**5. Conclusions**

All in all, these preliminary results confirm that the addition of shredded CFs as stabilizing fibers for bituminous mixture could be a feasible application.

However, it is worth noting that in this exploratory study, the CFs were simply shredded and directly added to the mixture in a total substitution of commercial fibers. This could represent a simple way to re-use this waste, which can be easily reproduced on an industrial scale.

Nevertheless, the obtained promising results highlighted some downsides that might be exceeded with a proper CFs treatment that could make this material much more similar to the common stabilizing fibers or could mean that it gives an even better performance. In fact, the presence of limited quantities of plug wrap paper and tipping paper after the CF shredding are probably responsible for the lower cohesion properties of the experimental SMA, if compared to the reference one.

Following the positive outcomes of this preliminary experimental application, in the development of this research project, the use of waste cigarette butts will be investigated.

**Author Contributions:** Conceptualization, P.T.; methodology, P.T. and C.S.; validation, C.S.; formal analysis, P.T.; investigation, P.T.; data curation, P.T.; writing—original draft preparation, P.T.; writing— review and editing, P.T. and C.S.; supervision, C.S. All authors have read and agreed to the published version of the manuscript.

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

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