## 4 Results and Discussion
In the next stage, for each bitumen, the fractions of maltene and asphaltene extracted using the mentioned procedure were analyzed. Thereafter, each fraction was dissolved in CCl4 and the \({}^{1}\)H-NMR spectrum was recorded for the provided samples. The \({}^{1}\)H-NMR spectra of Maltene and Asphaltene fractions are reported respectively in Figures 4b, 5b and 6b and in Figures 4c, 5c and 6c, while, in Table 4, fractional proton distributions of each samples are reported. Observing the results of \({}^{1}\)H-NMR analysis (Table 4), it is evident, as expected, that a higher percentage of aromatic hydrogen is present in the asphaltene fractions for all samples. Comparing the results for the asphaltene fractions, extracted from the three bitumens, it can be noted that the samples from the two bitumens with the same grade present a similar distribution of aromatic and aliphatic hydrogens (\(\approx\)19% and \(\approx\)81%, respectively), while the distribution of aliphatic hydrogen type is rather different. On the contrary, asphaltenes extracted from the paving bitumen (70/100) were characterized by a lower percentage of aromatic hydrogens. These data seem to point to a similar chemical composition for the asphaltene samples obtained from the two bitumen with the same degree of penetration and a different chemical composition for the asphaltene deriving from the paving bitumen (70/100). Figure 4: The \({}^{1}\)H-NMR spectra of Paving 70/100 bitumen in CCl4: (**a**) neat bitumen; (**b**) maltene fraction; and (**c**) asphaltene fraction. Moreover, the NMR data on the maltene fraction extracted from the two bitumens with high penetration show almost equal distribution of aromatic and aliphatic hydrogens, while the maltene sample from the paving bitumen 70/100 presents a lower aromatic percentage if compared to the other samples (4.49% vs. \(\approx\)7%). The results obtained on maltene and asphaltene fractions provided a better understanding of bitumens detailed characteristics needed for developing methods to improve their properties. For example, adding suitable substances, it will be possible to increase or decrease the aromatic percentage that could be the key to modulate the viscosity of bitumen. Considering the bitumen complex system, the resins (intermediate polarity compounds) play a crucial role in the mechanical properties and in general on the bitumen performance properties [26]. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Bitumen**} & \multicolumn{3}{c}{**Hydroogen Distribution of Maltenes \(\pm\)0.05**} & \multicolumn{3}{c}{**Hydroogen Distribution of Asphaltenes \(\pm\)0.05**} \\ \cline{2-9}  & \(\mathbf{H_{\pi}}\) & \(\mathbf{H_{\alpha}}\) & \(\mathbf{H_{\beta}}\) & \(\mathbf{H_{\gamma}}\) & \(\mathbf{H_{\pi}}\) & \(\mathbf{H_{\alpha}}\) & \(\mathbf{H_{\beta}}\) & \(\mathbf{H_{\gamma}}\) \\ \hline Paving 70/100 & 4.49 & 12.34 & 64.01 & 19.16 & 14.25 & 15.75 & 61.80 & 8.19 \\ Paving 160/220 & 7.43 & 11.77 & 60.55 & 20.24 & 18.30 & 16.77 & 55.47 & 9.31 \\ Industrial 160/220 & 7.54 & 11.61 & 61.00 & 19.86 & 19.58 & 8.19 & 60.79 & 11.44 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Fractional proton distribution of the maltene and asphaltene fractions obtained from the \({}^{1}\)H-NMR spectra reported in Figure 4b,c, Figure 5b,c and Figure 6b,c. Figure 5: The \({}^{1}\)H-NMR spectra of Paving 160/220 bitumen in CCl\({}_{4}\): (**a**) neat bitumen; (**b**) maltene fraction; and (**c**) asphaltene fraction. As mentioned earlier, for understanding the needed additives/modifiers to alter the characteristics of bitumens for specific uses, it is required to fractionate the bitumen with a preparative TLC and to analyze the obtained zones by NMR. The recognized three zones included: the C zone (on the top) should contain the apolar parts, i.e., the maltenes; the B zone is where the molecules with medium polarity are present; and the A zone, the lower spot, includes highly polar molecules. The B zone and A zone together should count for all the asphaltenes present in the sample.