# Comparison of Embankment Properties with Clay Core and Asphaltic Concrete Core
## 2 Materials and Methods
### Testing of Asghtlic Concrete in the Laboratory
#### 2.2.1 Analysis of Asphaltic Concrete Mixture Design Results
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{AV (\%)} & \multicolumn{3}{c}{**Properties of Asphalt Concrete**} & \multirow{2}{*}{**Remark**} \\ \cline{2-2} \cline{4-4}  & **Density (g/mL)** & **Stability (lbs)** & **Flow (1/100 inch)** \\ \hline
1 & 2438 & 2440 & 1267 \\
2 & 2415 & 2400 & 1267 \\
3 & 2393 & 2280 & 1267 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Density, stability, and flow from a mix design based on AV at 1, 2, and 3% and AC at 6%. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{
\begin{tabular}{c} **Air Void** \\ **Content (\%)** \\ \end{tabular} } & \multicolumn{4}{c}{**Aggregate Material Proportions (\% by Weight)**} & \multirow{2}{*}{**Remark**} \\ \cline{2-2} \cline{4-4}  & **Hot Bin 1** & **Hot Bin 2** & **Hot Bin 3** & **Hot Bin 4** \\  & **(size < 4.75 mm)** & **(Size 9.53 mm)** & **(Size 12.70 mm)** & **(Size 19.05 mm)** \\ \hline
1 & 42 & 30 & 18 & 10 \\
2 & 38 & 37 & 15 & 10 \\
3 & 35 & 35 & 15 & 15 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Aggregate material proportions of asphaltic concrete according to AV values of 1%, 2%, and 3%, and an AC of 6%. Table 6 clearly shows that setting AV to 1%, 2%, and 3%, with 6% AC, results in varying proportions of aggregate materials. Consequently, the properties of asphaltic concrete also change in accordance with the aggregate mix proportions. Density and stability are the highest for the mix proportion with 1% AV. However, the flow values remain consistent across the three mix proportions. Further examination of the relationship between various AC values and the density, stability, flow, and AV of the three mix proportions, as depicted in Figure 4, reveals that when AC is altered between 5.5% and 7.5%, the properties of asphaltic concrete exhibit the following characteristics. * The density of Mix No. 1 increases until it reaches its peak at 6.5% AC, and then de-creases as AC increases. However, Mix Nos. 2 and 3 exhibit an increase in density until reaching their maximum at 7% AC, and then a decrease as AC increases. When comparing the three mix proportions, Mix No. 1 provides the highest density at each AC level, followed by Mix No. 2 and then No. 3. Notably, at 7.5% AC, the density values of all three mix proportions are nearly identical. Overall, this study suggests that the appropriate AC leads to the highest density value, depending on the aggregate mix proportions. * Stability values obtained from the experiments reveal that as AC increases, stability also increases until reaching its peak at 7.0% AC. Then, it decreases as AC further in-creases. This trend is observed across all three mix proportions. When comparing the three mix proportions, Mix No. 1 provides the highest stability at each AC level, followed by Mix No. 2 and then No. 3. * Flow values indicate the mobility or compactness of a mixture. The flow values obtained from the experiments for all three mix proportions are relatively similar at  
Figure 3: The graph of the particle size distribution according to the air void content (AV) at 1%, 2%, and 3%, and the asphalt cement content (AC) at 6%. each AC level. High flow values indicate a low resistance to deformation, making asphalt concrete more susceptible to shape distortion. * The void content values of the three mix proportions decrease as AC increases. However, when AC increases to 7.5%, the AV values of the three mix proportions are equal. On the basis of this study, the suitable AC for use in asphalt concrete mixtures for embankment projects is between 6.0% and 6.5%. This range ensures the highest density values, ranking first and second, respectively. It yields stability values ranging from 2277 lbs to 2570 lbs, and flow values ranging from 12.67 to 14.00 (in units of 0.01 inch), with an AV below 3%. This optimal AC aligns with international research, which generally recommends an asphalt content between 5.5% and 6.5%. However, the current study specifically choses an AC of 6.0%