SBS改性沥青老化特性研究

Study on aging characteristics of SBS modified asphalt

为研究SBS改性沥青的老化特性,首先对SBS改性剂在热氧和真空加热条件下分别进行模拟老化,分析不同老化条件下SBS的宏观和微观结构变化,然后通过三大指标、多重应力蠕变恢复试验(MSCR)和红外光谱分析SBS改性沥青的老化特性。结果表明:相较于真空加热,热氧老化后的SBS发生严重的交联反应,失去了其原有的弹性和韧性;同时由其制备的改性沥青也出现改性剂颗粒凝聚现象,且高低温性能均有所下降;从官能团的变化可以看出,热氧老化使沥青中的碳元素以及SBS改性剂中丁二烯的CC键与氧气反应生成含有羰基的酮、醛类物质。综上可得,热氧老化会引起SBS改性剂的降解和特性损失,同时使基质沥青发生氧化硬化,进而对SBS改性沥青的性能产生影响。

In order to study the aging characteristics of SBS modified asphalt,firstly,the SBS modifier was simulated under hot oxygen and vacuum heating conditions,and the macro and microstructure changes of SBS under different aging conditions were analyzed.Then,three indicators and multiple stresses were passed.Creep recovery test(MSCR)and infrared spectroscopy analyze the aging characteristics of SBS modified asphalt.The results show that:compared with vacuum heating,the SBS after thermal oxidative aging undergoes severe cross-linking reaction and loses its original elasticity and toughness;at the same time,the modified asphalt prepared from it also exhibits agglomeration of modifier particles,and the high and low temperature performance has decreased;from the change of functional groups,it can be seen that the carbon element in the asphalt and the CC bond of the butadiene in the SBS modifier react with oxygen to form ketones and aldehydes containing carbonyl groups substance.In summary,thermal oxidative aging will cause degradation of SBS modifiers and loss of characteristics,and at the same time cause oxidative hardening of the base asphalt,which will affect the performance of SBS modified asphalt.