# The Use of Volcanic Powder as a Cement Replacement for the Development of Sustainable Mortars
## 4 Conclusions  
The main conclusions to be drawn from the previously discussed results can be summarized as follows:  
* In all the mortars studied, the pore structure was probably refined as the curing days increased due to the progressive development of clinker hydration and the pozzolanic reactions of the VP;
* Compared to the CEM I mortar, in the mortars with VP a greater refinement of the microstructure was observed, which could be due to the formation of additional solid phases, a result of the pozzolanic reactions of the VP;
* The findings of the non-destructive impedance spectroscopy technique were generally compatible with those obtained with mercury intrusion porosimetry. It is possible to use impedance spectroscopy as a way to follow the development of the pore network in the mortars that incorporate VP as clinker replacement;
* The addition of VP, up to 20% of the binder, allowed the durability-related properties of the mortars to be improved. These improvements could be linked to the more refined microstructure produced by the pozzolanic activity of VP;
* The addition of 10% volcanic powder did not present losses in the compressive strength of the mortars, fulfilling the compressive strength requirements of the corresponding standard;
* From the results obtained in this study, it has been noted that the mortars that incorporate 10% or 20% VP as a clinker replacement showed good service properties at high hardening times (400'days), even exceeding the properties of the CEM I control mortars;
* From an environmental point of view, the proposed material is attractive since it makes use of VP, in this way, avoiding or reducing the harmful effects in the short term that VP could produce in the natural soil on which it is deposited. In addition, the potential of this replacement was shown to reduce the total greenhouse gas emissionsup to 18.66%, when 20% of CEM I is replaced by VP;
* Volcanic powder as a raw material reduces the energy costs related to mortar production, which in addition to reducing CO\({}_{2}\) emissions, could also reduce costs. However, this must be proven in future studies. Conceptualization, V.L., J.M.O., M.A.C and I.S. ; Data curation, J.M.O., R.M.T., I.F., T.R.-H., G.M. and M.A.C; Formal analysis, V.L., J.M.O., R.M.T., B.I.H.-J., I.F., T.R.-H. and M.A.C; Funding acquisition, V.L., J.M.O. and M.A.C; Investigation, V.L., J.M.O., R.M.T., B.I.H.-J., I.F., T.R.-H. and G.M. ; Methodology, V.L., J.M.O.,  
Figure 18: Results of total greenhouse gas emissions (GHG\({}_{\text{tot}}\)) associated with the mortars studied. R.M.T., T.R.-H., M.A.C. and I.S. ; Supervision, J.M.O., M.A.C. and I.S. ; Writing - original draft, V.L. and R.M.T. ; Writing - review and editing, J.M.O. The results included in this paper regarding the effects at initial hardening ages of volcanic powder addition in the studied mortars are part of the work developed along a research stay of [PERSON] at the University of Alicante, under the supervision of [PERSON], [PERSON] and [PERSON]. The results included in this paper related to the influence in the short- and long-term of the abovementioned addition, have been obtained in the PhD thesis carried out by [PERSON] at University of Alicante (Spain), under the supervision of [PERSON] and [PERSON]. All authors have read and agree to the published version of the manuscript. This research was funded by the Universidad de La Frontera (Chile) (grant code DI19-0019, project entitled \"Desarrollo de una dosificacion de morteros con baja conductividad termica para utilizen en prefabricados\"), by the Conselleria de Educacion, Investigacion, Cultura y Deporte (at present renamed as Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital) de la Generalitat Valenciana (Spain) (grant code GV/2019/070), by the Spanish Agencia Estatal de Investigacion (grant code BIA2016-80982-R) and by the European Regional Development Fund (grant code BIA2016-80982-R). Authors wish to thank Cementos Portland Valderrivas S.A. for providing the ordinary Portland cement used in this study.