## 3 Results and Discussion
### Rheological Characteristics at High Temperature  
The results of the DSR test and corresponding statistical analysis for G*/sin \(\delta\) (kPa) at 64 \({}^{\circ}\)C are presented in Figure 3 and Table 5 to evaluate the high-temperature rheological performance of PG64-22 bituminous binders altered with TLA and SBS under both original and RTFO-aged conditions. This value shows the binder's rutting resistance, which is important for asphalt performance in hot climates and under heavy loads.  
The base binder, PG64-22, exhibited the lowest G*/sin \(\delta\) values of 2.03 kPa (original) and 5.38 kPa (RTFO). The addition of 10% and 20% TLA improved rutting resistance moderately, with values increasing to 2.57 kPa and 3.08 kPa for the original condition and 5.96 kPa and 6.52 kPa for the RTFO-aged condition, respectively. However, statistical analysis shows that these increases are significant (S) compared to PG64-22, indicating that TLA alone positively impacts rutting resistance.  
Figure 3: G*/sin of the modified bituminous binders both before and following conditions of short-term aging at 64 \({}^{\circ}\)C.  
The incorporation of SBS alongside TLA produced substantial improvements in rutting resistance. For 5% SBS, the results were as follows:  
* PG64-22 + 10% TLA + 5% SBS achieved 10.10 kPa in the original condition and 19.70 kPa during the RTFO-aged condition.
* PG64-22 + 20% TLA + 5% SBS exhibited 14.54 kPa (original) and 25.18 kPa (RTFO). Statistical analysis confirms these improvements as significant compared to the PG64-22 and PG64-22 + TLA combinations, highlighting the effectiveness of SBS in enhancing binder performance.
* Further increasing SBS content to 10% and 15% showed remarkable gains as described below.
* PG64-22 + 10% TLA + 10% SBS reached 32.40 kPa (original) and 45.40 kPa (RTFO).
* PG64-22 + 20% TLA + 15% SBS recorded the highest values of 74.79 kPa (original) and 94.62 kPa (RTFO). Statistical analysis indicates that these combinations demonstrate significant differences (S) compared to all other binders, reinforcing the superiority of SBS-modified binders in achieving excellent rutting resistance.  
In terms of statistical comparisons, all modified combinations (TLA and TLA + SBS) were significantly better than the base PG64-22 binder across both conditions. Particularly, SBS modification combined with 20% TLA produced significant improvements, with 15% SBS content yielding the most exceptional performance.  
The results demonstrate a clear trend: while TLA enhances stiffness, the addition of SBS not only mitigates the potential brittleness introduced by TLA but also significantly increases the rutting resistance. This is critical for pavement engineering applications, where high resistance to permanent deformation ensures durability under extreme temperatures and heavy traffic. The highest-performing binder, PG64-22 + 20% TLA + 15% SBS, emerges as a prime candidate for pavements requiring extended service life and reduced maintenance costs. Statistical analysis further validates these findings, confirming the consistent and significant improvements brought about by TLA and SBS modification.