沥青自愈合指标修正及影响因素分析

Correction on Self-healing Index of Asphalt Binder and Influence Factors Analysis

通过动态剪切流变仪(DSR)对70~#基质沥青和SBS改性沥青进行无间歇和有间歇条件下的时间扫描试验,分析了沥青自愈合对其疲劳寿命的影响.评价了常见自愈合评价指标HI_1,HI_2和HI_3,并修正了HI_3,得到新指标HI_4,通过愈合行为方程拟合证明了HI_4的适用性.针对上述2种沥青在不同损伤度和间歇时间条件下进行试验,分析了损伤度和间歇时间对其自愈合能力的影响.结果表明:SBS改性沥青的自愈合能力优于70~#基质沥青;随着间歇时间的增长,沥青自愈合情况越来越好,但呈现逐渐减缓趋势;损伤度越大的沥青,在同一间歇时间段内愈合越困难.

In order to analyze the effect of self-healing on fatigue life of 70#base asphalt binder and SBS modified asphalt binder,the dynamic shear rheometer(DSR)was employed to perform the time sweep tests with and without rest periods.The deficiency of the common healing index HI 1,HI 2,HI 3 were analyzed and compared,the applicability of the new index HI 4 which was corrected by HI 3,was proved in terms of fitting of healing equation.Time sweep tests were used at different damage degree and rest periods to analyze their effects on self-healing ability.The results indicate that self-healing ability of SBS modified asphalt binders was better than 70#base asphalt binders.With the increase of rest periods,the healing condition of asphalt was getting better and better,but the trend was gradually slowing down.The higher the degree of damage,the more difficult it was to heal in the same rest period.