## 3 Results and Discussion
### Flexural Response
[41], while the modulus of rupture range is similar to those reported in [27; 42], and fits the prediction obtained through the model presented in [43]. The results in non-corroded composites are in agreement with the finding of [PERSON] et al. [7], i.e., fiber volume is the dominant parameter on the peak load. Under moderate corrosion, the flexural performance rank follows the reinforcing index, RI, rank. \[\text{RI}=V_{f}\frac{l}{d}, \tag{3}\]  
where \(V_{f}\)is the fiber content (\(vol./vol.\)), and \(l\) and \(d\) are the fiber length and diameter, respectively. Concerning severe corrosion conditions, the best-performing composite was F40 RC, while there is a notorious loss of bending stiffness for F80 ZP and F40 ZP. Figure 9 depicts the flexural behavior of the same composite at different corrosion levels. The loss of flexural performance with increasing corrosion level is remarkable for composites with ZP fibers (F80 ZP and F40 ZP), while for RC fibers (F40 RC), it is less pronounced. Nevertheless, the performance loss is masked by the behavior of F40 RC between cracking and the maximum load for the uncorroded condition. This is attributed to the fact that for light corrosion, the stresses built up by the corrosion products, along with the irregularities created at the fiber surface, enhance the friction between the fiber and matrix [14; 26], increasing the gap between \(P_{cr}\) and \(P_{max}\). Apart from this, the loss of flexural performance increases with the level of corrosion. Figure 7: Definition of toughness indexes: (**a**) ASTM; (**b**) JSCE. All corroded specimens showed a lower peak load than their uncorroded companions. Both the peak load and the cracking load showed a negative association with the corrosion level, i.e., they decreased with the increase of the corrosion level. The same is valid for JSC toughness. For \(f_{MOR}\) and \(f_{e}\), the relative variation is equivalent to that of \(P_{max}\) and \(T_{b}\), respectively, as there is a linear relationship between them. The losses on \(T_{b}\) for intermediate corrosion are comparable to those obtained by [PERSON] et al. [44] in SFRC mixed with seawater, while the losses in flexural strength are comparable to those found in [45]. For severe corrosion, the relative losses in flexural toughness and strength are in line with the results reported in [26] and with those reported in [26]. Figure 8: Load–deflection curves for: (**a**) no-corrosion; (**b**) intermediate corrosion; and (**c**) severe corrosion of the 3 composites. by [PERSON] et al. [20] for diametral compression, in SFRC subject to severe corrosion also through imposed current. The variation in the displacement ductility and toughness indexes with the corrosion level was not consistent. [PERSON] et al. [7] reported that, concerning fiber reinforcement, the displacement ductility index is mostly ruled by the fiber volume, which is in agreement with the results for the non-corroded composites. The same authors defend that the most influential factor on the displacement ductility index is the peak load. As peak load decreases with increasing corrosion level and the corrosion impact in the pre-peak response is higher than in the post-peak response, the displacement ductility index turns out to be a  
Figure 9: Load–deflection curves for composites: (**a**) F80 ZP; (**b**) F40 ZP; and (**c**) F40 RC concerning the 3 corrosion levels. bad indicator of corrosion influence on flexural performance. The influence of corrosion in the pre-peak response is shaped in Figure 9, with noticeable lower flexural stiffness of the composites under severe corrosion. This can be attributed to both the microcracks caused by the volume increase due to corrosion products, the corrosion products acting as voids, given their non-cohesive nature, and the decrease in effective fiber volume. The residual load bearing capacity at a midspan deflection of 1/150, already used by [PERSON] and [PERSON] (2016), showed to be consistent with the corrosion level as well as with the reinforcing index.