为了研究沥青混合料在宽频范围内的动态粘弹性能,采用AR-2000型动态剪切流变仪对不同空隙率沥青混合料进行动态频率扫描,得到了复数剪切模量和相位角等粘弹参数。根据时温等效原理,得到了复数剪切模量、相位角随频率变化的主曲线,同时分析了频率、沥青种类、温度和空隙率对沥青混合料粘弹性能的影响;基于主曲线采用CAM模型拟合分析了不同空隙率沥青混合料试件的粘弹性能。结果表明:频率与温度对不同空隙率沥青混合料粘弹性能的影响规律相同;沥青混合料相位角主曲线在中高温时欠光滑;沥青混合料粘弹性能对空隙率有较强的依赖性;应用CAM模型可以较好地分析不同空隙率沥青混合料的粘弹性能,为沥青混合料设计和性能评价提供参考。
In order to study the dynamic viscoelastic performance of asphalt mixtures with different void contents in the width-frequency range,a dynamic shearing rheometer AR-2000 was applied to dynamic frequency sweeping for asphalt mixtures with different void contents,and some viscoelastic parameters,such as complex shear module and phase angle etc.were obtained.Based on time-temperature superposition principle,the master curve on complex shear module and phase angle changing with the frequency respectively was obtained and the influences of frequency,type of asphalt,temperature and air void content on the viscoelastic performance of asphalt mixtures were analyzed.Then,Christensen-Anderson-Marasteanu(CAM) model was used to analyze and compare the rheological performances of asphalt mixtures with different void contents based on the obtained master curves.The results show that the frequency and the temperature have the same influence on the viscoelastic performances of asphalt mixtures with different void contents and the phase angle master curves of mixtures are not continuous or smooth at middle and high temperature.Meanwhile,the viscoelastic performances of asphalt mixtures have strong dependency on void content;the CAM model can be used to analyze the viscoelastic performances of asphalt mixtures with different void contents and can provide the reference for design and performance evaluation of asphalt mixtures.