老化对沥青流变性能和自愈合温度的影响

Effect of Ageing on Rheological Properties and Self-healing Temperature of Asphalt

沥青路面具有一定的微裂纹自愈合能力,但其自愈合能力会受到沥青结合料老化及流变性能变化的影响。采用动态剪切流变仪(Dynamic Shear Rheometer,DSR),对比分析了未老化沥青、短期老化沥青、不同老化程度的长期老化沥青的复合模量、相位角等流变参数以及自愈合温度的差异,研究了老化对沥青流变性能和自愈合温度的影响规律。结果表明:老化使沥青的复合剪切模量增大、相位角减小,沥青变硬、粘性成分减少,流动性下降。短期老化、长期老化、延时长期老化分别使沥青的初始愈合温度增加了8.4℃、20.9℃和28.0℃。

Asphalt pavements have some self-healing capacity for microcracks,but the self-healing capacity is affected by ageing of the asphalt binder and changes in rheological properties.The differences in rheological parameters such as composite shear modulus,phase angle and self-healing temperature of unaged asphalt,short term aged asphalt and long term aged asphalt with different degrees of aging,as well as the self-healing temperature,were comparatively studied using a Dynamic Shear Rheometer(DSR)and the effects of aging on rheological properties of the asphalt and the self-healing temperature were investigated.The results showed that aging increased the composite shear modulus of asphalt,decreased the phase angle,hardened the asphalt,decreased the viscous component,and decreased the fluidity.Short-term aging,long-term aging,and delayed long-term aging increased the initial healing temperature of asphalt by 8.40℃,20.90℃,and 28.00℃,respectively.