Solution of pavement temperature field in ＂Environment-Surface＂ system through Green＇s function

In order to simplify the boundary conditions of pavement temperature field, the ＂Environment-Surface＂ system which considered the natural environment and pavement surface was established. Based on this system, the partial differential equations of the one-dimensional heat conduction in the pavement were established on the basis of the heat transfer theory. Furthermore, the function forms of the initial and boundary conditions of the equations were created through the field experiments. The general solution of the pavement one-dimensional heat conduction partial differential equations was acquired by using Green＇s function, and the explicit expression of pavement temperature field under specific constraint conditions was derived. For the purpose of analysis, the pavement temperatures in different seasons were calculated using the explicit expression of pavement temperature field, and the calculation accuracy was analyzed through the comparison between measured and calculated values. Then, the relationship between fitting accuracy and calculation accuracy of pavement temperatures was analyzed. The analysis results show that： the usage of ＂Environment-Surface＂ system simplifies the calculation of pavement temperature field; the relative error between calculated and measured values is generally less than 7% and is seldom influenced by seasons; there is a positive correlation between the calculation accuracy and the fitting accuracy of pavement surface temperature; high fitting accuracy would result in less error of pavement temperature prediction.