沥青流变性能研究

Study on the Rheological Properties of Asphalt

通过应力扫描、温度扫描两种控制模式下的流变试验对70#基质沥青、SBS改性沥青流变性能进行研究分析,结果表明:应力扫描试验中,70#基质沥青流变指标随应力变化存在平稳阶段和屈服阶段,在平稳阶段中沥青处于线性粘弹区间,屈服阶段复数模量G*减小,相位角增大,抵抗塑性变形能力逐渐丧失;而SBS改性沥青G*先增大后减小,相位角增大,流变指标始终处于不稳定状态,整体上存在屈服变化趋势。温度扫描试验中,70#基质沥青G*随温度递减,相位角增大,表明沥青弹性成份比例在减小,抵抗变形能力变弱;试验温度35℃后,老化20 h的基质沥青相位角变化平缓,说明经过模拟长期老化后沥青在高温段的温度敏感性严重降低;老化后SBS改性沥青在10~35℃相位角逐渐增大,而在35~60℃相位角变化趋于平缓,可见SBS改性剂在温度较高状态时沥青内部结构变得稳定,高温性能具有显著的优势。

In this paper,the rheological property of 70#matrix asphalt and SBS modified asphalt are study and analysis by rheological test under two kinds of control mode,which is stress sweep and temperature sweep.The results show that in stress scanning experiment,the rheological index of 70#asphalt matrix change with stress,exist stationary phase and yield stage.In stationary phase asphalt is in the linear viscoelastic range.In yield stage,complex modulus G*reduce and phase angle increases,losing ability to resist plastic deformation.However,the G*of SBS modified asphalt first increases and then decreases,and the phase angle increases.The rheological index is always in an unstable state,and exist a yielding overall variation trend.In the temperature scanning test,the complex modulus G*of 70#matrix asphalt decrease as temperature decreasing,while phase angle increasing,indicating that the elastic components proportion of asphalt decreases and the resistance to deformation becomes weaker during the temperature increase.After 20 hours aging and the temperature up to 35℃,the phase angle of matrix asphalt change smooth,which indicate the temperature sensitivity seriously decrease after simulate aging for a long time.After aged,the phase angle of SBS modified asphalt increase at 10~35℃,and the phase angle tend to be smoother at 35~60℃.It can be seen that SBS modifier makes the asphalt internal structure become stable at a higher temperature,and has a significant advantage in high temperature performance.