基于DSR的沥青胶结料自愈合评价指标分析

Analysis of Self-healing Evaluation Index of Asphalt Binder Based on DSR

为充分认识沥青胶结料自愈合评价指标的适用性,通过动态剪切流变仪(DSR)进行“疲劳愈合疲劳”试验,对比分析5种常见沥青胶结料自愈合评价指标(HI1~HI5),得到不同自愈合时间、不同损伤程度下70^#基质沥青、SBS改性沥青和橡胶改性沥青的自愈合能力,并讨论了各指标的优缺点及适用性.结果表明:不同自愈合评价指标下,3种沥青胶结料自愈合能力排序不同;HI1可区分不同条件下沥青胶结料的自愈合程度,自愈合时间较短时更敏感;HI2仅适用于评价相同损伤程度的沥青胶结料自愈合性能;HI3可反映自愈合后沥青胶结料疲劳损伤的恢复程度;HI4不仅受沥青胶结料承受荷载作用能力的影响,还与其初始复数模量的恢复能力有关,不适用于评价沥青胶结料自愈合能力;HI5同时考虑了沥青胶结料初始复数模量和疲劳损伤的恢复,可反映沥青胶结料综合性能的恢复能力,最适合作为沥青胶结料自愈合性能评价指标.

In order to fully understand the applicability of the self-healing evaluation index of asphalt binder,a dynamic shear rheometer(DSR) was used to perform the “fatigue-healing-fatigue” test. The self-healing ability of 70^# matrix asphalt,SBS modified asphalt and rubber modified asphalt under different healing time and different damage degree were obtained with five common asphalt binders. And the characteristic and applicability of each index were analyzed. The results show that under different self-healing evaluation indexes,the three kinds of asphalt binder have different healing ability ranking;HI 1 can distinguish the self-healing degree of asphalt under different conditions,and the sensitivity is lower when the healing tine is shorter;HI 2 is only suitable for evaluating the same damage degree;HI 3 can reflect the recovery degree of fatigue damage of asphalt binder after self-healing;HI 4 is not only affected by the ability of asphalt to withstand load,but also is related to restoring ability of its initial complex modulus,but it is not suitable for evaluating the healing ability of the asphalt binder. HI 5 also considers the recovery of modulus and anti-fatigue damage,reflecting the recovery ability of asphalt comprehensive performance,and is most suitable as an index for self-healing performance evaluation of asphalt binder.