改性沥青及混合料流变学性能研究

Experimental Study on Rheological Properties of Modified Asphalt and Mixture

利用扫描电子显微镜(SEM)、动态剪切流变试验(DSR)、小梁弯曲蠕变试验及三轴压缩蠕变试验,分别从微观和宏观角度对比研究了胶粉改性沥青(CR)和SBS改性沥青及其混合料的微观结构、高温及低温对其流变性能的影响。SEM试验结果表明,橡胶粉及SBS改性剂都能与沥青达到良好共融,但在沥青混合料中胶粉改性沥青与石料界面的粘结性要优于SBS改性沥青;DSR试验结果表明,CR具有更好的温度稳定性、低温抗裂能力和高温抗变形能力;小梁弯曲蠕变试验在-15、0、15、30,45℃5种温度下对比研究了配合比相同的2种沥青混合料,得到不同温度下的弯曲蠕变速率对比曲线,试验结果表明,CR混合料比SBS改性沥青混合料具有更好的高、低温性能;此外,还进行了45℃下2种沥青混合料的三轴压缩蠕变试验,证明CR沥青混合料具有更好的抗高温变形特性。

The scanning electron microscope （ SEM）, dynamic shear rheological test （ DSR）, tra- becular bending creep and triaxial compression creep were used to observe CR,SBS modified asphalt and mixture. Effect of the microstructure,high and low temperature on rheological properties of the modified asphalt were analysed though these test. SEM show that rubber powder and SBS modifier has good fusion with asphalt, but interface bonding between aggregate and asphalt in CR mixture is better. The result of DSR show that CR has better temperature stability,low temperature deformation ability and high tempera- ture performance. The rheological properites of two asphalt mixture with same mix component is studied by trabecular bending creep test at - 15.0.15.30 and 45 ℃. The correlation curve of bending creep rate is obtained. It is proved, CR miature has better high and low temperature properites compare to SBS modified asphalt mixture. Moreover, triaxial compression creep test is carried on for two asphalt mixture at 45℃. We can see CR mixture has better resistance to high temperature deformation performance.