Indoor dynamic light-thermal aging evaluation method for asphalt pavement based on equivalent temperature

Abstract

The application discloses an asphalt pavement indoor dynamic light-heat aging evaluation method based on equivalent temperature, and comprises the following steps: preparing an asphalt mixture test piece, setting the irradiation time length of the asphalt mixture test piece under the monthly ultraviolet irradiation intensity and the total aging test time length according to the total monthly ultraviolet irradiation amount and the monthly maximum ultraviolet irradiation intensity of a target place, and setting the asphalt mixture test piece aging test temperature according to the total heat energy obtained by the unit actual pavement of the target place and the total aging test time length; performing dynamic light-heat coupling aging on the asphalt mixture test piece according to the monthly maximum ultraviolet radiation intensity and the corresponding irradiation time length and the aging temperature, detecting the asphalt penetration at different depths of the asphalt mixture test piece, and evaluating the aging degree of the asphalt mixture test piece at different depths according to the size of the asphalt penetration. The application can ensure that the absorbed ultraviolet radiation and heat energy during indoor aging conforms to the actual situation on site, can simulate the actual aging process of the asphalt pavement, and makes the aging test result more accurate.

Description

Technical Field

[0001] This invention belongs to the field of asphalt pavement testing technology, and in particular relates to an indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature. Background Technology

[0002] Asphalt pavement structures are completely exposed to the natural environment, directly subjected to the effects of continuous climate changes such as solar radiation, atmospheric radiation, ambient temperature, and rainfall. This leads to macroscopic aging and hardening of asphalt, consequently affecting the performance of asphalt pavements. To ensure proper maintenance and regeneration of aging-affected asphalt pavements, a thorough analysis and study of the aging patterns and mechanisms of asphalt is essential. Existing indoor aging methods for asphalt mixtures simulate the on-site aging of asphalt surface layers using high-temperature aging. However, during actual service operation, asphalt pavements are subjected to temperature aging and continuous exposure to ultraviolet radiation from the sun. Indoor high-temperature aging tests neglect the influence of ultraviolet radiation experienced during service, resulting in significant discrepancies between indoor aging results and actual on-site conditions, thus failing to effectively guide asphalt pavement maintenance. Existing aging methods that consider the influence of ultraviolet radiation simply apply a single ultraviolet irradiation intensity throughout the test process, failing to reflect the dynamic ultraviolet irradiation process of the actual pavement. This leads to a large deviation between the total heat energy generated during aging and the actual on-site conditions, failing to accurately reflect the aging effects during pavement service. Many shortcomings and deficiencies remain in the indoor aging research of asphalt mixture pavement materials. Therefore, to address the above problems, an indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature is proposed to improve and refine experimental research on indoor aging of asphalt mixed pavement, and to provide technical support for subsequent research on photoaging of asphalt mixed pavement. (Invention Content)

[0003] The purpose of this invention is to provide an indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature. This invention couples the aging temperature with ultraviolet irradiation intensity over time, using different temperatures under varying total heat conditions, rather than setting a fixed aging temperature. This ensures that the absorbed ultraviolet radiation and heat energy during indoor aging matches actual field conditions, thus better simulating the actual aging process of asphalt pavement. This makes the aging test results more accurate, reduces the deviation between the total radiation and heat energy generated during aging and actual field conditions, and thus truly reflects the aging effect of the pavement during its service life. To achieve the above objective, this invention adopts the following technical solution:

[0004] According to one aspect of the present invention, the present invention provides an indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature, the dynamic photothermal aging evaluation method comprising the following steps:

[0005] Step 1: Select a new sample of asphalt mixture identical to the target site, and prepare the new sample of asphalt mixture into asphalt mixture specimens;

[0006] Step 2: Based on the total monthly UV radiation at the target location i And the maximum monthly ultraviolet radiation intensity I i The irradiation time of asphalt mixture specimens under photothermal coupling irradiation intensity was set, and the total heat energy Q obtained per unit actual road surface at the target location was determined. 实际 The aging test temperature for asphalt mixture specimens was set to T. s ;

[0007] Step 3: Perform photothermal coupled aging on the asphalt mixture specimens. After aging, remove the aged asphalt mixture specimens and then test the asphalt penetration P at different depths of the asphalt mixture specimens using the penetration test in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Hl According to the bitumen penetration P Hl The size of the specimen is used to evaluate the degree of aging of asphalt mixture specimens at different depths.

[0008] In a further preferred embodiment of the above scheme, in step 2, based on historical data, the total monthly UV radiation is calculated as 6% of the solar radiation. i ;

[0009] In a further preferred embodiment of the above scheme, step 2, setting the irradiation time of the asphalt mixture specimen under photothermal coupling irradiation intensity, includes the following steps:

[0010] Based on historical data, the maximum monthly ultraviolet radiation intensity I is calculated. i The indoor aging test time is t. i satisfy:

[0011] t i =UV i / I i ; i To select the first of each year i moon;

[0012] Considering the actual road surface's service life (n) on site, and performing n cycles in years, with any period less than one year counted as one year, the total aging test time (t) is thus obtained. 总 That is, the irradiation time under photothermal coupling irradiation intensity, the total aging test time t. 总 satisfy:

[0013] ;in, i Indicates selecting the first [number] of each year. i Months.

[0014] A further preferred embodiment of the above scheme is based on the total heat energy Q obtained per unit of actual road surface at the target location. 实际 The aging test temperature for asphalt mixture specimens was set to T. s Includes the following steps:

[0015] Calculate the temperature difference T between the highest and lowest temperatures in each month of the year. iX =T imax - T imin , among which, T imax and T imin They represent the first i The highest and lowest temperatures of the month; then the... i The actual heat energy absorbed by the road surface per day per unit month meets Q im = C*M*T imX Among them, T imX =T iX +K;T imX For the asphalt surface layer in the first i Maximum monthly temperature difference;

[0016] Calculate the total heat energy Q obtained per unit actual pavement of the asphalt mixture specimen. 实际 Q is the total heat energy Q obtained per unit of actual road surface during actual operating time. 实际 satisfy:

[0017] ;

[0018] Where C is the specific heat capacity of the asphalt mixture specimen, M is the mass of the asphalt mixture specimen, and T is the mass of the asphalt mixture specimen. iX For the destination i Maximum monthly temperature difference, K is a correction factor;

[0019] Based on the principle of energy equivalence, the total heat energy obtained per unit of actual pavement is converted into the total energy of indoor photothermal coupling aging of asphalt mixture specimens, then Q = ... 实际 =Q 室内 The indoor photothermal coupling aging test temperature T for asphalt mixture specimens was calculated and determined. s ,

[0020] T s =Q 室内 / (t 总 *C*M)=Q 实际 / (t 总 *C*M);

[0021] Using a dynamic cycle of 12 months, the ultraviolet irradiation intensity I is set. i The corresponding indoor aging time t iMeanwhile, the aging test temperature was set to T. s Then, based on the actual number of years the highway has been in operation (n), an aging test is set up with n dynamic cycles, thus obtaining a complete indoor aging test process.

[0022] In a further preferred embodiment of the above scheme, the correction coefficient K is in the range of 5 to 10.

[0023] In a further preferred embodiment of the above scheme, in step 3, the asphalt penetration P at different depths of the asphalt mixture specimen is measured. Hl Includes the following steps:

[0024] Step 31: Remove the aged asphalt mixture specimen and cut off the four sides of the asphalt mixture specimen, keeping the central specimen. Divide the central specimen into four equal parts along the depth direction.

[0025] Step 32: Extract the asphalt content in each asphalt mixture by centrifugation according to the specification "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019.

[0026] Step 33: Measure the asphalt penetration P at different depths in each center specimen using the penetration test in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Hl The ratio of penetration to that of new asphalt was compared and analyzed, and the ratio of penetration to that of new asphalt was used as the evaluation index A for the aging degree of asphalt mixture specimens.

[0027] In a further preferred embodiment of the above scheme, the ratio of the penetration to the penetration of the new sample asphalt is less than or equal to 1.

[0028] In a further preferred embodiment of the above scheme, when the asphalt mixture specimens are subjected to photothermal coupling aging, if the aging time is longer than the preset time, the ultraviolet irradiation intensity is increased by 10 to 30 times, and the penetration results obtained are then corrected.

[0029] A further preferred embodiment of the above scheme includes the following steps for correcting the needle penetration result:

[0030] Under conditions of 20℃, the month with the strongest radiation was selected from historical records. i The two asphalt mixture specimens were subjected to the first... i Actual radiation intensity in the month I i 、 Actual irradiation time t i Photothermal coupled ultraviolet irradiation aging test, and actual irradiation intensity I i expand b Times, actual irradiation time t i Shrink bThe photothermal coupled ultraviolet irradiation aging test was carried out twice;

[0031] After the aging test, the penetration values ​​P2 and P2 at a depth of 2 cm were measured for the two asphalt mixture samples. 2b The penetration ratio P2 / P 2b As a correction coefficient B, the final aging evaluation index B satisfies:

[0032] B= A *P2 / P 2b ;

[0033] If the irradiation intensity is not increased, the final aging degree evaluation index is: A If the irradiation intensity is increased, the final aging evaluation index will be: A 修正， but A 修正 = A *B= A *P2 / P 2b .

[0034] In summary, because the present invention adopts the above-described technical solution, the present invention has the following beneficial technical effects:

[0035] (1) By obtaining the irradiation time under a specific irradiation intensity through the monthly ultraviolet irradiation intensity and total radiation, the actual condition of the specimen can be simulated more realistically; by using ultraviolet dynamic irradiation, the actual aging process of asphalt pavement can be simulated more accurately, making the aging test results more accurate.

[0036] (2) The aging test temperature is calculated by the total duration of ultraviolet aging and the actual total heat absorbed. The aging temperature is coupled with the ultraviolet irradiation intensity by time. Different temperatures are obtained under different total heat conditions, rather than a fixed aging temperature is set separately, to ensure that the heat energy absorbed during indoor aging is consistent with the actual situation on site. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating the indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, preferred embodiments will be listed below with reference to the accompanying drawings to provide a clear and complete description of the invention. However, it should be noted that the examples in this specification are preferred examples, not all examples. Furthermore, many details listed in the specification are merely to provide the reader with a deep understanding of the key issues of this invention; the invention can be implemented even without these specific details.

[0039] This invention provides a method for evaluating the dynamic photothermal aging of asphalt pavement indoors based on equivalent temperature. The dynamic photothermal aging evaluation method includes the following steps:

[0040] Step 1: Select a new sample of asphalt mixture identical to the target site, and prepare asphalt mixture specimens from the new sample. The dimensions of the asphalt mixture specimens are: 0.3m*0.3m*0.04m.

[0041] Step 2: Based on historical data, calculate the total monthly UV radiation at 6% of solar radiation. i Based on the total monthly UV radiation at the target location i And the maximum monthly ultraviolet radiation intensity I i The irradiation time of asphalt mixture specimens under photothermal coupled irradiation intensity was set; the total monthly ultraviolet irradiation (UV1, UV2, UV3, ..., UV4) was calculated from 6% of the solar radiation. 12 And the monthly maximum ultraviolet radiation intensity I1, I2, I3, ..., I 12 ; and the total heat energy Q obtained per unit of actual road surface at the target location. 实际 The aging test temperature for asphalt mixture specimens was set to T. s ;

[0042] The process of setting the irradiation duration of asphalt mixture specimens under photothermal coupled irradiation intensity includes the following steps: Calculating the maximum monthly ultraviolet irradiation intensity I based on historical data. i The indoor aging test time is t. i satisfy:

[0043] t i =UV i / I i ; i To select the first of each year i moon;

[0044] Based on the total monthly UV irradiation and the maximum monthly irradiation intensity, the indoor aging test times t1, t2, t3, ..., t3 under the quarterly irradiation intensity were obtained. 12 ;

[0045] Considering the actual road surface's service life (n) on site, and performing n cycles in years, with any period less than one year counted as one year, the total aging test time (t) is thus obtained. 总， That is, the irradiation duration under photothermal coupling irradiation intensity; t 总 satisfy:

[0046] ;in, i Indicates selecting the first [number] of each year.i Months;

[0047] If the calculated aging time is too long, the ultraviolet irradiation intensity can be increased by 10 to 30 times to shorten the aging time; that is, the irradiation intensity can be changed to I. i *b, Irradiation time t i / b, calculate the total time t to recalculate 总 ;

[0048] Step 3: Perform photothermal coupled aging on the asphalt mixture specimens. After aging, remove the aged asphalt mixture specimens and then test the asphalt penetration P at different depths of the asphalt mixture specimens using the penetration test in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Hl According to the bitumen penetration P Hl The size of the specimen is used to evaluate the degree of aging of asphalt mixture specimens at different depths;

[0049] In this invention, the total heat energy Q obtained per unit actual road surface at the target location is determined. 实际 The aging test temperature for asphalt mixture specimens was set to T. s Includes the following steps:

[0050] Calculate the first in a year i The temperature difference T between the highest and lowest temperatures in a month iX =T imax - T imin T imax and T imin They represent the first i The highest and lowest temperatures of the month; firstly, the heat energy Q absorbed by a unit of asphalt pavement over one year is calculated. 实际 Determine the average maximum temperature T for each month. 1max T 2max T 3max T 12max and the average minimum temperature T each month 1min T 2min T 3min T 12min Then, based on the average temperature of each month, a temperature difference T is obtained. iX Over time i The changing functional relationship:

[0051] ;

[0052] Temperature difference T of asphalt surface layer under different weather conditions imX As follows: T imX =T iX +K, then the firsti The actual heat energy absorbed by the road surface per day per unit month meets Q im = C*M*T imX Among them, T imX For the first i Maximum monthly temperature difference in asphalt surface layer; calculation of the total heat energy Q obtained per unit actual pavement of asphalt mixture specimen. 实际 (A month is calculated as 30 days), that is, the total heat energy Q obtained per unit of actual road surface during the actual operating time of the road surface. 实际 satisfy:

[0053] ;

[0054] Where C is the specific heat capacity of the asphalt mixture specimen, M is the mass of the asphalt mixture specimen, and in this embodiment of the invention, the mass of the asphalt mixture specimen M = 0.3 * 0.3 * 0.04 * ρ, where ρ is the density of the mixture; M can be directly measured in laboratory tests; T iX For the destination i The maximum monthly temperature difference, K is a correction factor, and the value of the correction factor K ranges from 5 to 10;

[0055] Based on the principle of energy equivalence, the total heat energy obtained per unit of actual pavement is converted into the total energy of indoor photothermal coupling aging of asphalt mixture specimens, then Q = ... 实际 =Q 室内 Hourly heat per unit Q 室内 =Q 实际 / t 总 And calculate and determine the indoor photothermal coupling aging test temperature T for asphalt mixture specimens. s Then the following condition is met:

[0056] T s =Q 室内 / (t 总 *C*M)=Q 实际 / (t 总 *C*M);

[0057] Thus, the total heat energy Q obtained per unit of actual road surface 实际 The aging test temperature for asphalt mixture specimens was set to T. s A dynamic cycle is set with 12 months as the unit, and the ultraviolet irradiation intensity I is set accordingly. i The corresponding indoor aging time t i Meanwhile, the aging test temperature was set to T. sThen, based on the actual service life n of the highway, an aging test is set up with n dynamic cycles, thus obtaining a complete indoor aging test process. Therefore, the aging test process is set up according to the determined aging time and aging temperature, i.e., within the irradiation intensity I1, the irradiation time is t1; within the irradiation intensity I2, the irradiation time is t2, ..., within the irradiation intensity I... 12 Within the irradiation intensity range, the irradiation time is t. 12 This forms a dynamic cycle, and then based on the highway's operating years n, n cycles are set to obtain a complete indoor aging test process.

[0058] In this embodiment of the invention, the asphalt penetration P at different depths of asphalt mixture specimens is measured. Hl Includes the following steps:

[0059] Step 31: Remove the aged asphalt mixture specimen and cut off the four sides of the specimen, retaining the central specimen block. The central specimen block should have dimensions of 0.2*0.2*0.04m. Divide the central specimen block into four equal parts along the depth direction. l ( l =1, 2, 3, 4);

[0060] Step 32: Extract the asphalt content in each asphalt mixture by centrifugation according to the specification "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019.

[0061] Step 33: Measure the asphalt penetration P at different depths in each center specimen using the penetration test in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Hl ( l =1, 2, 3, 4), the ratio of the penetration to the penetration of the new asphalt sample is less than or equal to 1. The lower the penetration, the harder and more brittle the asphalt, and the more severe the aging. Based on this, the degree of aging at different depths is evaluated. The ratio of the penetration to the penetration of the new asphalt sample is compared and analyzed. The ratio of the penetration to the penetration of the new asphalt sample is used as the evaluation index A of the aging degree of asphalt mixture specimens; specifically, when the penetration ratio P of the new asphalt sample is less than or equal to 1, the ratio of the penetration to the penetration of the new asphalt sample is less than or equal to 1. 新 The ratio of is used as the evaluation index A. An A value between 0.9 and 1.0 indicates mild aging, a value between 0.7 and 0.9 indicates moderate aging, and a value less than 0.7 indicates severe aging. The specific formula for calculating A is as follows.

[0062] A Hl =P Hl / P 新 ;

[0063] A Hl = indicates H l Degree of aging of asphalt layer; PHl Indicates in H l The penetration of asphalt extracted from the central test block; P 新 Indicates the penetration of the new asphalt sample;

[0064] When performing photothermal coupled aging on asphalt mixture specimens, if the aging time exceeds the preset time (e.g., the preset aging time should not exceed 15 days), the ultraviolet irradiation intensity should be increased by 10 to 30 times, and the penetration results obtained should be corrected. The correction of the penetration results includes the following steps:

[0065] Under conditions of 20℃, the month with the strongest radiation was selected from historical records. i The two asphalt mixture specimens were subjected to the first... i Actual radiation intensity in the month I i 、 Actual irradiation time t i Photothermal coupled ultraviolet irradiation aging test, and actual irradiation intensity I i expand b Times, actual irradiation time t i Shrink b The photothermal coupled ultraviolet irradiation aging test was carried out twice;

[0066] After the aging test, the penetration values ​​P2 and P3 at a depth of 2-3 cm were measured for the two asphalt mixture samples. 2b The penetration ratio P2 / P 2b As the correction factor B, the final aging evaluation index is A 修正 satisfy:

[0067] A 修正 = A * B = A *P2 / P 2b ;

[0068] Therefore, if the irradiation intensity is not increased, the final aging degree evaluation index is: A If the irradiation intensity is increased, the final aging evaluation index will be: A 修正 Based on this, the aging degree of asphalt mixtures at different depths can be classified.

[0069] Example 1:

[0070] A certain section of road has been in service for 5 years, and the total monthly solar radiation from January to December was found to be 146.96 MJ / m². 2 273.10 MJ / m 2 278.00 MJ / m2 220.89 MJ / m 2 445.63 MJ / m 2 443.22 MJ / m 2 448.13 MJ / m 2 474.50 MJ / m 2 439.32 MJ / m 2 460.53 MJ / m 2 349.68 MJ / m 2 253.20 MJ / m 2 The maximum ultraviolet radiation intensity from January to December is 35 W / m². 2 38W / m 2 47W / m 2 53W / m 2 59W / m 2 61W / m 2 63W / m 2 67W / m 2 65W / m 2 57W / m 2 43W / m 2 33W / m 2 Based on this, the area is calculated to be 0.3 * 0.3 m. 2 The total ultraviolet radiation received by the asphalt mixture from January to December of that year was 0.794 MJ, 1.475 MJ, 1.501 MJ, 1.193 MJ, 2.406 MJ, 2.393 MJ, 2.420 MJ, 2.562 MJ, 2.372 MJ, 2.487 MJ, 1.888 MJ, and 1.367 MJ, respectively.

[0071] Based on the total monthly ultraviolet radiation and radiation intensity, the irradiation time t1~t2 under the irradiation intensity for 1-12 months within a cycle is obtained. 12The values ​​are: 146.96 * 10^6 * 6% / 35 = 252063 (s) = 70h, 120h, 99h, 69h, 126h, 121h, 119h, 118h, 113h, 135h, 136h, 128h. Considering the relatively long cycle duration, the UV irradiation intensity is increased by 10-30 times. Taking 20 times as an example, the irradiation time within one cycle is calculated to be: 3.5h, 6h, 4.95h, 3.45h, 6.3h, 6.05h, 5.95h, 5.9h, 5.65h, 6.75h, 6.8h, 6.9h, that is, the total time t is 67.6 * 5 = 338h. The average monthly high temperatures in this area are 17, 19, 22, 28, 31, 32, 33, 34, 33, 28, 24, and 20℃, while the average monthly low temperatures are 10, 12, 15, 20, 23, 25, 25, 25, 24, 20, 16, and 12℃. The monthly temperature difference T on the road surface can then be calculated using the formula. 1mx ~T 12mx Given the following temperatures: 12, 12, 12, 13, 13, 12, 13, 14, 14, 13, 13, 13℃, and a mass m = 9.1 kg, with a specific heat capacity C = 850 J / (kg·℃), the calculated values ​​are:

[0072] Q 实际 =5* =178678500J, k is set to 5;

[0073] Q 室内i =Q 实际 / t=178678500 / 338=528634.6154J;

[0074] The indoor aging temperature is then T = 528634.6154 / (9.1 * 850) = 68.3℃;

[0075] The parameters for the aging test were obtained through the above calculations. Then, the aging test was conducted, and a 0.2*0.2m section was cut out after the test. 2 The sample was divided into four equal parts along the depth direction, and asphalt was extracted to obtain the asphalt penetration P at different depths. H1 P H2 P H3 P H4 The penetration values ​​are 43, 46, 54, and 60 (0.1 mm), respectively, and the penetration value of the original asphalt sample is P. 原If the thickness is 70 (0.1 mm), then the aging degree is 0.61 (severe aging), 0.66 (severe aging), 0.77 (moderate aging), and 0.86 (mild aging). However, the UV irradiation intensity was increased by 20 times in the previous calculation, so it needs to be corrected. The specific correction process is as follows: Select the month with the strongest irradiation in history: If it is August, conduct UV aging tests on two asphalt mixture specimens at 20℃ with the actual irradiation intensity I8 and irradiation time t8 in August, and conduct UV aging tests with the increased irradiation intensity I8*b and irradiation time t8 / b. The penetration depth P8 at the center depth of the specimen is 2 cm after the test. 8b If the values ​​are 65 and 62 respectively, then the correction factor B is 65 / 62=1.05. Based on the aging degree classification of asphalt mixtures at different depths, the corrected aging degree A is 0.61*1.05=0.64 (severe aging), 0.74 (moderate aging), 0.87 (moderate aging), and 0.96 (slight aging).

[0076] This invention obtains the irradiation duration at each irradiation intensity by measuring the monthly irradiation intensity and total radiation, and calculates the actual total heat absorbed. The aging test temperature is then calculated based on the aging duration and total heat, thus coupling the aging temperature with the irradiation intensity over time. Different aging temperatures can be obtained under different total heat and aging times, ensuring that the heat absorbed during indoor aging matches actual field conditions, rather than using the same fixed aging temperature for all aging tests. This better simulates the actual aging process of asphalt pavement, resulting in more accurate results and reducing the deviation between the total heat generated during aging and actual field conditions. Therefore, it can truly reflect the aging effect of the pavement during its service life. Through indoor dynamic aging tests, the changing patterns and photoaging mechanisms of asphalt pavement during ultraviolet light aging can be effectively revealed.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, any improvements, equivalent substitutions, and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the indoor dynamic photothermal aging of asphalt pavement based on equivalent temperature, characterized in that: The dynamic photothermal aging evaluation method includes the following steps: Step 1: Select a new sample of asphalt mixture identical to the target site, and prepare the new sample of asphalt mixture into asphalt mixture specimens; Step 2: Based on the total monthly UV radiation at the target location i And the maximum monthly ultraviolet radiation intensity I i The irradiation time of asphalt mixture specimens under photothermal coupling irradiation intensity was set, and the total heat energy Q obtained per unit actual road surface at the target location was determined. 实际 The aging test temperature for asphalt mixture specimens was set to T. s ; Step 3: Perform photothermal coupled aging on the asphalt mixture specimens. After aging, remove the aged asphalt mixture specimens and then test the asphalt penetration P at different depths of the asphalt mixture specimens using the penetration test in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Hl According to the bitumen penetration P Hl The size of the specimen is used to evaluate the degree of aging of asphalt mixture specimens at different depths; Setting the irradiation time of asphalt mixture specimens under photothermal coupling irradiation intensity includes the following steps: Based on historical data, the maximum monthly ultraviolet radiation intensity I is calculated. i The indoor aging test time is t. i satisfy: t i =UV i / I i ; i To select the first of each year i moon; Considering the actual road surface's service life (n) on site, and performing n cycles in years, with any period less than one year counted as one year, the total aging test time (t) is thus obtained. 总 That is, the irradiation time under photothermal coupling irradiation intensity, the total aging test time t. 总 satisfy: ;in, i Indicates selecting the first [number] of each year. i Months; Based on the total heat energy Q obtained per unit of actual road surface at the target location 实际 The aging test temperature for asphalt mixture specimens was set to T. s Includes the following steps: Calculate the temperature difference T between the highest and lowest temperatures in each month of the year. iX =T imax - T imin , among which, T imax and T imin They represent the first i The highest and lowest temperatures of the month; then the... i The actual heat energy absorbed by the road surface per day per unit month meets Q im = C*M*T imX Among them, T imX =T iX +K;T imX For the asphalt surface layer in the first i Maximum monthly temperature difference; Calculate the total heat energy Q obtained per unit actual pavement of the asphalt mixture specimen. 实际 Q is the total heat energy Q obtained per unit of actual road surface during actual operating time. 实际 satisfy: ； Where C is the specific heat capacity of the asphalt mixture specimen, M is the mass of the asphalt mixture specimen, and T is the mass of the asphalt mixture specimen. iX The first destination i Maximum monthly temperature difference, K is a correction factor; Based on the principle of energy equivalence, the total heat energy obtained per unit of actual pavement is converted into the total energy of indoor photothermal coupling aging of asphalt mixture specimens, then Q = ... 实际 =Q 室内 The indoor photothermal coupling aging test temperature T for asphalt mixture specimens was calculated and determined. s , T s =Q 室内 / (t 总 *C*M)=Q 实际 / (t 总 *C*M); Using a dynamic cycle of 12 months, the ultraviolet irradiation intensity I is set. i The corresponding indoor aging time t i Meanwhile, the aging test temperature was set to T. s Then, based on the actual number of years the highway has been in operation (n), an aging test is set up with n dynamic cycles, thus obtaining a complete indoor aging test process.

2. The indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to claim 1, characterized in that: In step 2, based on historical data, the total monthly UV radiation is calculated as 6% of the solar radiation. i .

3. The indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to claim 1, characterized in that: The correction coefficient K ranges from 5 to 10.

4. The indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to claim 1, characterized in that: In step 3, the asphalt penetration P at different depths of the asphalt mixture specimen is measured. Hl Includes the following steps: Step 31: Remove the aged asphalt mixture specimen and cut off the four sides of the asphalt mixture specimen, keeping the central specimen. Divide the central specimen into four equal parts along the depth direction. Step 32: Extract the asphalt content in each asphalt mixture by centrifugation according to the specification "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Step 33: Measure the asphalt penetration P at different depths in each center specimen using the penetration test in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2019. Hl The ratio of penetration to that of new asphalt was compared and analyzed, and the ratio of penetration to that of new asphalt was used as the evaluation index A for the aging degree of asphalt mixture specimens.

5. The indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to claim 4, characterized in that: The ratio of the penetration to the penetration of the new asphalt sample is less than or equal to 1.

6. The indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to claim 4, characterized in that: When photothermal coupling aging is performed on asphalt mixture specimens, if the aging time is longer than the preset time, the ultraviolet irradiation intensity is increased by 10 to 30 times, and the penetration results obtained are then corrected.

7. The indoor dynamic photothermal aging evaluation method for asphalt pavement based on equivalent temperature according to claim 6, characterized in that: Correcting the needle penetration results involves the following steps: Under conditions of 20℃, the month with the strongest radiation was selected from historical records. i The two asphalt mixture specimens were subjected to the first... i Actual radiation intensity in the month I i 、 Actual irradiation time t i Photothermal coupled ultraviolet irradiation aging test, and actual irradiation intensity I i expand b Times, actual irradiation time t i Shrink b The photothermal coupled ultraviolet irradiation aging test was carried out twice; After the aging test, the penetration values ​​P2 and P3 at a depth of 2 cm were measured for the two asphalt mixture samples. 2b The penetration ratio P2 / P 2b As the correction factor B, the final aging evaluation index is A 修正 satisfy: A 修正 = A * B = A *P2 / P 2b ; If the irradiation intensity is not increased, the final aging degree evaluation index is: A If the irradiation intensity is increased, the final aging evaluation index will be: A 修正 .

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