Permafrost degradation, which is temperature-dependent, is the primary cause of embankment and pavement diseases in permafrost regions. In this article, we tried to analyze the thermal properties of asphalt properties in permafrost environments.
Asphalt Concrete Properties
Based on field monitoring results of ground temperature along G214 Highway in high-temperature permafrost regions, both the ground temperatures in the superficial layer and the annual average temperatures under the embankment for concrete pavements and asphalt pavements, respectively, were discussed. The maximum depth of the temperature field beneath the embankment for concrete and asphalt pavements was also investigated using the finite element method. The numerical analysis results show that there were significant seasonal differences in the ground temperatures in the superficial layer between the asphalt and concrete pavements. The maximum influencing depth of the temperature field beneath the permafrost embankment was 8 meters for each pavement. The thawed cores beneath both embankments are closely related to the maximum thawed depth, embankment height, and service time. The findings will be proposed as effective measurements for maintaining the highway embankment's thermal stability. Because permafrost degradation directly jeopardizes the stability of building foundations, permafrost, a seasonal active layer sensitive to temperature, has piqued the interest of an increasing number of researchers worldwide. If the constructed embankments were not properly protected beforehand, all types of embankment pavement diseases would be easy to develop in high-temperature permafrost regions. For example, the uneven transverse settlement of pavement is caused by the asymmetric distribution of the thermal field beneath the permafrost embankment. This is why the thermal stability of cement concrete pavements in permafrost areas has always been studied. The thermal state difference between the embankment's south and north faces is thought to be the most significant contributing factor to the unevenly transverse settlement of pavement. 
As a result of the thermal state difference, the embankment may experience an asymmetric thermal regime. Then there could be uneven transverse deformation. According to Yu, the primary cause of permafrost degradation is the destruction of the natural thermal equilibrium beneath the permafrost embankment. After highway pavements were built in permafrost regions, the heat exchange between the atmosphere and the ground surface changed, which was influenced by global warming and embankment construction disturbances. The rate of permafrost degradation acceleration begins to accelerate as a result of changing heat exchange conditions. Permafrost degradation would accelerate in warm permafrost regions if the embankments were not adequately protected, making all types of pavement diseases easy to manifest. Pavement and embankment diseases, according to previous research on the accelerated degradation of permafrost, are closely related to the thermal stability of permafrost embankments in permafrost regions. It is critical to maintain the thermal stability of the embankment in order to address the issues of embankment diseases and pavement diseases. The uneven distribution of the thermal field beneath the embankment is the direct cause of embankment deformation in permafrost regions of the Qinghai-Tibetan Plateau. The permafrost roadbed on highways experiences the most deformation in the center of the embankment. In order to fully comprehend the failure mechanisms of the Qinghai-Tibetan highway embankment in permafrost regions, radiation and thermal balance on the surface of the asphalt pavement were observed. Furthermore, these observation stations were located on the ground levels of various types of permafrost embankments between the Kunlun Pass and the No. 66 station port. The primary cause of the Qinghai-Tibetan highway embankment failure is thought to be the part of the heat that has a significant impact on the embankment's heat regime, according to calculated results based on observation. as a result of the heat, the high-temperature permafrost section formed a thawed core beneath the embankment. 
Thermal Properties
According to geohazard investigations of the embankments along the Qinghai-Tibet Railway, permafrost degradation causes some major geohazards, such as thawing settlement, frost-heave, and freezing-thawing-induced hazards. The settlement, burying, and lateral thermal erosion are just a few of the factors that can affect an embankment's stability. The thermal stability properties of the permafrost embankment will have changed significantly because thermal effect issues with slope orientations cause the maximum thawed depth position to deviate in the roadbed transverse direction rather than thaw on the embankment central line. The sunny-shady slope has a significant impact on the thermal and deformation stability of the highway embankment in a warm permafrost region, according to an examination of both observational geotemperature and deformation data of the embankment in the experimental section K369+100 along the National Highway 214 on the Qinghai-Tibet Plateau. According to in situ geothermal data collected from five typical sections along the Qinghai-Tibet Highway for up to 15 years, embankment settlement is closely related to the process of the underling permafrost degrading significantly. The thawing rate rises initially with an increase in the mean annual ground temperature, fluctuates as the temperature rises, and then falls at about 0.5°C. By examining the temperature characteristics of tested embankments at the Harbin to Dalian Passenger Dedicated Line's Changchun site, researchers discovered that, contrary to previous research, the temperature under the reinforced concrete component was higher in cold seasons than in the shoulders. This difference becomes smaller as roadbed depth increases. During the warm months, this phenomenon reverses, and the temperature difference typically decreases with roadbed depth. In various areas of the roadbed, the maximum seasonal frozen depths were all greater than the natural ground. As a result, the materials used for the roadbed altered how heat is exchanged between the air and the ground surface. According to survey data from the Qinghai-Tibet Highway, thaw settlement is the primary cause of embankment distress in permafrost regions. It can be successfully reduced or even controlled by increasing the embankment height. According to the studies mentioned above, cement concrete pavement and asphalt concrete pavement are the two most common pavement structures used in permafrost embankment engineering at the moment. The temperature of a black asphalt surface is extremely sensitive. Furthermore, it absorbs more solar radiation than cement concrete pavement. As a result, the temperature of the road surface on the black asphalt pavement is higher. This, as well as the temperature field, will have a significant impact on the stability of the permafrost beneath the asphalt concrete pavement embankment. The studies mentioned above only consider the temperature field beneath a permafrost embankment with a high-temperature susceptibility. Although some steps were taken to address pavement and embankment diseases, the disease issues could not be resolved completely. The main factor is that the thermal stability beneath the permafrost embankment is still poorly understood. As a result, cement concrete pavement has begun to be preferred over black asphalt pavement in permafrost areas for stabilizing embankment temperature fields. No evidence of embankment or cement concrete pavement diseases has been found because cement concrete pavement has not yet been widely used in permafrost regions under natural conditions. Furthermore, these illnesses are linked to the temperature field beneath both permafrost embankments and pavement structures. As a result, the temperature field beneath both permafrost embankments will be calculated using the finite element method. The temperature field variations between asphalt pavement and cement concrete pavement will be investigated at various embankment widths. The study's findings will provide a sound theory for designing embankment stability. They support permafrost engineering because it can maintain thermal stability beneath embankments by utilizing natural ventilation efficiently. 
The asphalt section of K375+300 and the cement section of K374+975 form the bordering sections. The ground temperature of the two pavements has been measured since July 2003. Figure 1 compares the ground temperature at 0.5 m depth. Time spent under the three different types of pavement between August 1, 2003, and August 1, 2006, as determined by ground temperature observation results. These observations were obtained primarily through geological drilling through a variety of drill holes. And we can see that the ground temperature differs significantly between the K374+975 section and the K375+300 section. The construction of both the cement and asphalt pavements resulted in a significant change in the shallow thermal regime. Furthermore, at 0.5 m depth, there is a noticeable difference in ground temperature between the two pavements. Ground temperatures are always lower on cement-paved surfaces than on asphalt-paved surfaces. There is a distinct seasonal difference in ground temperature between them at a depth of 0.5 m. It is obviously larger in the summer than in the winter. In the summer, the ground temperature beneath cement pavement is 5-6°C higher than the ground temperature beneath the natural ground at a depth of 0.5 m. However, at a depth of 0.5 m, the ground beneath the asphalt pavement is 10°C hotter than the surrounding natural ground. In the winter, there isn't much of a distinction between them. They are both below 1.0°C. The reason for this is that asphalt is more susceptible to temperature changes than cement. The temperature field beneath cement concrete pavement embankment and asphalt pavement embankment are first independently examined at a pavement width of 8.5 meters. The cause is the gradual increase in temperature caused by the two embankments' complete construction. The depth beneath permafrost embankments at which the residual layers first appear to be thawed is known as the maximum thawed depth. The type, height, and width of the pavement all influence when the residual thawed layers appear. For the 8.5 m pavement width, the maximum thawed depth under asphalt pavement has always been greater than cement concrete pavement from the first year to the 30th year after the embankments were fully constructed. The maximum thawed depth differences between the two pavements increase as the embankment height decreases. 
Asphalt Permafrost Environment
The aforementioned results and analyses allow us to draw several important conclusions for the thermal stability analysis under embankments with asphalt pavement and cement pavement in the permafrost Environment. There is a difference in ground temperature between concrete and asphalt pavement within 8 meters of the pavement. The difference in ground temperature is affected by seasonal variations. The difference in temperature ranges from 2.2 to 5.2°C in the summer and is essentially less than 1°C in the winter. The maximum thawed depth difference between asphalt pavement and cement pavement decreases with increasing embankment height. As the embankment height decreases, the maximum thawed depth development rate increases. The development rate of the maximum thawed depth first manifests itself in the first 20 years after the embankments begin to function. The maximum thawed depth development rate begins to slow after that point. At the same service time, the temperature beneath cement concrete pavement is always lower in the computational region than the temperature beneath the asphalt pavement. The maximum thawed depth under asphalt pavement is greater than that under cement concrete pavement to the same width of permafrost embankment. The maximum thawed depth difference between the two pavement structures becomes more noticeable as the embankment width increases. The maximum thawed depth development rate exhibits the characteristic of initially increasing and then decreasing at different embankment heights. The thawing core beneath asphalt pavement appears sooner than the thawing core beneath cement concrete pavement. The temperature of the ground beneath the embankment is significantly affected by the materials used in the pavement. Pavement widths, on the other hand, have less of an effect on the temperature of the ground beneath the embankment. As a result, the ground temperature change caused by the pavement material beneath the embankment is greater than the ground temperature change caused by the pavement widths. Furthermore, the temperature field beneath the concrete and asphalt pavement has a 5 m influence zone away from the embankment slope. Beyond 5 meters from the embankment slope, the temperature field under both the concrete and asphalt pavement has a smaller influence area. The influence area has begun to shrink as the height of the embankment increases. When the pavement widths are reduced, the maximum thawed depth differences between the two pavement structures show a decreasing trend with increasing service time after the pavements begin to operate. The maximum thawed depth differences between the two pavement structures roughly present linearity with operating time as the pavement widths increase. The maximum thawed depth of asphalt pavement is always less than that of cement concrete pavement. Because the permafrost region has a high average temperature and an extremely fragile ecological environment, ensuring the sustainability of embankment engineering in this area is even more critical. 