## 3 Results
### Relationships between Asphalt Binder Performance and Carbonyl and Sulfoxide Indices  
The measurements of high-temperature stiffness (\(\mathrm{G^{*}/sin(\delta)}\)), non-recovery compliance (\(\mathrm{J_{nr}}\,\mathrm{3.2\,\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{ \mathrm{\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{\mathrm{ \mathrm{\mathrm{\mathrm{\mathrm{    }}}}}}}}}}}}}}}\)) and percent recovery (R) taken before and after RTFOT ageing of the investigated binders were used to evaluate the relationships between the measured changes in chemical indices and the high-temperature performance of the asphalt binders. As indicated in the introduction, it is typically assumed that the changes in the high-temperature characteristics of asphalt binders that have undergone oxidative ageing correlate well with the formation of carbonyl and sulfoxide species. Figures 7 and 8 present how the high-temperature performance and the measured FTIR chemical indices of the individual asphalt binders changed with short-term ageing. In the case of the performance characteristics shown in Figure 7, it can be seen that, although the additives caused some changes in the high-temperature properties of both asphalt binders, these changes were mostly consistent through the ageing process, regardless of the additives used. This can be particularly seen in case of the high-temperature stiffness (Figure 7a), but also in case of the non-recoverable creep compliance (Figure 7b) and percent recovery from the multiple stress creep recovery(MSCR) test (Figure 7c). This can be inferred based on the fact that, in most cases, the lines connecting respective points on the plots are roughly parallel, meaning that the changes in the measured properties due to the RTFOT ageing were comparable in magnitude. The only major exception was the 45/80-55 asphalt binder with 0.3% additive A, which exhibited a decrease in the percent recovery after RTFOT. \begin{table}
\begin{tabular}{l l l l l l l l l} \hline
**Asphalt** & \multicolumn{2}{c}{**Additive (\%)**} & \multicolumn{2}{c}{**\(\mathrm{I_{PB}}\)**} & \multicolumn{2}{c}{**\(\mathrm{I_{PS}}\)**} \\
**Binder** & **A** & **B** & **Non-Aged** & **RTFOT** & **RTFOT+PAV** & **Non-Aged** & **RTFOT** & **RTFOT+PAV** \\ \hline \multirow{8}{*}{45/80-55} & 0.0 & 0.0 & 0.0034 & 0.0038 (12\%) & 0.0033 (\(-3\%\)) & 0.0022 & 0.0023 (5\%) & 0.0020 (\(-9\%\)) \\  & 0.0 & 2.0 & 0.0028 (\(-18\%\)) & 0.0037 (9\%) & 0.0032 (\(-6\%\)) & 0.0019 (\(-14\%\)) & 0.0021 (\(-5\%\)) & 0.0019 (\(-14\%\)) \\ \cline{1-1}  & 0.3 & 0.0 & 0.0038 (12\%) & 0.0035 (3\%) & 0.0031 (\(-9\%\)) & 0.0022 (\(0\%\)) & 0.002 (\(-9\%\)) & 0.0018 (\(-18\%\)) \\ \cline{1-1}  & 0.3 & 2.0 & 0.0037 (9\%) & 0.0037 (9\%) & 0.0027 (\(-21\%\)) & 0.0021 (\(-5\%\)) & 0.0021 (\(-5\%\)) & 0.0016 (\(-27\%\)) \\ \cline{1-1}  & 0.15 & 1.0 & 0.0034 (0\%) & 0.0039 (15\%) & 0.0029 (\(-15\%\)) & 0.0020 (\(-9\%\)) & 0.0022 (0\(\infty\)) & 0.0017 (\(-23\%\)) \\ \hline \end{tabular}
\end{table} 
Table 9: Quantitative changes in the polybutadiene and polystyrene index values in the 45/80-55 asphalt binder due to the use of additives after different ageing protocols. Different results can be observed in Figure 8 showing the trajectories of the changes in the FTIR chemical indices. The values of carbonyl (Figure 8a) and sulfoxide (Figure 8b) indices were highly affected by the additives, resulting either in their increases or decreases before the RTFOT ageing and due to it. The four outlying values that can be observed in the \(\text{Is}=\text{O}\) plot (in the 0.006 and 0.008 range) correspond to the values of sulfoxide indices of non-aged binders with 1% and 2% additive B. Additionally, very strong effects of additive A in quenching the \(\text{Is}_{\text{s-O}}\) values can be observed. Had it not been for these highlighted values, a strong correlation between the high-temperature stiffness and \(\text{Is}_{\text{s-O}}\) index would have been observed.