## 3 Results and Discussion
### Penetration and Softening Point Test Results
This was followed by mixing speed, with a value of 0.263, mixing temperature, with a value of 0.257, and mixing time, with a value of 0.226. The penetration values after RTFOT varied between 34.97 and 45.87 (0.1 mm). During the experiments conducted according to the test plan, the highest penetration value was 45.87 (0.1 mm), which indicated an increase of 18.00% compared to virgin bitumen. Furthermore, the penetration value was calculated according to the optimum levels that \begin{table}
\begin{tabular}{c c c} \hline \hline
**Factors** & **Levels** & **Contributions to S/N** \\ \hline Cecabase & A3 & 0.571 \\ Temperature & B1 & 0.220 \\ Time & C4 & 0.306 \\ Speed & D2 & 0.285 \\ Total contribution (S/N) & & 1.382 \\ Performance statistics average (S/N) & & 36.210 \\ Expected S/N and value at optimum levels (S/N)/(0.1 mm) & & 37.592/75.788 \\ Result of verification experiment (S/N)/(0.1 mm) & & 37.200/72.400 \\ Confidence interval (\(\alpha\) = 95\%) (S/N) & & 37.180/38.005 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Performance estimations for the optimum conditions that maximize the penetration before RTFOT. maximized it, which resulted in a value of 46.911 (0.1 mm), indicating an increase of 20.684% compared to virgin bitumen. As shown in Figure 7, the optimum levels for the softening point before RTFOT were A3, B4, C4, and D2. The softening point of bitumen decreased until the third level of the Cecabase RT BIO10 additive ratio and increased slightly at the fourth level. As the temperature and time increased, the softening point decreased. It reached the lowest point at the second level of mixing speed and increased at the third and fourth levels. In the experiments, according to the test plan, the lowest softening point value was 50.3 \({}^{\circ}\)C, a decrease of 2.43% compared to virgin bitumen. The softening point value calculated according to the optimum levels that minimize the softening point value was 49.677 \({}^{\circ}\)C, a decrease of 3.628% compared to virgin bitumen. According to [PERSON] et al. (2016), the addition of Cecabase RT BIO 10 reduced the softening point of 50/70 bitumen by 4.08%. [PERSON] et al. (2016) found that the addition of the additive resulted in a 2.8% decrease in the bitumen's softening point. Figure 6: Softening point test results. \begin{table}
\begin{tabular}{c c c} \hline
**Factors** & **Levels** & **Contributions to S/N** \\ \hline Cecabase & A3 & 0.561 \\ Temperature & B4 & 0.257 \\ Time & C4 & 0.226 \\ Speed & D2 & 0.263 \\ Total contribution (S/N) & & 1.308 \\ Performance statistics average (S/N) & & 32.118 \\ Expected S/N and value at optimum levels (S/N)/(0.1 mm) & & 33.425/46.911 \\ Result of verification experiment (S/N)/(0.1 mm) & & 33.100/45.200 \\ Confidence interval (\(\alpha\) = 95\%) (S/N) & & 32.998/33.853 \\ \hline \end{tabular}
\end{table} 
Table 9: Performance estimations for the optimum conditions that maximize the penetration after RTFOT. Variance (ANOVA) analysis was performed to determine whether the softening tests performed before RTFOT were statistically significant. The F value of each parameter in the experimental plan shows its effect on optimization. It is simply the ratio of the squared deviation to the mean of the squared error [60]. A larger F value indicates a more significant effect on the softening point. The optimum combination of parameters and levels determined in the experimental plan can be estimated using ANOVA statistical testing and performance statistics. ANOVA results for minimizing the softening point are given in Table 10. The F table value for (3.3) is 9.277 at the 95% confidence level. The F value for all factors is greater than that extracted from the table for the 95% confidence interval. This shows that the variance of all factors is significant, that is, statistically valid, compared to the variance of the error. Additionally, it was observed that Cecabase made the most significant contribution to the softening point value, with 70.408%. This was followed by temperature, speed, and time, respectively.