行车荷载与温度综合作用下沥青路面疲劳损伤分析

Analysis of Traffic Loading and Temperature on Fatigue Damage in Asphalt Pavement

沥青混合料的劲度模量是温度与荷载作用时间的函数,沥青路面疲劳损伤不仅与行车荷载的反复作用有关,而且需要考虑温度因素的影响。文中采用沥青结构层温度场预估模型和疲劳寿命预测方程,结合沥青混合料劲度模量和Miner疲劳损伤累积定律,预估并分析行车荷载与温度综合作用下沥青路面的疲劳损伤,进而对不同的行车荷载与温度组合作用下沥青路面疲劳损伤的结果进行比较。结果表明：温度对沥青结构层的疲劳损伤有较大的影响,随着温度的升高,沥青混合料劲度模量减小,沥青结构层的疲劳损伤增加;行车荷载与温度综合作用下沥青路面疲劳损伤比仅考虑行车荷载作用下沥青路面疲劳损伤增加30%～40%;考虑温度作用时,重载车辆对沥青路面疲劳损伤的影响更大。

The stiffness modulus of asphalt mixture mainly depends on temperature and loading time. The permanent strain due to traffic loading in asphalt pavement and in consequence the fatigue damage of pavement structures are temperature dependent. According to the temperature profiles within asphalt layers and the fatigue model to predict the number of repetitions at failure, based on Miner＇s rule, the fatigue damage of asphalt pavement is predicted and analyzed as a combination of traffic loading and the influence of temperature on the stiffness modulus of asphalt mixture. In addition, the fatigue damage of pavement structure is compared under the same temperature and different traffic loading. The results show that： （1）temperature has the greater influence on stiffness modulus of asphalt mixture,and the stiffness modulus decreases with the increase of temperature; （2）the fatigue damage of asphalt pavement due to traffic loading and temperature is higher by 30%- 40 % than the fatigue damage affected by traffic loading; and（3） the heavy axle loading has more significant effect on the fatigue damage within asphalt layer considering temperature.