## 3 RR-FRC Under Chloride Ingress
### Effects on Load-Bearing Capacity of RR-FRC  
A study by [PERSON] et al. [67] investigated the structural performance of beams simultaneously exposed to chloride ingress and sustained loads in a four-point bending test (4 PBT) configuration. Specimens were subjected to 72 days of wetting and drying cycles, after which a direct impressed current was imposed to accelerate corrosion until the target corrosion level (expressed as a percentage of lost mass of reinforcement, \(\eta\)) was achieved (5%, 10% and 15%). Sustained loads corresponded to the fraction of the yield load (\(F_{\text{y}}\)) of the uncorroded reference beam. Values of 10%, 20%, 30%, 40% and 50% of \(P_{\text{y}}\) were investigated. At the end of the exposure period, specimens were subjected to 4 PBT until failure. Based on the results obtained (Figure 6), the authors observed a correlation between the level of sustained load to which the beams were subjected during exposure and the recorded value of load-bearing capacity (\(F_{\text{max}}\)). Furthermore, it was observed that both the yield and ultimate loads decreased by a similar percentage, with a reduction in the ductility of the corroded specimens compared to those uncorroded. [PERSON] et al. [68] used drying and wetting cycles to compare the structural performance of tension ties. Specimens were pre-cracked in pure axial tension and subjected to a sustained axial load of 300 MPa. The authors observed corrosion only in the cracked region of all specimens. The extracted rebar was subjected to axial tensile loads until failure. The loss of tensile capacity of the rebar was comparable between RC and RR-SFRC elements. The reduction in the ultimate strain in bars extracted from RC specimens was larger (26%) compared to the bars extracted from RR-SFRC (22%). In another study stemming from the same experimental campaign, [PERSON] et al. [69] characterised the pitting corrosion of steel bars. After exposure, steel bars were extracted from tension ties, and their diameters were measured. The average loss of bar diameter due to corrosion was 6.2% and 5.3% for RC and RR-SFRC, respectively. The extracted bars were loaded in uniaxial tension until failure, and the yield load (\(F_{y}\)), ultimate load (\(F_{\text{u}}\)) and ultimate strain (\(\epsilon_{\text{u}}\)) were recorded. The results showed a greater scatter in the results of ultimate strain than that in the case of yield or ultimate load, indicating that this parameter is more affected by the corrosion process. [PERSON] et al. [71] investigated chloride-induced corrosion of specimens exposed to different environmental conditions (specimens were kept in fresh water and the atmospheric and tidal zones of the Oman Sea). Uncracked and pre-cracked elements in 4 PBT in an unloaded state were considered. Specimens were loaded until failure in bending tests after 28, 90 and 180 days of exposure. In the tidal exposure conditions, the authors observed  
Figure 6: Load–deflection curves of beams: (**a**) Uncorroded beams; (**b**) Corroded beams under sustained load of \(0.2F_{y}\); (**c**) Corroded beams under sustained load of \(0.4F_{y}\); (**d**) Corroded beams under varied sustained loads. CX designates corroded RR-SFRC beams, where X stands for the corrosion level achieved; similarly, PX designates beams under different levels of sustained loads, where X is a fraction of \(F_{y}\)[67]. losses of load-bearing capacity of cracked RC elements of 22% (90 days) and 31% (180 days). In the case of RR-SFRC elements, the load-bearing capacity of cracked elements in the tidal zone increased by 5% (90 days) and 16% (180 days). A similar trend was observed for cracked RC and RR-SFRC elements in the atmospheric conditions of the tidal zone and laboratory conditions. For uncracked specimens, the reduction in load-bearing capacity in the tidal zone of RC specimens was 15% (90 days) and 18% (180 days). The reduction in load-bearing capacity of uncracked RR-SFRC specimens in the tidal zone was 14% (90 days) and 22% (180 days).