考虑紫外辐射的交互老化对SBR 改性沥青流变性能的影响及其老化机理

考虑到紫外老化对丁苯橡胶SBR改性沥青性能的影响,分别采用2种交互老化方式(方式一:SBR改性沥青+旋转薄膜烘箱老化RTFOT+加压加速老化PAV+紫外老化UV;方式二:SBR改性沥青+RTFOT+UV+PAV)制备老化沥青,并对老化后5种沥青进行动态剪切流变试验DSR、蠕变劲度试验BBR、差示扫描量热试验DSC以及IR红外光谱分析。结果表明,经短期老化后的SBR改性沥青分别经历UV和PAV老化后的流变性能比较接近,但进一步分别经历PAV和UV老化后,其流变性能和老化程度变化显著,UV对于沥青的老化作用是非常明显的;不同老化顺序的交互老化结果也大不相同;相较于老化方式一,老化方式二对SBR改性沥青流变性能影响更显著;PAV和UV老化有着各自不同的老化机理,SBR改性沥青经历交互老化的实验结果正是这2种不同老化机理叠加的具体体现。

Effect of interactive aging considering ultraviolet on rheological properties of SBR modified asphalt and analysis of the aging mechanism

Considering the influence of ultraviolet aging on the properties of SBR modified asphalt, two interactive aging methods (1. SBR modified asphalt +RTFOT+PAV+UV; 2. SBR modified asphalt +RTFOT+ UV+PAV) were used to prepare aged asphalt, and the five kinds of aged asphalt were tested by DSR, BBR, DSC differential heat test and IR spectroscopy. The results showed that the rheological properties of SBR modified asphalt after short-term aging were similar to that after UV aging and PAV aging respectively. However, the rheological properties and aging degree of SBR modified asphalt after further aging were significantly changed after PAV aging and UV aging respectively, and UV aging effect on asphalt was very obvious. The interactive aging results of different aging sequences were also quite different. Compared with the first aging mode, the second one had a more significant effect on the rheological properties of SBR modified asphalt. PAV and UV aging have different aging mechanisms respectively, and the experimental results of SBR modified asphalt undergoing interactive aging were the concrete embodiment of the superposition of these two different aging mechanisms.