基于纳米材料的应用理念,采用纳米二氧化钛(TiO₂)粉体对2种标号的石油沥青进行了改性研究,采用常规路用检测方法、短期热老化(TFO)、紫外光老化方法和流变测试手段,对纳米TiO₂改性沥青进行了评价。研究结果表明,以纳米TiO₂为改性剂,以70号、90号沥青为基础沥青,制得纳米TiO₂改性沥青-70、纳米TiO₂改性沥青-90。在纳米TiO₂用量为3.5%(wt,质量分数)条件下,制得的纳米TiO₂改性沥青-70、纳米TiO₂改性沥青-90的针入度分别为60.0/0.1mm、79.0/0.1mm,软化点分别为48.1℃、45.7℃,60℃黏度分别为362Pa·s、208Pa·s,在紫外老化5h,疲劳时间分别达到620s、672s。从路用性能规定的常规指标来看,纳米TiO₂改性效果远比普通矿粉填料效果突出,提高了沥青的耐疲劳性能和耐热老化性能,提高了沥青的抗紫外老化能力;与聚合物改性沥青相比,纳米TiO₂对沥青高温性能提升幅度有限,对改性沥青的延展性有消极影响。

Based on the application concept of nano-materials,two kinds of petroleum asphalt were modified by nano-titanium dioxide (TiO₂) powder.The modified asphalt was evaluated by conventional road testing method,short-term thermal aging (TFO),ultraviolet aging method and rheological testing method.Nano-TiO₂ modified asphalt-70 and nano-TiO₂ modified asphalt-90 were prepared by using nano-TiO₂ as modifier and 70 and 90 asphalt as base asphalt.When the content of nano-TiO₂ was 3.5% (mass fraction),the penetration of asphalt-70 and asphalt-90 were 60.0/0.1mm and 79.0/0.1mm respectively,the softening point were 48.1℃ and 45.7℃ respectively,the viscosity at 60℃ were 362Pa·s and 208Pa·s respectively,and the fatigue time reached 620s and 672s respectively after 5h of ultraviolet aging.According to the conventional index of pavement performance,the effect of nano-TiO₂ modification was much more outstanding than that of ordinary mineral powder filler,and it can improve the fatigue resistance and heat aging resistance of asphalt,and improved the anti-ultraviolet aging ability of asphalt.But compared with polymer modified asphalt,nano-TiO₂ had a limited improvement in high temperature performance of asphalt,and had a negative impact on the ductility of modified asphalt.