微波胶粉改性沥青的热老化性能

Research on Thermal Aging Properties of Microwave Crumb Rubber Modified Asphalt

设计不同时间及温度条件对微波胶粉改性沥青进行老化试验,通过沥青三大指标及动态剪切流变试验,分析了微波胶粉改性沥青在热氧老化作用下性能的变化,并建立热老化动力学方程以揭示微波胶粉改性沥青在老化作用下的性能变化规律。研究结果表明:微波胶粉改性沥青在热氧老化作用下,其内部轻质组分大量逸出,同时部分转变为沥青质等重质组分,沥青变得脆硬,高温抗变形能力提高,而温度和时间的提高均会促进沥青老化程度的加深;微波胶粉改性沥青老化过程中仍存在强烈的胶粉溶胀与降解反应,两种作用共同促进了微波胶粉改性沥青180℃特殊的流变性;采用软化点作为老化参数建立的老化动力学方程能够准确模拟微波胶粉改性沥青的老化进程。

Two aging factors such as temperature and time are designed measurementsfor combination to age the MCRMA.A serious of tests including the dynamic shear test and three indexe measurements of asphalt were employed to analyze the properties of aged MCRMA.Through establishing aging kinetic equation,the characteristic of aging of MCRMA were revealed.The results show that the MCRMA of aging is brittleness due to the escape of light components of asphalt and the conversion of heavy components such as resin and asphaltene,by which the performance of deformation resistance of asphalt is increased.The aging temperature and time could accelerate the process of aging.There still exist strong swelling and degradation reaction of rubber powder during the aging process of asphalt,in which the rheological properties of asphalt at 180℃is changed by two kinds of action.The aging kinetics equation with softening point as the aging parameters can well simulate the MCRMA's actual aging process.