OMMT/ZnO复合改性沥青抗老化性能研究及机理分析

On the aging resistance and mechanism analysis of OMMT/ZnO composite modified asphalt

为改善沥青路面在使用过程中存在的老化问题,制备OMMT/ZnO复合改性沥青。借助旋转薄膜老化模拟沥青的短期热氧老化、压力老化模拟沥青的长期热氧老化,通过温度扫描试验研究沥青老化前后的宏观流变性能,利用红外光谱和原子力显微镜探究其内部的化学官能团及表面微观结构特征。试验结果表明:在评价复合改性沥青抗老化性能时,复数模量老化指数与相位角老化指数所反映的规律一致,OMMT/ZnO复合改性沥青可降低复数模量的增加程度和相位角的减小程度。微观试验结果表明:复合材料可减少热氧老化过程中羰基和亚砜基的产生,同时减少“蜂状”结构的破坏,延缓沥青微观结构从多相态向单一相态的转变。

OMMT/ZnO composite modified asphalt was prepared to improve the aging performance of asphalt pavement.The short-term thermal oxidative aging of asphalt was simulated by rotating film aging,and the long-term thermal oxidative aging of asphalt was simulated by pressure aging.The temperature scanning test was used to study the macroscopic rheological properties of asphalt pre-and post-aging.The fourier transform infrared spectroscopy and atomic force microscope were used to study the chemical functional group and microstructure characteristics of asphalt.The experimental result shows that the results of complex modulus aging index and phase angle aging index are consistent when evaluating the aging of composite modified asphalt,the nanocomposites can reduce the increment of complex modulus and the decrement of phase angle.The composite can reduce the formation of carbonyl group and sulfoxide group in the process of thermal oxidative aging.At the same time,it can prevent the destruction of‘bee-like’structure,and delay the transformation of asphalt microstructure from multi-phase state to single phase state.