| 摘要: |
| 采用动态剪切流变（DSR）、弯曲梁流变（BBR）试验，研究了再生剂对老化沥青高温抗车辙和低温抗开裂能力的影响，并以红外光谱（FTIR）和原子力显微镜（AFM）研究了原样、老化和再生沥青的官能团组成及微观结构.结果表明：再生剂能增强老化沥青的低温抗开裂能力，但同时会降低其高温抗车辙能力；再生剂A主要成分为富含芳烃的轻质组分，而再生剂B是包含多种极性官能团的复杂混合物,可与老化沥青发生化学反应，使老化沥青某些特定官能团的吸收峰强度降低；沥青老化后极性成分聚集受阻，加入再生剂可增强沥青分子运动能力，促进极性成分聚集，使蜂状结构尺寸变大、数量减小，面积比例和高度增大，这些微观结构的改变可能是沥青老化和再生过程中流变性能发生变化的内在原因. |
| 关键词: 沥青 老化 再生剂 流变性质 红外光谱 微观结构 |
| DOI：103969/j.issn1007 9629201806021 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(51668038)；长江学者和创新团队发展计划滚动资助项目(IRT_15R29)；甘肃省自然科学基金资助项目(1606RJZA042) |
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| Effects of Rejuvenators on Rheological Properties and Microstructures of Aged Asphalt |
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LI Xiaomin, WEI Dingbang, YAO Zhijie, LI Bo
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Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China
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| Abstract: |
| Rheological properties, including high temperature rutting resistance and low temperature cracking resistance, of virgin, aged and rejuvenated asphalts were investigated by dynamic shear rheometer(DSR) and blending beam rheometer(BBR). Afterward, asphalt functional groups and microstructures of virgin, aged and rejuvenated asphalts were analyzed by means of Fourier transform infrared spectroscopy(FTIR) and atomic force microscopy(AFM) techniques. Results clearly demonstrate that rejuvenator could soften aged asphalt and improve its low temperature cracking resistance. Rejuvenator A is mainly composed of light components which are rich in aromatics, while rejuvenator B is found to be a complex organic mixture containing many polar functional groups. Moreover, rejuvenator B is able to chemically restore aged asphalt, however, there is just physically mixing between rejuvenator B and aged asphalt. There may be an interaction between aged asphalt and rejuvenator B, which depresses the vibrations of some specific functional groups of aged asphalt. Meanwhile, the aggregation of polar components after aging can be mitigated. After the addition of rejuvenator, the diffusion ability of molecules is enhanced, and the aggregation of polar components is stimulated, so bee structures grow larger and the number of microstructures decreases, the area ratio and height of bee structure are improved as well. The changes of these microstructures may be the intrinsic reasons for the change of rheological properties in the process of asphalt aging and regeneration. |
| Key words: asphalt aging rejuvenator rheological property Fourier transform infrared spectroscopy microstructure |
