再生沥青自愈合影响因素及疲劳性能分析

Influential Factors and Fatigue Performance Analysis of Recycled Asphalt Self-healing

为研究再生沥青自愈合影响因素及自愈恢复后的疲劳性能,试验选择指标HI_6表征材料自愈性能,选择指标N_(f50)表征材料疲劳性能,利用动态剪切流变(DSR)仪以时间扫描模式进行疲劳-愈合-疲劳循环加载测试,分析了愈合温度、愈合时间、老化程度、损伤程度、再生剂种类和再生剂掺量对再生沥青自愈合性能及疲劳寿命的影响,并通过灰关联理论进行了自愈合关键影响因素分析.结果表明:较长的愈合时间、较高的愈合温度和再生剂掺量对再生沥青自愈度有促进作用,原沥青的老化、再生沥青的损伤均不利于再生沥青的自愈恢复;同种再生沥青之间,自愈度越高则疲劳寿命越长,不同再生沥青之间,自愈度与疲劳寿命之间没有绝对关系;再生沥青自愈合关键的影响因素为愈合温度,其次分别是愈合时间、再生剂种类、原沥青老化程度、损伤程度和再生剂掺量.

In order to study the influencing factors of self-healing of reclaimed asphalt and to consider the fatigue performance after self-healing,the dynamic shear rheometer(DSR)was used to perform the fatigue-healing-fatigue cyclic loading test in time scanning mode.The index HI6 was selected to characterize the self-healing properties of the material,and the index Nf50 was selected to characterize the fatigue properties of the material.The healing properties of regenerated asphalt and the impact of life expectancy at different healing temperature,healing time,degree of aging,degree of damage,regenerant type and regenerant dosage were compared and analyzed.The key influencing factors of self-healing was analyzed by gray correlation theory.The results show that longer healing time,higher healing temperature and the amount of regenerant will promote the self-healing of recycled bitumen.The aging degree of original bitumen and the damage of recycled bitumen are not conducive to self-healing and recovery of recycled bitumen.On the same self-healing bitumen higher self-healing fatigue life is longer,self-healing degree of different recycled bitumen and fatigue life is not absolute.Key factors of regeneration bitumen self-healing are the healing temperature,the healing time,the type of regenerant,the aging of the original asphalt,the degree of damage and the amount of regenerant.