沥青自愈合行为的影响因素及评价方法

利用加入间歇时间的动态剪切流变试验,研究了沥青自愈合行为的影响因素及其评价方法.通过试验得到70#基质沥青和SBS I-C改性沥青在4种间歇时间、3种应变水平下的疲劳寿命,并采用能量耗散理论分析了试验过程,得到了耗散能变化率的坪值PV.根据坪值PV与间歇时间的关系,定义了不受间歇时间影响的评价指标自愈合速率HR,并采用自愈合率HI及自愈合速率HR评价了2种沥青在不同条件下的自愈合性能.研究发现:2种沥青的HI值均随间歇时间的增大而提高;HI及HR值均随着应变水平的增大而减小;SBS I-C改性沥青的自愈合指标优于70#基质沥青.

Influential Factors and Evaluation Methods of Healing Behavior of Asphalt Binders

Influential factors and evaluation methods of healing behavior of asphalt binders were researched and developed based on dynamic shear rheometer tests with an intermittent loading sequence. Experiments were carried out to investigate fatigue behaviors of asphalt binder 70# and asphalt binder modified by SBS I C under 4 rest periods and 3strain levels. And the plateau values of the ratios of dissipated energy change in the experiments were calculated by dissipated energy theory. Through the analysis of the relationship between plateau values and rest periods, the healing rate(HR) was defined to quantify the healing potential of asphalt binders. The healing potentials were evaluated by HR and the healing index(HI). It is indicated that HI is improved with the increase of rest periods, HI and HR are decreased with the increase of strain levels, and both indexes of asphalt binder modified by SBS I C are superior to asphalt binder 70#.