# Experimental Study of Low Temperature Performance of Porous Asphalt Mixture
## 2 Low Temperature Performance Test
### Raw Materials  
The aggregate included S10, S12 and S16 diabase gravel produced in Heyuan, Guangdong Province of China. S10 and S12 were coarse aggregates with a maximum size of 13.2 mm and S16 was fine aggregates. The filler was limestone powder, and the asphalt used in the test was 70# matrix asphalt initially developed in a refinery laboratory in Nanjing City of China (the notion 70# refers to a needle penetration range of 70 \(\pm\) 10 at 25 \({}^{\circ}\)C in 5 s using a 100 g needle). The modifier was SINOTPS modifier manufactured by Shenzhen Oceanpower New Material Technology Company (Opmaterial) Ltd., China. It was a high-viscosity modifier and was a proprietary mixture of thermoplastic elastomer, thermoplastic resin, rubber-type polymers, and additives. Figure 1 depicts the SINOTPS modifier. The mean particle size of the SINOTPS modifier was 2.5 mm. The specifications and technical indicators of coarse aggregate are respectively summarized in Tables 1 and 2, and the specifications and technical indicators of fine aggregate are respectively tabulated in Tables 3 and 4. According to the test method described in Chinese Standard JTG E20-2011 [49], screening tests for aggregate and limestone powder were conducted. Figure 2 illustrates the test process, and the results are listed in Table 5. The technical requirements of limestone powder and the corresponding test results are given in Table 6.  
The properties of the matrix asphalt affect the properties of high-viscosity modified asphalt. The matrix asphalt used for preparing high-viscosity modified asphalt should meet the technical requirements of road petroleum asphalt in Chinese Standard JTG F40-2004 [50]. In this study, 70# matrix asphalt developed in Nanjing was adopted, and the test results of technical indicators per JTG E20-2011 [49] are shown in Table 7. It can be seen from the table that the matrix asphalt was classified per JTG F40-2004 [50] as a grade A asphalt, which is suitable for all grades of highways. Therefore, it is suitable to employ the matrix asphalt for preparing high viscosity modified asphalt. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{3}{*}{**Designation**} & \multirow{3}{*}{
\begin{tabular}{c} **Nominal Size** \\ **Range (mm)** \\ \end{tabular} } & \multicolumn{8}{c}{**Percentage Passing through the Following**} \\ \cline{3-10}  & & 4.75 & 2.36 & 1.18 & 0.6 & 0.3 & 0.15 & 0.075 \\  & & mm & mm & mm & mm & mm & mm & mm \\ \hline S16 & 0–3 & 100 & 80–100 & 50–80 & 25–60 & 8–45 & 0–25 & 0–15 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Technical indicator requirements and test results of fine aggregate. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Test Item**} & \multirow{2}{*}{**Unit**} & \multicolumn{3}{c}{**Test Result**} \\ \cline{3-6}  & & 5–10 mm & 10–15 mm \\ \hline Crushed value & \% & & 6.8 & \\ Los Angeles abrasion loss & \% & & 9.7 & \\ Apparent relative density & — & 2.930 & & 2.962 \\ Water absorption & \% & 0.74 & & 1.11 \\ Soundness (mass loss with sodium sulfate) & \% & & 5.2 & \\ Needle flake granule content & \% & 10.2 & & 8.5 \\ Silt content (\textless{}0.075 mm particle content by water washing method) & \% & 0.5 & & 0.9 \\ Soft mineral content & \% & 1.3 & & 0.7 \\ Polished stone value & — & & 45 & \\ Adhesion to asphalt & — & & 5 & \\ \hline \hline \end{tabular} Note: Tests were carried out according to Chinese Standard JTG E20-2011 [49].  
\end{table} 
Table 2: Test results of technical indicators of coarse aggregate.