SBS改性沥青高温流变性能与相态结构的关系

为量化表征SBS改性沥青网络化程度,确定控制其高温性能的形态学参数,采用荧光形态学方法、多重应力蠕变回复试验、频率扫描试验分别对5种掺量、6个剪切时间的线型SBS改性沥青在64℃下的荧光数字图像、不可恢复蠕变柔量、频率敏感性进行了定量分析。结果表明:通过增大改性剂掺量、延长剪切时间,SBS改性沥青高温流变性能得到改善。SBS掺量低于5%时,仅靠延长剪切时间无法形成网络结构;相同剪切时间下,增大SBS掺量即可形成网络结构。本文选取图像连通域和面积比率共同描述SBS改性沥青的相态变化特征,并建立了流变指标与形态学参数间的关系模型,为直接利用形态学方法预估、评价改性沥青高温性能提供理论依据。

Relationship between High Temperature Rheological Properties and Morphology Structure of SBS Modified Asphalt

To characterize the network degree and to determine morphology parameters of high temperature performance of SBS modified asphalt,linear SBS modified asphalt was firstly prepared with five contents and different shearing time.Then,fluorescent morphology method,multiple stress creep recovery test and frequency scanning test were used to obtain fluorescence digital image,unrecovered creep compliance and frequency sensitivity at 64℃.Results indicate that high temperature rheological performances are improved sharply by increasing SBS contents and extending the shearing time.However,polymer is unable to form network only by extending shearing time when SBS content is lower than 5％.But polymer network can be formed by increasing SBS contents even with short shearing time.Connected region and area ratio are selected to describe the morphology changing of SBS modified asphalt.Relation formulas of rheology indexes and morphology parameters are given by correlation analysis.It may provide support for high temperature performances evaluation directly by morphology method.