## 3 Results and Discussion
### Water Behaviour  
Table 5 reports the mean values of the capillary water absorption coefficient (CC), the asymptotic values (Abs. ), and the drying rates (D\({}_{1}\) and D\({}_{2}\)) for each mortar type at 28, 90, and 180 days. In Figures 9 and 10, the capillary water absorption and desorption curves of the mortars at 90 days are presented. As shown in Table 5 and Figure 9, it is possible to observe that all mortar compositions have a high rate of water absorption in comparison with the results obtained in the original mortars of the Fort (capillary water absorption coefficient between 0.4 and 1.7 kg/m\({}^{2}\cdot\)min\({}^{1/2}\)[6]), which can make them more vulnerable to degradation. Nevertheless, in some mortar compositions, the capillary water absorption coefficient tends to decrease with the curing time due to the progression of carbonation. In general, the highest values of water absorption were observed in mortars with the addition of NS (A+NS), in agreement to the increase in the porosity (Table 4). However, the drying occurs faster than for the other mortars (high drying rates D\({}_{1}\) and D\({}_{2}\)). Contrarily, the lime mortar with quicklime (A+Q) and the natural hydraulic lime mortar (NHL) showed the lowest capillary water absorption coefficients and induced lower  
Figure 8: Mechanical properties of the A+Q30% and C:A mortars with substituting part of the siliceous sand by limestone aggregate. values of water absorption, attributed to the slight decrease in porosity and probably due to the main volume of pores being slightly shifted towards smaller diameters in the capillary range, in comparison with the other mortars, which have a significant influence on the transport processes of water [54]. Figure 9: Capillary water absorption curves of the mortars with siliceous sand at 90 days: (**a**) water absorption; (**b**) water desorption. Figure 10: Capillary water absorption curves of the mortars with fine-tuning of the aggregate, at 90 days: (**a**) water absorption; (**b**) water desorption. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Capillarity**} & \multicolumn{3}{c}{**Water Absorbed**} & \multicolumn{3}{c}{**Drying Rates**} \\ \cline{2-13}
**Mortar** & \multicolumn{3}{c}{**Coefficient**} & \multicolumn{3}{c}{**Water Absorbed**} & \multicolumn{3}{c}{**Drying Rates**} \\ \cline{2-13}
**Identification** & \multicolumn{3}{c}{**CC (kg/m\({}^{2}\cdot\)min\({}^{1/2}\))**} & \multicolumn{3}{c}{**Abs (kg/m\({}^{2}\))**} & \multicolumn{3}{c}{**D\({}_{\mathbf{1}}\) (kg/m\({}^{2}\cdot\)h)**} & \multicolumn{3}{c}{**D\({}_{\mathbf{2}}\) (kg/m\({}^{2}\cdot\)h \({}^{1/2}\))**} \\ \cline{2-13}  & **28d** & **9  
Despite the results of the drying rates being very heterogeneous, in general, the NHL mortar also shows the lowest drying rates, which means that the drying also occurs slower. On the other hand, regarding the mortars with quicklime (A+Q), the results generally show that the first drying phase (D\({}_{1}\)) occurs slower and the relative high values of the second drying rate (D\({}_{2}\)) indicates higher water vapour diffusion. The low D\({}_{1}\) and high D\({}_{2}\) may indicate a predominance of small capillary pores that slow down the first phase of desabsorption and thus increases the mechanical strengths (Figure 4b). The fine-tuning of the aggregate substituting part of the siliceous sand by limestone aggregate (Table 5 and Figure 10) decreases in general, as expected, the rate of water absorption of the two mortars and the drying also occurs slower, related to the filer effect, where the voids in the siliceous sand are filled by the calcareous sand. This effect could increase the volume of capillary porosity and lead to a reduction in the main pore diameter. Nonetheless, even though the porosity variations were relatively low, namely with M\({}_{2}\) and M\({}_{3}\) substitutions in A+Q mortars, a slight increase in the total water absorption was observed, namely at early ages.