溶解性胶粉改性沥青混合料疲劳性能

Fatigue Performance of Terminal Blend Rubberized Asphalt Mixture

应用四点弯曲疲劳试验机BFA(beam fatigue apparatus)对溶解性胶粉改性沥青混合料的疲劳性能进行研究,并在相同空隙率下对溶解性胶粉改性沥青密级配沥青混合料(AC13)和苯乙烯-丁二烯-苯乙烯改性沥青密级配沥青混合料(SBS-AC13)完成了考虑自愈合影响的疲劳性能比较,进一步完成溶解性胶粉改性沥青与SBS复合改性沥青混合料AC13的疲劳性能和高温性能研究.结果显示:归一化劲度次数积疲劳寿命比50%初始模量降低疲劳寿命更适合用于评价溶解性胶粉改性沥青混合料的疲劳寿命;总结溶解性胶粉改性沥青混合料的疲劳性能与应变、沥青用量和空隙率等三个因子的相关性,提出溶解性胶粉改性沥青混合料的疲劳方程;在4%的设计空隙率下,无论是否考虑自愈合的影响,SBS-AC13的疲劳寿命均高于溶解性胶粉改性沥青AC13,但溶解性胶粉改性沥青AC13的自愈合能力高于SBS-AC13;在4%的设计空隙率下,无论是否考虑自愈合的影响,溶解性胶粉复合SBS改性沥青AC13的疲劳寿命均达到SBS-AC13疲劳寿命的2倍,其自愈合能力高于SBSAC13,且高温性能亦远优于SBS-AC13.

The fatigue performance of terminal blend rubberized asphalt mixture was researched by BFA which was selected to do four-point bending beam fatigue tests.The fatigue performance considering self-healing between Terminal Blend-AC13 and SBS-AC13 was compared which had the same air voids.Further research was done on fatigue performance and high temperature performance of the compound modified asphalt mixture though mixing SBS into terminal blend rubberized asphalt.The results show that NfNM is more suitable than Nf50 to be the fatigue damage standard for terminal blend asphalt mixtures.The correlation of terminal blend asphalt mixture＇s fatigue performance and three factors which are strain,asphalt content and air void ratio is researched.Terminal blend asphalt mixture AC13＇s fatigue equations is regressed.Regardless of whether the self-healing is considered,when the air voids of mixture is 4%,SBS-AC13 has longer fatigue life than TB-AC13,but TB-AC13 gets better self-healing capability.Regardless of whether the selfhealing is considered,when the air voids of mixture is 4%,the fatigue life of TB＋SBS-AC13 is twice as much as the fatigue life of SBS-AC13,and also TB＋SBS-AC13 gets better self-healing capability than SBS-AC13.The high temperature performance of TB＋SBS-AC13 can far exceed the SBS-AC13.