老化沥青胶结料的疲劳特性研究

Research on Fatigue Characteristic of Aged Asphalt Binder

采用动态剪切流变仪(DSR)研究了短期老化与长期老化的沥青胶结料在应变模式,应力模式下的抗疲劳性能.实验中,采用了旋转薄膜烘箱实验(RTFOT)及压力老化(PAV)来模拟沥青胶结料的短期及长期老化.沥青胶结料的应变疲劳实验中选取1.0%,1.5%,2.0%以及2.5%四个应变值,应力疲劳实验中选取了0.25,0.35,0.45,0.55MPa 4个应力值.实验结果表明,采用应变疲劳实验能够区别老化对沥青抗疲劳性能的影响,而应力疲劳并不能很好的显示老化对沥青抗疲劳性能的影响.因此,应变模式下的疲劳实验更适合用来评价老化沥青胶结料的抗疲劳性能.

DSR is conducted to evaluate the fatigue resistance performance of asphalt under strain-controlled mode and stress-controlled mode.During the test,RTFOT and PAV test are used to simulate short-term and long-term aging of asphalt binder.The strain value of 1.0%,1.5%,2.0% and 2.5% is determined in strain-controlled mode fatigue test,whereas stress value of is determined as 0.25 MPa,0.35 MPa,0.45 MPa and 0.55 MPa in stress-controlled mode fatigue test.The test results indicate that strain-controlled fatigue mode is more suitable to evaluate the fatigue resistance performance of aged asphalt.