Feature analysis on performance and molecular structure of asphalt under coupling aging conditions(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年05期
- Page:
- 8-14
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Feature analysis on performance and molecular structure of asphalt under coupling aging conditions
- Author(s):
- HE Zhao-yi; CHEN Long; RAN Long-fei; WANG Xiao-dong
- 1. School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, China; 2. Chongqing Highway Quality Inspection Center, Chongqing 400060, China; 3. School of Material Science and Engineering, Chongqing Jiaotong University, Chongqing 400074, China
- Keywords:
- road engineering; aging condition; degree of association; asphalt performance; molecular structure
- PACS:
- U411
- DOI:
- -
- Abstract:
- In order to establish the correlation between the conventional macro-performance and the micro-molecular structure of asphalt under coupling aging conditions, the conventional macro-performances of matrix asphalt and SBS modified asphalt under different aging conditions were tested respectively by penetration, ductility, softening point and viscosity test, and the micro-molecular structure of asphalt under different aging conditions were tested by Fourier transform infrared spectroscopy (FTIR) and H-nuclear magnetic resonance spectroscopy(H-NMR). Finally, the grey system theory method was used to calculate the degree of association between conventional macro-performances and micro-molecular structure of asphalt under coupling aging conditions, and model formula was given. The results show that with the increase of aging degree and aging time, each conventional macro-performance of asphalt gradually deteriorates. Carbonyl index and sulfoxide index gradually increases, and chemical bonds breaking and oxidation addition reaction occur in the asphalt. Butadiene index gradually decreases, and —C=C— of SBS modifier gradually degrades. Additionally, aromatic rings of linear SBS modified asphalt undergo isomerization dealkylation, matrix asphalt and star-type SBS modified asphalt occur dehydrogenation and condensation reaction first and then isomerization dealkylation. Structure alienation happens to the aliphatic region of matrix asphalt and SBS modified asphalt. Length of aliphatic side of matrix asphalt gradually decreases, and star-type SBS modified asphalt increases, while linear-type SBS modified asphalt decreases first and then increases. Based on the analysis results of conventional macro-performances, micro-molecular structure and grey correlation degree between them, SBS modifier could significantly improve the aging resistance of asphalt and different types of SBS modifier are pretty on the effect of improving aging resistance of asphalt. Under coupling aging conditions, the changes of micro-molecular structure have the most significant relation to the softening point of matrix asphalt, the softening point, penetration and 5 ℃ ductility of SBS modified asphalt. It is feasible to predict the change rule of micro-molecular structure of asphalt by conventional macro-performance index.
Last Update: 2017-10-16