多尺度纳米材料对再生沥青长期老化性能的影响

Effect of Multi-dimensional Nanomaterials on Long-term Aging Properties of Recycled Asphalt

研究了由不同掺量有机蛭石(OEVMT)和纳米氧化锌(Nano-ZnO)组成的多尺度纳米材料对再生沥青长期热氧和光氧老化性能的影响。利用薄膜烘箱对普通基质沥青进行老化以制得老化沥青,采用熔融共混方法,先将老化沥青、普通基质沥青以及再生剂按照一定的比例混合以制得再生沥青,再将多尺度纳米材料加入到再生沥青中制得多尺度纳米材料改性再生沥青。采用压力老化箱老化(PAV)和加速紫外光老化(UV)分别模拟再生沥青的长期热氧老化和光氧老化条件。通过传统物理性能试验和动态剪切流变试验评价了再生沥青的老化性能。结果表明:添加多尺度纳米材料提高了再生沥青老化前的高温稳定性、剪切变形抵抗力和弹性行为,但一定程度上削弱了其低温塑性变形能力;多尺度纳米材料有效改善了再生沥青长期热氧和光氧老化抵抗力;综合考虑长期老化性能数据,多尺度纳米材料的推荐掺量(质量分数)为1%OEVMT+3%Nano-ZnO。

The effect of multi-dimensional nanomaterials made up of organic expanded vermiculite （OEVMT） and nano-zinc oxide （Nano-ZnO） on the long-term aging properties of recycled asphalt was investigated. Thin film oven was utilized to age base asphalt for preparing aged asphalt. The aged asphalt, base asphalt and rejuvenating agents were blended to obtain recycled asphalt according to special proportion by using melt blending method, then the multi-dimensional nanomaterials were added into the recycled asphalt for preparing multi-dimensional nanomaterials modified recycled asphalt. The long-term thermal-oxidative and photo-oxidative aging were simulated by pressure aging vessel （PAV） and ultraviolet （UV） aging, respectively. The conventional physical tests and dynamic shear rheological test were used to evaluate the aging properties of all binders. The results show that the addition of multi-dimensional nanomaterials can enhance the high temperature stability, shear deformation resistance and elastic behavior of recycled asphalt before aging while weaken the low temperature plastic deformation ability in some degree. As a result of PAV and UV aging, both long-term thermal-oxidative and UV aging resistance of recycled asphalt can be enhanced significantly by introducing multi-dimensionalnanomaterials. Moreover, the recommended ratio （mass fraction） of multi-dimensional nanomaterials in recycled asphalt is confirmed as 1%OEVMT＋3 %Nano-ZnO.