Study the diffusion characteristics of rejuvenator oil in aged asphalt binder by image thresholding and GC-MS tracer analysis

The objective of this study was to establish a fast and visible detecting methods to characterize the diffusion process of rejuvenator oil in aged asphalt binder. Contact angle of oil droplets on aged asphalt binder surface, interface image threshold analysis and GC-MS oil tracer analysis were proposed to characterize the diffusion between oil and aged asphalt binder. Results approved that gray value differential and statistical results from interface image threshold analysis can be successfully used to characterize the diffusion behavior. By applying interface image threshold analysis and oil tracer analysis, the diffusion between rejuvenator and aged asphalt binder can be visible and accurately studied. GC-MS were found to be useful for monitoring diffusion. Representative compounds in oil and in asphalt binder can be well traced during its diffusion process. The gravity influence the diffusion process in the top-down diffusion direction of rejuvenator applications, while surface tension, oil-water partition coefficient of compounds have remarkable influence on the diffusion characteristics. (C) 2020 Elsevier Ltd. All rights reserved.