## 3 Results and Analysis
### Results and Analysis of Modified Bitumen Mixture Test
#### 3.3.6 Results and Analysis of Compaction Performance of Modified Bitumen Mixtures  
Effect of Compaction Temperature  
The test set four initial compaction temperatures, i.e., 100 \({}^{\circ}\)C, 120 \({}^{\circ}\)C, 140 \({}^{\circ}\)C, and 160 \({}^{\circ}\)C, and calculated the gross bulk density and compaction degree under different compaction temperatures. The test results are shown in Figures 7 and 8, respectively. Figures 7 and 8 show that the gross bulk density and compaction of the bitumen mixture Marshall specimens increased linearly with an increase in compaction temperature. If the same compaction degree is achieved, the Sasobit-modified, XT-W3-modified, and Evotherm-modified bitumen mixtures require a temperature reduction of approximately 10-30 \({}^{\circ}\)C compared to the virgin bitumen mixture and the SBS-modified bitumen. This indicates that these modifiers can effectively reduce the mixing and construction temperatures of the bitumen mixture and save energy in line with the current energy-saving demands. Among them, the Sasobit-modified bitumen mixture exhibited the best performance. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Bitumen** & \multirow{2}{*}{**Stress Ratio**} & \multirow{2}{*}{\begin{tabular}{c} **Stress** \\ **Level/MPa** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **Logarithmic** \\ **Value of Stress** \\ **Level** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Fatigue Life** \\ **Fatigue Life** \\ \end{tabular} } & \multicolumn{2}{c}{\
\begin{tabular}{c} **Logarithmic** \\ **Value of Fatigue Life** \\ \end{tabular} } & \multicolumn{2}{c}{
\begin{tabular}{c} **Regression** \\ **Equation** \\ \end{tabular} } \\ \hline Virgin Bitumen & 0.3 & 1.77 & 0.2480 & 18,891 & 4.2763 & K = 199,986 \\  & 0.4 & 2.36 & 0.3729 & 7715 & 3.8873 & \(n\) = 3.9743 \\  & 0.5 & 2.95 & 0.4698 & 2694 & 3.4304 & R\({}^{2}\) = 0.9914 \\  & 0.6 & 3.54 & 0.5490 & 1239 & 3.0931 & \\  & 0.3 & 1.95 & 0.2900 & 23,879 & 4.3780 & K = 295,461 \\  & 0.4 & 2.60 & 0.4150 & 9541 & 3.9796 & \(n\) = 3.6818 \\  & 0.5 & 3.25 & 0.5119 & 3958 & 3.5975 & \(n\) = 3.6818 \\  & 0.6 & 3.90 & 0.5911 & 1864 & 3.2704 & R\({}^{2}\) = 0.9961 \\  & 0.3 & 1.83 & 0.2625 & 22,148 & 4.3453 & K = 223,924 \\
5\% XT-W3 & 0.4 & 2.44 & 0.3874 & 8469 & 3.9278 & \(n\) = 3.7675 \\  & 0.5 & 3.05 & 0.4843 & 3189 & 3.5037 & R\({}^{2}\) = 0.9971 \\  & 0.6 & 3.66 & 0.5635 & 1690 & 3.2279 & R\({}^{2}\) = 0.9971 \\  & 0.3 & 1.89 & 0.2765 & 23,116 & 4.3639 & \\  & 0.4 & 2.52 & 0.4014 & 8046 & 3.9056 & K = 251,826 \\
0.6\% Evotherm & 0.5 & 3.15 & 0.4983 & 4121 & 3.6150 & \(n\) = 3.7081 \\  & 0.6 & 3.78 & 0.5775 & 1649 & 3.2172 & R\({}^{2}\) = 0.9917 \\  & 0.3 & 2.02 & 0.3058 & 24,059 & 4.3813 & \\ SBS & 0.4 & 2.70 & 0.4307 & 11,896 & 4.0754 & K = 316,446 \\  & 0.5 & 3.37 & 0.5276 & 4259 & 3.6293 & \(n\) = 3.5099 \\  & 0.6 & 4.04 & 0.6068 & 2231 & 3.3485 & R\({}^{2}\) = 0.9834 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Results of the fatigue test. Figure 8: Relationship between compaction degree and compaction temperature. Figure 7: Relationship between gross bulk density and compaction temperature. Effect of the Number of Compactions  
The initial compaction temperatures of 145 \({}^{\circ}\)C, 135 \({}^{\circ}\)C, 135 \({}^{\circ}\)C, 135 \({}^{\circ}\)C, and 160 \({}^{\circ}\)C were set for the virgin, Sasobit-modified, XT-W3-modified, and Evotherm-modified bitumen mixtures. The SBS-modified bitumen mixture was processed with five different compaction times, i.e., 50, 60, 75, 85, and 100, to calculate the gross bulk density and compaction degree. The test results are shown in Figures 9 and 10. Figures 9 and 10 show that the gross bulk density and compaction number of bitumen mixture Marshall specimens increased exponentially with the increase in compaction number. The increase in gross bulk density and compaction leveled off with the increase in compaction number.