# Testing Concrete for the Construction of Winemaking Tanks
## 4 Conclusions  
The design of self-compacting concrete for the construction of winemaking tanks led to the selection of the optimum mixture that showed sufficient workability, no segregation tendency, and the desired mechanical properties. Due to the fact that this composition contained a percentage of natural pozzolan in replacement of cement to improve the environmental profile of the tank, a series of additional tests were carried out to determine whether the addition of pozzolan affects--and to what extent--the physical, mechanical and chemical properties of the concrete. For this purpose, the optimum mixture was compared with a corresponding reference mixture which had exclusively cement as a binder.  
The study revealed the following:  
* It is possible to manufacture SCC using 20% natural pozzolan as cement replacement and quartz as filler, in order to properly manufacture an oval-shaped tank with the required reinforcements.
* The use of natural pozzolan does not affect negatively the physical and mechanical characteristics of concrete, as well as its resistance to freeze-thaw cycles.
* The required strength class (C20/25) and the desired impermeability to water vapor were achieved, while the thermal characteristics of the concrete were considered satisfactory for the proposed use.
* The leachability test did not show the leaching of significant amounts of heavy metals from concrete into wine, after 30 days of partial immersion. Additionally, calcium and potassium leaching from plain concrete to wine were below the acceptable limits for concrete stability and wine preservation. After the present approach, it would be valuable to test the leachability of calcium and potassium over time, in a context of ongoing research. Furthermore, over time records will validate the present results and the suitability of the tank composition and the coatings effectiveness.  
* The acidity of the wine was influenced by the treatment of the concrete surface and specifically, the composition of the coating.
* The use of pozzolan and silicate aggregates reduced the amount of calcium that can leach into the wine, but surface treatment or the use of an appropriate coating is recommended to further reduce this amount.  
Conceptualization, E.K.A. and A.L.; methodology, E.K.A.; software, A.C.; validation, A.L., E.-C.T. and A.C.; formal analysis, A.C.; investigation, E.-C.T.; resources, A.G.; data curation, A.L. and E.-C.T.; writing--original draft preparation, A.L. and E.-C.T.; writing--review and editing, E.K.A.; visualization, A.C.; supervision, E.K.A.; project administration, E.K.A. and A.G.; funding acquisition, E.K.A. and A.G. All authors have read and agreed to the published version of the manuscript.  
The present work is funded within the framework of the Operational Program \"Central Macedonia\" of the NSRF 2021-2027, Innovation Investment Plans, grant No. KMP6-0071134, and is co-financed by the Greek State and the European Union, and in particular by the European Regional Development Fund (ERDF).  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
Author [PERSON] was employed by the company Gerovassiliou Esstate. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.