Long-term effects of electrochemical realkalization on carbonated concrete

Abstract

The long-term effects of electrochemical realkalization on carbonated reinforced concrete with a W/C ratio of 0.65 were studied. Fourteen out of 16 carbonated specimens had been subjected to realkalization seven years ago, and the alkalinity of the concrete, the electrochemical characters (corrosion current density and potential) of the specimens and the corrosion conditions of the steel bars were examined. Results of different specimens and also at different time (4, 10, 13 months and 7 years after realkalization) were compared. According to the phenolphthalein and pH meter test, the alkalinity of the concrete had disappeared after seven years. Based on the potentiodynamic polarization test, various corrosion conditions had developed on the steel bars, which was verified by visual observation. All bars were in the depassivated state, and their corrosion current densities increased significantly after seven years. Cracks developed in some of the specimens, and the diverse compactness of concrete and excessive current of realkalization were considered to be possible causes. The effects of the realkalization treatment vanished after seven years.

Keywords

realkalization / concrete / carbonation / polarization curve / corrosion

References

[1] Redaelli E, Carsana M, Gastaldi M, Lollini F, Bertolini L. Electrochemical techniques for the repair of reinforced concrete suffering carbonation-induced corrosion. Corrosion Reviews, 2011, 29(5–6): 179–190

[2] Yeih W, Chang J J. A study on the efficiency of electrochemical realkalisation of carbonated concrete. Construction & Building Materials, 2005, 19(7): 516–524

[3] Mietz J. Electrochemical realkalisation for rehabilitation of reinforced concrete structures. Materials and Corrosion, 1995, 46(9): 527–533

[4] Matsumoto K I, Ueda T, Ashida M, Miyagawa T. Study on realkalization with electrolyte containing lithium ion. International Journal of Modern Physics B, 2003, 17(8&9): 1446–1451

[5] Odden L. The repassivating effect of electrochemical realkalisation and chloride extraction. In: Proceedings of Corrosion and Corrosion Protection of Steel in Concrete. Sheffield: Sheffield Academic Press, 1994, 1473–1488

[6] Velivasakis E E, Henriksen S K, Whitmore D. Chloride extraction and realkalization of reinforced concrete stop steel corrosion. Journal of Performance of Constructed Facilities, 1998, 12(2): 77–84

[7] Andrade C, Castellote M, Sarría J, Alonso C. Evolution of pore solution chemistry, electro-osmosis and rebar corrosion rate induced by realkalisation. Materials and Structures, 1999, 32(6): 427–436

[8] Meitz J. Electrochemical Rehabilitation Methods for Reinforced Concrete Structures. A State of the Art Report. EFC Publication 24. London: The Institute of Materials, 1998

[9] Qu W J, Xiong Y, Guo L. Influencing factor of realkalization technique for carbonated concrete and study of its durability. Journal of Building Materials, 2008, 11(1): 21–27 (in Chinese)

[10] Tong Y Y, Bouteiller V, Marie-Victoire E, Joiret S. Durability evaluation of a realkalisation treatment using impressed current. In: 11DBMC International Conference on Durability of Building Materials and Components. Istanbul: Istanbul Technical University, 2008

[11] Ribeiro P H L C, Meira G R, Ferreira P R R, Perazzo N. Electrochemical realkalisation of carbonated concretes—Influence of material characteristics and thickness of concrete reinforcement cover. Construction & Building Materials, 2013, 40: 280–290

[12] Andrade C, Martínez I, Castellote M, García De Viedma P. Efficiency control of electrochemical repair techniques. In: Concrete Repair, Rehabilitation and Retrofitting II—Proceedings of the 2nd International Conference on Concrete Repair, Rehabilitation and Retrofitting, ICCRRR. Cape Town: CRC Press, 2009, 31–37

[13] Redaelli E, Bertolini L. Electrochemical repair techniques in carbonated concrete. Part I: Electrochemical realkalisation. Journal of Applied Electrochemistry, 2011, 41(7): 817–827

[14] Wang K, Qu W J, Li P H, Zhang J X. A long-term electrochemical study on carbonated reinforced concrete after realkalization. Journal of Tongji University (Natural Science), 2012, 40(3): 353–360 (in Chinese)

[15] GB/T50081. Standard for Test Method of Mechanical Properties on Ordinary Concrete. Beijing: China Architecture & Building Press, 2002 (in Chinese)

[16] Banfill P F G. Re-alkalisation of carbonated concrete-effect on concrete properties. Construction & Building Materials, 1997, 11(4): 255–258

[17] Garcia-Diaz E, Riche J, Bulteel D, Vernet C. Mechanism of damage for the alkali-silica reaction. Cement and Concrete Research, 2006, 36(2): 395–400

[18] Fournier B, Berube M A. Alkali-aggregate reaction in concrete: A review of basic concepts and engineering implications. Canadian Journal of Civil Engineering, 2000, 27(2): 167–191

[19] Siegwart M, Lyness J F, McFarland B J. Change of pore size in concrete due to electrochemical chloride extraction and possible implications for the migration of ions. Cement and Concrete Research, 2003, 33(8): 1211–1221

[20] CEN/TS 14038-1. Electrochemical Realkalisation and Chloride Extraction Treatments for Reinforced Concrete—Part 1: Realkalisation. London: European committee for standardization, 2004

[21] NACE SP0107. Standard Practice: Electrochemical Realkalization and Chloride Extraction for Reinforced Concrete. Houston: NACE international, 2007

[22] Basheer, P A M, Sloan, T D. Corrosion of Steel in Reinforced Concrete Structure. COST Action 521Final Report, 2003

[23] ASTM C876. Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete. West Conshohocken: ASTM International, 2015

[24] GB/T 50344. Technical Standard for Inspection of Building Structure. Beijing: China Architecture & Building Press, 2004 (in Chinese)

[25] Vidal T, Castel A, François R. Analyzing crack width to predict corrosion in reinforced concrete. Cement and Concrete Research, 2004, 34(1): 165–174

[26] Djerbi A, Bonnet S, Khelidj A, Baroghel-bouny V. Influence of traversing crack on chloride diffusion into concrete. Cement and Concrete Research, 2008, 38(6): 877–883

[27] Bertolini L, Redaelli E, Lattanzi D, Mapelli M. Conservation techniques on the reinforced concrete pillars of the church of the San Carlo Borromeo hospital in Milan. European Journal of Environmental and Civil Engineering, 2010, 14(4): 411–425

[28] Tong Y Y, Bouteiller V, Marie-Victoire E, Joiret S. Efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete—Part 1: Sacrificial anode process. Cement and Concrete Research, 2012, 42(1): 84–94

[29] Montes P, Bremner T W, Lister D H. Influence of calcium nitrite inhibitor and crack width on corrosion of steel in high performance concrete subjected to a simulated marine environment. Cement and Concrete Composites, 2004, 26(3): 243–253

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