布敦岩沥青灰分胶浆动态流变性能和微细观特性

Dynamic Rheological Properties and Microscopic Characteristics of Ash Mastics

摘要:

将布敦岩沥青（BRA）中的矿物质（灰分）提取出来，与基质沥青拌合制备灰分胶浆（粉胶质量比=0.8∶1）.采用动态剪切流变性能试验、X衍射分析以及扫描电子显微分析技术，研究胶浆的动态流变特性以及灰分、矿粉物质的微细观特性.结果表明：灰分胶浆的高温流变性能比矿粉胶浆要好，抗变形能力更强，性能高温等级为76 ℃；灰分胶浆和矿粉胶浆的动态力学温度谱、频率谱具有一定的相似性；灰分物质表面存在较多的凸起和凹陷结构，外表呈蓬松的鳞片状，纵向起伏较大，微尺度振幅达到0.35 μm，比表面积远大于矿粉.其发达的孔隙和沟纹结构，可以增加结构沥青的膜厚度，使得水分子难以破坏沥青集料界面，增强填料对沥青的吸附作用，提高沥青与集料的黏结强度.

Abstract:

Ash components were extracted from button rock asphalt，which mixed with the pure asphalt with the mass proportion of ash and asphalt as 0.8∶1. The dynamic shear rheological tests，Xray diffraction analysis techniques and the scanning electron microscopy were applied to the study of the rheological properties of ash and mineral filler mastics, and microscopic characteristics of ash and mineral filler. The results show that ash mastics has a better high temperature rheological properties than filler mastics, with the high temperature grade up to PG76 ℃. However, the two mastics have a similar trend for the changes of performance when the temperature and the frequency increase. There are some protrusions and depressions structure in ash material with a fluffy scalelike surface. The vertical micro scale amplitude reaches 0.35 μm and the specific surface area is much larger than that of the mineral filler. A welldeveloped porosity and ditch grain structure can enhance the adsorption of filler for asphalt, and the bond strength of asphalt and aggregate improves. The film thickness of the structure of asphalt increases, which prevents the water molecules from damaging the asphaltaggregate interface.