Abstract: The 12-molecule model of the aged asphalt was established based on analyzing the functional groups changes in the aging process of asphalt by ATR-FTIR. Two kinds of aging asphalt-regenerant molecular dynamics models were constructed by adding steroids and carboxylic acids. The radial distribution function of asphaltene centroids at different temperatures was calculated, and then its aggregation behavior was investigated. The results show that the aggregation degree of asphaltene molecules decreases with the increment of temperature. Both rejuvenators exhibit better deagglomeration performance at ordinary temperature, and the performance of steroid is better than that of carboxylic acid. The deagglomeration effect is weakened at high temperature. And the optimal dosage of both two rejuvenators is 10% at ordinary temperature.

Key words: highway engineering; aged asphalt; molecular dynamics; rejuvenator; molecular aggregation

摘要： 采用傅里叶红外光谱(ATR-FTIR)试验分析了沥青老化过程中的官能团变化，建立了老化沥青12分子模型；加入类固醇和羧酸构建两种老化沥青-再生剂分子动力学模型，计算了不同温度下沥青质的质心径向分布函数(radial distribution function)，进而研究其聚集行为。研究结果表明：随着温度升高，沥青质分子的聚集程度逐渐降低；两种生物再生剂在低温下加剧了沥青质聚集，常温下均具有较好的解聚集效果，且类固醇性能优于羧酸，高温条件下其解聚集效果减弱；两种再生剂在常温下的最佳掺量均为10%。

关键词: 道路工程；老化沥青；分子动力学；再生剂；分子聚集