Method for determining service temperature domain of each structural layer of full-thickness LSAM-50 pavement

Abstract

The invention discloses a method for determining a service temperature domain of each structural layer of a full-thickness LSAM-50 pavement, which comprises the following steps: firstly, determining a'surface layer + binding layer + flexible base layer 'full-thickness structure of the pavement, collecting hourly air temperature and solar radiation data, and classifying according to day and night; calculating the temperature of each time point of the surface layer through a road surface temperature model, and counting an extreme value to determine a surface layer temperature domain; combining meteorological data and road surface temperature, segmentally calculating temperatures of the top and the bottom of the junction layer and the shallow layer and the deep layer of the flexible base layer, and respectively counting extreme values to determine a temperature domain of a corresponding layer; according to the method, fine analysis of the full-depth temperature field of the full-thickness LSAM-50 pavement is realized for the first time through structure layering, data classification and segmented modeling, accurate temperature boundary conditions are provided for material selection, full-thickness structure thickness design and maintenance decision, the disease risk and engineering cost caused by misalignment of full-thickness temperature parameters are effectively reduced, and the method is suitable for large-scale popularization and application of the full-depth temperature field of the full-thickness LSAM-50 pavement. And the method has remarkable engineering application value and technical innovation.

Description

Technical Field

[0001] This invention belongs to the field of road engineering technology, specifically relating to a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement. Background Technology

[0002] In the field of road engineering, LSAM-50 pavement, as a new type of flexible base structure, features an ultra-large aggregate skeleton with a nominal maximum particle size of 53mm and a proportion exceeding 30%, along with a full-thickness asphalt mixture layer design, resulting in significantly different thermal conductivity characteristics compared to traditional pavements. In actual engineering projects, the service temperature of each structural layer of a full-thickness pavement directly determines the material performance and structural lifespan design. For example, high temperatures in the surface layer can easily lead to material softening and rutting, while low temperatures at the bottom of the base layer may induce aggregate shrinkage cracking. Furthermore, the service temperature threshold of the deep layer (≥30cm) in a full-thickness structure, dominated by ground temperature, is crucial for fatigue performance. Inaccurate prediction of service temperatures will lead to a disconnect between material performance and the design requirements of the full-thickness structure, significantly increasing the risk of early-stage defects such as high-temperature rutting and low-temperature cracking, as well as the overall maintenance costs. Therefore, accurately defining the service temperature range of each layer (surface layer, bonding layer, and LSAM-50 flexible base course) of the full-thickness LSAM-50 pavement structure is a core prerequisite for optimizing material ratios (such as high softening point binders and low shrinkage aggregates), determining the thickness of the LSAM-50 base course, and formulating a full life-cycle maintenance strategy.

[0003] However, existing pavement temperature domain determination technologies are mainly geared towards semi-rigid base courses or shallow pavement structures, and cannot meet the specific requirements of LSAM-50 pavements. Traditional pavement temperature prediction models do not consider the thermal insulation effect of the LSAM-50 flexible base course, the nonlinear thermal conductivity of ultra-large aggregates, and the temperature distribution patterns across the entire pavement thickness. They only cover a shallow depth of 0–20 cm and assume linear temperature decay, making it difficult to describe the unique "shallow dynamic-deep stable" stratification characteristic of full-thickness structures. The shallow layer (0–30 cm) exhibits diurnal positive and negative temperature gradient transitions due to solar radiation and air temperature (negative gradient during the day, positive gradient at night), while the deep layer (≥30 cm) forms a stable temperature domain dominated by ground temperature due to low thermal conductivity. This results in prediction errors exceeding 20% ​​when traditional pavement temperature models are applied to LSAM-50 pavements. Furthermore, existing methods rely on simple fitting of single environmental parameters or redundant parameter models, making them difficult to apply. When applied across climate zones, prediction errors often exceed 10°C, failing to meet the precise requirements of LSAM-50 pavement design for full-depth temperature boundary conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining the service temperature domain of each structural layer of a full-thickness LSAM-50 pavement, thereby achieving an accurate characterization of the temperature distribution of each structural layer of the LSAM-50 pavement. This solves the problems of insufficient accuracy and poor applicability of traditional models in the temperature field analysis of novel LSAM-50 flexible base asphalt pavements through segmented modeling. It provides refined temperature boundary conditions for LSAM-50 pavement material selection, full-thickness structural thickness design, and life-cycle maintenance decisions, thereby improving the reliability of pavement design.

[0005] To address the aforementioned technical problems, this invention discloses a method for determining the service temperature range of each structural layer in a full-thickness LSAM-50 pavement, specifically implemented according to the following steps:

[0006] Step 1: Determine the target LSM-50 pavement structure combination. The LSM-50 pavement structure is a full-thickness combination of "surface layer + bonding layer + LSAM-50 flexible base course + subgrade"; specifically: h S Surface layer + h B Connection layer + h F LSAM-50 flexible base layer, of which h S ,h B ,h F These are the structural layer thicknesses of the surface layer, bonding layer, and LSAM-50 flexible base layer, respectively, in cm.

[0007] Step 2: Collect hourly temperature and solar radiation data for the initial design year in the area where the highway is to be built, and classify the data into two types based on solar radiation status: Q>0 (daytime) and Q=0 (nighttime);

[0008] Step 3: For the surface layer, calculate the surface temperature T at each time point t in the initial design year based on the surface temperature prediction model. s ;

[0009] Step 4: Determine the maximum road surface temperature T calculated in Step 3 by statistical sorting. Smax With minimum value T Smin The service temperature range of the surface layer is [T Smin ,T Smax ];

[0010] Step 5, for the connecting layer, combine the hourly temperature and solar radiation data of the initial design year obtained in Step 2, and the road surface temperature T at each time point t of the initial design year obtained in Step 3. s Calculate the temperatures at the top and bottom of the bonding layer at each time point t;

[0011] Step 6: Determine the maximum temperature of the bonding layer calculated in Step 5, max{T}, through statistical sorting. H＝hS ,T H＝hS+hB} and minimum value min{T H＝hS ,T H＝hS+hB}, then the service temperature range of the bonding layer is [min{T H＝hS ,T H＝hS+hB},max{T H＝hS ,T H＝hS+hB}];

[0012] Step 7: For the LSAM-50 flexible base course, combine the hourly air temperature and solar radiation data for the initial design year obtained in Step 2, and the road surface temperature T at each time point t in the initial design year obtained in Step 3. s Calculate the top and bottom temperatures of the flexible base layer at each time point t;

[0013] Step 8: Determine the maximum temperature of the flexible base layer calculated in Step 7, max{T}, through statistical sorting. H＝hS+hB ,T H＝hS+hB+hF或H＝30} and minimum value min{T H＝hS+hB ,T H＝hS+hB+hF或H＝30}, then the service temperature range of the flexible base layer is [min{T H＝hS+hB ,T H＝hS+hB+hF或H＝30},max{T H＝hS+hB ,T H＝hS+hB+hF或H＝30}).

[0014] The technical solution of the present invention also has the following characteristics:

[0015] As a further improvement to the technical solution of the present invention, in step 1, the surface layer uses AC-13 and SMA-13 ​​fine-grained asphalt mixture, with a thickness h. S Determined based on highway grade and traffic load: For expressways and Class I highways, h S =4~6cm; for Class II and below highways, h S =3~4cm, optimized based on traffic volume and construction cost.

[0016] As a further improvement to the technical solution of the present invention, in step 1, the bonding layer uses AC-20 and Sup-20 medium-grained asphalt mixture, with a thickness h. B Designed according to interlayer coordinated stress requirements: for expressways and Class I highways, h B =6~10cm; for Class II and below highways, the connecting layer can be omitted, i.e., h B =0cm.

[0017] As a further improvement to the technical solution of the present invention, in step 1, the LSAM-50 flexible base layer uses ultra-large aggregate with a nominal maximum particle size of 53mm, and the single-layer paving thickness follows the principle of ">2.5 to 3 times the nominal maximum particle size of the aggregate", that is, h FThe total thickness is determined based on traffic volume, design service life, and fatigue resistance requirements, ranging from 16 to 40 cm.

[0018] As a further improvement to the technical solution of the present invention, in step 2, the temperature and solar radiation data can be obtained from the meteorological department or obtained by setting up a meteorological monitoring station on one side of the highway.

[0019] As a further improvement to the technical solution of the present invention, in step 2, the frequency of the collected and used temperature and solar radiation data is selected according to the highway grade, design accuracy, meteorological database storage capacity, etc.

[0020] As a further improvement to the technical solution of the present invention, in step 3, the road surface temperature T at each time point t in the initial year of design is calculated based on the road surface temperature prediction model. s The calculation formula is:

[0021] T s =1.435 + 1.253T a +0.464T a Q+7.977Q3

[0022] In the formula: T a Q represents real-time temperature in °C; Q represents real-time solar radiation in kW·m³. -2 Q3 represents the average solar radiation over the first 3 hours, in kW·m³. -2 .

[0023] As a further improvement to the technical solution of the present invention, in step 5, the temperatures at the top and bottom of the bonding layer at each time point t are calculated, and the calculation formulas are as follows:

[0024]

[0025] In the formula: T H θ represents the target structural layer temperature of LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

[0026] As a further improvement to the technical solution of the present invention, in step 7, the temperatures at the top and bottom of the flexible base layer at each time point t are calculated, and the calculation formulas are as follows:

[0027] 2 < H < 30:

[0028] H≥30:

[0029]

[0030] In the formula: T Hθ represents the target structural layer temperature of LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

[0031] As a further improvement to the technical solution of the present invention, in step 5, the top and bottom depths of the bonding layer are H = h, respectively. S H = h S +h B In step 7, the top and bottom depths of the flexible base layer are H = h, respectively. S +h B H = h S +h B +h F When h S +h B +h F When the height is ≥30cm, that is, H=30.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) The present invention provides a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement. For the first time, it combines the day and night solar radiation state and the depth interval to establish pavement temperature calculation, accurately captures the difference between the shallow dynamic temperature gradient and the deep stable temperature range, and solves the problem of the traditional model only covering the shallow layer and assuming linear decay. This improves the accuracy of determining the extreme values ​​and gradient distribution of temperature of each structural layer by more than 30%, and provides a direct basis for the directional selection of surface anti-rutting materials and base anti-cracking aggregates.

[0034] (2) The present invention provides a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement, which can output the time probability of each temperature range (e.g., <10℃ accounts for 9% and >40℃ accounts for 11% in the annual distribution), providing a quantitative basis for construction and maintenance: the selection of paving time during high temperature period (adjusting the process when the probability of >35℃ is >60%) can reduce the risk of rutting by 20%, and the precise application of de-icing agent during low temperature period can reduce maintenance costs by 15%.

[0035] (3) The present invention provides a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement. Based on hourly air temperature, solar radiation data classification and highway grade differentiation design, it is compatible with heavy traffic on highways and light traffic on secondary highways. By introducing the lag effect of the average solar radiation in the first 3 hours and the parameter correction of measured data from multiple regions, the prediction error of full-thickness temperature across climate zones is controlled within 3℃, which significantly improves the reliability of engineering applications in different regions and avoids the prediction inaccuracy problem caused by parameter redundancy or single fitting in traditional methods.

[0036] (4) The present invention provides a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement. By accurately determining the service temperature range of each structural layer, it supports the optimization of the full-thickness structural thickness and the precise formulation of maintenance strategies. Engineering practice shows that this method can reduce the early-stage high-temperature rutting rate of LSAM-50 pavement by 25% and the low-temperature cracking area by 30%, effectively reducing the overall maintenance cost. It fills the technical gap in determining the temperature range of the new LSAM-50 flexible base course pavement and has significant engineering application value. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0038] Figure 1 This is a map showing temperature and solar radiation data for a certain area in Wuwei, Anhui Province, from August 1, 2021 to July 31, 2022.

[0039] Figure 2 The initial design temperature of the LSAM-50 road meter;

[0040] Figure 3 The initial year temperatures of the LSAM-50 bonding layer were designed;

[0041] Figure 4 The initial annual temperature of the LSAM-50 flexible substrate was determined. Detailed Implementation

[0042] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] To address the issues of insufficient accuracy and poor applicability of traditional models in the temperature field analysis of novel LSAM-50 flexible base asphalt pavements, this invention proposes a method for determining the service temperature domain of each structural layer in a full-thickness LSAM-50 pavement. First, the full-thickness structure of the pavement, consisting of a surface layer, a connecting layer, and a flexible base, is defined. Hourly air temperature and solar radiation data are collected and categorized by day and night. Then, the surface temperature model is used to calculate the temperature of the surface layer at each time point, and extreme values ​​are statistically analyzed to determine the surface layer temperature domain. Finally, combining meteorological data and surface temperature, the temperatures at each depth of the connecting layer (top and bottom) and the shallow and deep layers of the flexible base are calculated segmentally, and extreme values ​​are statistically analyzed to determine the temperature domain of the corresponding layer. This method, through structural layering, data classification, and segmented modeling, achieves for the first time a refined analysis of the full-depth temperature field of full-thickness LSAM-50 pavement. It solves the applicability problem of traditional technologies in determining the temperature domain of new full-thickness flexible base pavement, and provides precise temperature boundary conditions for material selection (such as aggregate gradation adapted to deep stable temperature domains), full-thickness structural thickness design, and maintenance decisions. It effectively reduces the risk of disease and engineering costs caused by inaccurate full-thickness temperature parameters, and has significant engineering application value and technological innovation.

[0044] The present invention provides a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement, which is implemented according to the following steps:

[0045] Step 1: Determine the target LSM-50 pavement structure combination. The LSM-50 pavement structure is a full-thickness combination of "surface layer + bonding layer + LSAM-50 flexible base course + subgrade"; specifically: h S Surface layer + h B Connection layer + h F LSAM-50 flexible base layer, of which h S ,h B ,h F These are the structural layer thicknesses of the surface layer, bonding layer, and LSAM-50 flexible base layer, respectively, in cm.

[0046] The surface layer uses AC-13 and SMA-13 ​​fine-grained asphalt mixture, with a thickness of h. S Determined based on highway grade and traffic load: For expressways and Class I highways, h S =4~6cm, meeting the requirements for anti-skid, wear-resistant, and high-temperature rutting resistance; for Class II and lower highways, h S =3-4cm, and optimized based on traffic volume and cost, such as a 3cm ultra-thin surface layer can be used in light traffic sections;

[0047] The bonding layer uses AC-20 and Sup-20 medium-grained asphalt mixtures, with a thickness of h. B Designed according to interlayer coordinated stress requirements: for expressways and Class I highways, h B=6~10cm, strengthening interlayer bonding and load diffusion; for Class II and lower highways, the bonding layer (i.e., h) can be omitted. B =0cm), utilizing the high-temperature stability of the LSAM-50 flexible base layer to directly support the surface layer, reducing engineering costs;

[0048] The LSAM-50 flexible base course uses ultra-large aggregate with a nominal maximum particle size of 53mm. The thickness of a single layer follows the principle of ">2.5 to 3 times the nominal maximum particle size of the aggregate", i.e., h F >16cm, the total thickness is determined according to traffic volume, design service life and fatigue resistance requirements, and is 16 to 40cm;

[0049] Step 2: Collect hourly temperature and solar radiation data for the initial design year in the area where the highway is to be built, and classify the data into two types based on solar radiation status: Q>0 (daytime) and Q=0 (nighttime);

[0050] Temperature and solar radiation data can be obtained from meteorological departments or from meteorological monitoring stations set up along the side of the highway;

[0051] When meteorological monitoring stations are set up on one side of a highway, the location of the measuring point should meet the following requirements: ① The measuring point must be well-ventilated, have sufficient sunlight, and not be blocked by trees or buildings; ② The measuring point must be able to provide the necessary protective facilities for the operation of the observation instruments.

[0052] Step 3: For the surface layer, calculate the surface temperature T at each time point t in the initial design year based on the surface temperature prediction model. s The calculation formula is:

[0053] T s =1.435 + 1.253T a +0.464T a Q+7.977Q3

[0054] In the formula: T a Q represents real-time temperature in °C; Q represents real-time solar radiation in kW·m³. -2 Q3 represents the average solar radiation over the first 3 hours, in kW·m³. -2 .

[0055] Step 4: Determine the maximum road surface temperature T calculated in Step 3 by statistical sorting. Smax With minimum value T Smin The service temperature range of the surface layer is [T Smin ,T Smax ];

[0056] Step 5, for the connecting layer, combine the hourly temperature and solar radiation data of the initial design year obtained in Step 2, and the road surface temperature T at each time point t of the initial design year obtained in Step 3.s The temperatures at the top and bottom of the bonding layer at each time point t are calculated using the following formulas:

[0057]

[0058] In the formula: T H θ represents the target structural layer temperature of LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

[0059] Step 6: Determine the maximum temperature of the bonding layer calculated in Step 5, max{T}, through statistical sorting. H＝hS ,T H＝hS+hB} and minimum value min{T H＝hS ,T H＝hS+hB}, then the service temperature range of the bonding layer is [min{T H＝hS ,T H＝hS+hB},max{T H＝hS ,T H＝hS+hB}];

[0060] Step 7: For the LSAM-50 flexible base course, combine the hourly air temperature and solar radiation data for the initial design year obtained in Step 2, and the road surface temperature T at each time point t in the initial design year obtained in Step 3. s The temperatures at the top and bottom of the flexible substrate at each time point t are calculated using the following formula: 2 < H < 30.

[0061] H≥30:

[0062]

[0063] In the formula: T H θ represents the target structural layer temperature of LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

[0064] Step 8: Determine the maximum temperature of the flexible base layer calculated in Step 7, max{T}, through statistical sorting. H＝hS+hB ,T H＝hS+hB+hF或H＝30} and minimum value min{T H＝hS+hB ,T H＝hS+hB+hF或H＝30}, then the service temperature range of the flexible base layer is [min{T H＝hS+hB ,T H＝hS+hB+hF或H＝30},max{T H＝hS+hB ,T H＝hS+hB+hF或H＝30}).

[0065] In step 5 of this invention, the top and bottom depths of the bonding layer are H = h, respectively.S H = h S +h B In step 7, the top and bottom depths of the flexible base layer are H = h, respectively. S +h B H = h S +h B +h F When h S +h B +h F When the height is ≥30cm, that is, H=30.

[0066] In steps 3, 5, and 7 of this invention, the time point t is consistent with the frequency of the temperature and solar radiation data collected and used in step 2.

[0067] Application examples

[0068] The present invention provides a method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement, which is implemented according to the following steps:

[0069] Step 1: The proposed LSAM-50 pavement structure combination in a certain area of ​​Wuwei, Anhui Province is determined to be a 4cm AC-13 surface layer + a 6cm AC-20 bonding layer + a 40cm LSAM-50 flexible base layer.

[0070] Step 2: Collect temperature and solar radiation data for this region from August 1, 2021 to July 31, 2022, and categorize them into two working conditions based on solar radiation status: Q>0 (daytime) and Q=0 (nighttime). See [link / reference]. Figure 1 Data collection frequency is 15 minutes per time.

[0071] Step 3: Based on the collected and statistically analyzed temperature and solar radiation data from Step 2, calculate the road surface temperature T at each time point t in the initial design year using the following empirical formula. s The calculation results are shown in Figure 2 .

[0072] T s =1.435 + 1.253T a +0.464T a Q+7.977Q3

[0073] In the formula: T a Q represents real-time temperature (°C); Q represents real-time solar radiation (kW·m³). -2 Q3 represents the average solar radiation in the first 3 hours, in kW·m³. -2 .

[0074] Step 4: Determine the maximum road surface temperature T calculated in Step 3 by statistical sorting. Smax With minimum value T SminThe temperatures are 66.5℃ and -0.7℃ respectively, so the service temperature range of the surface layer is [-0.7℃, 66.5℃].

[0075] Step 5: Based on the hourly temperature and solar radiation data collected and statistically analyzed in Step 2 for the initial design year, and the road surface temperature T at each time point t obtained in Step 3 for the initial design year... s The temperatures at the top and bottom of the bonding layer at each time point t were calculated using the empirical formula below. The results are shown in [the table below]. Figure 3 .

[0076]

[0077] In the formula: T H θ represents the target structural layer temperature of the LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

[0078] Step 6: Determine the maximum temperature of the bonding layer calculated in Step 5, max{T}, through statistical sorting. H＝hS ,T H＝hS+hB} and minimum value min{T H＝hS ,T H＝hS+hB The temperatures are 62.6℃ and -0.6℃ respectively, so the service temperature range of the bonding layer is [-0.6℃, 62.6℃].

[0079] Step 7: Based on the hourly temperature and solar radiation data collected and statistically analyzed in Step 2 for the initial design year, and the road surface temperature T at each time point t obtained in Step 3 for the initial design year... s The temperatures at the top and bottom of the flexible substrate at each time point t were calculated using the following empirical formula. The calculation results are shown in [the table below]. Figure 4 .

[0080] 2 < H < 30:

[0081]

[0082] H≥30:

[0083]

[0084] In the formula: T H θ represents the target structural layer temperature of the LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

[0085] Step 8: Determine the maximum temperature of the flexible base layer calculated in Step 7, max{T}, through statistical sorting. H＝hS+hB ,T H＝30} and minimum value min{T H＝hS+hB ,T H＝30If the temperatures are 59℃ and 0.8℃ respectively, then the service temperature range of the flexible base layer is [0.8℃, 59℃].

[0086] This invention achieves full-process repeatability from data acquisition to model application, providing an engineered modeling tool for LSAM-50 pavement temperature analysis and significantly improving the scientific rigor and reliability of temperature-related decisions.

[0087] The foregoing description illustrates and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement, characterized in that, The specific steps are as follows: Step 1: Determine the target LSM-50 pavement structure combination. The LSM-50 pavement structure is a full-thickness combination of "surface layer + bonding layer + LSAM-50 flexible base course + subgrade"; specifically: h S Surface layer + h B Connection layer + h F LSAM-50 flexible base layer, of which h S ,h B ,h F These are the structural layer thicknesses of the surface layer, bonding layer, and LSAM-50 flexible base layer, respectively, in cm. Step 2: Collect hourly temperature and solar radiation data for the initial design year in the area where the highway is to be built, and classify the data into two types based on solar radiation status: Q>0 (daytime) and Q=0 (nighttime); Step 3: For the surface layer, calculate the surface temperature T at each time point t in the initial design year based on the surface temperature prediction model. s ; Step 4: Determine the maximum road surface temperature T calculated in Step 3 by statistical sorting. Smax With minimum value T Smin The service temperature range of the surface layer is [T Smin ,T Smax ]; Step 5, for the connecting layer, combine the hourly temperature and solar radiation data of the initial design year obtained in Step 2, and the road surface temperature T at each time point t of the initial design year obtained in Step 3. s Calculate the temperatures at the top and bottom of the bonding layer at each time point t; Step 6: Determine the maximum temperature of the bonding layer calculated in Step 5, max{T}, through statistical sorting. H＝hS ,T H＝hS+hB } and minimum value min{T H＝hS ,T H＝hS+hB }, then the service temperature range of the bonding layer is [min{T H＝hS ,T H＝hS+hB },max{T H＝hS ,T H＝hS+hB }]; Step 7: For the LSAM-50 flexible base course, combine the hourly air temperature and solar radiation data for the initial design year obtained in Step 2, and the road surface temperature T at each time point t in the initial design year obtained in Step 3. s Calculate the top and bottom temperatures of the flexible base layer at each time point t; Step 8: Determine the maximum temperature of the flexible base layer calculated in Step 7, max{T}, through statistical sorting. H＝hS+hB ,T H＝hS+hB+hF或H＝30 } and minimum value min{T H＝hS+hB ,T H＝hS+hB+hF或H＝30 }, then the service temperature range of the flexible base layer is [min{T H＝hS+hB ,T H＝hS+hB+hF或H＝30 },max{T H＝hS+hB ,T H＝hS+hB+hF或 H = 30}).

2. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 1, characterized in that, In step 1, the surface layer uses AC-13 and SMA-13 ​​fine-grained asphalt mixture, with a thickness of h. S Determined based on highway grade and traffic load: For expressways and Class I highways, h S =4~6cm; for Class II and below highways, h S =3~4cm, optimized based on traffic volume and construction cost.

3. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 2, characterized in that, In step 1, the bonding layer uses AC-20 and Sup-20 medium-grained asphalt mixture, with a thickness of h. B Designed according to interlayer coordinated stress requirements: for expressways and Class I highways, h B =6~10cm; for Class II and lower highways, the connecting layer can be omitted, i.e., h B =0cm.

4. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 3, characterized in that, In step 1, the LSAM-50 flexible base course uses ultra-large aggregate with a nominal maximum particle size of 53mm. The thickness of a single layer follows the principle of ">2.5 to 3 times the nominal maximum particle size of the aggregate", i.e., h F The total thickness is determined based on traffic volume, design service life, and fatigue resistance requirements, ranging from 16 to 40 cm.

5. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 4, characterized in that, In step 2, temperature and solar radiation data can be obtained from meteorological departments or from meteorological monitoring stations set up on one side of the highway.

6. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 5, characterized in that, In step 2, the frequency of the collected and used temperature and solar radiation data is selected based on factors such as highway grade, design accuracy, and meteorological database storage capacity.

7. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 6, characterized in that, In step 3, the road surface temperature T at each time point t in the initial design year is calculated based on the road surface temperature prediction model. s The calculation formula is: T s =1.435+1.253T a +0.464T a Q+7.977Q3 In the formula: T a Q represents real-time temperature in °C; Q represents real-time solar radiation in kW·m³. -2 Q3 represents the average solar radiation over the first 3 hours, in kW·m³. -2 .

8. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 7, characterized in that, In step 5, the temperatures at the top and bottom of the bonding layer at each time point t are calculated using the following formulas: In the formula: T H θ represents the target structural layer temperature of LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

9. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 8, characterized in that, In step 7, the temperatures at the top and bottom of the flexible substrate at each time point t are calculated using the following formulas: 2＜H＜30： In the formula: T H θ represents the target structural layer temperature of LSAM-50 pavement at a depth of H cm from the road surface, in °C; H is the depth from the road surface, in cm; θ is the monthly average air temperature, in °C.

10. The method for determining the service temperature range of each structural layer of a full-thickness LSAM-50 pavement according to claim 9, characterized in that, In step 5, the top and bottom depths of the bonding layer are H = h, respectively. S H = h S +h B In step 7, the top and bottom depths of the flexible base layer are H = h, respectively. S +h B H = h S +h B +h F When h S +h B +h F When the height is ≥30cm, that is, H=30.

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