A hot-in-place recycling method for pavement rutting disease

Abstract

The application discloses a kind of road surface rut disease heat regeneration repair methods, belong to road maintenance technical field.The method includes: obtaining the rut section profile data and aging asphalt migration rate of the road surface to be repaired;The rut section profile data is analyzed in space spectrum, and the depth sequence under different wavelength scales is extracted;Preset power matrix of heating wall is constructed in combination with aging asphalt migration rate and depth sequence, and the heating wall is controlled to carry out non-uniform heating to form heat-softened layer with temperature gradient;The heat penetration depth and asphalt dynamic viscosity of each point of heat-softened layer are detected, and the multilayer differential spray volume of regenerant in heat-softened layer is determined based on this.The method realizes the accurate heat regeneration repair of rut disease by non-uniform power output and stratified quantitative supply.

Description

Technical Field

[0001] This invention relates to the field of road maintenance technology, specifically to a method for thermal recycling repair of road ruts. Background Technology

[0002] Thermal recycling repair of pavement rutting relies on the uniform softening of the old asphalt mixture and the proper penetration of recycling agents. Traditional methods, after obtaining pavement elevation information, typically use a heating wall with uniform power to heat the entire rutting area. This approach fails to consider the complexity of the lateral and longitudinal geometry of rutting, and especially lacks the ability to differentiate depth components at different wavelength scales. This results in short-wavelength wear-type rutting and long-wavelength unstable rutting receiving the same thermal radiation dose.

[0003] The drawback of uniform heating is that shallow rut areas often experience secondary aging of asphalt due to overheating, while the bottom of deep ruts or unstable ruts is not sufficiently softened due to insufficient heat penetration, preventing the recycling agent from effectively penetrating to the required depth. Furthermore, existing recycling agent spraying strategies are mostly based on experience or single parameters, failing to establish a dynamic response relationship between the actual state of the heated mixture and the amount of recycling agent used. The spraying amount is mismatched with the depth of the damage and the viscosity of the asphalt, resulting in an enrichment of recycling agent in the surface layer and a deficiency in the deeper layers. Consequently, the repaired pavement exhibits significant non-uniformity along the depth direction.

[0004] To address the above issues, it is necessary to solve how to accurately match the heat energy supply based on the multi-scale geometric characteristics of ruts so that rut components of different depths and wavelengths can reach the target softening state, and how to combine the actual thermodynamic and rheological states of the heated mixture to implement differentiated regenerator replenishment at different spatial locations and depths. Summary of the Invention

[0005] This invention provides a thermal recycling repair method for road rutting, which aims to solve the problems of insufficient softening of the deep rutting layer and excessive heating of the surface layer caused by uniform power heating in the prior art, and to solve the problem of the disconnect between the spraying of recycling agent and the rutting depth and the actual viscosity of asphalt, so as to achieve precise spatial and temporal distribution of heat energy and recycling agent.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a method for thermal recycling repair of pavement rutting defects. This method includes: acquiring rutting cross-sectional contour data and the migration rate of aged asphalt from the pavement to be repaired; performing spatial spectrum analysis on the rutting cross-sectional contour data to extract the depth sequence of the rutting at different wavelength scales; constructing a pre-set power matrix for the heating wall during the thermal recycling repair process based on the aged asphalt migration rate and the depth sequence; controlling the heating wall to perform non-uniform heating on the pavement according to the pre-set power matrix to form a thermally softened layer with a temperature gradient; detecting the thermal penetration depth and asphalt dynamic viscosity of the thermally softened layer at different spatial points; and determining the multi-layer differentiated spraying amount of rejuvenating agent within the thermally softened layer based on the thermal penetration depth and the asphalt dynamic viscosity. This method organically combines the multi-wavelength morphological characteristics of the rutting cross-section with the aging and migration state of the asphalt, constructs a temperature field adapted to the damage depth through differentiated heating, and accurately distributes the rejuvenating agent based on real-time thermophysical parameters, significantly improving the uniformity of aged asphalt recycling and the repair quality while reducing energy consumption.

[0007] As a preferred embodiment of the present invention, the specific implementation method for obtaining rut cross-sectional contour data is as follows: A linear laser profilometer is controlled to scan the rut groove at a preset transverse sampling interval, collecting discrete elevation point sets on multiple transverse sections along the driving direction to form the rut cross-sectional contour data; simultaneously, milled old material samples are collected from the sidewall of the rut groove, and gel permeation chromatography analysis is performed on the samples to obtain the relative molecular mass distribution ratio of asphalt and resin, which is then normalized and used as the migration rate of the aged asphalt. Preferably, the transverse sampling interval is 1mm to 5mm, and the longitudinal sampling interval of the linear laser profilometer is controlled in conjunction with the vehicle's driving speed to ensure high resolution and consistency of the cross-sectional data along the longitudinal direction.

[0008] Regarding spatial spectrum analysis, this invention further proposes: performing a one-dimensional discrete cosine transform on the rut profile data along the driving direction to obtain a spectral energy distribution curve in the spatial frequency domain; dividing the spectral energy distribution curve into wear wavelength intervals, instability wavelength intervals, and deformation wavelength intervals according to wavelength from long to short; and accumulating the depth component amplitudes corresponding to all frequency components within each wavelength interval, arranging the three sums in wavelength order to form the depth sequence. This processing can interpret complex rut profiles into three types of characteristic depths: long-wave wear, mid-wave instability, and short-wave deformation, enabling subsequent heating strategies to provide differentiated compensation for different damage mechanisms.

[0009] When constructing the preset power matrix, the preferred approach is as follows: the heating area of ​​the heating wall is divided into multiple independent heating channels along the transverse direction, with each heating channel corresponding to a transverse control unit; three depth values ​​from the depth sequence are used as the heating depth basis vector, and the aging asphalt migration rate is introduced to weight and correct the heating depth basis vector to obtain the target heating depth required for each transverse control unit; using the empirical coefficient of heat conduction obtained by pre-calibration on asphalt mixture specimens of the same gradation, the initial heating power required for each transverse control unit is calculated from the target heating depth, and all initial heating powers are arranged in channel order to form the preset power matrix. The empirical coefficient of heat conduction is obtained through a pre-calibration experiment, which records the temperature distribution curves along the depth direction under different heating powers and heating times, providing a reliable empirical basis for power calculation.

[0010] For the non-uniform heating stage, this invention sends each initial heating power value in the preset power matrix to the power regulator of the corresponding lateral control unit. Each lateral control unit simultaneously activates infrared thermal radiation according to the received power value, so that the intensity of thermal radiation received at the bottom of the rut is asymmetrically distributed along the lateral direction. Heating continues until the surface temperature difference between the lateral center region and the lateral edge region of the rut reaches a preset temperature gradient threshold, thereby forming a thermally softened layer with a spatial gradient. This method ensures that the deeper parts of the rut receive stronger heat input, while the shallower parts are prevented from overheating, so that the temperature distribution in the depth direction of the thermally softened layer closely matches the wear depth of the cross-section.

[0011] In the detection phase, this invention employs a micro-penetration probe for in-situ detection: within a predetermined time window after heating is stopped, the micro-penetration probe is driven to sequentially penetrate multiple predefined grid nodes on the heat-softened layer in a vertical orientation; the vertical distance the probe descends from the contact surface of the heat-softened layer to the point of sudden increase in resistance at each grid node is recorded as the thermal penetration depth at that node; simultaneously, during probe penetration, the flow resistance of the asphalt mixture is measured in real time by a shear force sensor integrated into the probe's sidewall, and the dynamic viscosity of the asphalt at that node is calculated based on the comparison between the flow resistance and a preset calibration curve. Preferably, the penetration speed of the micro-penetration probe is 0.5 mm / s to 2 mm / s, and the predetermined time window is within 10s to 30s after heating is stopped, to accurately capture the thermodynamic state of the material within the actual construction window, providing crucial information for precise application of the recycling agent.

[0012] When determining the differentiated spraying amount of recycling agent in multiple layers, this invention divides the thermally softened layer along the depth direction into a surface repair zone, a middle layer connection zone, and a bottom layer reinforcement zone. Each zone corresponds to a preset recycling agent demand coefficient. The preferred method for zone division is as follows: obtain the highest heating temperature of the road surface and the glass transition temperature of the asphalt mixture during the thermal softening process; divide the temperature difference range between the highest heating temperature and the glass transition temperature into three equal parts, obtaining three continuous temperature difference intervals; the portion of the thermally softened layer with the highest temperature difference interval is defined as the surface repair zone, the portion with the middle temperature difference interval is defined as the middle layer connection zone, and the portion with the lowest temperature difference interval is defined as the bottom layer reinforcement zone. After determining the actual thickness of the three zones below each grid node, the baseline recycling agent dosage is calculated based on the dynamic viscosity of the asphalt at that node. Then, the baseline recycling agent dosage is weighted and allocated according to the actual thickness of each zone multiplied by the corresponding recycling agent demand coefficient to obtain the spraying amount for each of the three zones at that node. This layered strategy ensures that the penetration depth and dosage of the recycling agent are precisely matched with the actual aging degree and temperature distribution of the asphalt, overcoming the defects of excessive surface spraying and insufficient bottom layer recycling.

[0013] During the spraying execution phase, this invention extracts the spray volume from all grid nodes belonging to the same depth region, forming a surface spraying matrix, a middle-layer spraying matrix, and a bottom-layer spraying matrix. Each spraying matrix is ​​then Gaussian smoothed to eliminate abrupt changes in spray volume between adjacent grid nodes. The three smoothed spraying matrices are sequentially sent to multiple independent nozzle arrays installed behind the heating wall, controlling the nozzle arrays to spray the regenerant layer-by-layer on the thermally softened layer. Through matrix control and smoothing, the continuous and uniform spatial distribution of the regenerant is ensured, preventing differences in regeneration effect caused by abrupt changes in spray volume.

[0014] As a further improvement, after the recycling agent is sprayed, the remixing bin is started to mill and mix the heat-softened layer, so that the recycling agent and the aged asphalt mixture are fully integrated; the screed is controlled to spread and pre-compact the mixed mixture to form a recycled pavement layer; the surface texture of the recycled pavement layer is optically scanned, and the preset power matrix of the heating wall in subsequent operations is finely adjusted according to the deviation between the texture depth obtained by scanning and the preset target texture depth, so as to achieve closed-loop optimization and continuously improve the repair quality of subsequent road sections.

[0015] The technical effects and advantages provided by the present invention in the above technical solution are as follows: By extracting the depth sequence of ruts at different wavelength scales through spatial spectrum analysis, the complex geometric shape of rut deformation is deconstructed into wear wavelength, instability wavelength, and deformation wavelength components. The target heating depth for the corresponding transverse channel is determined based on the depth of each component. After weighted correction of the target heating depth by incorporating the migration rate of aged asphalt, the initial heating power of each transverse control unit is calculated, ultimately forming a preset power matrix that spatially matches the multi-scale depth characteristics of the ruts. This power matrix drives a heating wall to perform non-uniform heating of the pavement, ensuring that the deep rut sections receive higher radiative flux to form deep softening, while the radiative flux in raised or shallow sections decreases accordingly. The resulting thermally softened layer has a temperature gradient in both depth and width directions that matches the severity of the damage, fundamentally avoiding the shallow overheating and deep underheating phenomena caused by uniform heating, while also reducing ineffective energy consumption.

[0016] Based on the thermal penetration depth and dynamic viscosity of asphalt obtained from testing, the thermally softened layer is defined in the depth direction as a surface repair zone, a middle layer bonding zone, and a bottom layer reinforcement zone. The baseline amount of recycler at each network node is calculated from the measured dynamic viscosity of asphalt and weighted according to the actual thickness and demand coefficient of each area below that node, ultimately generating a multi-layer differentiated spraying amount. This layered replenishment method driven by real thermodynamic and rheological parameters directly correlates the amount of recycler delivered at each spatial point with the actual softening depth and flow characteristics of the aged asphalt. This avoids the distribution defects of traditional spraying methods, where the recycler only stays on the surface or is scarce in the deep layers. It allows the active ingredients of the recycler to fully contact the old material with different degrees of aging along the depth direction, promoting the balanced improvement of the viscosity recovery of deep old asphalt and the interlayer bonding strength. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a flowchart of the hot recycling repair method for road rutting. Figure 2 This is a flowchart of the method for collecting rut profile data and determining the migration rate of aged asphalt. Figure 3 This is a flowchart of the rut depth sequence extraction process; Figure 4 This is a flowchart for the in-situ detection and control of non-uniform heating and thermal softening layer of rutted asphalt pavement. Figure 5 It is a two-dimensional elevation distribution map of the rut cross-section; Figure 6This is a distribution map of the thermal penetration depth of the thermal softening layer; Figure 7 This is a distribution map of the amount of regenerant sprayed in different depth areas of the thermal softening layer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] See Figure 1 This invention provides a method for thermal recycling repair of pavement rutting, comprising the following steps: acquiring rutting cross-sectional contour data and aged asphalt migration rate of the pavement to be repaired; performing spatial spectrum analysis on the rutting cross-sectional contour data to extract the depth sequence of the rutting at different wavelength scales; constructing a pre-set power matrix for the heating wall during the thermal recycling repair process based on the aged asphalt migration rate and depth sequence; controlling the heating wall to non-uniformly heat the pavement according to the pre-set power matrix to form a thermally softened layer with a temperature gradient; detecting the thermal penetration depth and asphalt dynamic viscosity at different spatial points of the thermally softened layer; and determining the multi-layer differentiated spraying amount of recycling agent within the thermally softened layer based on the thermal penetration depth and asphalt dynamic viscosity.

[0021] Example 1 See Figure 2 In practice, the step of acquiring the rut profile data of the road surface to be repaired is achieved using a line laser profilometer. The line laser profilometer is fixed to the front end of the inspection vehicle, with the laser line projection direction perpendicular to the driving direction. The lateral sampling interval of the line laser profilometer is set to a fixed value, selected between 1 mm and 5 mm. In one embodiment, the lateral sampling interval is set to 2 mm. The receiving sensor inside the line laser profilometer collects elevation information along the laser line at the lateral sampling interval, with each lateral section forming a set of discrete elevation points.

[0022] The longitudinal sampling interval of the line laser profilometer is linked to the vehicle's speed. A speed sensor installed on the vehicle acquires the vehicle's speed in real time, and the speed signal is sent to a synchronization controller. The synchronization controller has a pre-set longitudinal sampling interval distance, for example, 10mm. The synchronization controller calculates the trigger pulse time based on the vehicle's speed and the longitudinal sampling interval distance, ensuring that the line laser profilometer is triggered once every time the vehicle advances one longitudinal sampling interval, acquiring a new transverse cross-sectional profile. The longitudinal sampling interval distance remains constant during the scanning process and does not change due to variations in vehicle speed. Scanning is performed progressively along the driving direction, obtaining a series of transverse cross-sectional elevation points with equal longitudinal spacing. All transverse cross-sectional elevation points are combined to form the rut profile data. The rut profile data is stored in a two-dimensional matrix, where the row number corresponds to the longitudinal position, the column number corresponds to the transverse position, and the stored values ​​are elevation values.

[0023] The steps for obtaining the migration rate of aged asphalt include collecting milled waste rock samples and gel permeation chromatography (GPC) analysis. A handheld milling device is used to collect surface aged asphalt mixture from the sidewalls of ruts, serving as the milled waste rock sample. The milled waste rock sample is extracted and recovered to obtain aged asphalt. GPC is used to determine the aged asphalt, with tetrahydrofuran as the mobile phase, a cross-linked polystyrene gel column, and a differential refractive index detector. Characteristic peaks corresponding to asphaltenes and resins are identified from the chromatogram, and the integrated areas of the asphaltenes and resins are calculated respectively. The ratio of the integrated area of ​​the asphaltenes to the resin is defined as the relative molecular mass distribution ratio, denoted by the symbol [symbol missing]. express.

[0024] Subsequently, the ratio of relative molecular mass distribution was analyzed. The migration rate of aged asphalt is obtained by normalization. The normalization method uses the following formula: , in, The migration rate of aged asphalt. The value of is between 0 and 1; The ratio of the integral area of ​​the characteristic peak of the asphalt component to the integral area of ​​the characteristic peak of the resin component, as measured from the milled old material sample; This is the preset lower limit of the relative molecular mass distribution ratio. Determined by the minimum value of the relative molecular mass distribution ratio measured in unaged or slightly aged asphalt samples; This is the upper limit of the preset relative molecular mass distribution ratio. The molecular weight distribution ratio is determined by the maximum value of the relative molecular weight distribution ratio measured from severely aged asphalt samples. In practice, asphalt pavement samples with different service years are pre-selected, for example, three groups of samples each for 0 years, 3 years, 6 years, 9 years, and 12 years of service. The relative molecular weight distribution ratio is measured for each sample, and the minimum value among all measured results is taken as the molecular weight distribution ratio. The maximum value is used as The calculated migration rate of aged asphalt This reflects the degree of aging and migration of asphalt materials. A value close to 0 indicates slight aging; when... A value close to 1 indicates severe aging.

[0025] See Figure 5 The figure illustrates the spatial distribution of a two-dimensional matrix of rut profile data of the road surface to be repaired, obtained using a line laser profilometer in Example 1. The horizontal axis represents the lateral position of the rut profile, ranging from -500mm to 500mm, while the vertical axis represents the longitudinal position along the direction of travel, ranging from 0mm to 2000mm. Different gray levels are used to represent elevation ranges in the figure, specifically five levels: the lightest gray corresponds to an elevation range of -16.0mm to -12.6mm, and the darkest gray corresponds to an elevation range of -2.4mm to 1.0mm. The entire two-dimensional image exhibits a clear characteristic of the lowest elevation at the lateral center (i.e., the bottom of the rut), with the lightest gray level in the central area gradually increasing in intensity from left to right, indicating that the rut exhibits a typical rut profile morphology of a concave center and relatively higher sides.

[0026] The longitudinal elevation values ​​show minimal variation, indicating a relatively smooth rut profile along the direction of travel without significant longitudinal undulations, thus ensuring the continuity and integrity of the rut cross-section data. The transverse elevation gradually increases from the center to the edge, reflecting the decreasing depth trend of the rut profile, consistent with the physical properties of ruts. The overall elevation values ​​are negative, representing the depth of the depression above the measurement reference plane; the elevation range from -16.0 mm to 1.0 mm covers the measured range of typical rut depths.

[0027] Example 2 See Figure 3 In practical implementation, rut profile data is used as the object of spatial spectrum analysis. The rut profile data is stored in a two-dimensional matrix. The row number in the matrix represents the longitudinal position index along the driving direction, the column number represents the lateral position index, and the value of each element represents the road surface elevation at that coordinate position. A column of longitudinal elevation values ​​corresponding to the lateral position of the bottom center of the rut is extracted from the rut profile data as the longitudinal sequence of the rut profile to be transformed. During extraction, the column number of the lowest lateral point of the rut is first determined, and all row elevation values ​​of the corresponding column are extracted and arranged in longitudinal position index order to form a sequence of length [length missing]. A one-dimensional sequence, where It equals the total number of longitudinal sections.

[0028] A one-dimensional discrete cosine transform (DCT) is performed on the extracted longitudinal sequence of rut contours. The DCT uses the second type of DCT, and its forward transformation calculation process is as follows: Subtract the average value of each elevation value in the longitudinal sequence of rut contours to obtain a zero-mean elevation sequence. Then, apply a DCT kernel function to the zero-mean elevation sequence. The kernel function is located at the index... The positional components are ,in For time-domain sampling point index, For frequency index in the frequency domain, Where is the sequence length. The transformation yields a set of discrete cosine transform coefficients, each corresponding to a specific frequency index. Frequency index The corresponding spatial frequency is ,in This is the longitudinal sampling interval distance. Take a fixed value of 10mm. The wavelength corresponding to this spatial frequency is: .

[0029] Combine all discrete cosine transform coefficients with their corresponding wavelengths. By plotting the correlation, the spectral energy distribution curve in the spatial frequency domain is obtained. The horizontal axis of the spectral energy distribution curve uses wavelength. The unit is millimeters, and the vertical axis uses the squares of the discrete cosine transform coefficients to represent the energy of the frequency components. Wavelength The range is from greater than zero to infinity. In actual drawing, the upper limit of the wavelength is the total longitudinal length of the rut profile.

[0030] The spectral energy distribution curve is divided into three wavelength ranges in descending order of wavelength: the wear wavelength range, the instability wavelength range, and the deformation wavelength range. The wavelength range of the wear wavelength range is... The wavelength range of the unstable wavelength range is: The wavelength range of the deformation wavelength interval is: The above wavelength limits are determined based on the following: After analyzing the mechanical causes of ruts on multiple highways of different grades, the spatial frequency of longitudinal texture changes caused by tire wear is extremely low, corresponding to a wavelength greater than 200 mm; the wavelength of deformation characteristics caused by lateral flow instability of asphalt mixture is of medium scale, concentrated between 50 mm and 200 mm; the wavelength of the unevenness characteristics at the bottom of ruts caused by deformation of the base course or subgrade is shorter, less than or equal to 50 mm.

[0031] For the wear wavelength range, extract all frequency indices within that range. The corresponding discrete cosine transform coefficients, the absolute value of each discrete cosine transform coefficient is defined as the amplitude of the depth component of that frequency component, denoted by the symbol It means that among them Identify the wear wavelength range. This represents the index of the frequency component within the interval. The amplitudes of all depth components within the wear wavelength interval are summed to obtain the accumulated wear depth value. .

[0032] Similarly, within the instability wavelength range, the sum of the depth component amplitudes corresponding to all frequency components within that range is calculated to obtain the cumulative instability depth value. Within the deformation wavelength range, calculate the cumulative sum of the depth component amplitudes corresponding to all frequency components within that range to obtain the cumulative deformation depth value. The above accumulation calculations are uniformly expressed using the following formula, taking the wear wavelength range as an example: , in, This represents the cumulative wear depth value corresponding to the wear wavelength range; This indicates the total number of frequency components contained within the wear wavelength range; Indicates the first wavelength in the wear wavelength range The depth component amplitude of each frequency component The value is equal to the absolute value of the discrete cosine transform coefficient corresponding to that frequency component.

[0033] Arrange the three accumulated values ​​in the order of wear wavelength range, instability wavelength range, and deformation wavelength range to form a depth sequence, which takes the form of { , , The three values ​​in this depth sequence represent the cumulative magnitude of the depth components of ruts at different wavelength scales, reflecting the contribution of wear, instability, and deformation to the total rut depth.

[0034] Example 3 In implementation, the heating area of ​​the heating wall is divided into multiple independent heating channels laterally. The working width of the heating wall covers the maximum lateral span of the rut and extends outwards by a preset allowance of 100mm. Within the working width, independent heating channels are set at equal intervals, with each channel having a lateral width of 100mm. Insulation baffles, made of ceramic fiber and 3mm thick, are installed between adjacent heating channels to block heat radiation crosstalk between channels. Each heating channel contains a set of infrared heat radiation tubes arranged longitudinally, sharing the same power input. Each heating channel is equipped with a lateral control unit, which includes a power regulator and a temperature feedback module. The power regulator receives the target power value and adjusts the supply voltage to a level that makes the output power of the infrared heat radiation tube equal to the target power value.

[0035] The three depth values ​​in the depth sequence are used as the heating depth basis vectors. The depth sequence is represented as { , , },in This is the cumulative value of wear depth. This is the cumulative value of the instability depth. This represents the cumulative value of the deformation depth. The heating depth basis vector is indicated by the symbol... express, ,in , , These correspond to the cumulative values ​​of wear depth, instability depth, and deformation depth, respectively.

[0036] The heating depth basis vector is weighted and corrected based on the migration rate of aged asphalt to obtain the target heating depth required for each lateral control unit. The weighting correction operation is achieved by multiplying the heating depth basis vector by a weighting coefficient matrix, which incorporates the influence of the aged asphalt migration rate. In one embodiment, the target heating depth is expressed numerically as follows: , in, Indicates the first The target heating depth corresponding to each lateral control unit is in millimeters; This refers to the channel number of the lateral control unit. The value ranges from 1 to the total number of horizontal control units. integers, It equals the total number of heating channels; The base depth correction factor is set to 1.0 × 10⁻⁶. ⁻³ ; The migration rate of aged asphalt, with a value between 0 and 1, was obtained by gel permeation chromatography analysis and normalization. This is the accumulated wear depth value, derived from the first element of the depth sequence; This is the cumulative value of the instability depth, derived from the second element of the depth sequence; This is the accumulated deformation depth value, derived from the third element of the depth sequence; This is the wear depth weighting coefficient. Set a fixed value of 0.25; The instability depth weighting coefficient, Take a fixed value of 0.35; This is the deformation depth weighting coefficient. A fixed value of 0.40 is used. The above weighting coefficients are allocated in ascending order according to the degree of need for regeneration depth in terms of deformation, instability, and wear; repair of deformation depth requires a greater thermal penetration depth. Basic Depth Correction Factor Used to convert weighted composite depth values ​​into engineering-feasible thermal softening depths.

[0037] In some implementations, the migration rate of aged asphalt The correction effect on the target heating depth exhibits a multiplicative relationship. When the migration rate of aged asphalt... When the value is close to 1, it indicates severe asphalt migration. A higher heat input is required to achieve sufficient softening at the same depth of deformation. The target heating depth is... The migration rate of aged asphalt increases accordingly. When approaching 0, the target heating depth Decrease.

[0038] Based on the target heating depth of each lateral control unit The initial heating power required for each lateral control unit is calculated by using a pre-embedded empirical coefficient of thermal conductivity. This pre-embedded empirical coefficient of thermal conductivity is obtained through calibration experiments on asphalt mixture specimens of the same gradation. In the calibration experiment, rutted slab specimens of asphalt mixture with the same gradation as the pavement to be repaired were prepared, with dimensions of 300mm × 300mm × 100mm. Infrared thermal radiation tubes of the same specifications as the heating wall channel were arranged above the specimens, and heating was performed using different power levels and heating time combinations. For each combination, a thermocouple array was embedded into the specimen along the depth direction at 5mm intervals, and the temperature values ​​at each depth were recorded. Based on the temperature records, a bundle of temperature distribution curves along the depth direction was plotted for different heating powers and heating times. The correspondence between the critical heating power required to reach each depth and the corresponding heating time was extracted from the temperature distribution curve bundle, and a power inverse calculation formula was obtained by fitting the formula. The power inverse calculation formula is expressed as: reaching the target heating depth... Required initial heating power Equal to the empirical coefficient of heat conduction Multiply by the square of the target heating depth, then divide by the heating duration. ,Right now .in The empirical coefficient of thermal conductivity. It was obtained from statistical regression of the calibration experimental data. The unit is In the calibration test, for the same graded asphalt mixture, The average test result was 4.2. Heating duration. This is the preset total duration of the heating phase. Set a fixed value of 180 seconds.

[0039] For each lateral control unit, the target heating depth is determined. Empirical coefficient of thermal conductivity and heating duration Substituting into the relation, we can calculate the first... Initial heating power required for each horizontal control unit . All initial heating power Arranged in channel order into a one-dimensional row matrix, this one-dimensional row matrix is ​​the preset power matrix. Each item in the preset power matrix corresponds to a lateral control unit, expressing the initial power distribution of each lateral channel under the non-uniform heating strategy.

[0040] Example 4 See Figure 4 In practice, each initial heating power value in the preset power matrix is ​​sent to the power regulator of the corresponding horizontal control unit. The preset power matrix is ​​a one-dimensional row matrix, with matrix elements arranged in channel number order. Indicates the first The initial heating power value corresponds to each horizontal control unit. The transmission operation is completed via an industrial fieldbus, with the central controller of the heating wall acting as the bus master and each horizontal control unit as a bus slave. The central controller parses the preset power matrix into power command frames corresponding one-to-one with the slave addresses. Each power command frame contains a target power value field and a check field. After receiving its own power command frame, the power regulator of each horizontal control unit extracts the target power value field and stores it in the setpoint register inside the power regulator.

[0041] Each lateral control unit simultaneously initiates infrared thermal radiation heating according to the received initial heating power value. The control loop within the power regulator adjusts the conduction angle of the AC voltage regulator module based on the initial heating power value in the setpoint register, ensuring that the electrical power output to the infrared thermal radiation tube matches the setpoint. The peak wavelength of the infrared thermal radiation tube's radiation spectrum is in the range of 2.5μm to 3.5μm, matching the infrared absorption peak of the asphalt mixture. All lateral control units simultaneously initiate heating under the drive of the same synchronization trigger signal, which is sent by the central controller via parallel I / O lines.

[0042] Because the initial heating power received by each lateral control unit is different, the thermal radiation intensity received at the bottom of the rut is asymmetrically distributed along the lateral direction. In the heating channel corresponding to the lateral center of the rut, the target heating depth is usually larger, resulting in higher initial thermal radiation intensity; in the heating channels corresponding to the lateral edges of the rut, the target heating depth is usually smaller, resulting in lower initial thermal radiation intensity. The thermal radiation intensity of the intermediate channels transitions smoothly according to the target heating depth.

[0043] During the heating process, the temperature feedback module in each lateral control unit continuously monitors the road surface temperature. The temperature feedback module includes an infrared temperature probe, which is aimed at the road surface area corresponding to the center of the heating channel at a fixed angle, with a sampling frequency set to 10Hz. The temperature feedback module sends the real-time road surface temperature value back to the central controller. The central controller calculates the difference between the road surface temperature in the lateral center region and the lateral edge region of the rut in real time. The lateral center region is defined as the road surface area within 50mm to the left and right of the geometric center of the rut, and its temperature value is the average of the temperatures measured by the corresponding temperature feedback modules of the heating channels within this region. The lateral edge region is defined as the road surface area within 25mm inward and 75mm outward from the two sides of the rut boundary, and its temperature value is the average of the temperatures measured by the corresponding temperature feedback modules of the heating channels within this region.

[0044] Heating continues until the surface temperature difference between the transverse center region and the transverse edge region of the rut reaches a preset temperature gradient threshold, at which point heating stops. The preset temperature gradient threshold expression is: , in, This is a preset temperature gradient threshold, in degrees Celsius. Based on the fundamental temperature gradient constant, The value is 15℃, which is based on the empirical value of the allowable temperature drop along the transverse direction for AC-13 type asphalt mixture in the paving temperature range of 150℃ to 180℃. The migration rate of aged asphalt, with values ​​between 0 and 1, was obtained through gel permeation chromatography analysis and normalization. The migration rate of aged asphalt was nonlinearly compressed using the natural logarithm function, which slowed the rate of increase of the temperature gradient threshold at higher aging levels, thus preventing excessive heating of the road surface.

[0045] In each temperature sampling cycle, the central controller determines whether the road surface temperature difference between the lateral center area and the lateral edge area reaches or exceeds a preset temperature gradient threshold. When the difference first reaches or exceeds Upon receiving the command, the central controller immediately sends a stop heating command to all lateral control units. Each lateral control unit, after receiving the stop heating command, reduces the output power of its power regulator to zero and cuts off the power supply to the infrared heat radiation tubes. At this point, a thermally softened layer with a temperature gradient has formed on the road surface, and the temperature inside this layer is non-uniformly distributed along both the depth and lateral directions.

[0046] In-situ testing of the physical properties of the heat-softened layer is performed within a predetermined time window after heating is stopped. The predetermined time window is defined as 10 to 30 seconds after heating is stopped. Within this window, a miniature penetration probe is driven vertically to sequentially penetrate multiple predefined grid node positions on the heat-softened layer. The grid nodes are predefined on the surface of the heat-softened layer, with a lateral spacing of 100 mm and a longitudinal spacing of 200 mm, forming a regular lattice aligned with the heating channel direction. The miniature penetration probe is mounted on a three-axis motion platform, which is fixed to a detection beam behind the heating wall. The central controller positions the grid nodes point by point according to the longitudinal index sequence.

[0047] At each grid node location, a miniature penetration probe is initiated vertically from above the surface of the thermally softened layer and penetrates downwards. The penetration speed of the miniature penetration probe is set to a constant value, selected within the range of 0.5 mm / s to 2 mm / s, and in one embodiment, 1.0 mm / s is selected. The tip of the miniature penetration probe is conical with a cone angle of 30° and a tip diameter of 1 mm. During penetration, a displacement sensor inside the probe records the vertical position of the probe tip at a sampling rate of 100 Hz, and a force sensor simultaneously records the axial resistance experienced by the probe.

[0048] The vertical distance the miniature probe descends from the surface of the thermally softened layer to the point of sudden resistance rise at each grid node is recorded as the thermal penetration depth at that node. The moment of contact with the thermally softened layer surface is determined by the force sensor signal first exceeding a contact threshold, which is set to 0.05 N. The point of sudden resistance rise is defined as the point where the slope of the axial resistance curve first exceeds a preset slope threshold, which is 5 N / mm. The vertical distance the probe tip descends from the contact surface point to the point of sudden resistance rise, recorded in millimeters, is stored as the thermal penetration depth of that grid node.

[0049] During the insertion of the miniature needle penetration probe, a shear force sensor integrated into the probe's sidewall measures the flow resistance of the asphalt mixture in real time. The shear force sensor is a strain gauge type, mounted on the sidewall of the cylindrical section behind the probe's conical surface, with its sensing direction along the probe's axis. The shear force sensor outputs a voltage signal at a 100Hz sampling rate. This voltage signal is conditioned and amplified before being converted into a flow resistance value, measured in Newtons.

[0050] Based on the comparison between flow resistance and the preset calibration curve, the dynamic viscosity of asphalt at the corresponding node location is calculated. The preset calibration curve is established through pre-calibration experiments. In the calibration experiments, standard cylindrical specimens are prepared using asphalt mixtures with the same gradation and asphalt-aggregate ratio as the pavement to be repaired. The standard cylindrical specimens are heated to different temperatures to achieve different viscosities, and the dynamic viscosity reference values ​​of each standard cylindrical specimen are measured using a rotational viscometer. For the same standard cylindrical specimen, a miniature needle penetration probe is inserted at an insertion speed of 1.0 mm / s, and the flow resistance value output by the shear force sensor is recorded. The dynamic viscosity reference values ​​of each standard cylindrical specimen are plotted against the corresponding flow resistance values ​​in a scatter plot, and the calibration curve is obtained by least-squares fitting. The calibration curve is expressed as follows: ,in For the dynamic viscosity of asphalt, For flow resistance, and The fitting coefficient is used. During field testing, the flow resistance value collected by the shear force sensor at a certain grid node is substituted into the calibration curve to calculate the dynamic viscosity of asphalt at that grid node location. The thermal penetration depth and the dynamic viscosity of asphalt together constitute the in-situ evaluation basis for the physical state of the thermally softened layer.

[0051] See Figure 6 The figure shows the thermal penetration depth distribution of the heat-softening layer in Example 4. The horizontal axis represents the lateral position of the road surface heating area in millimeters, ranging from -400mm to 400mm. The vertical axis represents the longitudinal position along the vehicle travel direction in millimeters, ranging from 0mm to 2000mm. The figure uses grayscale gradients to fill different intervals of thermal penetration depth. The legend indicates the thermal penetration depth range corresponding to the grayscale, which are 8–15mm (darkest black), 15–22mm, 22–30mm, and 30–40mm (lightest gray).

[0052] As shown in the figure, the thermal penetration depth exhibits a distinctly non-uniform distribution along the lateral direction. The central location (near 0 mm in the lateral direction) shows the greatest thermal penetration depth, reaching 30–40 mm, appearing as a light gray band, indicating high heating intensity and deep thermal penetration in this area. Moving laterally away from the center of the rut, the penetration depth gradually decreases, passing through gray ranges of 22–30 mm and 15–22 mm respectively. The outermost region's thermal penetration depth drops to a dark black band of 8–15 mm, reflecting that the lateral control units of the heating wall achieve non-uniform distribution of heating power according to the preset power matrix.

[0053] In the longitudinal direction, the penetration depth is relatively uniform and the gray band width remains stable, indicating that the heating depth in the longitudinal position does not decrease significantly during the heating process. This meets the design requirements of synchronous triggering and continuous heating of the heating wall in this embodiment, ensuring that the thickness of the thermal softening layer is consistent in the longitudinal range.

[0054] Example 5 In practice, the thermal softening layer is divided along its depth into a surface repair zone, a middle layer connection zone, and a bottom layer reinforcement zone. The method for obtaining the highest road surface heating temperature during the thermal softening process is to collect road surface temperature data from the temperature feedback modules of each lateral control unit throughout the entire heating process, extract the maximum value among all temperature values ​​recorded by all temperature feedback modules at all sampling times, and use this as the highest road surface heating temperature, denoted by the symbol... The method for obtaining the glass transition temperature of asphalt mixtures is as follows: after sampling the pavement material to be repaired, differential scanning calorimetry (DSC) is performed. The temperature is scanned from -30℃ to 80℃ at a heating rate of 10℃ / min. The midpoint temperature of the step-like transition on the heat flow curve is identified as the glass transition temperature, denoted by the symbol [symbol missing]. express.

[0055] The highest heating temperature of the road surface With glass transition temperature The temperature difference range is divided into three equal parts, resulting in three consecutive temperature difference intervals. The total span of the temperature difference range is... The span of each temperature difference interval after being divided into three equal parts is... The lower bound of the highest temperature difference range is... The upper boundary is The lower bound of the intermediate temperature difference range is The upper boundary is The lower bound of the lowest temperature difference range is The upper boundary is .

[0056] The temperature field within the softened layer was synchronously acquired by a pre-embedded thermocouple array at the moment heating stopped, with the thermocouple array embedded at 5mm intervals. The temperature values ​​at each depth within the softened layer were compared to the boundaries of three temperature difference zones. The portion of the softened layer with the highest temperature difference zone was defined as the surface repair zone, the portion with the middle temperature difference zone as the middle layer connection zone, and the portion with the lowest temperature difference zone as the bottom reinforcement zone. At each grid node, the upper and lower interface depths of the surface repair zone, middle layer connection zone, and bottom reinforcement zone were determined based on the pre-measured longitudinal temperature distribution curve of the softened layer. The difference between these two depths represents the actual thickness of the corresponding area. The actual thickness of the surface repair zone was determined using... This indicates that the actual thickness of the middle layer connection area is... This indicates that the actual thickness of the bottom reinforcement zone is... This indicates that the sum of the actual thicknesses of the three regions equals the thermal penetration depth at the corresponding mesh node location.

[0057] Each depth region corresponds to a preset regenerant demand coefficient. The surface repair zone corresponds to a regenerant demand coefficient. , A fixed value of 1.2 is chosen because the surface asphalt, directly exposed to ultraviolet light and oxygen, ages most severely and requires a higher concentration of recycling agent; the intermediate layer transition zone corresponds to a higher recycling agent demand coefficient. , A fixed value of 1.0 is used; the recycling agent demand coefficient corresponding to the bottom reinforcement zone is... , A fixed value of 0.8 was chosen because the bottom layer is bonded to the original road surface and the temperature is low, resulting in a slow diffusion rate of the regenerator. Excessive spraying can easily cause interface slippage.

[0058] For each grid node, the baseline dosage of recycling agent is calculated based on the dynamic viscosity of the asphalt at the corresponding node location. The baseline dosage of recycling agent is indicated by the symbol. The expression for calculation is: , in, This is the standard dosage of regenerant, expressed in grams per square centimeter. This is the regenerant penetration coefficient, expressed in square seconds per gram. A fixed value of 0.015 was selected, which was obtained by linear regression of experimental data on the penetration rate of standard viscosity rejuvenator in asphalt mixtures of known viscosity. The dynamic viscosity of asphalt at the corresponding grid node location is measured in Pascals per second and calculated using a miniature needle penetration probe shear force sensor and a calibration curve. This represents the thermal penetration depth at the corresponding grid node location, in millimeters. For reference depth, Take a fixed value of 10mm. The setting makes the logarithmic term value when the heat penetration depth is 10mm. Approximately 0.693 provides a reasonable baseline dosage level.

[0059] The standard dosage of regenerant The allocation is weighted and determined by multiplying the actual thickness of each depth zone by the corresponding regenerant demand coefficient. Spraying volume for the surface remediation zone... The calculation formula is Spraying volume in the middle layer connecting zone The calculation formula is Spraying volume in the underlying reinforcement zone The calculation formula is The denominators of the three calculation formulas above are exactly the same, ensuring that the sum of the three spraying amounts at a grid node location equals the baseline amount of regenerant. .

[0060] After obtaining the spraying amounts for the surface repair zone, intermediate transition zone, and bottom reinforcement zone on all grid nodes, the spraying amounts belonging to the same depth region on all grid nodes are extracted to form a spraying matrix for the corresponding depth region. Each element of the surface spraying matrix corresponds to the surface repair zone spraying amount of a grid node. Each element of the mid-layer spraying matrix corresponds to the spraying volume of the mid-layer junction zone of a grid node. Each element of the bottom-layer spraying matrix corresponds to the spraying volume of the bottom-layer reinforcement zone of a grid node. The row and column arrangement of the three spraying matrices is consistent with the horizontal and vertical layout of the grid nodes. The number of rows in the matrix is ​​equal to the number of vertical grid nodes, and the number of columns in the matrix is ​​equal to the number of horizontal grid nodes.

[0061] Gaussian smoothing was applied to the surface, middle, and bottom spray matrices respectively. The Gaussian smoothing used a two-dimensional Gaussian kernel function, and the standard deviation of the Gaussian kernel function was [value missing]. The value is 1.0 grid spacing unit. For the matrix located at the [number]th [unit]... Line number The elements of the column, after smoothing, are equal to the elements of the column. Centered on, with side length as The sum of the products of all original spray amounts and their corresponding Gaussian weights within the window. The Gaussian kernel function is normalized within the window to ensure that the sum of the weights within the window is 1. Gaussian smoothing eliminates abrupt changes in spray amount caused by detection noise or local differences between adjacent grid nodes, ensuring a continuous transition of spray amount within the field.

[0062] Three smoothed spray matrices are sequentially sent to multiple independent nozzle arrays installed behind the heated wall. There are three nozzle arrays, arranged sequentially along the direction of travel, named the first, second, and third nozzle arrays. The first nozzle array sprays the regenerant in the surface repair zone, the second in the middle layer transition zone, and the third in the bottom reinforcement zone. Each nozzle array contains an equal number of independent nozzles corresponding to the number and position of the lateral control unit. The on / off state and flow rate of each nozzle are controlled by a corresponding solenoid valve. The smoothed surface spray matrix is ​​sent row by row to the controller of the first nozzle array. The controller converts the spray volume for the corresponding row into a flow command based on the current vehicle position, controlling the solenoid valve opening duration or duty cycle to ensure each nozzle outputs a specified amount of regenerant per unit time. The second and third nozzle arrays receive the smoothed middle and bottom layer spray matrices in the same manner and spray them sequentially layer by layer on the heat-softened layer. After the first nozzle array finishes spraying on the surface of the heat-softened layer, the second nozzle array begins spraying. After the second nozzle array finishes spraying, the third nozzle array begins spraying. The time interval between the three spraying layers is naturally formed by the spacing between each set of nozzle arrays along the direction of travel.

[0063] After the recycling agent spraying is completed, the remixing bin is activated to mill and mix the softened layer. The remixing bin is suspended behind the nozzle array and contains a rotating milling drum and a mixing paddle. The rotating milling drum cuts into the softened layer to a preset milling depth, which is equal to the average thermal penetration depth of all grid nodes, rounded up to an integer multiple of 5 mm. The loose mixture produced by milling is continuously agitated by the mixing paddle within the remixing bin for 15 seconds, ensuring thorough integration of the recycling agent and the aged asphalt mixture.

[0064] The screed is used to spread and pre-compact the mixed asphalt, forming a recycled pavement layer. The screed is installed behind the mixing bins, with its base width matching the maximum lateral span of the ruts. The screed's vibration frequency is set to 30Hz, and the paving speed is synchronized with the vehicle's speed. The pre-compacted recycled pavement layer has an initial macroscopic texture.

[0065] The surface texture of the recycled pavement layer is optically scanned. The optical scanning device is a line structured light sensor mounted behind the screed. The line structured light sensor acquires elevation data of the recycled pavement layer surface at a lateral sampling interval of 0.5 mm, generating a recycled texture cross-sectional curve. The texture depth is calculated from the recycled texture cross-sectional curve, defined as the root mean square value of the peak-to-valley height difference within a 10 mm window. The scanned texture depth is compared with a preset target texture depth, which is pre-set according to road design skid resistance standards, for example, 0.8 mm. The texture depth deviation is calculated, equal to the scanned texture depth minus the target texture depth.

[0066] The preset power matrix of the heated wall in subsequent operations is fine-tuned based on the texture depth deviation. The fine-tuning operation involves adjusting the initial heating power value in the current preset power matrix. Add a correction amount Correction amount The calculation method is as follows ,in This represents the texture depth deviation, in millimeters. For power fine-tuning gain coefficient, A fixed value of 0.05 is used, in millimeters. When the scanned texture depth is greater than the target texture depth, the texture depth deviation is positive, the correction amount is positive, and the initial heating power values ​​in the preset power matrix are increased, resulting in higher subsequent heating temperatures, greater thermal softening depth, and enhanced fluidity of the mixed material after mixing. During paving, the surface texture tends to close and decrease. When the scanned texture depth is less than the target texture depth, the correction amount is negative, and the initial heating power values ​​in the preset power matrix are decreased. The fine-tuned preset power matrix is ​​stored and replaces the original preset power matrix, serving as the power input for the heating wall in the next work cycle, forming a closed-loop adjustment.

[0067] See Figure 7 In the diagram, the horizontal axis represents the lateral position of the road ruts, ranging from approximately -200mm to 600mm, and the vertical axis represents the amount of recycler sprayed at the corresponding location, in grams per square centimeter. The legend distinguishes the spraying amount for three depth zones: the surface repair zone, the intermediate layer transition zone, and the bottom layer reinforcement zone, each represented by a different filling pattern.

[0068] As shown in the figure, the overall spraying volume exhibits a clear horizontal fluctuation trend, and the combined spraying volumes of the three layers form a columnar distribution with varying heights. The surface repair zone has a relatively high spraying volume, with most values ​​above 0.4 g / cm², and its contribution is the largest among all depth zones, reflecting the technical principle that this area requires more regenerant due to severe aging. The middle layer transition zone has a moderate spraying volume, ranging from approximately 0.2 g / cm² to 0.35 g / cm², exhibiting a smooth fluctuation pattern, indicating that the regenerant dosage in this zone is relatively uniform and serves as a transitional connection. The bottom reinforcement zone has the lowest spraying volume, with relatively stable values, generally maintaining within the range of 0.1 g / cm² to 0.15 g / cm², consistent with the setting that this area has a low temperature and requires less regenerant.

[0069] The variation in spray volume exhibits periodic peaks and troughs with lateral position, indicating that the two-dimensional Gaussian smoothing process eliminated local abrupt changes, achieving a continuous transition and ensuring the uniformity and rationality of the spray volume distribution. The peak and trough positions of the spray volume curves in different depth zones are basically consistent, with the surface repair zone showing the largest fluctuation and the bottom reinforcement zone showing the smallest fluctuation, reflecting the spatial correlation between the temperature gradient division within the thermal softening layer and the regenerant spraying requirements.

[0070] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for repairing a pavement rutting distress by hot-in-place recycling, characterized in that, Includes the following steps: Obtain the rut cross-sectional profile data and the migration rate of aged asphalt on the road surface to be repaired; Spatial spectrum analysis was performed on the rut profile data to extract the depth sequence of the ruts at different wavelength scales; Based on the migration rate and depth sequence of the aged asphalt, a pre-set power matrix for the heating wall in the thermal regeneration repair process is constructed. The heating wall is controlled by the preset power matrix to heat the road surface non-uniformly, forming a thermal softening layer with a temperature gradient. The thermal penetration depth of the thermal softening layer and the dynamic viscosity of the asphalt were detected at different spatial points. Based on the thermal penetration depth and the dynamic viscosity of the asphalt, the multi-layer differentiated spraying amount of the recycling agent in the thermal softening layer is determined.

2. A method of repairing a pavement rut defect by thermal regeneration according to claim 1, characterized in that, The specific steps for obtaining the rut cross-sectional profile data and the migration rate of aged asphalt on the road surface to be repaired are as follows: The control line laser profiler scans the rut groove at a preset lateral sampling interval, and collects discrete elevation point sets on multiple lateral sections along the driving direction to form the rut section profile data. Milled old material samples were collected from the sidewalls of ruts. The relative molecular mass distribution ratio of asphalt and resin was obtained by gel permeation chromatography analysis of the samples. The normalized relative molecular mass distribution ratio was used as the migration rate of the aged asphalt.

3. A method of repairing a pavement rut defect by thermal regeneration according to claim 2, characterized in that, The lateral sampling interval is 1mm to 5mm, and the longitudinal sampling interval of the line laser profilometer is controlled in conjunction with the vehicle's driving speed.

4. The method for thermal recycling repair of pavement rutting defects according to claim 1, characterized in that, The specific steps for performing spatial spectrum analysis on the rut cross-sectional profile data and extracting the depth sequence of the ruts at different wavelength scales are as follows: A one-dimensional discrete cosine transform is performed on the rut profile data along the driving direction to obtain the spectral energy distribution curve in the spatial frequency domain. On the aforementioned spectral energy distribution curve, the wear wavelength range, the instability wavelength range, and the deformation wavelength range are divided according to the wavelength from long to short. Calculate the sum of the depth component amplitudes corresponding to all frequency components within each wavelength interval, and arrange the three sums in wavelength order to form the depth sequence.

5. The method for thermal recycling repair of road rutting defects according to claim 1, characterized in that, Based on the migration rate and depth sequence of the aged asphalt, the specific steps for constructing the pre-set power matrix of the heating wall during the thermal regeneration repair process are as follows: The heating area of ​​the heating wall is divided into multiple independent heating channels along the horizontal direction, and each heating channel corresponds to a horizontal control unit; The three depth values ​​in the depth sequence are used as the heating depth basis vector, and the heating depth basis vector is weighted and corrected according to the migration rate of the aged asphalt to obtain the target heating depth required for each lateral control unit. Based on the target heating depth of each lateral control unit, the initial heating power required for each lateral control unit is calculated using the pre-embedded empirical coefficient of heat conduction, and all initial heating powers are arranged in channel order to form the preset power matrix.

6. The method for thermal recycling repair of road rutting defects according to claim 5, characterized in that, The pre-embedded thermal conductivity empirical coefficient was obtained by conducting a calibration experiment on asphalt mixture specimens of the same gradation. The calibration experiment recorded the temperature distribution curves along the depth direction under different heating powers and heating times.

7. The method for thermal recycling repair of pavement rutting defects according to claim 1, characterized in that, The specific steps for controlling the heating wall to perform non-uniform heating of the road surface according to the preset power matrix to form a thermal softening layer with a temperature gradient are as follows: Each initial heating power value in the preset power matrix is ​​sent to the power regulator of the corresponding horizontal control unit; Each lateral control unit simultaneously activates infrared thermal radiation heating according to the received initial heating power value, so that the intensity of thermal radiation received at the bottom of the rut is asymmetrically distributed along the lateral direction. Heating continues until the surface temperature difference between the transverse center region and the transverse edge region of the rut reaches a preset temperature gradient threshold, at which point heating is stopped, thus forming the thermal softening layer.

8. The method for thermal recycling repair of road rutting defects according to claim 7, characterized in that, The specific steps for detecting the thermal penetration depth of the thermally softened layer and the dynamic viscosity of asphalt at different spatial points are as follows: Within a predetermined time window after heating is stopped, the micro-needle penetration probe is driven to sequentially penetrate multiple predefined grid node positions on the thermal softening layer in a vertical orientation. Record the vertical distance that the micro-needle penetration probe drops from the surface of the contact thermal softening layer to the point of sudden increase in resistance at each grid node location, as the thermal penetration depth at that node location; Meanwhile, during the insertion of the micro-needle penetration probe, the flow resistance of the asphalt mixture is measured in real time by a shear force sensor integrated on the side wall of the probe. Based on the comparison between the flow resistance and the preset calibration curve, the dynamic viscosity of the asphalt at that node position is calculated.

9. A method for thermal recycling repair of pavement rutting defects according to claim 8, characterized in that, The insertion speed of the micro needle penetration probe is 0.5 mm / s to 2 mm / s, and the predetermined time window is within 10s to 30s after heating is stopped.

10. The method for thermal recycling repair of pavement rutting defects according to claim 1, characterized in that, The specific steps for determining the multi-layer differentiated spraying amount of recycling agent within the thermally softened layer based on the thermal penetration depth and asphalt dynamic viscosity are as follows: The thermal softening layer is divided into a surface repair zone, a middle layer connection zone, and a bottom layer reinforcement zone along the depth direction. Each zone corresponds to a preset regenerator demand coefficient. Based on the thermal penetration depth detected at each grid node location, determine the actual thickness of the three regions below that node; For each grid node, the baseline amount of recycling agent is calculated based on the dynamic viscosity of the asphalt at that node. Then, the baseline amount of recycling agent is weighted and allocated according to the actual thickness of each area multiplied by the corresponding recycling agent demand coefficient to obtain the spraying amount for each of the three areas at that node.

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