**4. Conclusions**

The research methodology followed and the results of the tests, as well as the discussions held, reflect a series of partial conclusions that will lead to the final conclusion. In turn, it should be mentioned that the initial hypothesis was the aptitude of electric arc furnace slag, ladle furnace slag and cellulose fibers from the papermaking industry for the conformation of Stone Mastic Asphalt type bituminous mixtures. The partial conclusions obtained are described below:


Based on the partial conclusions derived from the methodology presented in this investigation and according to the tests carried out, it can be stated that the incorporation of electric arc furnace slag, ladle furnace slag and cellulose fibers from the paper industry, creates Stone Mastic Asphalt type bituminous mixtures with a higher percentage of bitumen, greater Marshall stability, better behavior towards permanents deformations and with a similar content of voids or deformations. The quality of these materials is therefore assured for use in bituminous mixtures dedicated to roads for important traffic. It is important to highlight the importance of using unused waste to conformed materials, not only of similar but superior quality, as it reduces their disposal in landfills and avoids the extraction of new raw materials.

**Author Contributions:** Conceptualization, F.A.C.-I., F.J.I.-G., J.M.T.-S. and J.S.-M.; methodology, F.A.C.-I., F.J.I.-G., J.M.T.-S. and J.S.-M.; software, J.M.T.-S. and J.S.-M.; validation, F.A.C.-I. and F.J.I.-G.; formal analysis, F.A.C.-I. and F.J.I.-G.; investigation, J.M.T.-S. and J.S.-M.; resources, F.A.C.-I.; data curation, F.J.I.-G.; writing—original draft preparation, J.S.-M.; writing—review and editing, J.M.T.-S.; visualization, J.M.T.-S.; supervision, F.A.C.-I.; project administration, J.S.-M.; funding acquisition, F.A.C.-I. All authors have read and agreed to the published version of the manuscript.

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

**Acknowledgments:** Technical and human support provided by CICT of Universidad de Jaén (UJA, MINECO, Junta de Andalucía, FEDER) is gratefully acknowledged.

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