学术论文

      沥青内金属离子的水污特征及组分扩散的分子动力学模拟

      Water quality degradation due to metal in asphalt and molecular dynamics simulation on SARA fraction diffusion

      摘要:
      为了研究路面沥青引起的水污染,把沥青膜浸泡在受压的去离子水中,并采用电感耦合等离子体质谱,测试浸泡沥青前后水中10种金属离子的浓度,分析沥青老化、去离子水pH值和浸泡时间对沥青内金属离子浸出的影响.采用分子动力学,分别建立沥青四组分(饱和分、芳香分、胶质、沥青质)和水的分子结构模型,模拟了不同水温、水压、pH值和沥青老化条件下沥青四组分在水中的扩散过程,并计算四组分在水中的扩散系数.结果表明,浸泡沥青后,水中金属离子浓度增大,新鲜沥青和基质沥青的金属污染程度分别高于老化沥青和SBS改性沥青;沥青四组分在水中的扩散系数从小到大排序为:胶质、沥青质、芳香分、饱和分;降低温度和水压,有助于减缓沥青四组分在水中的扩散.
      Abstract:
      In order to study the water quality degradation after the interaction with asphalt film, the thin film leaching tests were carried out using a pressurized device.Ten metals in deionized water before and after the leaching tests were measured by the inductively coupled plasma mass spectrometry (ICP-MS).The effects of asphalt aging, pH value of fresh water, and submersion time on the concentration of ten metal ions leached from asphalt film were investigated.Molecular models of asphalt fractions (saturates, aromatics, resins and asphaltenes (SARA)) and water were developed.The diffusion process of four SARA fractions of asphalt in water was simulated, respectively.The effects of water temperature, pH value, and pressure on diffusion behavior were considered and the diffusion coefficients of SARA components were calculated.Results show that metallic components can be leached from asphalt binder.Compared with aged and SBS modified asphalt, virgin and base asphalt has higher leaching potential for water contamination.The diffusion coefficient of asphalt SARA fractions into water are ranked in the order resins<asphaltenes<saturates<aromatics.Decrease of the temperature and pressure of water can reduce the diffusion of asphalt SARA.
      作者: 陈俊 [1] 殷小晶 [1] 张倩倩 [1] 黄晓明 [2]
      Author: Chen Jun [1] Yin Xiaojing [1] Zhang Qianqian [1] Huang Xiaoming [2]
      作者单位: 河海大学土木与交通学院,南京,210098 东南大学交通学院,南京,210096
      年,卷(期): 2017, 47(4)
      分类号: U414
      在线出版日期: 2017年8月15日
      基金项目: 国家自然科学基金资助项目,中央高校基本科研业务费专项资金资助项目