## 3 Results  
### Results of X-Ray Investigations Obtained for the Sampled Mortars  
X-ray diffraction (XRD) is a non-destructive and versatile analytical technique used for identifying and quantitatively determining various crystalline compounds (attributing crystal structure, classifying within a space group, determining lattice parameters), commonly referred to as phases, which are present in solid materials and powders [34]. For diffraction analysis, the polycrystalline powder is applied to a flat plate fixed on a rotating holder. The incident radiation passes through a slit and reaches the surface of the sample. The diffracted radiation is recorded by a counter, with the counter's impulses being amplified and recorded, thus generating the diffraction spectrum of the analyzed sample [34; 35]. Figure 9 presents the results of the X-ray investigations conducted on the collected mortar samples. The semi-quantitative analysis derived from the X-ray diffraction determinations of the mortar samples is shown in Table 2, while Table 3 lists the crystalline mineral phases identified in the analyzed samples. Figure 8: Material in situ tests: (**a**) brick sclerometry; (**b**) ultrasonic CPP brick tests; (**c**) mortar penetrometry; (**d**) reinforced concrete beam sclerometry; (**e**) mortar shear test; (**f**) concrete floor inspection. Figure 9: _Cont._Figure 9: X-ray diffraction pattern for: (**a**) Sample 1; (**b**) Sample 2a; (**c**) Sample 2b; (**d**) Sample 3; (**e**) Sample 4. \begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Samples** & **Crystalline Phase** & **Abundance** \\ \hline
1 & & & CaCO\({}_{3}\) (Calcite) & ++ \\
2 & & & CaCO\({}_{3}\) (Aragonite) & ++ \\
3 & 1 & & SiO\({}_{2}\) (Quartz) & + \\
4 & & (Na,H\({}_{3}\)O)(Al,Mg,Fe)\({}_{2}\)(Si,Al)\({}_{4}\)O\({}_{10}\)[(OH)\({}_{2}\),(H\({}_{2}\)O)] & - \\ \hline
5 & & & CaCO\({}_{3}\) (Calcite) & ++ \\
6 & 2a & & CaCO\({}_{3}\) (Aragonite) & + \\
7 & & SiO\({}_{2}\) (Quartz) & ++ \\
8 & & (Na,H\({}_{3}\)O)(Al,Mg,Fe)\({}_{2}\)(Si,Al)\({}_{4}\)O\({}_{10}\)[(OH)\({}_{2}\),(H\({}_{2}\)O)] & + \\ \hline
9 & & & CaCO\({}_{3}\) (Calcite) & ++ \\
10 & 2b & & CaCO\({}_{3}\) (Aragonite) & + \\
11 & & SiO\({}_{2}\) (Quartz) & ++ \\
12 & & (Na,H\({}_{3}\)O)(Al,Mg,Fe)\({}_{2}\)(Si,Al)\({}_{4}\)O\({}_{10}\)[(OH)\({}_{2}\),(H\({}_{2}\)O)] & - \\ \hline
13 & & & CaCO\({}_{3}\) (Calcite) & ++ \\
14 & 3 & & CaCO\({}_{3}\) (Aragonite) & + \\
15 & & SiO\({}_{2}\) (Quartz) & + \\
16 & & (Na,H\({}_{3}\)O)(Al,Mg,Fe)\({}_{2}\)(Si,Al)\({}_{4}\)O\({}_{10}\)[(OH)\({}_{2}\),(H\({}_{2}\)O)] & - \\ \hline
17 & & & CaCO\({}_{3}\) (Calcite) & ++ \\
18 & 4 & & CaCO\({}_{3}\) (Aragonite) & - \\
19 & & SiO\({}_{2}\) (Quartz) & ++ \\
20 & & (Na,H\({}_{3}\)O)(Al,Mg,Fe)\({}_{2}\)(Si,Al)\({}_{4}\)O\({}_{10}\)[(OH)\({}_{2}\),(H\({}_{2}\)O)] & + \\ \hline \end{tabular} +++abundant, ++ present, + small amount, - not detectable.  
\end{table} 
Table 2: Semiquantitative XRD analysis of the investigated mortar samples. The results obtained through X-ray diffraction (XRD) revealed the presence of multiple crystalline phases in the collected samples. Specifically, the diffraction peaks corresponded to a mixture of crystalline phases primarily composed of calcium carbonate (CaCO\({}_{3}\)), silicon dioxide (SiO\({}_{2}\)), and other minor phases that were not detectable via X-ray analysis [34]. Consequently, the main diffraction peaks were attributed to calcium carbonate, CaCO\({}_{3}\) (in its polymorphic forms, i.e., calcite and aragonite), silicon dioxide, SiO\({}_{2}\) (quartz), as well as trace amounts of an illitic clay rich in sodium, specifically the compound brammallite ((Na, H\({}_{3}\)O)(Al, Mg, Fe)\({}_{2}\)(Si, Al)\({}_{4}\)O\({}_{10}\)((OH)\({}_{2}\)\(\cdot\)(H\({}_{2}\)O))) [36].