## 3 Results and Discussion
### Characterization of Fiber-Cement Nanohybrids
#### 3.2.6 Mercury Intrusion Porosimetry (MIP)  
For the fiber-cement pastes based on F.PC60 LS40 PVA3 SP2, only two formulations were tested indicatively via MIP. These were the reference paste itself (F.PC60 LS40 PVA3 SP2) and the 1% nC3 modified paste (F.PC60 LS39 PVA3 SP2+1%nC3), which seemed to be a successful formulation according to the analyses presented above. Both samples were tested at day 28 (Table 5).  
It can be seen that the total pore area, median volume pore diameter, and porosity were increased. This can be attributed to the presence of the fibers and mixing effects. The apparent and bulk density; however, showed small fluctuations.  
Although it is acknowledged that the MIP results are not conclusive, the two formulations were tested indicatively to assist the discussion on the impermeability tests, reinforce the mechanical strength results, and provide suggestions for future research. The increase in pore diameter and porosity can be attributed to the presence of fibers, because separate studies on the _PC60 LS40_ matrix, without the presence of fibers and superplasticizers but with varying amounts of nC3, showed that nC3, possibly because of the better exfoliation and dispersion of the nMt platelets in the bulk of the aqueous dispersion, showed decreased porosity compared with the reference paste [29], in support of the argument that inorganic nMt can act as nucleation point and nanofiller improving the particle packing.  
Further research on the pore structure of nMt and fiber-reinforced nanohybrids could involve the use of other techniques, such as X-ray tomography (CT) scan, to determine the absolute values  
Figure 12: Effect of nMt type (at 1% dosage) on the impermeability of fiber–cement nanohybrids based on F.PC60 LS40 PVA3 SP2.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Mercury Intrusion Data Summary at 28 Days**} & \\ \hline \multirow{2}{*}{**Paste**} & **A**\({}_{\text{Paper-Total}}\) & **F**\({}_{\text{Paper Volume-Med}}\) & **F**\({}_{\text{Paper Area-Med}}\) & **R**\({}_{\text{bulk}}\) & **F**\({}_{\text{Paper-Average}}\) (**mm**) & **R\({}_{\text{Paper-Average}}\) (**mm**) & **Porosity** & **V\({}_{\text{Atom-Level}}\) \\  & **(m\({}^{2}\)/g)** & **(mm)** & **(mm)** & **(g/mL)** & **(g/mL)** & **(g/mL)** & **(\%)** & **(\%)** \\ \multirow{2}{*}{**FPC60 LS40 PVASSP2**} & 45.8 & 76.8 & 5.1 & 1.6 & 18.9 & 2.4 & 34.1 & 50.0 \\  & **FPC60 LS39 PVASSP2+1\%nC3** & 51.2 & 29.1 & 5.5 & 1.7 & 14.1 & 2.5 & 30.6 & 37.0 \\ \hline \multicolumn{8}{c}{Where: **A**\({}_{\text{Paper-Total}}\) = Total pore area, **F**\({}_{\text{Paper Volume-Med}}\) = Median volume pore diameter, **F**\({}_{\text{Paper Area-Med}}\) = Median pore area diameter, **R**\({}_{\text{bulk}}\) = Bulk density, **F**\({}_{\text{Paper-Average}}\) = Average Pore diameter, **R**\({}_{\text{Paper}}\) = Apparent density, **V**\({}_{\text{stem-Used}}\) = Stem Volume Used-} \\ \end{tabular}
\end{table}
Table 5: Mercury intrusion data summary comparison of F.PC60 LS40 PVA3 SP2 and F.PC60 LS39 PVA3 SP2+1%nC3.  
of porosity, pore area, and other parameters. However, it should be noted that, since nc3 showed acceptable density, water permeability, and pore structure performance (along with better flexural strength and thermal properties), further research into applications that necessitate these characteristics, such as pervious concrete pavements [52], could yield interesting results.