## 2 Experimental Program
### Testing Campaign  
As explained before, a total of 40 cylinders of each mixture were cast and divided into two series of 20 cylinders each. The two series were labeled as L-Series and H-Series, as explained later. Additionally, three cylinders, 150 mm in diameter and 300 mm in height, were cast to define the concrete quality. These cylinders were kept in the curing room with the rest of the specimens until day 28, when they were tested under static compression. The tests were performed according to the European Standards [31; 32]. The average compressive strength, \(f_{cm}\), was 75.95 MPa and the characteristic compressive strength, \(f_{\mathrm{c}k}\), was 73.0 MPa. According to Eurocode 2 [33], the strength class was therefore C70/85. The abovementioned 40 cylinders, 100 mm in diameter and 200 mm in height, were tested at an age of 180 days, as follows. Four specimens of each series, i.e., eight cylinders, were tested under static compression until failure just before starting the cyclic testing campaign, in order to define the real loads to be applied during the cyclic tests to the rest of the specimens. Tables 2 and 3 show the average values of the main mechanical parameters of the concrete for each series. The value in brackets represents the standard deviation. The compressive modulus of elasticity was obtained following the method described in standard EN 12390-13 [31]. The static compression test was then performed, as per standard EN 12390-3 [32], and the compressive strength and maximum compressive strain values were extracted. The rest of the cylinders, that is, 16 specimens of each series, were tested under cyclic load up to a pre-defined number of cycles. The main parameters of the cyclic tests were:  
* Stress level. In this case, two stress levels were considered, one per series. The compression load for the first series of cylinders ranged from 35% to 50% of the characteristic compressive strength, defined through the static tests described above. This first stress level was labeled \"high level series\" or \"H-Series.\" For the second series, compression loading ranged from 25% to 40% of the characteristic compressive strength, defined again through the static tests described above. This second stress level was labeled \"low level series\" or \"L-Series.\" \begin{table}
\begin{tabular}{c c c c} \hline
**Mechanical Parameter** & **HPC** & **SFHPC** & **PPFHPC** \\ \hline f\({}_{\mathrm{c}}\) (MPa) & 91.8 (0.8) & 94.8 (2.1) & 88.9 (1.1) \\ E\({}_{\mathrm{c}}\) (MPa) & 33,326.3 (1184.4) & 36,880.3 (2368.3) & 35,690.5 (2568.0) \\ \(\epsilon_{\mathrm{c,max}}\) & 0.0037 (0.0003) & 0.0028 (0.0003) & 0.0032 (0.0002) \\ \hline \end{tabular}
\end{table} 
Table 2: Mechanical parameters of the concrete before starting the cyclic tests. L-Series. \begin{table}
\begin{tabular}{c c c c} \hline
**Mechanical Parameter** & **HPC** & **SFHPC** & **PPFHPC** \\ \hline f\({}_{\mathrm{c}}\) (MPa) & 94.6 (0.5) & 102.7 (2.6) & 92.4 (1.9) \\ E\({}_{\mathrm{c}}\) (MPa) & 38,812.8 (1748.6) & 43,093.2 (1410.7) & 38,711.7 (2014.7) \\ \(\epsilon_{\mathrm{c,max}}\) & 0.0029 (0.0002) & 0.0032 (0.0001) & 0.0026 (0.0002) \\ \hline \end{tabular}
\end{table} 
Table 3: Mechanical parameters of the concrete before starting the cyclic test. H-Series. * Number of cycles. Four specimens of each series were subjected to cyclic loads of up to 2000 cycles. Another set of four specimens from each series was subjected to cyclic loads of up to 20,000 cycles. A third set of four specimens from each series was tested up to 200,000 cycles, and the last set of four specimens, up to 2,000,000 cycles. * Test frequency. In all cases, the test frequency was 6 Hz. According to Model Code 2010 [34], the expected fatigue life for the H-Series was \(1.5\times 10^{3}\) cycles, while the expected fatigue life for the L-Series was \(1.9\times 10^{8}\) cycles. These values were obtained considering the characteristic compressive strength at 28 days, i.e., 70 MPa, which was the reference value for concrete design.