CN-116840134-B - Indoor dynamic photo-thermal aging evaluation method for asphalt pavement based on equivalent temperature

CN116840134BCN 116840134 BCN116840134 BCN 116840134BCN-116840134-B

Abstract

The invention discloses an indoor dynamic photo-thermal aging evaluation method of an asphalt pavement based on equivalent temperature, which comprises the steps of preparing an asphalt mixture test piece, setting the irradiation time and the aging test total time of the asphalt mixture test piece under the irradiation intensity of ultraviolet rays per month according to the total ultraviolet irradiation amount and the maximum irradiation intensity of ultraviolet rays per month of a target place, setting the aging test temperature of the asphalt mixture test piece according to the total heat energy and the aging test total time obtained by a unit actual pavement of the target place, carrying out dynamic photo-thermal coupling aging on the asphalt mixture test piece according to the maximum ultraviolet irradiation intensity per month, the corresponding irradiation time and the aging temperature, detecting the asphalt penetration at different depths of the asphalt mixture test piece, and evaluating the aging degrees of different depths of the asphalt mixture test piece according to the size of the asphalt penetration. The invention can ensure that the ultraviolet radiation and heat energy absorbed during indoor aging accord with the field reality, and can simulate the actual aging process of the asphalt pavement, so that the aging test result is more accurate.

Inventors

ZHOU HUAIDE
LUO JUNHUI
XIE CHENG
CHEN JIANGCAI
YAN ZENAN
HUANG XIAOFENG
WEI DI

Assignees

广西北投交通养护科技集团有限公司

Dates

Publication Date: 20260508
Application Date: 20230620

Claims (7)

1. The indoor dynamic photo-thermal aging evaluation method for the asphalt pavement based on the equivalent temperature is characterized by comprising the following steps of: step 1, selecting a new asphalt mixture which is the same as a target place, and preparing the new asphalt mixture into an asphalt mixture test piece; Step 2, setting the irradiation time of the asphalt mixture test piece under the photo-thermal coupling irradiation intensity according to the total ultraviolet irradiation amount UV i and the maximum ultraviolet irradiation intensity I i of each month of the target place, and setting the aging test temperature of the asphalt mixture test piece to be T s according to the total heat energy Q Actual practice is that of obtained by the unit actual road surface of the target place; Step 3, photo-thermal coupling aging is carried out on the asphalt mixture test piece, the asphalt mixture test piece after aging is taken out after aging is finished, then the penetration test in JTG E20-2019 of highway engineering asphalt and asphalt mixture test procedure is used for detecting the penetration P Hl of asphalt at different depths of the asphalt mixture test piece, and the aging degree of the asphalt mixture test piece at different depths is evaluated according to the magnitude of the penetration P Hl of asphalt; The method for setting the irradiation time of the asphalt mixture test piece under the light-heat coupling irradiation intensity comprises the following steps: based on the calendar year data, calculating an indoor aging test time based on the ultraviolet maximum irradiation intensity per month I i , wherein the indoor aging test time t i satisfies: t i =UV i /I i , i is the ith month of the selected calendar year; Considering the on-site actual road surface traffic years n, carrying out n cycle cycles in a year unit, and calculating less than one year part in one year, thereby obtaining the total aging test time t Total (S) , namely the irradiation duration under the light-heat coupling irradiation intensity, wherein the total aging test time t Total (S) meets the following conditions: wherein i represents the i-th month of the selected calendar year; Setting the aging test temperature of the asphalt mixture test piece to be T s according to the total heat energy Q Actual practice is that of obtained by the unit actual road surface of the target area comprises the following steps: Calculating a temperature difference T iX =T imax - T imin between the highest air temperature and the lowest air temperature of each month in one year, wherein T imax and T imin respectively represent the highest air temperature and the lowest air temperature of the ith month, and the heat energy absorbed in the ith month unit actual pavement in one day meets Q im = C*M*T imX , wherein T imX =T iX +K;T imX is the maximum temperature difference of the asphalt surface layer in the ith month; The total heat energy Q Actual practice is that of obtained by the unit actual pavement of the asphalt mixture test piece is calculated, namely the total heat energy Q Actual practice is that of obtained by the unit actual pavement in the actual operation time of the pavement is as follows: ; Wherein C is the specific heat capacity of the asphalt mixture test piece, M is the mass of the asphalt mixture test piece, T iX is the i-th month maximum air temperature difference of the target area, and K is a correction coefficient; According to the energy equivalent principle, the total heat energy obtained by the unit actual road surface is converted into the total heat energy of indoor photo-thermal coupling aging of the asphalt mixture test piece, Q Actual practice is that of =Q Indoor unit exists, the indoor photo-thermal coupling aging test temperature T s of the asphalt mixture test piece is calculated and determined, T s =Q Indoor unit /(t Total (S) *C*M)=Q Actual practice is that of /(t Total (S) *C*M); And setting the corresponding indoor aging time T i under the ultraviolet irradiation intensity I i by taking 12 months as a dynamic cycle, setting the aging test temperature to be T s , and setting the aging test to have n dynamic cycles according to the actual traffic age n of the highway, thereby obtaining a complete indoor aging test process.
2. The method for evaluating indoor dynamic photo-thermal aging of asphalt pavement based on equivalent temperature according to claim 1, wherein in step 2, total ultraviolet irradiation amount UV i per month is calculated by 6% of solar radiation amount based on calendar data.
3. The method for evaluating indoor dynamic photo-thermal aging of asphalt pavement based on equivalent temperature according to claim 1 is characterized in that the value range of the correction coefficient K is 5-10.
4. The method for evaluating indoor dynamic photo-thermal aging of asphalt pavement based on equivalent temperature according to claim 1, wherein in step 3, detecting the penetration P Hl of asphalt at different depths of an asphalt mixture test piece comprises the following steps: Step 31, taking out the aged asphalt mixture test piece, cutting off the periphery of the asphalt mixture test piece, reserving a central test block of the asphalt mixture test piece, and uniformly dividing the central test block into four equal parts along the depth direction; Step 32, extracting to obtain asphalt contained in each asphalt mixture according to a centrifugal separation method in JTG E20-2019 of the specification of highway engineering asphalt and asphalt mixture test procedure; And step 33, measuring the penetration P Hl of the asphalt at different depths of each central test block through a penetration test in JTG E20-2019 of the highway engineering asphalt and asphalt mixture test procedure, comparing and analyzing the penetration ratio of the asphalt to the new sample asphalt, and taking the penetration ratio of the asphalt to the new sample asphalt as an aging degree evaluation index A of the asphalt mixture test piece.
5. The method for evaluating indoor dynamic photo-thermal aging of asphalt pavement based on equivalent temperature according to claim 4, wherein the ratio of penetration to penetration of new asphalt is less than or equal to 1.
6. The method for evaluating indoor dynamic photo-thermal aging of asphalt pavement based on equivalent temperature according to claim 4, wherein when photo-thermal coupling aging is carried out on the asphalt mixture test piece, if the aging time is longer than a preset time, the ultraviolet irradiation intensity is enlarged by 10-30 times, and then the penetration result obtained through detection is corrected.
7. The method for evaluating indoor dynamic photo-thermal aging of asphalt pavement based on equivalent temperature according to claim 6, wherein the step of correcting penetration results comprises the following steps: Under the condition of 20 ℃, selecting month I with strongest irradiation in the selected calendar year, carrying out photo-thermal coupling ultraviolet irradiation aging test on the two asphalt mixture test pieces with actual irradiation intensity I i and actual irradiation time t i of the ith month, and carrying out photo-thermal coupling ultraviolet irradiation aging test on the actual irradiation intensity I i by b times and the actual irradiation time t i by b times; The penetration P 2 、P 2b at the depth of 2cm of the two asphalt mixtures is measured after the aging test, the penetration ratio P 2 /P 2b is used as a correction coefficient B, namely the final aging degree evaluation index A Correction meets the following conditions: A Correction =A*B= A*P 2 /P 2b ; If the irradiation intensity is not increased, the final aging degree evaluation index is a, and if the irradiation intensity is increased, the final aging evaluation index is a Correction .

Description

Indoor dynamic photo-thermal aging evaluation method for asphalt pavement based on equivalent temperature Technical Field The invention belongs to the technical field of asphalt pavement tests, and particularly relates to an indoor dynamic photo-thermal aging evaluation method for an asphalt pavement based on equivalent temperature. Background The asphalt pavement structure is completely exposed in natural environment and is directly subjected to the influence of continuous change climate such as solar radiation, atmospheric radiation, outside air temperature, rainfall and the like, so that the aging hardening phenomenon of asphalt on a macroscopic scale is caused, and the service performance of the asphalt pavement is further influenced. In order to reasonably maintain and regenerate asphalt pavement affected by aging, the aging rule and aging mechanism of asphalt must be carefully analyzed and studied. The existing indoor aging method of the asphalt mixture adopts high-temperature aging to simulate the on-site aging condition of an asphalt surface layer, and the asphalt pavement is subjected to temperature aging and continuously subjected to the action of ultraviolet rays in solar radiation in the actual service operation process, so that the influence of ultraviolet rays and the like in the service process of the asphalt pavement is ignored in the indoor high-temperature aging test process, the difference between the indoor aging result and the on-site actual aging condition is larger, and the maintenance of the asphalt pavement cannot be effectively guided. The existing aging method considering the influence of ultraviolet rays only adopts one ultraviolet irradiation intensity to be applied to the whole test process, and does not reflect the actual pavement dynamic ultraviolet irradiation process, so that the total heat energy generated in the aging process has overlarge actual deviation with the site, and the aging effect in the pavement service process cannot be truly reflected. There are also many drawbacks and deficiencies in the study of indoor aging of asphalt mixing road fabrics. Therefore, aiming at the problems, the indoor dynamic photo-thermal aging evaluation method of the asphalt pavement based on the equivalent temperature is provided to improve and perfect experimental research on the indoor aging of the asphalt mixed pavement, so as to provide technical support for the follow-up related research on the photo-aging of the asphalt mixed pavement. Disclosure of Invention The invention aims to provide an indoor dynamic photo-thermal aging evaluation method for asphalt pavement based on equivalent temperature, which is characterized in that the aging temperature is coupled with ultraviolet irradiation intensity through time, and according to different temperatures under different total heat conditions instead of independently setting fixed aging temperature, ultraviolet radiation and heat energy absorbed during indoor aging are ensured to be in accordance with field reality, so that the actual aging process of asphalt pavement can be simulated more, the aging test result is more accurate, the deviation between the total radiation and heat energy generated during aging process and the field reality is reduced, and the aging effect during pavement service process can be reflected truly. In order to achieve the above purpose, the present invention adopts the following technical scheme: according to one aspect of the invention, the invention provides an equivalent temperature-based indoor dynamic photo-thermal aging evaluation method for an asphalt pavement, which comprises the following steps of: step 1, selecting a new asphalt mixture which is the same as a target place, and preparing the new asphalt mixture into an asphalt mixture test piece; Step 2, setting the irradiation time of the asphalt mixture test piece under the photo-thermal coupling irradiation intensity according to the total ultraviolet irradiation amount UV i and the maximum ultraviolet irradiation intensity I i of each month of the target place, and setting the aging test temperature of the asphalt mixture test piece to be T s according to the total heat energy Q Actual practice is that of obtained by the unit actual road surface of the target place; and 3, carrying out photo-thermal coupling aging on the asphalt mixture test piece, taking out the aged asphalt mixture test piece after the aging is finished, detecting asphalt penetration P Hl at different depths of the asphalt mixture test piece through a penetration test in JTG E20-2019 of highway engineering asphalt and asphalt mixture test procedure, and evaluating the aging degree of different depths of the asphalt mixture test piece according to the size of the asphalt penetration P Hl. It is further preferable that the above-mentioned scheme is that, in step 2, the total amount of ultraviolet irradiation UV i per month is calculated as 6% of the solar radiation amount bas