## Materials and Methods
### Methods
#### 2.2.2 Analytical Testing  
Characterization of nMt  
The characterization of the powder nC4 followed the methodology presented in literature [19], nc4 was, therefore, characterized in terms of basal spacing via X-ray diffraction (XRD), in terms of shape, size, and basal spacing via transmission electron microscopy (TEM) and elemental composition via scanning electron microscopy/ X-ray energy dispersive spectroscopy (SEM/EDX). The thermal properties of nC4 were examined via thermal gravimetric analyses (TGA). In greater detail:  
X-ray Diffraction: XRD measurements were performed using a D8 ADVANCE X-ray diffractometer with CuK\(\alpha\) radiation. Spectra were obtained in the range \(4^{\circ}<2\theta<20^{\circ}\) at an angular step-size of \(0.016^{\circ}\)\(2\theta\). The state and extent of dispersion-exfoliation of the NMt can be examined by XRD and TEM analysis with monitoring changes in basal spacing [19]. Transmission Electron Microscopy (TEM): Suspension of 10 ng/mL was prepared using nC4 and distilled water. Small drops of the diluted solutions were then deposited on copper mesh grids coated with a thin carbon film. Grids were dried at 25 \({}^{\circ}\)C prior to the insertion in the instrument. Samples were examined at a voltage of 120 kV with a GATAN Jeol JEM 1200 mkII. Images were recorded on a Gatan Dual View camera. As explained in [19], when a polycrystalline structure, with randomly oriented grains, forming rings is detected, having the camera constant known, the calculation of the lattice spacing is allowed according to the following adapted formula [39]:  
\[\frac{\mathrm{r}}{2\mathrm{L}}=\frac{\lambda}{d}\to d=\frac{2\lambda \mathrm{L}}{\mathrm{r}} \tag{2}\]  
where \(L\): the camera length and \(\lambda\): the electron wavelength, which are independent of the specimen and constant for the TEM instrument and \(d=d\)-value and \(r=\) distance from the diffraction center. Since \(d\) is inversely proportional to \(r\), the largest \(d\) value is obtained by the innermost ring. For the specific TEM diffraction analysis, \(\lambda L=1\). These results can be compared with \(d\) value measured by XRD. The only variable measured with the help of the TEM software was \(r\), manually taken to be equal to the distance between the center of the diffraction and the center of each individual ring. As an effect, greater error is expected when comparing TEM and XRD \(d\)-value measurements. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample** & **PC (\%)** & **LS (\%)** & **nMt (\%solids)** & **SP (\%)** & **PVA fibres (\%)** & **W/S** \\ \hline
**FPC60 LS40 PVA3 SP2+0\%nC** & 60 & 40 & 0 & 2 & 3 & 0.3 \\
**FPC60 LS39 PVA3 SP2+1\%nC2** & 60 & 39 & 1 & 2 & 3 & 0.3 \\
**FPC60 LS39 PVA3 SP2+1\%nC3** & 60 & 39 & 1 & 2 & 3 & 0.3 \\
**FPC60 LS39 PVA3 SP2+1\%nC4** & 60 & 39 & 1 & 2 & 3 & 0.3 \\ \hline \hline \end{tabular} Where, PC stands for Portland cement, LS for limestone, nMt for nanomontmorillonite, SP for superplasticizer, PVA for Polyvinyl alcohol and W/S for water to solids ratio.  
\end{table} 
Table 2: Composition of ternary fiber cement nanohybrids—proportions % by total mass of solids. Scanning electron microscopy/ X-ray energy dispersive spectroscopy (SEM/EDX): For SEM/EDX elemental composition analyses nC4 was placed uncoated on a sheet of molybdenum, an element absent from the LnS dispersions for unbiased elemental analyses. A matrix of \(5\times 5\) spectra was acquired and the median of the elemental composition was presented. The Si/Al ratio was also calculated. Thermal gravimetric analyses (TGA) and derivative thermogravimetry (dTG) were carried out using a Setaram TGA92 instrument. Approximately 20 mg of nC4 were placed in an alumina crucible and heated at a rate of 10 \({}^{\circ}\)C/min from 20 to 1000 \({}^{\circ}\)C under 100 mL/min flow of inert nitrogen gas. The differential thermogravimetric curve (DTG) was derived by the TG curve.