## 2 Materials and Methods
### Cost Estimation and Application  
The estimated cost of each concrete mixture was calculated to analyse the economic viability of the mixtures designed compared to the controls. The costs of the different mixtures were determined using the values shown in Table 1. As well as the functional capacity and strength of the mixtures, the economic viability was analysed according to the particular manufacturing conditions of the area studied. Moreover, an average cost of EUR 3.5/m\({}^{3}\) was estimated for the recycled aggregate production [37], considering this value  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & & & & & & & & & & & & & & & \\ \hline \multicolumn{12}{c}{Cement (kg/m\({}^{3}\) of concrete)} & 420 & 360 & 360 & 300 & 360 & 360 & 360 & 360 & 360 & 320 & 250 \\ \hline \multirow{12}{*}{Cement} & W\({}_{\text{ef}}\)/C ratio & 0.34 & 0.39 & 0.37 & 0.48 & 0.38 & 0.43 & 0.41 & 0.41 & 0.43 & 0.43 & 0.46 & 0.59 \\  & W\({}_{\text{total}}\)/C ratio & 0.38 & 0.44 & 0.42 & 0.54 & 0.44 & 0.48 & 0.46 & 0.46 & 0.54 & 0.58 & 0.52 & 0.67 \\ \hline \multirow{12}{*}{Cement} & Sand (\%) & 47.8 & 47.8 & 47.8 & 47.8 & 47.8 & 51.9 & 51.9 & 51.9 & 51.9 & 51.9 & 51.9 & 51.9 \\  & Gravel N (4–10) (\%) & 26.1 & 26.1 & 26.1 & 26.1 & 26.1 & 26.4 & 26.4 & 26.4 & 13.2 & – & 26.4 & 26.4 \\  & Gravel N (10–20) (\%) & 26.1 & 26.1 & 26.1 & 26.1 & 26.1 & 21.7 & 21.7 & 21.7 & 10.8 & — & 21.7 & 21.7 \\  & Gravel RCA (4–10) (\%) & – & — & – & – & — & — & — & — & 13.2 & 26.4 & — & — \\  & Gravel RCA (10–20) (\%) & – & — & – & – & — & — & — & — & 10.8 & 21.7 & — & — \\ \hline \multirow{12}{*}{Cement} & \multirow{2}{*}{Accelerator} & (l/m\({}^{3}\) of concrete) & \multirow{2}{*}{0.00} & \multirow{2}{*}{0.00} & \multirow{2}{*}{0.00} & \multirow{2}{*}{0.00} & \multirow{2}{*}{0.94} & \multirow{2}{*}{0.00} & \multirow{2}{*}{1.88} & \multirow{2}{*}{0.91} & \multirow{2}{*}{0.91} & \multirow{2}{*}{0.92} & \multirow{2}{*}{0.94} \\  & & (\%) ** & & & & & & & & & & & \\ \cline{1-1} \cline{5-12}  & \multirow{2}{*}{Plasticiser} & (l/m\({}^{3}\) of concrete) & \multirow{2}{*}{3.00} & \multirow{2}{*}{2.53} & \multirow{2}{*}{2.68} & \multirow{2}{*}{2.07} & \multirow{2}{*}{4.25} & \multirow{2}{*}{2.99} & \multirow{2}{*}{2.99} & \multirow{2}{*}{2.99} & \multirow{2}{*}{2.92} & \multirow{2}{*}{2.92} & \multirow{2}{*}  
as the costs exclusively necessary for converting the waste from the concrete production waiting to be converted into recycled aggregates.  
The estimated average cost for the waste management is significantly lower than the previously referenced EUR 10/t, since the management of the materials at the location significantly reduces costs, e.g., costs of transport or dumping taxes.  
As the application of the economic results, three different hypotheses were analysed for different mix combinations on a real concrete structure model. These analyses compare the actual manufacturing mixtures with two combinations of the new proposed mixtures according to the required functionality conditions for each structural element. In this case, we analysed an industrial building model with an 890 m\({}^{2}\) surface and 10 m pillar height of the typology shown in Figure 2.  
Thus, the pre-casting structure was formed by supports and wall panels of reinforced concrete together with roof beams, main beams and ceiling panels of pre-stressed concrete. The measurements of the items and the concrete strength (_f_.) of each element type are shown in the Results (Section 3.4).