基于动态老化过程的沥青抗老化性能对比研究

旨在运用动态表征模型评价沥青的老化过程,并采用多指标评价方法对比不同沥青的优劣。对4种沥青进行不同时间的RTFOT老化试验,采用动态表征模型拟合,得到沥青针入度、延度、软化点和粘度的老化参数和老化方程；采用灰色关联决策评价方法,以沥青针入度、延度、软化点和粘度的老化参数L和r为评价指标,综合对比不同沥青的抗老化性能。研究结果表明：沥青针入度、软化点、延度和粘度与老化时间存在非线性关系,在开始时刻,老化速率大,后期随着时间的推移,老化速率趋于缓慢,最后达到平衡；沥青的老化过程可用动态模型表征,参数L和r能很好地表征沥青老化过程的老化度和老化速率,不同沥青的不同指标的老化参数排序不一致；采用灰色关联决策评价四种沥青的抗老化性能排序为：室内制备改性沥青优于90号A级基质沥青优于成品改性沥青优于70号A级基质沥青。

Comparative Study on Anti-aging Performance of Asphalt Based on Dynamic Aging Process

The purpose of this paper is to use dynamic characterization model to evaluate the dynamic process of asphalt aging and compare the pros and cons of different asphalt. First, the RTFOT aging tests at different aging time for four kinds of asphalt are carried out and the aging test data are fitted with dynamic characterization model. As a result, the aging parameters and aging equation of penetration, ductility, softening point and viscosity of different asphalt are determined. Then, grey relational evaluation method is used to evaluate the anti-aging performance of different asphalt, which setting the aging parameters L and r of penetration, ductility, softening point and viscosity as the evaluation indexes. The results show that: the aging rate of penetration, softening point, ductility of asphalt reaches the peak at the beginning and becomes smaller as the variation of aging time and balances at last; The aging process of asphalt can be described accurately by dynamic characterization mode and parameters L and r can be a good characterization of aging degree and aging rate; The sort of anti-aging properties of the four asphalt is determined as following: the indoor modified asphalt is better than matrix 90 asphalt and better than SBS modified asphalt and better than matrix 70 asphalt.