PSI - Issue 10

S. Tsouli et al. / Procedia Structural Integrity 10 (2018) 41–48 S. Tsouli et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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(c)

Fig. 3. 304L reinforced concrete after 4 m in the salt spray chamber: (a) Side-view; (b) Top-view of 304L reinforced concrete containing 20 wt.% FA; (c) Stress-strain curves of 304L rebars embedded in concrete with different fly ash (FA) contents before (0 m) and after salt spraying (2 m).

Table 3. Tensile properties of 304L rebars embedded in concrete with different fly ash contents before (0 m) and after salt spraying (2 m). Fly ash (wt.%) Duration (m) σ y 0.2% (MPa) σ t (MPa) σ f (MPa) % EL 0 0 611± 31 782± 31 726±50 44± 0 2 605± 50 776± 58 720±57 42± 1 15 0 619± 30 790± 27 732±3 43± 1 2 555± 44 729± 52 667±24 41± 2 20 0 586± 15 754± 16 686±20 43± 1 2 594± 19 771± 18 735±4 40± 2 25 0 592± 8 753± 11 669±1 42± 1 2 598± 41 780± 38 706±31 43± 0

4. Conclusions

Cyclic polarization of 304L stainless steel rebars in s. Ca(OH) 2 containing an acid rain simulating solution and different fly ash (FA) amounts revealed slow corrosion kinetics, passive-like regimes and low susceptibility to localized corrosion (10-20 wt.% FA). An increase in the FA addition led to a decrease in the thermodynamic tendency for corrosion and corrosion kinetics. This trend was reversed at 25 wt.% FA. Corrosion-wise, 304L can replace 316L stainless steel in the restoration of ancient monuments provided that FA is included in the concrete mixture as a corrosion inhibitor, even at low contents (10 or 15 wt.%). Salt spraying for 2 m did not affect the mechanical properties of the 304L rebars embedded in concrete cubes. Not any macrostructural signs of corrosion were observed in 304L reinforced concrete cubes after a 4 m salt spray test. Apostolopoulos, Ch.A., Demis, S., Papadakis, V.G., 2013. Chloride-induced corrosion of steel reinforcement - Mechanical performance and pit depth analysis. Construction and Building Materials 38, 139-146. Apostolopoulos, A., Matikas, Th.E., 2016. Corrosion of bare and embedded in concrete steel bar – Impact on mechanical behavior. International Journal of Structural Integrity 7, 240-259. Blanco, G., Bautista, A., Takenouti, H., 2006. EIS study of passivation of austenitic and duplex stainless steels reinforcements in simulated pore solutions. Cement & Concrete Composites 28, 212-219. Camuffo, D., 2014. Atmospheric Water and Stone Weathering, in “Microclimate for Cultural Heritage. Conservation, Res toration, and Maintenance of Indoor and Outdoor Monuments” . 2 nd Ed., Elsevier Science, pp. 203-243. Chousidis, N., Ioannou, I., Rakanta, E., Koutsodontis, C., Batis, G., 2016. Effect of fly ash chemical composition on the reinforcement corrosion, thermal diffusion and strength of blended cement concretes. Construction and Building Materials 126, 86-97. References