## Materials and Methods
### Methods  
Ten cylindrical specimens (\(\phi\) = 10 cm, h = 20 cm) of each one of the mixtures were made subjecting them to standard curing for 28 days by water immersion. The compaction method used was manual rodding. Compressive strength was evaluated on each mixture on three simple concrete specimens under ASTM C39. Total porosity of each concrete mixture was evaluated on six slices of 10 cm diameter and 5 cm thickness following the ASTM C642 procedure. Three samples of each type of concrete were dried at 100 \({}^{\circ}\)C in a furnace until constant mass was reached, and dry weight (Wdry) was determined. Then samples were water saturated (boiled for 5 h and allowed to cool by natural loss of heat for not less than 14 h to a final temperature of 20 to 25 \({}^{\circ}\)C). After completing the saturation process, samples were weighted in a hydrostatic scale to determine submerged weight (Wsub). Finally, the surface of the samples was dried and saturated weight (Wsat) was determined. Open porosity was calculated by Equation (1).  
\[Total\ P porosity\ (\%)=\frac{\mathrm{Wsat-W_{dry}}}{\mathrm{Wsat-W_{sub}}}*100 \tag{1}\]  
To evaluate other durability parameters such as \(\mathrm{i_{corr}}\) and \(\rho\), a corrugated steel rod was embedded in one cylindrical specimen of each mixture with a 40 cm\({}^{2}\) exposed area in the center. After the curing period and to accelerate the process of corrosion, the specimens were subjected to wet-dry weekly cycles (the specimens were submerged in a 3.5% NaCl aqueous solution for 3 days for the wet cycles and kept for 4 days in an oven at 40 \({}^{\circ}\)C for the dry cycles).  
At the end of the wetting period, the electrochemical tests were carried out in order to determine \(\mathrm{i_{corr}}\) and \(\rho\) using the arrangement shown in Figure 4. An ACM Instruments Field Machine potentiostat-galvanostat series 1525, an Ag/AgCl (silver/silver chloride) reference electrode (RE), a stainless steel auxiliary electrode (AE), and the reinforcement steel acted as the working electrode (WE).  
Figure 4: Experimental arrangement for the electrochemical tests. AE: auxiliary electrode; WE: working electrode; RE: reference electrode.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Material** **(kg/m)**} & \multicolumn{1}{c}{**Identification of the mixtures**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} & \multicolumn{1}{c}{**} \\ \cline{2-10}  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** \\ \cline{2-10}  & **NAT** & **RCA-20** & **RCA-30** & **RCA-60** & **RCA-100** & **RFA-20** & **RFA-30** & **RFA-60** & **RFA-100** & **RA-100** \\ \hline Water & 175 & 175 & 175 & 175 & 175 & 175 & 175 & 175 & 175 & 175 \\ \hline NCA & 1050 & 840 & 735 & 420 & 0 & 1050 & 1050 & 1050 & 0 \\ \hline RCA & 0 & 210 & 315 & 630 & 1050 & 0 & 0 & 0 & 1050 \\ \hline NFA & 700 & 700 & 700 & 700 & 700 & 560 & 490 & 280 & 0 & 0 \\ \hline RFA & 0 & 0 & 0 & 0 & 0 & 140 & 210 & 420 & 700 & 700 \\ \hline PCC & 350 & 350 & 350 & 350 & 350 & 350 & 350 & 350 & 350 & 350 \\ \hline \hline \multicolumn{10}{c}{Aggregates were used in their superficially dried saturated state to avoid altering the w/c ratio.} \\ \hline \hline \end{tabular}
\end{table}
Table 3: Proportion of the test mixtures. PCC: Portland composite cement.