关键词: 沥青混合料, 裂纹扩展, 疲劳寿命, 预测模型, 半圆弯曲试验, 能耗

Abstract:

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 .

Key words: asphalt mixture, crack growth, fatigue life, prediction model, semi-circular bending test, energy consumption