STUDY ON NANOSCALE IMAGING OF BITUMEN USING AFM-IR

Abstract

 With the increasing use of reclaimed asphalt pavements, including polymer modified bitumen, and repeated recycling of asphalt mixtures, the composition and aging state of bitumen after using has been more complex. In order to maintain preferable pavements and continue recycling, it is necessary to clarify the mechanisms of bitumen aging and recycling. This study attempted analysis using AFM-IR, which can measure both physical and chemical properties at nanoscale at the same coordinates on the sample surface, to microscopically analyze the homogeneity, compatibility, colloidal state, etc. of four mixes from bitumen and rejuvenators. The results demonstrated that the wrinkled structure like bees in the bitumen can be captured and confirmed how this structure changes due to aging and the components of the rejuvenator. We also observed the distribution of carbonyl groups, which are an indicator of aging, in the bitumen microstructure and their increase with aging by AFM-IR.