## 2 Materials and Experiment  
### Materials  
#### 2.1.1 Asphalt and Aggregate  
Anti-icing asphalt mixtures are primarily used in low-temperature regions, which require a good stability at a low temperature. Hence, Styrene Butadiene Styrene Block Polymer (SBS) modified asphalt was used in this study, as the main parameters listed in Table 1.  
Chloride ions, the anti-icing filler, will accelerate the peeling of asphalt. To ensure the mixture's adhesion and the pavement's performance, the adhesion of asphalt and aggregate is up to level 5 and water absorption of aggregate is less than 1%. The coarse aggregates were the diories from Shangzhou City in Shaanxi Province, China and the fine aggregates were limestones from Pucheng City in Shaanxi Province, China. The mineral powders were ground limestones provided by Jinghe Stone Factory in Beijing, China. Technical details are shown in Tables 2-4.  
\begin{table}
\begin{tabular}{l c c c} \hline \hline
**Technical Indicators** & **Measured Values** & **Standard Values** & **Test Method [26]** \\ \hline Penetration 25 \({}^{\circ}\)C (0.1 mm) & 57 & 40–60 & T0604 \\ Penetration Index PI & 0.125 & \(\geq\)0 & T0604 \\ Softening point T\({}_{\text{R\&B}}\) (\({}^{\circ}\)C) & 85 & \(\geq\)60 & T0606 \\ Ductility (5 \({}^{\circ}\)C, 5 cm/min)/cm & 23.3 & \(\geq\)20 & T0605 \\ Kinematic viscosity 135 \({}^{\circ}\)C (Pa-s) & 1.12 & \(\leq\)3 & T0625 \\ Flashing point (\({}^{\circ}\)C) & 326 & \(\geq\)230 & T0611 \\ Solubility (\%) & 99.6 & \(\geq\)99 & T0607 \\ Elastic recovery 25 \({}^{\circ}\)C (\%) & 88 & \(\geq\)75 & T0662 \\
48 h Thermal storage softening & 1.8 & \(\leq\)2.5 & T0661 \\ point difference (\({}^{\circ}\)C) & 1.023 & Measured & T0603 \\ Density (g:cm\({}^{-3}\)) & 0.04 & \(\leq\)1.0 & T0609 \\ Penetration ratio 25 \({}^{\circ}\)C (\%) & 75.9 & \(\geq\)65 & T0604 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Styrene Butadiene Styrene Block Polymer (SBS) modified asphalt technology index.  
\begin{table}
\begin{tabular}{l c c c} \hline \hline
**Technical Indicators** & **Measured Values** & **Standard Values** & **Test Method [27]** \\ \hline Crushing value (\%) & 11.9 & \(\leq\)26 & T0316 \\ \hline Abrasion value (\%) & 10.5 & \(\leq\)28 & T0317 \\ \hline Clay content (\%) & 0.75 & \(\leq\)3 & T0314 \\ \hline Adhesivity with asphalt & Level 5 & Above level 4 & T0616 \\ \hline Apparent density (g:cm\({}^{-3}\)) & 9.5–16 mm & 2.924 & \(\geq\)2.6 & T0304 \\ \hline Gross bulk density (g:cm\({}^{-3}\)) & 9.5–16 mm & 2.898 & - & T0304 \\ \hline Needle flake content (\%) & \(\geq\)9.5 mm & 4.23 & \(\leq\)15.0 & T0312 \\ \(<\)9.5 mm & 6.40 & \(\leq\)20.0 & \\ \hline Bibulous rate (\%) & 9.5–16 mm & 0.47 & \(\leq\)2.0 & T0304 \\ \(4.75\)–9.5 mm & 0.73 & \(\leq\)2.0 & T0304 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Coarse aggregate test results.  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Technical Indicators** & **Measured Values** & **Standard Values** & **Test Method [27]** \\ \hline Apparent density (g:cm\({}^{-3}\)) & 2.36–4.75 mm & 2.729 & \(\geq\) 2.5 & T0328 \\  & 0–2.36 mm & 2.722 & \(\geq\) 2.5 & T0328 \\ \hline Gross bulk density (g:cm\({}^{-3}\)) & 2.36–4.75 mm & 2.667 & - & T0304 \\  & 0–2.36 mm & 2.661 & - & T0304 \\ \hline Sand equivalent & 97 & \(\geq\)60 & T0334 \\ \hline Clay content & 1.3 & \(\leq\)3.0 & T0333 \\ \hline Bibulous rate & 0.85 & - & T0330 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Fine aggregate test results.