# Comparison of Embankment Properties with Clay Core and Asphaltic Concrete Core
## 2 Materials and Methods
### Testing of Asghtlic Concrete in the Laboratory
#### 2.2.3 Analysis of Triaxial Compressive Strength Test Results  
The objective of the triaxial compressive strength tests is to study the behavior of asphaltic concrete under conditions that simulate the effects of radial stress, similar to those experienced by a section of an embankment subjected to circumferential pressure. For these tests, asphaltic concrete test specimens were prepared in accordance with the three different mix proportions of the designed mixtures. An AC of 6% was utilized. The details of the test results are presented in Table 8.  
The information in Table 8 is summarized from the stress-strain graphs and Mohr's Coulomb envelope of the triaxial compressive strength tests for the asphaltic concrete specimens of each mix proportion. Three samples were tested, and each was subjected to different effective confining pressure values (\(\sigma\)3). The comparison at \(\sigma\)3 = 3 kg/cm\({}^{2}\) (the highest) shows that for Mix No. 1, the axial stress (\(\sigma\)1) at failure was 28.10 kg/cm\({}^{2}\), which was the highest among all three mix proportions. However, the Young's modulus (Es) was 319 kg/cm\({}^{2}\), which was not the highest among the mix proportions. For Mix Nos. 1, 2, and 3, the cohesion (c) and friction angle (\(\phi\)) values ranged from 2.70 kg/cm\({}^{2}\) to 4.66 kg/cm\({}^{2}\) and from 30.23\({}^{\circ}\) to 45.80\({}^{\circ}\), respectively.  
To assess the load-bearing capacity of the asphaltic concrete specimens for all three mix proportions from the triaxial compressive strength tests, stress path graphs (which illustrate changes in stress units) were plotted, as shown in Figure 6, Mix No. 1 exhibited a higher load-bearing capacity than Mix Nos. 2 and 3.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Mix No.**} & \multirow{2}{*}{**Test No.**} & \multirow{2}{*}{**\begin{tabular}{c} **Effective Confining** \\ **Pressure, \(\sigma_{3}\) (ksc)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Axial Stress at** \\ **Failure, \(\sigma_{1}\) (ksc)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **\(\sigma_{1}\)/\(\sigma_{3}\)** \\ **at Failure** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Young/s** \\ **Modulus, ES** \\ **(ksc)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Cohesion, c** \\ **(ksc)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Friction Angle,** \\ **\(\phi\) (degree)** \\ \end{tabular} } \\ \hline \multirow{3}{*}{1} & 1 & 1 & 18.16 & 18.16 & 305 & & \\  & 2 & 23.11 & 11.55 & 269 & 2.7 & 45.8 \\  & 3 & 3 & 28.10 & 9.37 & 319 & & \\  & 4 & 1 & 18.63 & 18.63 & 342 & & \\
2 & 5 & 2 & 19.62 & 9.81 & 257 & 4.66 & 30.23 \\  & 6 & 3 & 22.53 The post-test condition of the specimens for Mix. No. 1 after the triaxial compressive strength tests is illustrated in Figure 7. The specimens tested under \(\sigma\)3 = 1 kg/cm\({}^{2}\) exhibited more significant deformation and cracking compared with those tested under \(\sigma\)3 = 2-3 kg/cm\({}^{2}\). Although the post-test condition of the specimens for Mix Nos. 2 and 3 resembled that of Mix No. 1, their ability to withstand stress differed.  
In Figure 7, the post-test condition of the specimens for Mix Proportion 1 after the triaxial compressive strength tests is illustrated. It was observed that specimens tested under \(\sigma_{3}\) equal to 1 kg/cm\({}^{2}\) exhibited more significant deformation and cracking compared to those tested under \(\sigma_{3}\) equal to 2 and 3 kg/cm\({}^{2}\). Although the post-test condition of the specimens for Mix Proportions 2 and 3 resembled that of Mix Proportion 1, their ability to withstand stress differed.