## 2 Materials and Methods
### Research Method  
The modified binders were produced by mixing 50/70 penetration virgin bitumen with the Cecabase RT BIO10 additive using a High Shear Mixer, following the experimental setup outlined in Table 5. The virgin bitumen was removed from storage in its solid state at 25 \({}^{\circ}\)C. The necessary amounts of Cecabase RT BIO10 were calculated based on the measured bitumen weights according to the experimental plan, and the bitumen was then placed in a preheated High Shear Mixer set to the specified temperatures. The mixture was subsequently blended at the specified speeds and for the durations indicated in the experimental plan. After preparation, the mixtures were transferred from the mixer into appropriate containers for testing, with each container carefully labeled. Following this, the modified mixtures were subjected to a comprehensive range of tests. As shown in Figure 3, penetration tests, softening point tests, flash point tests, \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Color** & **Odor** & **Aspect** & \begin{tabular}{c} **Viscosity at** \\ **25 \({}^{\circ}\)C** \\ \end{tabular} & **Density** & \
\begin{tabular}{c} **Water** \\ **Solubility** \\ \end{tabular} & **Flash Point** &
\begin{tabular}{c} **Freeze** \\ **Point** \\ \end{tabular} \\ \hline Yellow & None & Liquid & 800 cP & 1.00 kg/m\({}^{3}\) & Insoluble & 174 \({}^{\circ}\)C & \(-\)7 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Physical properties of Cecabase RT BIO10. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Experiment No** & \begin{tabular}{c} **(A)** \\ **Cecabase RT BIO10 (\%)** \\ \end{tabular}  & \begin{tabular}{c} **(B)** \\ **Temperature (\({}^{\circ}\)C)** \\ \end{tabular}  & \ \begin{tabular}{c} **(C)** \\ **Time (min)** \\ \end{tabular}  & \begin{tabular}{c} **(D)** \\ **Speed (RPM)** \\ \end{tabular}  \\ \hline
2 & 1 & 2 & 2 & 2 \\
3 & 1 & 3 & 3 & 3 \\
4 & 1 & 4 & 4 & 4 \\
5 & 2 & 1 & 2 & 3 \\
6 & 2 & 2 & 1 & 4 \\
7 & 2 & 3 & 4 & 1 \\
8 & 2  
and RTFOT tests were conducted in accordance with the ASTM D5 [39], ASTM D36 [40], ASTM D92 [41], and ASTM D2872 [50] standards, respectively. Penetration and softening point tests were conducted again on aged samples following the RTFOT. Elastic recovery tests were conducted following ASTM D6084 [51] to evaluate the bitumen's performance under repeated loading conditions. To evaluate the impact of the additive on the performance properties of the bitumen, specimens were prepared using both virgin and modified binders, following the Marshall design method in accordance with ASTM D6927 [52]. The ultrasonic pulse velocity (UPV) test was conducted on Marshall specimens to estimate the seismic modulus of asphalt mixtures and assess the influence of various components, in accordance with ASTM C597 [53]. FTIR analysis was performed to examine the chemical composition and morphological characteristics of the modified binders. The flow chart for the experimental plan is presented in Figure 4.  
The use of multiple parameters in studies, along with numerous experiments to determine the best parameters, can negatively impact time and cost efficiency. The Taguchi experimental design method helps to optimize experimental processes, improve product quality, and use time and resources efficiently. This experimental design method focuses on eliminating or minimizing the variability of parameters that can affect the production process [54]. Applying the Taguchi method has resulted in high-quality products while minimizing costs and ensuring profitability [55]. This method has been successfully applied in transportation and other engineering fields [56; 57; 58; 59]. The Taguchi method utilizes performance statistics (S/N) as a primary criterion for optimization. It encompasses three types of performance statistics: larger is better, nominal is better, and smaller is better. These statistics were used to calculate S/N values by applying the following equations to the data obtained from the experiments.