Through four-point fatigue bending test, the cumulation process of gussasphalt(GA) mixture stiffness modulus with load cycles was divided into three stages, and the third stage when the macro mechanical performances were greatly changed was defined as fatigue crack appearance stage of GA mixture. The respective relations among strain level, asphalt content, test temperature and stiffness modulus as well as fatigue life were researched in the experiment. The results show that; the first stage when the specimen exhibits an 80% reduction in stiffness modulus relative to the initial stiffness accounts for 5%-10% of total fatigue life; the second stage during which the reduction becomes slowly and demonstrats a liner relationship with load number accounts for 70%- 85% of the fatigue life; and the third stage is about 5%- 10%. The results indicate that gussasphalt mixture has excellent fatigue durability at a higher strain level; and the fatigue life of gussasphalt mixture can't be improved by increasing asphalt content. Fatigue life of gussasphalt mixture is susceptible to temperature, and it increases with temperature.%根据四点弯曲疲劳试验曲线特征,将浇注式沥青(GA)混合料劲度模量随加载循环次数的累积过程分为3个阶段,并将宏观力学性能发生剧烈变化的第3阶段定义为沥青混合料疲劳裂缝出现区域.试验研究了应变水平、沥青用量和试验温度与沥青混合料劲度模量和疲劳寿命的关系,结果显示:第1阶段GA混合料劲度模量衰变至初始劲度模量的80%左右,占总疲劳寿命的5%～10%；第2阶段劲度模量衰变较为缓慢,与加载次数呈线性关系,占总疲劳寿命的70%～85%；第3阶段占总疲劳寿命的5%～10%.较高应变水平下GA混合料也有非常好的疲劳耐久性；增大沥青用量不能显著提高GA混合料的疲劳寿命；GA混合料疲劳寿命对温度非常敏感,且随着温度的升高而增加.
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