微观尺度下浇筑式沥青混合料超热老化机理

摘要

In order to reveal the epithermal aging mechanism of Gussasphalt from microcosmic perspective,real-time scanning on change rule of molecular groups and light components of Gussasphalt modified asphalt was conducted by Fourier transform infrared spectroscopy(FTIR) and thermal gravimetric analysis (TG) at different epithermal temperature.The impact of volatilization and oxidation on the aging of the modified asphalt at epithermal temperature was investigated.The results show that volatilization at epithermal temperature has a great impact on epithermal aging,which also runs through the whole aging process.At the same time,the acting time of oxidation in asphalt aging process is determined by oxygen concentration.Oxidation acts in preliminary process and volatilization of light components acts mainly in late process under high oxygen concentration.%为了揭示浇筑式沥青混合料超热老化机理,采用傅里叶红外光谱法(FTIR)和热失重法(TG)实时追踪扫描了微观尺度下浇筑式沥青不同超热温度下分子基团以及轻质组分的变化规律,分析了超热温度下挥发和氧化对改性沥青老化的影响进程.结果表明:在超热温度下,挥发对浇筑式沥青混合料老化所起的作用明显,并且一直贯穿整个超热老化过程,而氧气浓度决定了氧化在其整个老化过程中的作用时间,在高氧气浓度下,氧化主要发生在老化前期,而老化后期轻质组分的挥发起主导作用.