基于控制应变周期荷载试验预估沥青混凝土疲劳寿命

摘要

Fatigue crack is a road damage,as the road being long,repeated loads,small damage generated by the internal start,gradually deepened,extending from the bottom of the asphalt surface from the bottom up to become similar to the cumulative surface alligator turtle-like crack,thereby affecting the performance of the pavement.The main purpose of this study was to investigate the generation of cracks and fatigue life of asphalt concrete,the use of the type of site grading a highway AC-20 drill core speci-mens,the fracture strain controlled fatigue test generation indoor applications curves of stiffness mecha-nisms,and stress-strain dissipated energy theory loop area,estimating the fatigue life of asphalt concrete and critical strain.%疲劳裂缝是路面破坏的一种，为路面受到长期、反复的荷载后，由内部产生的微小破坏开始，渐渐加深、延长，从沥青面层底部由下而上累积成为类似鳄鱼皮般的表面龟裂，进而影响路面的性能。研究的主要目的是探讨沥青混凝土的裂缝生成与疲劳寿命，采用级配类型为 AC-20的某高速公路的现场钻芯试件，进行室内控制应变疲劳试验，应用劲度变化曲线的裂缝生成机制，与应力-应变回圈面积的消散能理论，推估沥青混凝土疲劳寿命与临界应变。结果表明，应用劲度变化曲线与消散能理论，所得的疲劳寿命都有一致性，故可判断其都可作为疲劳寿命的定义。其中以劲度变化曲线较为便捷，可以作为推估裂缝生成与疲劳寿命的参考方法。可作为沥青混凝土路面疲劳研究与设计的参考。