沥青混合料自愈合特性四点弯曲疲劳试验研究

通过应变控制四点弯曲疲劳试验,变化加载频率分析沥青混合料的即时自愈合,变化愈合温度、时间、荷载和损伤程度分析沥青混合料的后期自愈合.结果表明:沥青混合料的即时自愈合伴随加载产生,愈合效果为SBS-AC13TB-AC13基质-AC13;愈合温度、时间、荷载对沥青混合料的后期愈合具有正面作用,而损伤程度具有负面作用;橡胶沥青混合料疲劳寿命对自愈合条件的依赖性小于SBS沥青混合料,对沥青用量变化敏感性低于SBS沥青混合料;橡胶沥青混合料的劲度模量恢复率大于疲劳寿命恢复率,且疲劳寿命恢复率的离散性较大,劲度模量恢复率的离散性较小.

Evaluation of Self healing of Asphalt Mixture ThroughFour Point Bending Fatigue Test

To analyze self healing characteristic of asphalt mixture, variable loading frequencies for synchronous self healing and variable rest period conditions for after loading self healing were conducted through four point bending fatigue test. The results indicate that synchronous self healing is induced by loading, and the ratio of fatigue life(RL) of synchronous self healing for different type of mixture ranges in SBS AC13>TB AC13>Virgin asphalt AC13. Rest period temperature, rest time and extra load have positive influence on after loading self healing while damage ratio has negative influence on after loading self healing. After loading self healing of AR mixture is less influenced by rest period conditions than SBS mixture, also less sensitive to asphalt content than SBS mixture. Stiffness recovery is bigger than fatigue life recovery in evaluating after load self healing while fatigue life recovery is scattered but stiffness recovery is stable.