**4. Conclusions**

In this study, the application of FTIR microscopy in ATR mode on RA granulates was evaluated. A specific methodology for the preparation and the analysis of coated granulates was proposed. The samples engineered for this research were suitable for microscopic analysis, and by utilizing characteristic infrared bands, it was possible to trace zones of different composition and intensity.

The conclusions of this research are as follows:


• The ageing index (carbonyls) for the rejuvenated area is lower than the sample areas covered with neat bitumen.

It should be noted that the described method requires an adequate amount of time for the collection of the spectra. Since this study is at a demonstrative stage, the number of samples was rather limited. Based on these results, the application of this technique is promising for future research to quantitatively evaluate the impact of different fabrication methods (mixing time and temperature) in the degree of blending, as well as its application on different and actual asphalt mixture samples.

**Author Contributions:** Conceptualization, A.M. and W.V.d.b.; Data Curation, A.M. and G.T.; Investigation, A.M., G.T. and G.J.; Methodology, A.M. and G.T.; Resources, W.V.d.b.; Supervision, W.V.d.b. and J.B.; Visualization, A.M. and G.J.; Writing—Original Draft, A.M.; Writing—Review and Editing, W.V.d.b., C.V. and S.T.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors would like to acknowledge Patricia Dath and Pieter Ballieu from Holcim, Belgium, for their technical support and for preparation of the samples used in this study.

**Conflicts of Interest:** The authors declare no conflict of interest.
