应力控制模式下微胶囊沥青疲劳自愈特性研究

Study on the Self-healing Characteristic of Microcapsule Asphalt Binder under Stress-controlled Model

研究应力控制模式下微胶囊沥青的疲劳自愈特性,采用一次间歇和多次间歇的时间扫描试验测试了微胶囊沥青模量随荷载作用次数的变化规律,分别以微胶囊掺量、损伤度及愈合时间对微胶囊沥青自愈能力的影响进行分析。结果表明:高频(低温)条件下,微胶囊沥青动态模量明显低于基质沥青动态模量,且随着微胶囊掺量的增加而降低;微胶囊沥青相位角明显高于基质沥青相位角,且随着微胶囊掺量的增加而增加。相同测试条件下,微胶囊沥青的荷载作用次数比基质沥青长,但随微胶囊掺量的增加而降低。多次疲劳-自愈条件下,微胶囊沥青的自愈性能高于基质沥青,且随着微胶囊掺量的增加而增加。总之,微胶囊沥青的低温性能、抗疲劳性能和自愈性能均强于基质沥青,且损伤度越低,自愈时间越短,基质沥青及微胶囊沥青的自愈性能越弱。

In order to fully understand the fatigue self-healing properties of microcapsule asphalt binder under stress-controlled model,the evolution of dynamic modulous with the change of the loading cycles for microcapsule asphalt binder was analyzed by one time interval time sweep and multi-times interval time sweep.The influences of the dosage of microencapsulated asphalt,damage degree and healing time on the self-healing properties of microcapsule asphalt binder were also studied.The results show that the dynamic modulus of microcapsule asphalt is significantly lower than that of neat asphalt under high frequency(low temperature)and decreases with the increase of microcapsule contents.The phase angle of microcapsule asphalt was significantly higher than that of matrix asphalt and increased with the increase of the dosages of microcapsule.The fatigue life of microcapsules binder is longer than that of neat asphalt binder,but decreases with the increase of the microcapsule contents under the same test conditions.Under the condition of multiple fatigue and self-healing,the self-healing property of microcapsule asphalt is still higher than that of neat asphalt and increases with the increase of the dosages of microcapsule.Whether it is neat asphalt or microcapsule asphalt,the lower the damage degree,the worse the self-healing performance,and the longer the self-healing time,the better the self-healing performance.In a word,the lower temperature performance,anti-fatigue property and self-healing property of microcapsule binder is higher than that of neat asphalt binder.