半刚性基层沥青路面与全厚式沥青路面疲劳特性比较

Comparison between asphalt pavement with semi-rigid base and full depth asphalt pavement in regard to fatigue properties

沥青混合料疲劳试验的荷载控制模式有应力控制和应变控制两种。文章经理论计算分析了半刚性基层沥青路面和全厚式沥青路面的沥青层在交通荷载作用下疲劳时的应力和应变状态。从而研究相应于两类沥青路面沥青混合料疲劳试验合适的荷载控制模式。计算表明 ,随着面层和基层材料劲度的逐渐下降 ,两类沥青路面的沥青层层底的弯拉应力和弯拉应变的变化规律有所不同 ;全厚式沥青路面沥青层层底的弯拉应力和弯拉应变随混合料劲度的变化规律 ,更加类似于应变控制模式的疲劳试验时小梁试件的应力、应变的变化规律。因此 ,全厚式沥青路面沥青混合料的疲劳试验更适宜采用应变控制的荷载模式。

There are two kinds of load controlling mode for asphalt mixture fatigue testing-stress controlling mode and strain controlling mode. In the paper,through theoretic computation,the stress and strain states of the asphalt pavement with semi rigid base and the full depth asphalt pavement are analyzed when the bituminous pavement is being fatigued under the traffic load. With gradual descending of modulus, the changing regularity of the flexural tensile stress and flexural tensile strain at the bottom of the bituminous layer of the two kinds of bituminous pavement are different. Finally, a convenient load mode to test their fatigue properties is put forward. It is shown that strain controlling mode is adequate for asphalt mixtures of asphalt stabilized base course as for fatigue test.