Analysis Of High Temperature Field And Rutting Of Asphalt Pavement

With the continuous improvement of the highway network in our country,the problem of road maintenance is becoming more and more serious.according to the statistics of road maintenance by the Ministry of Transport,Rutting is the main damage form of asphalt pavement,which requires a large amount of maintenance funds to repair rutting,so it was very necessary to study the main influencing factors of rutting.In the summer high temperature environment,the road was very easy to produce rutting damage,so it was necessary to study the temperature distribution of the pavement structure at high temperature,and to predict the rutting of the road according to the environment and load after the road was put into use.it can provide corresponding support for the maintenance and management technology of asphalt pavement.The study of the influence of temperature and load on the formation of rutting has a certain engineering guiding significance for the prevention of high temperature rutting.In this paper,Through the investigation and statistics of summer high temperature in Huiyang area,four typical high temperature weather are selected for finite element simulation,the distribution of pavement temperature field under different high temperature was studied,and the cumulative effect of pavement temperature was studied combined with high temperature wave.and the data regression analysis was used to study the temperature correlation between the ambient temperature and each structural layer of the pavement.The influence of solar emissivity,solar radiation absorptivity,heat capacity of surface material and thermal conductivity of surface material on pavement temperature field was analyzed by grey correlation degree,and the stress of road was studied by dynamic load.through the study of different temperature field,different speed and different grounding stress,the main factors affecting pavement rutting are analyzed.According to the local environment and load in Huiyang area,a rutting prediction model was established for roads during operation,and preventive maintenance measures were put forward according to the extreme high temperature in summer.According to the research results of this paper,the main conclusions are as follows:(1)Under the condition of continuous high temperature,the temperature of asphalt pavement will also produce accumulation effect,which leads to the further increase of pavement temperature,and there was a good cubic polynomial correlation between pavement temperature and ambient air temperature.the correlation between other structural layers and air temperature decreases gradually with the increase of depth,but the temperature of each layer was basically consistent with the change of air temperature.(2)By simulating and analyzing the influence of solar emissivity,solar radiation absorptivity,heat capacity of surface material and thermal conductivity of surface material on pavement temperature field,it was found that the solar radiation absorptivity of pavement material was most closely related to the pavement temperature field.therefore,the high temperature of pavement can be effectively prevented by controlling the solar radiation absorptivity.(3)By using the load subroutine,the dynamic load of the road surface was simulated by locating the coordinates and combining with the speed,and the stress under the action of different temperature field,different speed and different grounding stress is analyzed.The results show that with the increase of temperature,the number of road ruts increases obviously,the increase of speed was beneficial to reduce rutting,and the increase of grounding stress increases linearly the stress of each structure of the road.(4)The action of dynamic load was transformed into the accumulation of load,and the rutting was simulated by the method of static instead of dynamic;the local monthly average temperature was used to predict road rutting,and then the number of loads was modified.the rut prediction model has high accuracy and can accurately predict the rutting of the road during the operation period.For the sudden increase of high temperature rutting,road high temperature prevention can be carried out from the selection of materials and corresponding measures.