再生剂对沥青分子量和尺寸分布的作用研究

Effects of Rejuvenators on the Molecular Weight and Size Distribution of Asphalt Binders

摘要:

分析了三种不同类型再生剂对三种不同老化沥青的再生作用，以探究再生过程对沥青分子量分布和分子尺寸分布的影响。首先通过分子凝胶色谱，分析了沥青再生前后分子量分布的变化。通过动态流变剪切仪测试获得的沥青再生前后的主曲线，计算得到相应的沥青松弛谱图和分子尺寸分布的变化。最后对沥青分子量分布、沥青分子尺寸分布和沥青物理性质的关联进行了分析讨论。结果表明，再生剂对老化沥青同时存在对大分子的降解作用和稀释作用，且受到老化沥青种类和再生剂种类的影响。沥青再生过程中，再生剂对沥青大尺寸分子的分散效果和沥青的宏观软化效果存在很强的正相关关系。

Abstract:

Abstract: To explore the influence of rejuvenators on the molecular weight distribution and molecular size distribution of aged asphalt binders, the interaction between three rejuvenation agents and three long-term aged asphalt binders was investigated. Gel permeation chromatography was first used to detect the change of molar weight distribution during rejuvenation process. Then the change of molecular size distribution was measured by calculating the relative proportion of the relaxation spectrum, which was derived from the dynamic shear testing of asphalt binders. Results show that the rejuvenators could both dissolve and dilute the large molar weight molecules and large size molecules in aged asphalt binder, and the effects depended on the type of both asphalt binder and rejuvenator. The connection between molecular size distribution and physical properties of asphalt binder indicates that the reduction of asphalt large size molecules has a strong relationship with the rejuvenation performance.