## 3 Results and Discussion
### Multiple Stress Crep Recovery (MSCR) Test  
Percentage Recovery and J\({}_{\rm{nr}}\) Condition for Both Original and RTFO Conditions  
The data presented in Figure 4 and Tables 6 and 7 show the impact of various modifications on the performance of a base binder, PG64-22, when mixed with TLA and CRM. The key parameters analyzed are % recovery, which indicates the elastic recovery of the binder after deformation, essential for the material's ability to resist permanent deformation (rutting), and J\({}_{\rm{nr}}\) (kPa\({}^{-1}\)), the nonrecoverable creep compliance, which measures the material's susceptibility to permanent deformation under repeated loading. Lower J\({}_{\rm{nr}}\) values indicate better performance against rutting.  
Starting with the base binder PG64-22, the % recovery is very low, indicating poor elastic recovery, and the Jnr is high, showing high susceptibility to deformation. After RTFO aging, there is a slight improvement in % recovery and a marginal decrease in Jnr, indicating only a slight enhancement in aging resistance. When 10% and 20% TLA are added to PG64-22, there is a noticeable increase in % recovery, showing improved elastic recovery. Simultaneously, Jnr decreases significantly, indicating reduced susceptibility to deformation. After RTFO aging, the % recovery improves further, and Jnr values continue to decrease, highlighting the beneficial effects of TLA on aging resistance.  
The addition of CRM, at both 5% and 10%, results in significant improvements in both % recovery and Jnr. Higher percentages of CRM (10%) exhibit even better performance in these parameters, indicating enhanced elasticity and reduced deformation. Combining TLA and CRM in various proportions shows substantial improvement in % recovery and a notable decrease in Jnr. For example, PG64-22 with 10% TLA and 5% CRM shows significant improvement, suggesting a synergistic effect. Increasing the TLA content to 20% with 5% CRM further improves % recovery and slightly reduces Jnr, though the improvement is less pronounced compared to lower TLA content, possibly due to the high stiffness imparted by TLA.  
The combination of PG64-22 with 10% TLA and 10% CRM exhibits excellent % recovery, indicating high elasticity, with a significantly reduced Jnr, showing the best performance among all combinations. Similarly, the combination of 20% TLA and 10% CRM results in maximum % recovery and low Jnr, similar to the 10% TLA and 10% CRM combination, suggesting a saturation point in the benefits provided by the additives. The increase in % recovery with the addition of TLA and CRM indicates improved elasticity. TLA contains  
Figure 4: Percentage recovery and Jnr at 64 \({}^{\circ}\)C of the modified asphalt binders at original and RTFO conditions.  
natural asphalt components that enhance viscoelastic properties, while CRM provides rubbery characteristics, improving elasticity. Lower Jnr values with the addition of TLA and CRM suggest reduced permanent deformation under load. TLA contributes to increased stiffness and resistance to flow, while CRM's elastic nature helps in distributing stress and reducing creep.  
The presence of TLA and CRM helps maintain performance even after aging. TLA's complex hydrocarbon structure resists oxidation and aging, while CRM's rubber components retain elasticity, reducing the degradation effects seen in unmodified binders. The data clearly show that the combined use of TLA and CRM in the PG64-22 binder significantly enhances its performance, especially in terms of elasticity and resistance to permanent deformation. The improvements are more pronounced with specific combinations, particularly at higher CRM content, suggesting that TLA and CRM can be effectively used to produce high-performance asphalt binders suitable for demanding applications, providing both immediate and long-term benefits in pavement durability and performance.