# Evaluation of Fatigue Life of Asphalt Concrete Mixtures with Reclaimed Asphalt Pavement
## 4 Tests Results
### Results of Fatigue Tests  
Table 2 presents the fatigue characteristics parameters of the mixtures of asphalt concrete AC22P 35/50 and high modulus asphalt concrete ACWMS16 25/55-60 with reclaimed asphalt. Additionally, the same parameters of that type of mixture, but without the reclaimed asphalt content, were included for comparison. The results come from the research works carried out in the Road and Bridge Research Institute in recent years. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**Mixture** & **AC22P 35/50** & **AC16W 25/55-60** & **ACWMS16** & **AC11S 45/80-55** & **SMA11 45/80-55** \\  & **50\%**RAP** & **50\%**RAP** & **25/55-60 50\%**RAP** & **30\%**RAP** & **15\%**RAP** \\ \hline Added (fresh) asphalt binder & 35/50 & 25/55-60 & 25/55-60 & 45/80-55 & 45/80-55 \\ \hline Contents of reclaimed asphalt, \% m/m & 50 & 50 & 50 & 30 & 15 \\ \hline Properties of recovered asphalt & & & & & \\ \hline Penetration at 25 °C, 0.1 mm & 28 & 28 & 32 & 49 & 52 \\ \hline Softening point according to & & & & & \\ ring and ball method, °C & & 62.3 & 66.5 & 64.5 & 60.5 & 58.9 \\ \hline Properties of bituminous mixtures & & & & & \\ \hline Density, kg/m\({}^{3}\) & 2431 & 2417 & 2430 & 2419 & 2379 \\ \hline Maximum density, kg/m\({}^{3}\) & 2540 & 2518 & 2500 & 2480 & 2429 \\ \hline Contents of soluble asphalt, \% _m/m_ (by weight) & & 3.7 & 4.4 & 5.0 & 5.2 & 6.3 \\ \hline Contents of aggregate mixture, \% _m/m_ (by weight) & & 96.3 & 95.6 & 95.0 & 94.8 & 93.7 \\ \hline Air voids content, \% _v_/v (by volume) & & 4.3 & 4.0 & 2.8 & 2.5 & 2.1 \\ \hline Contents of soluble asphalt, \% _v_/v (by volume) & & 10.3 & 11.8 & 12.2 & 14.6 \\ \hline Contents of aggregate, \% _v_/v (by volume) & & 87.0 & 85.7 & 85.4 & 85.3 & 83.4 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Properties of recovered binders and bituminous mixtures with reclaimed asphalt. Evaluation of the durability of AC22P and ACWMS16 mixtures with reclaimed asphalt must be carried out separately, because these are mixtures of different types and with different binders (unmodified asphalt and polymer-modified asphalt). Therefore, it is not surprising that those mixtures significantly differ in terms of fatigue resistance with an indication of the better properties of ACWMS16. It should be noted that the addition of reclaimed asphalt in a relatively large amount of 50% did not affect the scatter of results. The regression correlation coefficient R\({}^{2}\) at the level of 0.9 is the result proving small scatter of results, and does not deviate from the values obtained for mixtures without reclaimed asphalt. The AC22P 35/50 asphalt concrete is one of the basic mixtures for base courses according to the Technical Recommendations in Poland [24], and is very often used for different traffic categories. It is designed using the empirical method and the requirements in terms of fatigue resistance were not specified. Therefore, it is not possible to determine the suitability of the AC22P 35/50 mixture with reclaimed asphalt with respect to the applicable technical requirements. However, the results obtained for this mixture may be referred to the results from other research. Hence, Table 2 and Figures 4 and 5 provide the results for two AC22P 35/50 reference mixtures. The comparison of the \(\varepsilon_{6}\) parameter indicates higher results of the fatigue life of the mixture with reclaimed asphalt compared to the reference mixtures. This effect is also visible in diagrams of fatigue characteristics. Characteristics of AC22P mixtures have similar incline; however, the line of the mixture with RAP is shifted in the