## 3 Results and Discussion
### Adsorption/Desorption Isotherms of Activated Dry Mortars (Mix 2, Mix 3 et Mix 4)  
This section present the test results of the samples activated by different activators. These samples are mortars prepared with three types of activators: Na\({}_{2}\)CO\({}_{3}\), Na\({}_{2}\)O\({}_{3}\)Si and CaCl\({}_{2}\). The isothermal curves thus obtained are presented in Figures 5-7. The isotherms relating to the samples with the addition of sodium carbonate activator show a clear difference in the volume adsorbed. As presented in Figure 5, when 5% to 10% Na\({}_{2}\)CO\({}_{3}\) is added, there is a decrease in the volume of N\({}_{2}\) adsorbed from 28 cm\({}^{3}\)/g (Figure 3) to 20 to 23 cm\({}^{3}\)/g, respectively. The increase of 5% of Na\({}_{2}\)CO\({}_{3}\) leads to a slight increase in the adsorbed volume. For the same formulation and implementation, the increase in the w/b ratio from 0.5 to 0.6 leads to a significant increase in the adsorbed N\({}_{2}\) volume. The increase is 12 cm\({}^{3}\)/g for 5% and 10 cm\({}^{3}\)/g for 10% Na\({}_{2}\)CO\({}_{3}\). However, the hysteresis volume seems to be little impacted by the addition. This phenomenon is well-explained in the above Figure 3 for references samples. The \"ink bottle\" effect is more present for samples prepared with a higher amount of water, see Figure 5. \begin{table}
\begin{tabular}{l c c c} \hline  & **BJH Adsorption** & **BJH Desorption** & **Difference** \\  & **Pore Size (\(\mu\)m)** & **Pore Size (\(\mu\)m)** & **(\(\mu\)m)** \\ \hline Mix 1 (E * = 400 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.5 & 0.0198 & 0.0061 & 0.0137 \\ Mix 1 (E = 600 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.5 & 0.0197 & 0.0062 & 0.0135 \\ Mix 1 (E = 800 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.5 & 0.0191 & 0.0060 & 0.0131 \\ Mix 1 (E = 1000 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.5 & 0.0191 & 0.0061 & 0.0130 \\ Mix 1 (E = 400 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.6 & 0.0228 & 0.0079 & 0.0150 \\ Mix 1 (E = 600 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.6 & 0.0206 & 0.0072 & 0.0134 \\ Mix 1 (E = 800 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.6 & 0.0222 & 0.0067 & 0.0146 \\ Mix 1 (E = 1000 kN\(\cdot\)m/m\({}^{3}\)), w/b = 0.6 & 0.0218 & 0.0073 & 0.0145 \\ \hline \end{tabular} Note: * E = compaction energy applied.  
\end{table} 
Table 7: Average pore size. Figure 4: Pore size distribution of reference samples (Mix 1). Figure 5: Adsorption/desorption isotherms of activated samples Mix 2 with two W/B ratios. Figure 6: Adsorption/desorption isotherms of activated samples Mix 3 with two W/B ratios. Figure 7: Adsorption/desorption isotherms of activated samples Mix 4. This mechanism of interaction is a little different for samples activated by sodium metasilicate. When 6% Na2O3 Si is added for the WSA+GGBBS mixture and a w/b = 0.5 to 0.6, then, an increase in N2 adsorbed volume is observed with very little impact on the hysteresis evolution. This indicates that the kinetics of N2 restitution is very close. If we compare the mixtures containing WSA+GGBS with 3% and 6% Na2O3 Si, for the same w/b:0.5 or 0.6 ratio, increasing the concentration of Na2O3 Si leads to a significant decrease in the volume of hysteresis and the volume of adsorbed N2. A 3% addition of Na2O3 Si results in an increase in the volume of the hysteresis compared to the reference mixture Mix 1. Increasing the concentration to 6% leads to a significant decrease in the volume of the hysteresis and the volume of adsorbed N2. This decrease indicates a certain ease of N2 to leave the porous matrix. The amount of adsorbed N2 also decreased drastically. This decrease indicates a decrease in the accessible network volume in the porous matrix. This information is also coherent with the specific surface area values presented in (see Table 8). The specific surface area values decrease with the raise of Na2O3 Si concentration whatever the ratio w/b selected. Figure 7 shows the curves with very little hysteresis obtained for the samples with the addition of calcium chloride as activator for a ratio w/b = 0.5 (Mix 4).