Study On The Permanent Deformation Of Asphalt Pavement On The Basis Of Factors With Nonlinear Characteristics

Research on permanent deformation of asphalt pavement at high temperature is of great engineering significance because visco-plastic deformation will occur under the wheel load at high temperature due to its temperature sensitivity. The dominant factor of permanent deformation is the pavement surface temperature condition in service period, thus this paper started with research on structural temperature of asphalt pavement.Time-varying nonlinearly distributing hour temperature and solar radiation intensity were firstly regressed on the basis of meteorological data in this paper. And also the time-varying nonlinear hour temperature data of pavement surface on the basis of prediction model of pavement surface temperature field, and the traffic distribution frequency in each temperature interval in accordance with hour traffic distribution. After the time-varying nonlinear hour pavement surface temperature distribution frequency and temperature interval traffic distribution frequency were regressed in Jinan, Xi'an, Shanghai and Guangzhou, it was found that the two parameters in Guangzhou are highly larger than those of other three cities at high temperature condition, and temperature distribution features in the four cities are different from each other.Base on the time-varying nonlinearly distributing monthly surface hour temperature in each city, result was obtained through temperature field analysis in finite element software. It was found that temperature amplitude and phase in inner pavement structural lagged behind that of pavement structural surface. Result of numerical simulation on permanent deformation of pavement structure, which is based on temperature field simulation, showed that rut quantity in Guangzhou is highly larger than those of other three cities. The rut quantity in Shanghai is smallest because near shoring though low latitude. The contributing months on rut in Guangzhou are March to September, in Jinan and Shanghai they are April to September, Xi'an April to August. The daily contributing hours to rut are 12:00 am to 20:00 pm in one day. Referring to pavement structure, the rut quantity of mid-course is largest, which is larger than 50% of total, while that of upper-course is less and the down-course least.The computation of the rutting effective temperature of asphalt temperature was conducted through Miner linear Cumulative damage law and isostrain law. Result showed that the former law cannot be applied in computation which is on the basis of nonlinear factors, while the later law can describe the relationship between rut deformation and temperature, on condition that taking equivalent temperatures of courses in consideration respectively.