## 3 Results and Discussion
### Results of Advanced Performance-Related Characterization Tests
#### 3.3.3 LAS Tests  
As mentioned in Section 2.4, results coming from LAS tests were processed by referring to the failure criterion proposed by [PERSON] et al., based on the evaluation of the maximum value of the stored pseudo-strain energy density (PSE) [33; 34]. An example of this type of analysis is provided in Figure 11, where such an identification of failure conditions is compared to that which derives from the maximum shear stress criterion indicated in AASHTO TP101-14. In most cases, strain at failure coming from the energy-based criterion was found to be higher than the one associated to maximum stress. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & & \multicolumn{3}{c}{**High T\({}_{\text{c}}\) from**} \\
**Binder Code** & \begin{tabular}{c} **High T\({}_{\text{c}}\) from** \\ **G*/sin\(\delta\) Criterion** \\ **(Unaged Samples) [\({}^{\circ}\)C]** \\ \end{tabular} & \begin{tabular}{c} **H** \\ **(RTFOFOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] **C** \\ \end{tabular} & \begin{tabular}{c} **H** \\ **(RTFOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] **C** \\ \end{tabular} & \begin{tabular}{c} **H** \\ **(RTFOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] **C** \\ \end{tabular} & \begin{tabular}{c} **H** \\ **(RTFOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] **C** \\ \end{tabular} & \
\begin{tabular}{c} **H** \\ **(RTFOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] **C** \\ \end{tabular} &
\begin{tabular}{c} **V** \\ **(E** \\ \end{tabular} \\ \hline NB & 68.9 & 66.8 & 61.4 & 56.9 & 52.9 \\ \hline SW3 & 71.9 & 69.9 & 64.2 & 59.8 & 55.5 \\ SQ3 & 72.2 & 70.0 & 64.5 & 60.1 & 55.8 \\ SW4 & 74.4 & 69.9 & 64.2 & 59.8 & 55.6 \\ SQ4 & 74.3 & 70.7 & 64.9 & 60.4 & 56.0 \\ SW5 & 76.6 & 71.9 & 66.1 & 61.5 & 57.2 \\ \hline PW3 & 72.7 & 70.3 & 64.7 & 60.3 & 56.2 \\ PQ3 & 72.1 & 69.0 & 63.4 & 58.9 & 54.6 \\ PW4 & 75.2 & 71.4 & 65.9 & 61.4 & 57.2 \\ PQ4 & 76.3 & 70.9 & 65.2 & 60.7 & 56.3 \\ PW5 & 77.1 & 72.2 & 66.2 & 61.6 & 57.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: High critical temperatures. Fatigue lines derived from the processing of experimental data are shown in Figure 12, where they are separately represented for SBR-modified and PBR-modified binders. The fatigue line and fitting parameters of neat bitumen are also displayed for comparative purposes. Values of fitting parameters A and B, as per Equation (5), are listed in Table 7 for all binders subjected to testing. From the analysis of Figure 12, it can be observed that use of the two types of polymer (SBR and PBR) yielded completely different effects in terms of damage under repeated loading. The SBR products clearly induced an improvement in fatigue resistance, with curves that were progressively shifted upwards as a function of polymer dosage. Furthermore, similar effects were obtained with the premium quality and waste products, which led to almost overlapping fatigue curves. On the contrary, the PBR polymers (both of premium quality and of the waste type) did not have any appreciable effect on the fatigue response of the base bitumen. All fatigue lines were contained within a very narrow range, with no possibility of discriminating between binders containing PBR polymers with different dosage or quality. Such an outcome seems to be consistent with the results of FTIR analyses (see Section 3.1), which indicated that the PBR polymers were dissolved in the bitumen phase. The outcomes synthesized above were confirmed by analyzing the values of the A and B parameters presented in Table 7. SBR modification produced a clear increase in the A parameter and had a marginal  
Figure 11: Results of Linear Amplitude Sweep (LAS) tests—identification of failure conditions: (**a**) at maximum stored pseudo-strain energy density; (**b**) at maximum shear stress.