# Evaluation of Fatigue Life of Asphalt Concrete Mixtures with Reclaimed Asphalt Pavement
## 5 Analyses of Pavement Design Life
### Calculations of Structure Fatigue Life  
Tables 4 and 5 summarize the results of calculations of strains in the asphalt base course and in the subgrade according to the individual structural variants and the results of structure durability calculations according to the 2004 AASHTO criteria (Equation (2)) and the Asphalt Institute criteria (Equation (6)). Regardless of the method used for determining the stiffness or the fatigue criterion, the results of the structure durability calculations were higher than the upper limit of the range of the design number of equivalent standard axles for the specific traffic category (red dashed lines in Figures 8 and 9). In general (with some exceptions), the results obtained according to the 2004 AASHTO criterion were higher than the results according to the French method. In the case of ACWMS structures, AASHTO results were two to four times higher than those obtained using the French method. For the corresponding constructions with typical asphalt concrete, the relation is reversed. From the designer's point of view, on this basis, it can be indicated as a safer application of the French method to the structures of ACWMS, and AASHTO methods for structures with classic asphalt concrete. The smallest differences between these methods were in the case of medium thickness structures (KR4-KR5) with AC.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline
**Configuration** & **KR7 ACWMS** & **KR7** & **KR6 ACWMS** & **KR6** & **KR5 ACWMS** & **KR5** & **KR4** & **KR3** & **KR2** & **KR1** \\ \hline \(\varepsilon_{def}\), \(\mathrm{\SIUnitSymbolMicro m}/\mathrm{m}\) & 55.3 & 36.5 & 61.5 & 49.5 & 78.2 & 64.0 & 73.0 & 84.7 & 139.0 & 175.0 \\ \(\varepsilon_{gr}\), \(\mathrm{\SIUnitSymbolMicro m}/\mathrm{m}\) & 149 & 133 & 164 & 149 & 206 & 192 & 218 & 251 & 411 & 538 \\ \(\mathrm{N}_{gr}\), MSA* (100 kN) & 193.4 & 321.9 & 125.8 & 193.4 & 45.3 & 62.1 & 35.1 & 18.7 & 2.0 & 0.6 \\ \hline \multicolumn{8}{c}{2004 AASHTO method} \\ \hline \(\mathrm{N}_{self}\), MSA (100 kN) & 153.6 & 111.0 & 101.8 & 33.6 & 40.  
Figure 8: Results of calculations of pavement structure durability according to the 2004 AASHTO criterion.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Configuration** & **KR7 ACWMS** & **KR7** & **KR6 ACWMS** & **KR6** & **KR5 ACWMS** & **KR5** & **KR4** & **KR3** & **KR2** & **KR1** \\ \hline \(\epsilon_{\text{sig}}\), \(\mu\)m/m & 43.8 & 38.3 & 49.1 & 43.1 & 62.8 & 55.6 & 63.6 & 73.9 & 125.6 & 162 \\ \(\epsilon_{\text{gr}}\), \(\mu\)m/m & 133 & 117 & 141 & 131 & 179 & 168 & 192 & 223 & 404 & 502 \\ \(N_{\text{gr}}\), MSA (100 kN) & 321.9 & 567.6 & 247.7 & 344.6 & 85.0 & 112.3 & 62.1 & 31.7 & 2.2 & 0.8 \\ \hline \multicolumn{10}{c}{2004 AASHTO method} \\ \hline \(N_{\text{sigf}}\), MSA (100 kN) & 255.8 & 78.4 & 164.3 & 49.6 & 63.0 & 18.4 & 10.8 & 6.4 & 0.9 & 0.5 \\ \(N_{\text{init}}\), MSA (100 kN) & 255.8 & 78.4 & 164.3 & 49.6 & 63.0 & 18.4 & 10.8 & 6.4 & 0.9 & 0.5 \\ \hline \multicolumn{10}{c}{The French method} \\ \hline \(N_{\text{sigf}}\), MSA (100 kN) & 127.6 & 241.3 & 68.9 & 116.1 & 18.2 & 23.9 & 9.2 & 3.6 & 0.1 & 0.03 \\ \(N_{\text{init}}\), MSA (100 kN) & 127.6 & 241.3 & 68.9 & 116.1 & 18.2 & 23.9 & 9.2 & 3.6 & 0.1 & 0.03 \\ \hline \hline \end{tabular}
\end{table}
Table 5: The results of calculations of design life of the structures (stiffness of the asphalt layers according to laboratory tests).  
Figure 9: Results of calculations of pavement structure according to the French method for asphalt courses.