高黏剂对高黏弹改性沥青宏观性能和微观结构的影响

Effects of High Viscosity Additives on Macroscopic Properties and Microstructure of High Viscoelastic Modified Asphalt

通过常规性能试验、动力黏度试验、弹性恢复试验和Brookfield黏度试验,研究了高黏剂种类和掺量对高黏弹改性沥青宏观性能的影响,利用荧光显微镜探究了改性沥青微观结构变化,评价了自主研发的高黏剂制备的STC-10高黏弹沥青混合料路用性能。结果表明:不同类型高黏剂均能显著降低改性沥青针入度,提高软化点和延度,但对60℃动力黏度和135℃黏度有不同影响。高黏剂掺量提高导致改性沥青中零散的聚合物微粒向网络结构转变,网络结构间出现明显过渡区,对改性沥青高低温性能的增强具有重要作用。STC-10沥青混合料各项性能指标均满足相关规范技术要求,证明高黏弹改性沥青和STC-10级配在超薄罩面中应用具有可行性。研究成果为新型高黏弹改性沥青在同步超薄罩面中的应用提供了科学依据。

The effects of the type and dosage of high viscosity additives on the macroscopic properties of high viscoelastic modified asphalt are studied through the conventional property tests,dynamic viscosity test,elastic recovery test and Brookfield viscosity test.The microstructure of modified asphalt is explored by fluorescence microscope.The pavement performance of STC-10 high viscoelastic asphalt mixture prepared with the self-developed high viscosity additive is evaluated.The results show that the different types of high viscosity additives can significantly reduce the penetration of modified asphalt,and increase the softening point and ductility,but have the different effects on the dynamic viscosity at 60℃and the viscosity at 135℃.The increase of the high viscosity additive dosage leads to the transformation of the scattered polymer particles in the modified asphalt to the network structure,and an obvious transition zone appears between the network structures,which plays an important role in the enhancement of the high-temperature and low-temperature performances of the modified asphalt.All performance indexes of STC-10 asphalt mixture meet the relevant technical requirements,which prove that the application of high viscoelastic modified asphalt and STC-10 grading in ultra-thin overlay is feasible.The research results provide a scientific basis for the application of a new type of high viscoelastic modified asphalt in synchronous ultra-thin overlays.