# Comparison of Embankment Properties with Clay Core and Asphaltic Concrete Core
## 2 Materials and Methods
### Testing of Asghtlic Concrete in the Laboratory
#### 2.2.2 Analysis of Permeability Test Results  
Test samples were prepared in accordance with the three mix proportions, utilizing 6% AC. The samples were tested for permeability by using specimens with AV values of 0.30%, 2.65%, and 4.71% for Mix Nos. 1, 2, and 3, respectively. The test results are presented in Table 7.  
Figure 4: Comparison of the relationship between various AC contents and the density, stability, and flow of the three mix proportions.  
From the test results in Table 7, when test samples were prepared with different densities in accordance with the different mix proportions, a reduction in AV occurred. This reduction in AV led to a decrease in permeability, corresponding to the decreased AV. For Mix No. 1, the water permeability value was 8.50 \(\times\) 10\({}^{-9}\) cm/s, which was the lowest, indicating the highest water resistance of the material. Mix Nos. 2 and 3, with AV values of 2.65% and 4.71%, respectively, yielded permeability values close to each other but higher than 1 \(\times\) 10\({}^{-6}\) cm/s. These void contents may be unsuitable for use as an embankment core material. A plot of the permeability values was obtained from this study against AV and compared with the data from [PERSON] et al. [27]. The relationship is depicted in Figure 5.  
From Figure 5, the data show the relationship between AV and permeability values compiled from various international studies, along with the data obtained from the permeability tests conducted in the current study. The comparison of the test results with data from international research indicates that the water permeability values obtained for AV values of 0.30%, 2.65%, and 4.71% in the current study are relatively higher than those reported in international research. This finding suggests that the properties of the asphaltic concrete mix used in the current study may differ from those studied internationally.  
In accordance with the relationship between AV and permeability from international research, permeability rapidly increases as AV increases. For example, at an AV of 3%, permeability is approximately 1 \(\times\) 10\({}^{-11}\) cm/s, and it increases rapidly to 1 \(\times\) 10\({}^{-4}\) cm/s at an AV of 6%.  
Based on the preliminary findings of the current study, asphaltic concrete mixtures used as core materials in embankments within a country should ideally have an AV of less than 1% to achieve permeability lower than 1 \(\times\) 10\({}^{-6}\) cm/s, in accordance with the specified criteria.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Mix No.** & **AV (\%)** & **Density (g/cm\({}^{3}\))** & **Permeability (cm/s)** \\ \hline
1 & 0.30 & 2.395 & 8.50 \(\times\) 10\({}^{-9}\) \\
2 & 2.65 & 2.334 & 2.71 \(\times\) 10\({}^{-5}\) \\
3 & 4.71 & 2.309 & 4.56 \(\times\) 10\({}^{-5}\) \\ \hline \end{tabular}
\end{table}
Table 7: Permeability test results of asphaltic concrete.  
Figure 5: Permeability values from the study’s tests vs. the relationship between the air void content and permeability values, compiled by [PERSON] et al., 1966 [27].