SBS含量对沥青老化性能的影响

为提高苯乙烯-丁二烯-苯乙烯（SBS)改性沥青的路用性能，延长路面使用寿命，通过物理指标试验、流变测试、傅里叶红外光谱法和凝胶色谱法（GPC）对比分析不同含量SBS改性沥青老化前后的性能差异，探究SBS含量对沥青老化性能的影响. 结果表明：短期老化后，随着SBS含量的增加，沥青粘度和复数模量增大，针入度减小，延度迅速下降，沥青显示出脆性；改性剂发生降解，GPC图谱中改性沥青SBS特征峰峰面积均有所减小；改性沥青的红外光谱图在1696cm^-1（C=O伸缩振动）处出现新的特征吸收峰. 长期老化后，改性沥青中大分子物质几乎完全降解，SBS特征峰均消失；红外光谱图中1696cm^-1处吸收峰强度加强，丁二烯指数（BI）减小一半；随着SBS含量的增加，羰基指数和亚砜基指数变化不大，而BI指数持续增加,并与SBS含量呈现良好的线性关系.

Influence of SBS content on asphalt aging performance

In order to improve the road performance of styrene-butandiene-styrene(SBS) modified asphalt and prolong the service life of the pavement. This paper compared and analyzed the performance of different contents of SBS-modified asphalt before and after aging through various tests (such as physical index test,rheological test,Fourier infrared spectroscopy and gel chromatography (GPC)),and explored the influence of SBS content on the aging performance of asphalt. The results show that after short-term aging,with the increase of SBS content,the viscosity and complex modulus of the asphalt increased,the penetration degree decreased,and the ductility dropped rapidly,and the asphalt exhibited brittleness. The modifier degraded,and the peak area of the modified asphalt SBS characteristic peak in gel permeation chromatography decreased. The infrared spectrum of the modified asphalt showed a new characteristic peak at 1696cm^-1 (C=O stretching vibration). After long-term aging,the macromolecular substances of the modified asphalt were almost completely degraded,and the SBS characteristic peaks disappeared. The intensity of the absorption peak at 1696cm^-1 in the infrared spectrum increased and butadiene index (BI) decreased by half. With the increase of SBS content,carbonyl and sulfonyl indexes changed little,while BI index increased continuously and showed a good linear relationship with SBS content.