting on the crack tip within the (t - 1)-th hour; A and a are both fracture parameters of the asphalt mixture; β1 is the field calibration coefficient; E * is the stiffness modulus of the asphalt mixture; σ m is the indirect tensile strength of the asphalt mixture in the structural layer where the crack tip is located; m is the creep rate of the asphalt mixture in the structural layer where the crack tip is located;

[0025] The modified transverse crack length model is:

[0026]

[0027] In the formula, l is the modified value of the transverse crack length of the asphalt pavement structure; α is the transverse crack length calibration coefficient.

[0028] Preferably, the permanent deformation model is:

[0029]

[0030] Among them,

[0031]

[0032] In the formula, R a is the calculated rut depth of the asphalt pavement structure; λ is the calibration coefficient; x is the number of vehicle load applications, X is the total number of vehicle load applications; y is the asphalt layer number, Y is the total number of asphalt layers; t is the time sequence number, T is the total duration; is the rut depth generated by the x-th vehicle load application within the t-th hour of the current year in the y-th sub-layer of the asphalt layer; k Ry is the comprehensive correction coefficient of the y-th sub-layer in the asphalt layer; T yt is the internal temperature of the y-th sub-layer in the asphalt layer; P yt is the vertical compressive stress at the top of the y-th sub-layer of the asphalt layer at the t-th hour; N xet is the number of standard axle load applications received by the asphalt pavement structure when the x-th vehicle load passes; h y is the thickness of the y-th sub-layer in the asphalt layer; h0 is the thickness of the rut test specimen; is the rut depth corresponding to the asphalt mixture in the y-th sub-layer of the asphalt layer at the t-th hour.

[0033] Preferably, the calculation formula for the structural damage rate of the asphalt pavement is:

[0034] DR = 100D (12)

[0035] Wherein, DR is the structural damage of the asphalt pavement; D is the structural damage rate of the asphalt pavement;

[0036] The calculation formula for the permanent deformation rate of the asphalt pavement is as follows:

[0037]

[0038] Wherein, RDR is the permanent deformation rate of the asphalt pavement structure; R a is the rut depth value of the asphalt pavement structure.

[0039] The beneficial technical effects brought by the present invention are as follows:

[0040] The present invention proposes a dynamic evaluation method for the structural performance of asphalt pavements. By obtaining the internal temperature data and traffic load data in the historical monitoring data of asphalt pavements in real time, the structural damage of asphalt pavements is accurately calculated in a way of dividing by time, axle type, and axle load interval, and the transverse crack length model and permanent deformation model of asphalt pavements are corrected by combining the pavement crack and vertical permanent deformation data measured in real time. By combining the structural performance of asphalt pavements with asphalt pavement materials and service environments, accurate calculations of the structural damage rate, transverse crack length growth rate, and permanent deformation rate of asphalt pavements are realized, the problem that it is difficult to obtain the internal stress of asphalt pavement structures during the dynamic evaluation process is solved, technical support is provided for the accurate evaluation of the structural performance of asphalt pavements, and it is beneficial to the formulation of asphalt pavement structure maintenance and repair plans. Description of the Drawings

[0041] Figure 1 It is a schematic diagram of the pavement structure of the experimental section.

[0042] Figure 2 It is a schematic diagram of the master curve of the dynamic modulus of the modified upper layer asphalt mixture.

[0043] Figure 3 Shown is the permanent deformation development trend diagram of the asphalt pavement.

[0044] In the figure, 1. upper layer, 2. middle layer, 3. lower layer, 4. upper base course, 5. lower base course, 6. subbase course. Detailed Embodiments

[0045] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0046] Embodiment 1

[0047] In this embodiment, a highway in a certain area is taken as an example, and an experimental section is selected on the highway. The experimental section is an asphalt pavement with a road age of 10 years. The pavement structure of the experimental section is as Figure 1 shown, from top to bottom are the asphalt layer and the base layer; the asphalt layer is sequentially arranged as the surface course 1, the middle course 2, and the bottom course 3 from top to bottom. Among them, the surface course is an SMA-13 layer with a thickness of 4 cm, the middle course is an AC-20 layer with a thickness of 6 cm, and the bottom course is an AC-25 layer with a thickness of 8 cm; the base layer is sequentially the upper base course 4, the lower base course 5, and the sub-base course 6 from top to bottom. Among them, the upper base course is an LSPM25 layer with a thickness of 16 cm, the lower base course is a cement stabilized macadam layer with a thickness of 36 cm, and the sub-base course is a cement stabilized macadam layer with a thickness of 18 cm.

[0048] Adopt the dynamic evaluation method of asphalt pavement structure performance proposed by the present invention to dynamically evaluate the asphalt pavement structure performance of the experimental section, which specifically includes the following steps:

[0049] Step 1, obtain the historical monitoring data of the asphalt pavement from the time of opening to traffic to the current moment. According to the annual temperature field and traffic load data of the asphalt pavement in the historical monitoring data, obtain the hourly average temperature, traffic volume, and axle load spectrum data of the asphalt pavement. Table 1 shows the hourly average temperature of each structural layer of the asphalt pavement within 24 hours of a certain day in the historical monitoring data.

[0050] Table 1 Hourly average temperature of each structural layer of the asphalt pavement within 24 hours of a certain day

[0051]

[0052] Step 2, conduct strength tests on the asphalt pavement at multiple temperatures. In this embodiment, a falling weight deflectometer is mainly used to conduct strength tests on the asphalt pavement in the high-temperature range, medium-temperature range, and low-temperature range. Among them, 35°C ≤ high-temperature range < 50°C, 15°C ≤ medium-temperature range < 35°C, and 0°C ≤ low-temperature range < 15°C.

[0053] By back-calculating the structural layer modulus of the asphalt pavement, as shown in Table 2, determine the dynamic modulus of each structural layer in the asphalt pavement at different temperatures, and based on the least squares method, use the dynamic modulus of each structural layer of the asphalt pavement determined at different temperatures in the asphalt pavement strength test to correct the back-calculated dynamic modulus, and obtain the modulus master curve of each structural layer of the asphalt pavement after correction, as Figure 2 shown.

[0054] Table 2 Results of modulus back-calculation of each structural layer of the asphalt pavement at different pavement temperatures

[0055]

[0056] Step 3: Use an integrated inspection vehicle to detect the surface cracks and permanent deformation of the asphalt pavement at the current moment, and obtain the pavement crack and vertical permanent deformation data at the current moment, as shown in Table 3, so as to determine the measured value of the transverse crack length and the measured value of the rut depth of the asphalt pavement structure at the current moment.

[0057] Table 3 Pavement Crack and Vertical Permanent Deformation Data Sheet

[0058]

[0059] Step 4: According to the hourly average temperature, traffic volume, and axle load spectrum data obtained in Step 1, combined with the master curve of the modulus of each structural layer of the asphalt pavement after correction, use a calculation method that divides by time, axle type, and axle load interval, and use the asphalt pavement structure fatigue damage model to calculate the asphalt pavement structure damage at the current moment. At the same time, use the asphalt pavement structure fatigue damage model to predict the asphalt pavement structure damage at a specified future moment, as shown in Table 4.

[0060] Table 4 Asphalt Pavement Structure Damage in the Current Year and Subsequent Years

[0061] Year Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Asphalt Pavement Structure Damage Rate / % 0.112 0.316 0.794 1 3.162 8.916

[0062] When using the asphalt pavement structure fatigue damage model to predict the asphalt pavement structure damage at a specified future moment, due to the lack of historical monitoring data from the current moment to the specified future moment, it is necessary to use the monitoring data preset by the staff when predicting the asphalt pavement structure damage at the specified future moment. In this embodiment, the hourly average temperature, traffic volume, and axle load spectrum data corresponding to the same moment in the most recent year in the historical monitoring data are used as the monitoring data for the future moment of the asphalt pavement.

[0063] In this embodiment, the asphalt pavement structure fatigue damage model adopts a calculation method that divides by time, axle type, and axle load interval, and is based on the fatigue damage caused by various axle loads in each axle load interval at each moment from the time when the asphalt pavement was opened to traffic to the current moment, as shown in Formula (1):

[0064]

[0065] Among them,

[0066]

[0067] In the formula, D is the asphalt pavement structure damage; t is the time serial number, T is the total duration, in hours; i is the axle type serial number; j is the axle load interval serial number; D ijt is the fatigue damage generated when the i-th axle type passes through the asphalt pavement in the j-th axle load interval within the t-th hour; NA ijt is the total number of loadings of the i-th axle type in the j-th axle load interval within the t-th hour; is the fatigue life of the asphalt pavement when the i-th axle type passes through the j-th axle load interval within the t-th hour; β is the target reliability; k a is the adjustment coefficient for the seasonal frozen soil area; k b is the fatigue loading mode coefficient; is the temperature adjustment coefficient; is the bottom tensile strain of the asphalt layer generated when the i-th axle type passes through the j-th axle load interval within the t-th hour; is the dynamic modulus of the asphalt mixture when the i-th axle type passes through the j-th axle load interval within the t-th hour; VFA is the asphalt saturation of the asphalt mixture; h a is the layer thickness of the asphalt mixture, with the unit of mm.

[0068] Step 5: Use the transverse crack length model and the permanent deformation model to calculate the calculated values of the transverse crack length and rut depth of the asphalt pavement at the current moment. Combine the measured values of the transverse crack length and rut depth of the asphalt pavement at the current moment to correct the transverse crack length model and the permanent deformation model of the asphalt pavement, and obtain the corrected transverse crack length model and permanent deformation model.

[0069] In this embodiment, the transverse crack length model is:

[0070]

[0071] Among them,

[0072]

[0073] In the formula, l′ is the calculated value of the transverse crack length of the asphalt pavement structure, with the unit of m; β2 is the crack length calculation coefficient, and its value is 400; N(·) is the standard normal distribution function; SD is the standard deviation parameter of the transverse crack depth of the asphalt pavement structure, and its value is 0.769; H a is the asphalt layer thickness of the asphalt pavement structure, with the unit of m; t is the time serial number, T is the total duration; C is the crack depth value of the asphalt pavement structure, with the unit of m; C2 is the crack depth value of the asphalt pavement structure at the end of the 2nd hour, with the unit of m; C t-1 is the crack depth value of the asphalt pavement structure at the end of the (y - 1)-th hour, with the unit of m; C t-2 is the crack depth value of the asphalt pavement structure at the end of the (t - 2)-th hour, with the unit of m; Δk t is the change amount of the stress intensity factor within the t-th hour; k t is the stress intensity factor of the t-th hour; k t-1 is the stress intensity factor of the (t - 1)-th hour; σ t is the internal force received at the crack tip within the t-th hour; σ t-1is the internal force received at the crack tip within the (t - 1)-th hour; both A and a are fracture parameters of the asphalt mixture; β1 is the field calibration coefficient with a value of 6.0; E * is the stiffness modulus of the asphalt mixture, with a value of 10,000; σ m is the indirect tensile strength of the asphalt mixture in the structural layer where the crack tip is located, in MPa; m is the creep rate of the asphalt mixture in the structural layer where the crack tip is located;

[0074] The modified transverse crack length model is:

[0075]

[0076] In the formula, l is the modified value of the transverse crack length of the asphalt pavement structure; α is the calibration coefficient of the transverse crack length.

[0077] In this embodiment, according to the pavement crack and vertical permanent deformation data measured by the comprehensive inspection vehicle at the current moment, the least squares method is used to process the pavement crack and vertical permanent deformation data, and it is compared with the transverse crack length of the asphalt pavement calculated by the transverse crack length model before correction to determine the calibration coefficient α of the transverse crack length, so as to obtain the modified transverse crack length model.

[0078] The permanent deformation model is:

[0079]

[0080] Among them,

[0081]

[0082] In the formula, R a is the calculated value of the rut depth of the asphalt pavement structure; λ is the calibration coefficient; x is the number of vehicle load applications, X is the total number of vehicle load applications; y is the asphalt layer number, Y is the total number of asphalt layers; t is the time number, T is the total duration; is the rut depth generated by the x-th vehicle load application in the y-th layer of the asphalt layer within the t-th hour of the current year; k Ry is the comprehensive correction coefficient of the y-th layer in the asphalt layer; T yt is the internal temperature of the y-th layer in the asphalt layer, in °C; P yt is the vertical compressive stress at the top of the y-th layer in the asphalt layer within the t-th hour, in MPa; N xet is the number of standard axle load applications received by the asphalt pavement structure when the x-th vehicle load passes; h y is the thickness of the y-th layer in the asphalt layer, in mm; h0 is the thickness of the rut test specimen, in mm; is the rut depth corresponding to the asphalt mixture in the y-th layer of the asphalt layer within the t-th hour, in mm.

[0083] In this embodiment, according to the pavement crack and vertical permanent deformation data measured by the comprehensive inspection vehicle at the current moment, the rut depth measurement value of the asphalt pavement structure at the current moment is obtained, and in combination with the rut depth of the asphalt pavement structure calculated by the permanent deformation model before correction, the calibration coefficient λ is determined, so as to correct the permanent deformation model and obtain the corrected permanent deformation model.

[0084] Step 6: According to the master curves of the moduli of each structural layer of the asphalt pavement after correction, using the corrected transverse crack length model and permanent deformation model, calculate the transverse crack length and rut depth of the asphalt pavement at the current moment, and then use the corrected transverse crack length model and permanent deformation model to predict the transverse crack length and rut depth of the asphalt pavement at a specified future moment, as shown in Table 5.

[0085] Table 5 Transverse crack length and permanent deformation of the asphalt pavement in the current year and subsequent years

[0086] Year Year 10 Year 11 Year 12 Year 13 Year 14 Year 15 Transverse Joint Length / (m / km) 70.56 73.45 85.16 96.49 119.1 136.53 Rutting Depth / mm 11.55947 12.11097 12.63739 13.14184 13.62682 14.0944

[0087] Figure 3 As shown is the development trend diagram of the permanent deformation of the asphalt pavement. According to the structural damage of the asphalt pavement calculated at the current moment in Step 5, calculate the structural damage rate of the asphalt pavement at the current moment. Then, according to the measured values of the transverse crack length and rut depth of the asphalt pavement at the current moment, calculate the growth rate of the transverse crack length and the permanent deformation rate of the asphalt pavement at the current moment. Evaluate the structural performance of the asphalt pavement based on the structural damage rate, growth rate of the transverse crack length, and permanent deformation rate of the asphalt pavement. At the same time, according to the predicted structural damage of the asphalt pavement at a specified future moment in Step 5, use the calculation formula for the structural damage rate of the asphalt pavement to predict the structural damage rate of the asphalt pavement at the specified future moment, and according to the corrected transverse crack length model and permanent deformation model, predict the transverse crack length and rut depth of the asphalt pavement at the specified future moment, predict the growth rate of the transverse crack length and the permanent deformation rate of the asphalt pavement at the specified future moment, and evaluate the structural performance of the asphalt pavement at the specified future moment based on the structural damage rate, growth rate of the transverse crack length, and permanent deformation rate of the asphalt pavement at the specified future moment.

[0088] In this embodiment, the calculation formula for the structural damage rate of the asphalt pavement is:

[0089] DR = 100D (12)

[0090] In the formula, DR is the structural damage of the asphalt pavement; D is the structural damage rate of the asphalt pavement.

[0091] The calculation formula for the permanent deformation rate of the asphalt pavement is:

[0092]

[0093] In the formula, RDR is the permanent deformation rate of the asphalt pavement structure; R a is the rut depth value of the asphalt pavement structure, specifically the calculated value or measured value of the rut depth; when calculating the permanent deformation rate of the asphalt pavement structure at the current moment, R a is the measured value of the rut depth at the current moment, determined according to the road surface crack and vertical permanent deformation data measured at the current moment; when calculating the permanent deformation rate of the asphalt pavement structure at a specified future moment, R a is the calculated value of the rut depth, determined by the modified permanent deformation model.

[0094] In this embodiment, the current year of the dynamic evaluation of the asphalt pavement structure performance is 10 years. Further calculation shows that the structural damage rate of the asphalt pavement in the current year is 1.2%, the growth rate of the transverse crack length is 4%, and the permanent deformation rate is 4%. That is, the structural strength and performance of the asphalt pavement in the current year still remain in good condition, and at this stage, only corresponding functional maintenance is required for the asphalt pavement.

[0095] Meanwhile, when the dynamic evaluation of the asphalt pavement structure performance at the current moment is completed, it immediately enters the next moment to continue the dynamic evaluation of the asphalt pavement structure performance, repeating steps 1 to 6 until the asphalt pavement ends its service life and stops the dynamic evaluation of the asphalt pavement structure performance.

[0096] When entering the next moment for the dynamic evaluation of the asphalt pavement structure performance, the temperature data and traffic load data monitored at the previous moment are automatically stored in the historical monitoring data. And each time after entering the next moment, combined with the road surface crack and vertical permanent deformation data collected in real time, the master curve of the modulus of each structural layer of the asphalt pavement, the transverse crack length model, and the permanent deformation model are re-corrected. By using the calculation method of dividing by moment, axis type, and axle load interval, the dynamic evaluation of the structural damage rate, transverse crack length growth rate, and permanent deformation rate of the asphalt pavement at the current moment realizes the cumulative application of the monitoring data during the service life of the asphalt pavement. By using the cumulative monitoring data from the time of opening to traffic to the evaluation moment, during each dynamic evaluation process of the asphalt pavement structure performance, the master curve of the modulus of each structural layer of the asphalt pavement, the transverse crack length model, and the permanent deformation model, rather than setting the modulus of each structural layer of the asphalt pavement to a fixed value, and cooperating with the successive correction of the transverse crack length model and the permanent deformation model, greatly improves the calculation accuracy of the transverse crack length and rut depth, and further improves the accuracy of the asphalt pavement structure performance evaluation.

[0097] Certainly, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those skilled in the art within the substantial scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A dynamic evaluation method for the structural performance of asphalt pavement, characterized in that, It includes the following steps: Step 1: Obtain the hourly average temperature, traffic volume, and axle load spectrum data of the asphalt pavement based on the annual temperature field and traffic load data in the historical monitoring data since the asphalt pavement was opened to traffic. Step 2: Conduct asphalt pavement strength tests at multiple temperatures. By back-calculating the structural layer modulus of the asphalt pavement, determine the dynamic modulus of each structural layer in the asphalt pavement at different temperatures, and correct the modulus master curve of each structural layer of the asphalt pavement based on the least squares method. Step 3: Use an integrated inspection vehicle to detect the surface cracks and permanent deformation of the asphalt pavement, measure the pavement crack and vertical permanent deformation data of the asphalt pavement at the current moment, and obtain the measured values of the transverse crack length and rut depth of the asphalt pavement at the current moment. Step 4: According to the hourly average temperature, traffic volume, and axle load spectrum data obtained in Step 1, combined with the corrected modulus master curve of each structural layer of the asphalt pavement, use the asphalt pavement structural fatigue damage model to calculate the structural damage of the asphalt pavement at the current moment and predict the structural damage of the asphalt pavement at a specified future moment. Step 5: Use the transverse crack length model and permanent deformation model to calculate the calculated values of the transverse crack length and rut depth of the asphalt pavement at the current moment. Combine the measured values of the transverse crack length and rut depth of the asphalt pavement at the current moment to correct the transverse crack length model and permanent deformation model of the asphalt pavement. Step 6: According to the corrected modulus master curve of each structural layer of the asphalt pavement, use the corrected transverse crack length model and permanent deformation model to predict the transverse crack length and rut depth of the asphalt pavement at a specified future moment. Then, combined with the asphalt pavement structural damage, calculate the structural damage rate, transverse crack length growth rate, and permanent deformation rate of the asphalt pavement at the current moment and predict the values at a specified future moment to complete the performance evaluation of the asphalt pavement structure at the current moment. Step 7: Enter the next moment, and repeat Steps 1 to 6 to continue the dynamic evaluation of the asphalt pavement structure until the asphalt pavement ends its service life and stop the dynamic evaluation of the asphalt pavement structure performance.

2. The dynamic evaluation method for the structural performance of an asphalt pavement according to claim 1, characterized in that, The asphalt pavement strength test is carried out using a falling weight deflectometer, and the strength of the asphalt pavement structure is tested in the high-temperature range, medium-temperature range, and low-temperature range respectively, where 35°C ≤ high-temperature range < 50°C, 15°C ≤ medium-temperature range < 35°C, and 0°C ≤ low-temperature range < 15°C.

3. The dynamic evaluation method for the structural performance of asphalt pavement according to claim 1, characterized in that The asphalt pavement structural fatigue damage model adopts a calculation method that divides by time, axle type, and axle load interval, based on the fatigue damage caused by various axle loads in each axle load interval to the asphalt pavement at each moment from the time when the asphalt pavement was opened to traffic to the current moment, as shown in Formula (1): Where, Wherein, D is the damage of the asphalt pavement structure; t is the time serial number, T is the total duration; i is the axle type serial number; j is the axle load interval serial number; D i j t is the fatigue damage generated when the i-th axle type passes through the asphalt pavement within the j-th axle load interval in the t-th hour; NA ijt is the total number of loadings of the i-th axle type within the j-th axle load interval in the t-th hour; is the fatigue life of the asphalt pavement when the i-th axle type passes through within the j-th axle load interval in the t-th hour; β is the target reliability; k a is the adjustment coefficient for the seasonal frozen soil area; k b is the fatigue loading mode coefficient; is the temperature adjustment coefficient; is the bottom tensile strain of the asphalt layer generated when the i-th axle type passes through within the j-th axle load interval in the t-th hour; is the dynamic modulus of the asphalt mixture when the i-th axle type passes through within the j-th axle load interval in the t-th hour; VFA is the asphalt saturation of the asphalt mixture; h a is the layer thickness of the asphalt mixture.

4. The dynamic evaluation method for the structural performance of an asphalt pavement according to claim 1, characterized in that, The transverse crack length model is: Where, Wherein, l′ is the calculated value of the transverse crack length of the asphalt pavement structure; β2 is the crack length calculation coefficient; N(·) is the standard normal distribution function; SD is the standard deviation parameter of the transverse crack depth of the asphalt pavement structure; H a is the asphalt layer thickness of the asphalt pavement structure; t is the time serial number, T is the total duration; C is the crack depth value of the asphalt pavement structure; C2 is the crack depth value of the asphalt pavement structure at the end of the 2nd hour; C t-1 is the crack depth value of the asphalt pavement structure at the end of the (t - 1)th hour; C t-2 is the crack depth value of the asphalt pavement structure at the end of the (t - 2)th hour; Δk t is the change amount of the stress intensity factor within the tth hour; k t is the stress intensity factor of the tth hour; k t-1 is the stress intensity factor of the (t - 1)th hour; σ t is the internal force received at the crack tip within the tth hour; σ t-1 is the internal force received at the crack tip within the (t - 1)th hour; A and a are both asphalt mixture fracture parameters; β1 is the field calibration coefficient; E * is the stiffness modulus of the asphalt mixture; σ m is the indirect tensile strength of the asphalt mixture of the structural layer where the crack tip is located; m is the creep rate of the asphalt mixture of the structural layer where the crack tip is located; The corrected transverse crack length model is: In the formula, l is the corrected value of the transverse crack length of the asphalt pavement structure; α is the transverse crack length calibration coefficient.

5. The dynamic evaluation method for the structural performance of an asphalt pavement according to claim 1, characterized in that, The permanent deformation model is: Where, Wherein, R a is the calculated rut depth of the asphalt pavement structure; λ is the calibration coefficient; x is the number of vehicle load applications, X is the total number of vehicle load applications; y is the asphalt layer serial number, Y is the total number of asphalt layers; t is the time serial number, T is the total duration; is the rut depth generated by the x-th vehicle load application in the y-th sub-layer of the asphalt layer within the t-th hour of the current year; k Ry is the comprehensive correction coefficient of the y-th sub-layer in the asphalt layer; T yt is the internal temperature of the y-th sub-layer in the asphalt layer; P yt is the vertical compressive stress at the top of the y-th sub-layer of the asphalt layer in the t-th hour; N xet is the number of standard axle load applications received by the asphalt pavement structure when the x-th vehicle load passes; h y is the thickness of the y-th sub-layer in the asphalt layer; h0 is the thickness of the rut test specimen; is the rut depth corresponding to the asphalt mixture in the y-th sub-layer of the asphalt layer in the t-th hour.

6. The dynamic evaluation method for the structural performance of an asphalt pavement according to claim 1, wherein The calculation formula for the structural damage rate of the asphalt pavement is: DR = 100D (12) In the formula, DR is the structural damage of the asphalt pavement; D is the structural damage rate of the asphalt pavement; The calculation formula for the permanent deformation rate of the asphalt pavement is: In the formula, RDR is the permanent deformation rate of the asphalt pavement structure; R a is the rut depth value of the asphalt pavement structure.

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