高掺量胶粉-SBS复合改性沥青的高温流变性能

High temperature rheological properties of high content rubber-SBS composite modified asphalt

为了研究高掺量胶粉-SBS复合改性对基质沥青高温流变性能的影响,以高掺量胶粉-SBS复合改性沥青为主要研究对象,首先通过三大指标和布氏旋转黏度研究了高掺量胶粉-SBS复合改性沥青性能随胶粉掺量变化而变化的趋势;然后设计了6种试验方案,采用动态剪切流变仪探究了6种沥青的高温流变性能,并进行了比较详细的对比性研究。结果表明:高掺量胶粉-SBS复合改性沥青的高低温性能随着胶粉掺量的增加而增大,在胶粉掺量为42%时,可以同时满足良好的性能与施工要求;在高温流变性能试验中,与单一改性沥青相比,复合改性沥青的复数剪切模量(G*)、车辙因子(G*/sin(δ))、蠕变恢复率(R)得到明显提高,相位角(δ)和不可恢复蠕变柔量(Jnr)有一定程度的降低,具有更强的弹性性能、高温抗车辙能力、变形恢复能力和抗变形能力;随着胶粉掺量从21%增加到42%,胶粉-SBS复合改性沥青的弹性成分随之增多,变形恢复能力与抗变形能力更强,高温流变性能更好。

In order to study the effects of composite modification by high content rubber powder-SBS on the high-temperature rheological properties of matrix asphalt,the trend of the performance of high content crumb rubber-SBS composite modified asphalt with the change of crumb rubber content was studied firstly by three indexes and Brookfield rotational viscosity.Subsequently,six test schemes were designed and the high temperature rheological properties of six kinds of asphalt were explored by dynamic shear rheometer,based on which a detailed comparative study was carried out.The results show that the high and low temperature performance of high content crumb rubber-SBS composite modified asphalt increases with the increase of crumb rubber content.When the content of crumb rubber is 42%,good performance and satisfaction of construction requirements can be achieved simultaneously.In the high temperature rheological property test,compared with the single modified asphalt,the complex shear modulus(G*),rutting factor(G*/sin(δ))and creep recovery rate(R)of the matrix asphalt are significantly improved by the composite modification,and the phase angle(δ)and irrecoverable flexibility(Jnr)are reduced.Meanwhile,stronger elastic properties,high temperature rutting resistance,deformation recovery ability,and deformation resistance are obtained.In addition,with the increase of rubber powder content from 21%to 42%,the elastic components of rubber powder-SBS composite modified asphalt also increase,the deformation recovery ability and deformation resistance are stronger,and the high temperature rheological properties are improved.