PSI - Issue 11

Gibson R. Meira et al. / Procedia Structural Integrity 11 (2018) 122–129 Meira et al./ Structural Integrity Procedia 00 (2018) 000–000

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bars for pHs over the mentioned level. However, for pHs below this limit (pH ≈ 13.2), the galvanized bars present very low rates of corrosion even for carbonated media (pH ≈ 8.5), demonstrating their potential in comparison with non-galvanized bars that go into corrosive process under these conditions. This corroborates with the studies of Macias and Andrade (1990) and Maahn and Sorensen (1986). 5. Conclusions Considering the testing conditions adopted in this work, it was possible to identify, through the electrochemical measurements of corrosion potential (CSE) and corrosion current density, the initial stabilization of these parameters, the formation of the passive film and the behaviour of the bars over time in carbonated and non- carbonated media. Galvanized bars show electrochemical parameters that indicate a high degree of corrosion in environments with a pH higher than 13.2. Demonstrating that, probably, the passive film was not efficiently formed under these conditions. However, in medias of lower alkalinity (pH <13.2), galvanized bars show all their corrosion protection capacity, presenting superior performance in comparison with non-galvanized bars even in carbonated media. Therefore, it is recommended the use of galvanized bars in aggressive environments where there is a high concentration of carbon dioxide (viaducts, tunnels, etc.), which may be done in cement matrices of lower alkalinity, especially those that have pozzolanic additions References Alonso, C.; Andrade, C. (1990). Effect of nitrite as a corrosion inhibitor in contaminated and chloride-free carbonated mortars. ACI Materials Journal, V87, n2, p. 130-137. American Society for Testing and Materials. ASTM G-1 (1999). Standard practice for preparing, cleaning and evaluating corrosion test specimens. Annual Book of ASTM Standards. Philadelphia. American Society for Testing and Materials. ASTM C-876(1999). Standard test for half-cell potencials of uncoated reinforcing steel in concrete. Anual Book of ASTM Standards. Philadelphia. Andrade, C. (1988). Manual de inspección de obras dañadas porcorrosión de armaduras. Madrid: CSIC/IETcc. p. 122. Angst, U. M.; Vennesland, Ø. (2009). Critical chloride content in reinforced concrete - State of the art. Concrete Repair, Rehabilitation and Retrofitting II. Taylor & Francis Group, p. 311- 317. Cascudo, O. (1997). Controle da corrosão de armaduras em concreto-Inspeção e Técnicas Eletroquímicas. Co-edição, São Paulo; Ed. PINI. p. 25- 252. Cigna, R.; Andrade, C.; Nürnberger, U.; Polder, R.; Weydert, E.; Seitz, E. (1997). Corrosion and protection of metals in contact with concrete. COST Action 509 – Final Report. European Community: Luxembourg. Farina, S. B.; Duffó, G. S. (2007). Corrosion of zinc in simulated carbonated concrete pore solutions. Electrochemica Acta, 52, p. 5131-5139. González, J. A.; Andrade, C. (1982). Effect of carbonation, chlorides and relative ambient humidity on the corrosion of galvanized rebars embedded in concrete, Br. Corrosion Journal, 17, p. 21-28. Helene, P. R. L. (1993). Contribuição ao Estudo da Corrosão em Armaduras de Concreto Armado. Tese de Livre Docência. São Paulo: Universidade de São Paulo, 231 p. Macias, A.; Andrade, C. (1990). The behaviour of galvanized steel in chloride-containing alkaline solutions – the influence of the cation. Corrosion Science, 30, p. 393- 407. Maahn, E.; Sorensen, B. (1986). The influence of microstructure on the corrosion properties of hot-dip galvanized reinforcement in concrete. Corrosion, V42, p. 187-196. Mehta, P. K.; Monteiro, P. J. M. (2008). Concreto: Microestrutura, propriedades e materiais. Tradutora Cristina Borba. São Paulo: Ibracon. p.121– 123, p. 156, p. 161-170. Meira, G. R.; Andrade, C.; Vilar, E. O.; Neri, K. D. (2014). Analysis of chloride threshold from laboratory and field experiments in marine atmosphere zone. Construction and Building Materials, 55, p. 289- 298. Moreira, C. (2006). Realcalinização de estruturas de concreto carbonatados com a utilização de gel saturado de solução alcalina. Dissertação de mestrado – Universidade Federal de Goiânia. Tuutti, K. (1982). Corrosion of steel in concrete. Sweden: CBI.