基于能量法的浇注式沥青混合料疲劳特性分析

Study on fatigue durability of Steel Bridge Deck

浇注式沥青混合料的材料及组成与常规沥青混合料存在较大差异,对浇注式沥青混合料GA10进行了不同应变水平、不同温度条件下的四点弯曲疲劳对比试验,建立疲劳次数与应变相关的疲劳方程,并采用累计耗散能和累计耗散能比DER对GA10在不同温度下的能量变化趋势进行分析。结果表明:疲劳方程能很好地表征了沥青混合料的疲劳行为,疲劳次数随温度的升高疲劳寿命增加;而随着应变水平的增加,则引发沥青混合料疲劳次数成倍减少;以三阶段分析疲劳破坏初始劲度模量累计耗散能指标与温度、应变并不是单一变量关系,且以初始精度模量下降到50%为破坏条件不具有准确性。

The material and composition of pouring asphalt mixture are quite different from that of conventional asphalt mixture,and the four-point bending fatigue comparison test of pouring asphalt mixture GA10 under different strain levels and different temperature conditions is carried out,and the fatigue equations related to fatigue number and strain are established.The energy change trend of GA10 at different temperature was analyzed by using the index of cumulative dissipation energy.The results show that the fatigue equation can well characterize the fatigue behavior of asphalt mixture,the fatigue life of fatigue number increases with the increase of temperature,and with the increase of strain level,the fatigue times of asphalt mixture are doubled,and the cumulative Dissipation energy index and temperature based on dissipation energy principle are different from the results obtained by the above fatigue equation.Strain is not a single variable relationship,and the failure condition is not accurate with the initial precision modulus falling to 50%.