SBS改性沥青短期老化规律与机理研究

Study on the Rule and Mechanism of Short-Term Aging of SBS Modified Asphalt

为研究不同SBS掺量下改性沥青短期老化规律,以四组分差异显著的两种典型基质沥青为研究对象,分别掺加不同嵌段比和掺量的SBS改性剂,研究不同老化时长后三大指标变化规律;为分析SBS改性沥青短期老化机理,采用荧光显微镜对比分析了SBS改性沥青原样和短期老化荧光图像,并用Image-Pro-Plus图像分析软件对荧光图像进行统计分析,定量分析了SBS相平均粒径和体积占比;同时对不同老化程度的试样进行了红外光谱测试。研究表明:改性沥青的老化过程中,存在沥青老化和聚合物降解两种作用,短期老化后,SBS相平均粒径减小、体积占比大大减小;改性沥青短期老化不同时长,SBS含量、SBS降解和沥青老化三种因素综合作用决定软化点升降规律;随着沥青老化程度不断加深,羰基和亚砜基含量增加,含氧基团的数量增加;饱和分含量高的基质沥青制备的改性沥青延度稳定性不足,基质沥青中芳香分含量直接影响改性沥青软化点的变化规律;在制作SBS改性沥青应注重选型合适的基质沥青和SBS掺量。研究结论可为SBS改性沥青制作和使用提供参考和借鉴。In order to study the short-term aging law of modified asphalt with different SBS content, two typical base asphalt with significant differences in four components were taken as the research object, and the change law of three indexes after different aging time was studied by adding different block ratio and different SBS modifier. In order to analyze the short-term aging mechanism of SBS modified asphalt, fluorescence microscopy was used to compare the original and short-term aging fluorescence images of SBS modified asphalt, and image-Pro-Plus Image analysis software was used for statistical analysis of the fluorescence images, and the average particle size and volume proportion of SBS phase were quantitatively analyzed. The results show that there are two effects of asphalt aging and polymer degradation in the aging process of modified asphalt. After short-term aging, the mean particle size and volume proportion of SBS phase decreased greatly. Different duration of short-term aging of modified asphalt, SBS content, SBS degradation and asphalt aging of three factors determine the softening point rise and fall rule. The saturated content of the matrix asphalt is high, and the stability of the modified asphalt ductility is insufficient. The content of carbonyl and sulfoxide groups and the number of oxygen-containing groups increase with the increasing of asphalt aging degree. The aromatic content of base asphalt directly affects the softening point of modified asphalt. In the production of SBS modified asphalt, attention should be paid to the selection of appropriate base asphalt and SBS content. The research results can provide reference for the production and use of SBS modified asphalt.