Regeneration of aged SBS modified asphalt and its mechanism analysis(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年03期
- Page:
- 1-8
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Regeneration of aged SBS modified asphalt and its mechanism analysis
- Author(s):
- LI Li-han; ZHANG Ming-jie; QI Wen-yang
- 1. Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai 201804, China; 2. Shanghai Road and Bridge (Group) Company Limited, Shanghai 201804, China
- Keywords:
- road engineering; regeneration method; microscopic mechanism; SBS modified asphalt; aged
- PACS:
- U416.217
- DOI:
- -
- Abstract:
- In order to explore the effective regeneration measures of aged SBS modified asphalt, two methods were designed to regenerate three types of aged SBS modified asphalt with different aging degree. The first method was to add regenerant or base asphalt, while the second method was to add regenerant and modified asphalt of SBS type. Penetration, ductility and toughness were adopted to evaluate the regeneration effect. Toughness reflects the crosslinking strength between SBS and base asphalt, namely SBC index. Then microscopic phase structure, infrared spectrum and gel permeation chromatography of asphalt were analyzed to explore the microscopic mechanism of aged asphalt regeneration. The results show that when adding regenerant or base asphalt to aged SBS modified asphalt, the contents of asphaltene and C=O groups decrease, while the contents of gum and light weight fractions increase. Thus the penetration and ductility of aged SBS modified asphalt increase. But the crosslinking strength between SBS and base asphalt can not be recovered, and there is no obvious improvement of toughness. The toughness of slightly aged SBS asphalt even decreases because of the softening effect of regenerant and base asphalt. For severely aged SBS modified asphalt, on the basis of adding regenerant, adding modified asphalt of SBS type, the content of asphaltene and C=O groups decreases further, while the content of gum increases and the content of light weight fractions decreases slightly. Thus the penetration decreases and the ductility increases. The crosslinking strength between SBS and base asphalt also recovers because of the supplement of SBS, and the toughness improves significantly. Compared with adding SBS modified asphalt, when adding high viscosity asphalt, the penetration of regeneration asphalt is smaller, while the ductility and toughness are higher. Therefore，it is not advisable to regenerate slightly aged SBS asphalt by adding too much regenerant or base asphalt. Otherwise, the asphalt will be softened and the crosslinking strength between SBS and base asphalt will be weakened, resulting in the decrease of toughness. In the case of severely aged SBS asphalt, it is advisable to regenerate it by adding regenerant and modified asphalt of SBS type. So that, its penetration, ductility and toughness will be as close as possible to the standard of the original SBS asphalt.
Last Update: 2017-06-05