高黏度沥青黏度的评价方法与评价指标  

Evaluation Method and Indicator for Viscosity of High-Viscosity Asphalt

作　　者：李立寒[1] 耿韩[1] 孙艳娜[1] 

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海200092

出　　处：《建筑材料学报》2010年第3期352-356,362,共6页Journal of Building Materials

基　　金：住房和城乡建设部2008年科学技术项目(2008-R2-24)

摘　　要：对高黏度改性沥青、SBS改性沥青以及A-70基质沥青进行真空减压毛细管试验和动态剪切速率扫描试验,得到沥青的毛细管黏度和零剪切黏度.基于2种黏度试验的试验原理以及沥青在路面结构中受力状态的分析,对比2种黏度试验中沥青所受的剪切速率水平及其与路面结构中沥青所受剪切速率水平之间的关系.结果表明:对于黏度大于3×104Pa.s的高黏度沥青,零剪切黏度所对应的第一牛顿流区范围的剪切速率与沥青在路面结构中所受的剪切速率水平一致,零剪切黏度可以较为合理地表征高黏度沥青在路面结构中的黏结特性;而高黏度沥青在毛细管试验中的剪切速率过小,毛细管黏度不宜用于评价高黏度沥青材料的黏度特性.OGFC-13沥青混合料的飞散试验结果验证了上述分析结果.建议采用动态剪切速率扫描试验方法并以零剪切黏度指标来评价高黏度沥青的黏度特性.Capillary viscosity and zero shear viscosity of high-viscosity modified asphalt,SBS modified asphalt and base asphalt were determined by vacuum capillary viscometer test and dynamic shear rate scanning test.Based on the test principles of two viscosity tests and stress condition of asphalt in asphalt pavement,the relation between the shear rate level in two viscosity tests and the shear rate level imposed on asphalt in road construction was established.The test results show that for asphalt with viscosity of above 3×10~4 Pa·s,the shear rate in first Newtonian region where the viscosity reaches the zero shear viscosity（agrees） with the shear rate imposed on asphalt in road construction.Therefore,the zero shear viscosity can reasonably reflect the viscosity characteristics of high-viscosity asphalt in road construction;however,the shear rate in vacuum capillary viscometer test is so slow that capillary viscosity can not be used to evaluate viscosity characteristics of high-viscosity asphalt.Besides,scattering loss test of OGFC-13 asphalt mixture supports the conclusion.Finally,the dynamic shear rate scanning test and zero shear viscosity are suggested to evaluate viscosity characteristics of high-viscosity asphalt.

关 键 词：指标 沥青 高黏度 剪切速率 毛细管黏度 零剪切黏度 Carreau模型 飞散试验 

分 类 号：U414[交通运输工程—道路与铁道工程]