AC+CRCP复合式路面温度场有限元分析

Thermal analysis for AC+CRCP composite pavement using finite element methods

根据传热学原理,利用有限元方法分析了AC+CRCP复合式路面的瞬态温度场.共考虑了3种路表与外界热交换的形式:太阳辐射、空气对流换热和空气辐射换热.计算结果与实测值的平均误差为2.0℃,并表现出明显的规律性:随着深度增加,温度、温度梯度、变温速率都会出现变化幅度减小、变化相位滞后的现象;而日温差随深度增加而减小情况可用指数函数来模拟.利用所建模型分析了复合式路面的温度场,结果表明:路表温度主要取决路表与外界环境的热交换;相同天气情况下路面表层材料对太阳辐射吸收率的不同是导致路表温度不同的主要原因;沥青层的临界厚度仅与沥青混合料的导热能力有关.

Based on the heat conduction theory, the transient thermal field of the AC （ asphalt concrete） ＋ CRCP （continuous reinforced concrete pavement） composite pavement is analyzed by using the finite element method （FEM）. Three kinds of heat conduction between the pavement and its surroundings are considered, including solar radiation, air heat flow and the radiation between air and pavement. The developed FEM simulation model can predict temperature distributions at different times of various pavement layers accurately with an average absolute error of 2. 0℃. The result shows obvious regularities： as the position deepens, the range of the temperature, thermal gradient and temperature changing velocity will decrease and the phases will be deferred; the relationship between temperature differences and the depth within a day can be described by an exponential function. The pavement thermal field was studied by using the developed model, and some conclusions are attained as follows. The surface temperature is mainly determined by the heat transfer between the pavement surface and the environment. The absorbency of surface pavement material for solar radiation is the main factor that leads to the difference between temperatures of different kind of pavement surface. Critical thickness of AC overlay is determined by the heat conductivity of asphalt mixture.