多级等幅荷载下沥青路面疲劳破坏研究

摘要

采用四点弯曲疲劳试验对沥青混合料的疲劳寿命进行了分析,并基于传统MINE疲劳损伤累积模型在多级等幅荷载沥下沥青混合料的疲劳损伤预测的弊端,结合非线性损伤模式提出了新型的沥青混合料疲劳预测模型.通过研究表明:多级荷载作用下,沥青混合料的耗散能、混合料的劲度模量及滞后角参数均表现出非线性变化趋势;由高应变水平向低应变水平转变时,沥青混合料劲度模量越易恢复;当多级荷载应变水平采用高-低,或由低-高-低的加载方式时,能有效提高沥青混合料的疲劳寿命,降低损伤进程.同时,根据多级荷载下沥青混合料的损伤变化呈一种非线性关系,建立的损伤累积模型能满足对沥青路面的疲劳损伤预测要求.%this paper USES the four-point bending fatigue test on the fatigue life of asphalt mixture were analyzed,and based on the traditional MINE in multistage fatigue damage cumulative model under constant amplitude loading drain the disadvantages of asphalt mixture fatigue damage prediction,combining the nonlinear damage model is put forward a new kind of asphalt mixture fatigue prediction model.Through research shows that:under multi-stage loading,the asphalt mixture can dissipation,stiffness modulus and lagging Angle change with different load loading sequence is nonlinear;From the high level of strain to low strain level,the asphalt mixture stiffness modulus is more easy to recover;When multistage loading strain level using high-low,or by the low-high-low loading method,can effectively improve the fatigue life of asphalt mixture,reduce the damage process.At the same time,vary according to the damage of the asphalt mixture of multistage load is a nonlinear relationship,establish the damage cumulative model can meet the requirement of the asphalt surface fatigue damage prediction.