## 2 Materials and Equipment
### Experimental Materials
#### 2.1.2. Asphalt  
Due to the large pore structure of the permeable asphalt pavement, the strength will be affected for a period of time after being put to use due to water damage, road damage and for other reasons. Therefore, the asphalt must have a higher viscosity. SBS (Styrene-Butadiene-Styrene) is a styrene thermoplastic elastomer and is a styrene-butadiene-styrene triblock copolymer. As construction materials, high-viscosity SBS modified asphalt is generally used. The performance indexes of SBS modified asphalt are obtained according to Standard Test Methods of Bitumen and Bituminous Mixtures for Highway Engineering (JTG E20-2011) standard. The asphalt used in this test is SBS-modified asphalt produced by Shandong Zibo Qi Cultural Industry Co., Ltd. Its various indicators are shown in Table 2.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Test Items** & **Unit** & **Required Value** & **Test Results** \\ \hline Stone crushing Value & \% & \(\leq\)26 & 21.2 \\ \hline Los angeles abrasion loss & \% & \(\leq\)30 & 25 \\ \hline Apparent density & g/cm\({}^{3}\) & \(\geq\)2.60 & 2.79 \\ \hline Water absorption & \% & \(\leq\)2.0 & 0.61 \\ \hline Asphalt adhesion & grade & \(\geq\)5 & 6 \\ \hline Robustness & \% & \(\leq\)12 & 10 \\ \hline Needle-like particle content (mixture) & \% & \(\leq\)14 & 9.3 \\ \hline The particle size is greater than 4.75 \(mm\) & \% & \(\leq\)10 & 6 \\ \cline{2-4} Particle size 2.36 \(mm\)–4.75 \(mm\) & \% & \(\leq\)18 & 12 \\ \hline Aggregate larger than 4.75 \(mm\) is obtained & & & \\ after washing method \textless{}0.075 \(mm\) & \% & \(\leq\)1.0 & 0.6 \\ particle content & & & \\ \hline
2.36 \(mm\)–4.75 \(mm\) aggregates obtained & & & \\ after washing method \textless{}0.075 \(mm\) & \% & \(\leq\)3.0 & 2.1 \\ particle content & & & \\ \hline Soft stone content & \% & \(\leq\)3 & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Coarse aggregate properties and technical requirements.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Pilot Projects** & **Unit** & \begin{tabular}{c} **Required** \\ **Value** \\ \end{tabular} & \
\begin{tabular}{c} **Measured** \\ **Value** \\ \end{tabular} &
\begin{tabular}{c} **Test** \\ **Procedure** \\ \end{tabular} & **Remarks** \\ \hline Penetration 25 \({}^{\circ}\)C & 0.1 mm & \(\geq\)40 & 56 & T0604 & qualified \\ Softening Point & \({}^{\circ}\)C & \(\geq\)80 & 85 & T0606 & qualified \\ Ductility 15 \({}^{\circ}\)C & cm & \(\geq\)80 & 81.4 & T0605 & qualified \\ Ductility 5 \({}^{\circ}\)C & cm & \(\geq\)30 & 33 & T0605 & qualified \\ Dynamic viscosity at & \(Pa\cdot s\) & \(\geq\)20,000 & 101,000 & T0620 & qualified \\
60 \({}^{\circ}\)C & \(N\cdot\text{m}\) & \(\geq\)20 & 22 & T0624 & qualified \\ Viscosity & \(N\cdot\text{m}\) & \(\geq\)15 & 18 & T0624 & qualified \\ Toughness & \(N\cdot\text{m}\) & \(\geq\)65 & 72.3 & T0609 & qualified \\ Film heating & \% & \(\geq\)65 & 72.3 & T0609 & qualified \\ penetration ratio & & & & \\ Loss of film heating & \% & \(\leq\)0.6 & 0.22 & T0609 & qualified \\ quality & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Properties and technical requirements of SBS modified asphalt.