## 4 Design and Performance Evaluation of High-Modulus Asphalt Mixtures
### Preparation of High-Modulus Asphalt Mixtures  
In this study, the preparation of high-modulus asphalt mixtures was carried out using the aggregate gradations in Tables 21 and 22. The preparation process for a high-modulus asphalt mixture is similar to that of an ordinary asphalt mixture but with higher requirements. Specifically: (1) High-modulus asphalt must be mixed with the aggregate at a temperature of \(185\pm 5\)\({}^{\circ}\)C due to its elevated softening point and viscosity; (2) Compared to ordinary asphalt mixture, the mixing time should be extended by at least 10 s, and it is recommended to maintain a duration of 50 s; and (3) the forming temperature must be carefully controlled at 170 \({}^{\circ}\)C.  
Additionally, the Marshall compaction method specified in \"Technical Specification for Highway Asphalt Pavement Construction\" can be used to determine the optimal asphalt dosage for a high-modulus asphalt mixture [27]. Test results are presented in Tables 23 and 24, which show that the best oil-to-stone ratio for ARHM-13 is 5.73%, and for ARHM-20 is 4.80%.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Specifications** & **Unit** & **Requirement** & **Mineral Power** \\ \hline Apparent Density & t/m\({}^{3}\) & \(\geq\)2.50 & 2.737 \\ \hline Exterior & \% & non-caking & non-caking \\ \hline Water Content & \% & \(\leq\)1 & 0.1 \\ \hline Hydrophilic Coefficient & - & \(\leq\)1 & 0.76 \\ \hline Heating Stability (200 \({}^{\circ}\)C) & - & Actual & Color invariance \\ \hline \hline \end{tabular}
\end{table}
Table 20: Technical specifications of mineral power.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Classification**} & \multicolumn{8}{c}{**Percentage through the Sieve**} \\ \cline{2-11}  & **16** & **13.2** & **9.5** & **4.75** & **2.36** & **1.18** & **0.6** & **0.3** & **0.15** & **0.075** \\ \hline
10–15 mm & 100 & 85.9 & 5.5 & 1.0 & 1.0 & 1.0 & 1.0 & 1.0 & 1.0 & 1.0 \\ \hline
5–10 mm & 100 & 100 & 96.3 & 11.5 & 1.7 & 0.5 & 0.5 & 0.5 & 0.5 & 0.5 \\ \hline
0–3 mm & 100 & 100 & 100 & 99.8 & 79.3 & 52.6 & 34.5 & 24.8 & 19.7 & 17.0 \\ \hline Mineral Power & 100 & 100 & 100 & 100 & 100 & 100 & 94.6 & 90.1 & 77.8 \\ \hline Gradation & 100 & 95.3 & 67.2 & 30.1 & 22.3 & 17.2 & 13.9 & 11.8 & 10.5 & 9.2 \\ \hline Mix Proportion & \multicolumn{8}{c}{10–15 mm:5–10 mm:0–3 mm:Mineral Power = 33\%:42\%:18\%:7\%} \\ \hline \hline \end{tabular}
\end{table}
Table 21: ARHM-13 gradation.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Classification**} & \multicolumn{8}{c}{**Percentage Through the Sieve**} \\ \cline{2-11}  & **26.5** & **19** & **16** & **13.2** & **9.5** & **4.75** & **2.36** & **1.18** & **0.6** & **0.3** & **0.15** & **0.075** \\ \hline
10–20 mm & 100 & 79.6 & 38.1 & 4.6 & 0.2 & 0.2 & 0.2 & 0.2 & 0.2 & 0.2 & 0.2 \\ \hline
10–15 mm & 100 & 100 & 93.8 & 16.5 & 1.5 & 0.9 & 0.9 & 0.9 & 0.9 & 0.9 & 0.9 \\ \hline
5–10 mm & & & 100 & 100 & 97.9 & 15.4 & 2.2 & 1.0 & 1.0 & 1.0 & 1.0 & 1.0 \\ \hline
3–5 mm & & & 100 & 100 & 100 & 97.2 & 17.1 & 6.9 & 3.8 & 3.8 & 3.8 & 3.8 \\ \hline
0–3 mm & & & 100 & 100 & 100 & 99.5 & 79.6 & 52.7 & 34.7 & 24.8 & 19.7 & 16.9 \\ \hline Mineral Power & & & 100 & 100 & 100 & 100 & 100 & 100 & 94.6 & 90.1 & 77.8 \\ \hline Gradation & 100 & 93.7 & 80.8 & 69.2 & 51.9 & 30.6 & 20.5 & 14.7 & 11.2 & 9.1 & 8.0 & 6.9 \\ \hline Mix Proportion & \multicolumn{8}{c}{10–20 mm:10–15 mm:5–10 mm:3–5 mm:0–3 mm:Mineral Power = 31\%:20\%:22\%:4\%:19\%:4\%} \\ \hline \hline \end{tabular}
\end{table}
Table 22: ARHM-20 gradation.