中文摘要：

由于沥青混合料的疲劳裂纹扩展一般难以用传统的Paris公式描述,文中基于能耗的观点,研究了沥青混合料裂纹扩展阶段的疲劳演化规律.试验采用半圆弯曲试验方法,在MTS试验系统上进行了3种级配的沥青混合料的断裂韧度试验和疲劳试验,定义了半圆弯曲试验方法中沥青混合料的裂纹起裂点和疲劳破坏点.研究结果表明：具有断级配的应力吸收层沥青混合料具有很好的抗裂性能和抗疲劳性能;混合料累积疲劳破坏能符合Miner线性假定;沥青混合料的疲劳寿命与断裂韧度有很好的相关性.通过拟合VanDijk能耗公式参数而建立的以断裂韧度为参数的预测模型可以方便地预测沥青混合料裂纹扩展阶段的疲劳寿命.

英文摘要：

In order to overcome the difficulty in the description of fatigue crack growth of asphalt mixture by the traditional Paris formula, the fatigue evolvement law of asphalt mixture in the crack growth stage was investigated based on the conception of energy consumption, and the fracture resistance and fatigue tests of three kinds of mixtures with different gradations were performed by adopting the semi-circular bending test method in a MTS testing system. Moreover, the initial cracking point and the fatigue destroying point were both defined. Experimental resuits show that （ 1 ） the asphalt mixture with gap gradation in the stress-absorbing layer is of better crack and fatigue resistances; （2） the accumulated energies in the crack growth stage accord well with the Miner linear hypothesis; and （3） the fatigue life of asphalt mixture is in good accordance with the fracture resistance. It is also found that the prediction model established by fitting the parameters of Van Dijk energy-consumption formula can conveniently predict the fatigue life of asphalt mixture in the crack growth stage .