老化时间对SBS改性剂与沥青胶结料官能团的影响

Effect of Aging Time on SBS Modifier and Asphalt Functional Groups

为探究基质沥青、苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene butadiene styrene,SBS)改性剂与其改性沥青的官能团随老化时间变化趋势,分析其老化方式,采用傅里叶变换红外光谱(fourier transform infrared spectroscopy,FTIR)和弯曲梁流变(bending beam rheometer,BBR)试验,对老化0、1、5、8、24、48、72 h条件下的2种沥青胶结料进行低温性能试验,并与SBS改性剂进行官能团分析,建立2种沥青胶结料官能团与其低温性能之间的关系。结果表明:SBS改性剂的老化是由聚丁二烯和聚苯乙烯的共同作用导致的,其老化方式主要是以烯烃和烷烃发生降解为主;基质沥青和改性沥青老化方式均是轻质油份挥发并与空气中氧气发生交联反应。SBS改性剂与其改性沥青在特征红外吸收峰处变化趋势不同,因此仅采用SBS改性剂特征红外吸收峰变化趋势不足以反映其改性沥青的特征峰变化。2种沥青胶结料的羰基指数与蠕变柔量导数指标存在良好的线性相关,可反映沥青低温变形能力。

To investigate the trend of functional groups of matrix asphalt,styrene butadiene styrene(SBS)modifiers,and their modified asphalt with aging time,and to analyze their aging modes.Using Fourier transform infrared spectroscopy(FTIR)and bending beam rheometer(BBR)tests,low-temperature performance tests were conducted on two types of asphalt binders aged for 0,1,5,8,24,48,72 h.Functional group analysis was conducted with SBS modifier to establish the relationship between the functional groups of the two asphalt binders and their low-temperature performance.The results show that SBS modifier aging are contributed by polybutadiene and polystyrene,the SBS modifier aging mode is degraded mainly alkene and alkane in the thermal oxidation process.Two kinds of asphalt binders aging mode are volatilized light oil and reacted with oxygen to form a cross-linked.The trend of SBS modifier at the characteristic peaks in infrared absorption spectra is different and independent of its modified asphalt.Two kinds of asphalt binders carbonyl index is correlative with creep compliance derivative,and low-temperature deformation capacity of asphalt binder is reflected by carbonyl index.