Diffusion characteristics of aged and virgin asphalt in reclaimed asphalt(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2018年05期
- Page:
- 18-24
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Diffusion characteristics of aged and virgin asphalt in reclaimed asphalt
- Author(s):
- LIU Zhao hui 1; GAO Xinwen 1; 2; ZHAI Long 1; LI Ping 1; LI Oujing1
- Keywords:
- road engineering; reclaimed asphalt; diffusion characteristics; DSR
- PACS:
- -
- DOI:
- -
- Abstract:
- To evaluate the diffusion characteristics of new and old asphalt in recycled asphalt， and to improve the performance of recycled asphalt mixture, twolayer asphalt samples were prepared using aged asphalt and virgin asphalt, and thermal insulation was used for the diffusion of virgin asphalt and old asphalt. Based on this, an evaluation method and index for the diffusion degree of virgin asphalt and old asphalts based on penetration and dynamic shear rheology (DSR) tests were established. Next, the influence of scanning insulation time, insulation temperature, type of aged asphalt, and aging degree on the diffusion degree of new and old asphalt was investigated. Orthogonal test using range analysis and variance analysis method was designed to study the degree and significance of the influence degree of each factor. The results show that under the condition of high temperature storage, the diffusion of new and old asphalt first increases with the insulation time and then becomes constant. The diffusion of asphalt increases with the aging degree. the SBS modified asphalt remains constant. The diffusion of SBS modified asphalt is better than that of asphalt when the aging degree is low， however, the opposite occurs when the aging degree is high. The influence of aging time, holding temperature, and holding time on the diffusion degree of new and old asphalt decreases. The aging time and holding temperature significantly influence the asphalt, but the holding time does not. Under the condition of middle temperature scanning, the diffusion degree increases with the increase of the scanning time and decreases with the increase of the aging degree. Further, the diffusion degree of asphalt is better than that of SBS modified asphalt. Under the condition of new and old asphalt the diffusion degree increases with the increase of temperature, and the optimum increase temperature range of asphalt is higher than that of SBS modified asphalt. Therefore, to improve the diffusion characteristics of asphalt in recycled asphalt mixture, the asphalt aging degree and the asphalt temperature must be considered. 3 tabs, 5 figs, 21 refs.
Last Update: 2018-10-23