## 5 Environmental Analysis of GERO Perforated Brick with Olive Stone Doped Mortar
### Environmental Results  
#### 5.2.1 Production Results 1 m\({}^{2}\) of Facade  
Figure 8 shows the results obtained for the E-LCA from the cradle to the door of the production of 1 m\({}^{2}\) of facade and its implementation in a building. The m\({}^{2}\) of the facade is composed of two layers of GERO bricks. The fine aggregate is replaced by a vegetable and residual aggregate such as ground olive stones. The results are assessed for the eight impact categories of the EPD methodology. As can be seen, as the percentage of olive stones is increased as a substitute for fine aggregate in the mortar, the environmental impacts increase. This is evident in all impact categories except water scarcity. In this category, an inverse behavior is observed, i.e., the greater the amount of olive stone material, the lower the impact. It is justified since the production of natural aggregates involves the use of large quantities of water, used for internal washing processes, to avoid dust production in quarries, filtering, etc. Therefore, reducing the amount of natural aggregate to be used in the mix reduces the associated water consumption. The alternatives with a doping percentage of 15% represent a 7.98% reduction in water consumption, which is equivalent to a saving of 0.61 m\({}^{3}\) of water per square meter of facade. In the global warming potential category, there is an increase in CO\({}_{2}\) emissions of 4.68% in the case of a 15% doping, which is equivalent to emitting a value of 0.8 kg CO\({}_{2}\)/m\({}^{2}\) of facade. These increases are a direct consequence of the higher consumption of energy and resources to dope the mortar with ground olive stones. In impact categories directly linked to the production of natural aggregates such as acidification, eutrophication and photochemical oxidation, there are increases of 29.13%, 30.28% and 21.56%, respectively, \begin{table}
\begin{tabular}{c c} \hline \hline
**Impact Categories** & **Unit** \\ \hline Acidification & kg CO\({}_{2}\) eq \\ Eutrophication & kg PO\({}_{4}\) eq \\ Global warming potential (GWP) & kg CO\({}_{2}\) eq \\ Photochemical oxidation & kg NMVOC \\ Abiotic depletion, elements & kg Sb eq \\ Abiotic depletion, fossil fuels (ADFF) & MJ \\ Water scarcity & m\({}^{3}\) eq \\ Ozone layer depletion & kg CFC-11 eq \\ \hline \hline \end{tabular}
\end{table} 
Table 14: Impact indicators in the environmental product declaration (EPD) methodology. between the reference alternative and the 15% maximum doping alternative. The justification is due to the fact that the olive stone preparation process requires a certain amount of energy and material consumption (crushing process, transport), the impacts of which are greater than the amount of natural aggregate that prevents it from occurring. The transport process is crucial for the viability of recycled aggregates over natural aggregates. The transportation process generates a series of substances such as nitrogen oxides (NOx) and carbon oxides (COx), as well as the emission of solid particles that affect the ozone layer [59]. This is revealed in the results obtained in the ozone layer depletion category. For example, the alternative with a doping percentage of 15% represents an increase of 8.90%. The transport processes also have a major impact on the abiotic depletion of fossil fuels (ADFF) category. The result was an increase of 8.19% between the 15% doping option and the reference option, equivalent to a value of 6.90 MJ for each square meter of facade to be built. In general, it is shown that the use of olive stones in mortar products to be used in building facades produces greater environmental impacts than the use of undoped mortars. However, there are small percentage increases of less than 10% in certain impact categories such as GWP 4.68%, abiotic depletion of elements 6.00%, ADFF 8.19% and ozone layer depletion 8.90%. In other categories, the increase in impact is significant and exceeds 20%, as we have seen above.