老化时间对SBS改性剂与沥青胶结料官能团的影响

采用傅里叶变换红外光谱(FTIR)和弯曲梁流变(BBR)试验,对老化0h、1h、5h、8h、24h、48h和72h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,探究基质沥青、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,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应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。

Effect of aging time on SBS modifier and asphalt functional groups

Low-temperature performance of two kinds of asphalt binders after aging time of 0, 1, 5, 8, 24, 48, 72hours were tested by bending beam rheometer testing techniques. Asphalt, SBS modifier and its modified asphalt aging mode and the trends of functional groups along with aging time were tested by fourier transform infrared spectroscopy, and correlation were established between low-temperature performance and functional groups of two kinds of asphalt binders. 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.