Title:
Mobility of Chloride in Concrete Subjected to Electrochemical Treatment
Author(s):
C.-G. Cho, K. Y. Ann, H. Kim, W. Hwang, J. Kim, W. J. Cho, and H. S. Jung
Publication:
Materials Journal
Volume:
118
Issue:
2
Appears on pages(s):
189-198
Keywords:
chloride; corrosion; electrochemical treatment; steel
DOI:
10.14359/51730416
Date:
3/1/2021
Abstract:
In this study, chloride mobility after electrochemical treatment in concrete was evaluated. Once a concrete specimen containing three steel reinforcing bars was exposed to 4M NaCl for 365 days, electrochemical chloride extraction was applied to the reinforcing bars for 8 weeks at 750 mA/m2 (0.484 mA/in.2) direct current. To evaluate chloride mobility, chloride concentration at all depths was measured for total, free, and bound ones by chloride profiling. Simultaneously, the corrosion rate and potential were measured during the treatment. The removal efficiency for total chloride was significant, ranging from 26.2 to 70.2% compared to the untreated specimen. Free chlorides were mostly removed from the concrete body except for the nearer surface, and bound chloride concentration was surprisingly reduced to 0.67 to 0.74%, irrespective of the depth. Moreover, the corrosion rate and potential indicated that the risk of corrosion was mitigated. A visual examination for steel reinforcing bars confirmed that rust was dramatically reduced after the treatment.
Related References:
1. Manning, D. G., “Cathodic Protection of Concrete Highway Bridges,” in: Page C.L., Treadaway K.W.J., Bamforth P.B. (Eds.), Corrosion of Reinforcement in Concrete, Elsevier Applied Science, London UK, 1990, pp. 486-497.
2. Broomfield, J. P.; Langfor, P. E.; and Mcanoy, R., “Cathodic Protection for Reinforced Concrete: Its Application to Buildings and Marine Structures,” in: Virmani P. (Ed.), Corrosion of Metals in Concrete, NACE, Houston, TX, USA, 1987, pp. 222-235.
3. Pruckner, F.; Theiner, J.; Eri, J.; and Nauer, G. E., “In-Situ Monitoring of The Efficiency of The Cathodic Protection of Reinforced Concrete by Electrochemical Impedance Spectroscopy,” Electrochimica Acta, V. 41, No. 7-8, 1996, pp. 1233-1238. doi: 10.1016/0013-4686(95)00475-0
4. Slater, J. E.; Lankard, D. R.; and Moreland, P. L., “Electrochemical Removal of Chlorides from Concrete Bridge Decks,” Transportation Research Record: Journal of the Transportation Research Board, No. 604, 1976, pp. 6-15.
5. Orellan, J. C.; Escadeillas, G.; and Arliguie, G., “Electrochemical Chloride Extraction: Efficiency and Side Effects,” Cement and Concrete Research, V. 34, No. 2, 2004, pp. 227-234. doi: 10.1016/j.cemconres.2003.07.001
6. Perez, A.; Climent, M. A.; and Garces, P., “Electrochemical Extraction of Chlorides from Reinforced Concrete Using A Conductive Cement Paste as The Anode,” Corrosion Science, V. 52, No. 5, 2010, pp. 1576-1581. doi: 10.1016/j.corsci.2010.01.016
7. Canon, A.; Garces, P.; Climent, M. A.; Carmona, J.; and Zornoza, E., “Feasibility of Electrochemical Chloride Extraction from Structural Reinforced Concrete Using A Sprayed Conductive Graphite Powder-Cement Paste as Anode,” Corrosion Science, V. 77, No. 12, 2013, pp. 128-134. doi: 10.1016/j.corsci.2013.07.035
8. Elsener, B., and Angst, U., “Mechanism of Electrochemical Chloride Removal,” Corrosion Science, V. 49, No. 12, 2007, pp. 4504-4522. doi: 10.1016/j.corsci.2007.05.019
9. Martinez, I.; Rozas, F.; Ramos-Cillan, S.; Gonzalez, M.; and Castellote, M., “Chloride Electroremediation In Reinforced Structures: Preliminary Electrochemical Tests to Detect the Steel Repassivation During the Treatment,” Electrochimica Acta, V. 181, No. 1, 2015, pp. 288-300. doi: 10.1016/j.electacta.2015.06.005
10. Kim, K. B.; Hwang, J. P.; and Ann, K. Y., “Influence of Cementitious Binder on Chloride Removal Under Electrochemical Treatment in Concrete,” Construction and Building Materials, V. 104, No. 1, 2016, pp. 191-197. doi: 10.1016/j.conbuildmat.2015.12.052
11. Mietz, J., “Electrochemical Rehabilitation Methods for Reinforced Concrete Structures. A State-of-the-Art Report,” European Federation of Corrosion Publication, No. 24, IOM Communications Ltd., London, UK, 1998.
12. Song, H. W.; Jung, M. S.; Lee, C. H.; Kim, S. H.; and Ann, K. Y., “Influence of Chemistry of Chloride Ions in Cement Matrix on Corrosion of Steel,” ACI Materials Journal, V. 107, No. 4, July-Aug. 2010, pp. 332-339.
13. Chu, H. Q.; Zhang, B. Q.; Zhao, S. J.; Guo, M. Z.; Liang, Y. C.; Jiang, L. H.; and Song, Z. J., “Effect of Electric Current on The Stability of Bound Chloride,” Cement and Concrete Composites, V. 103, 2019, pp. 71-79. doi: 10.1016/j.cemconcomp.2019.04.015
14. Geng, J.; Easterbrook, D.; Li, L. Y.; and Mo, L. W., “The Stability of Bound Chlorides in Cement Paste with Sulfate Attack,” Cement and Concrete Research, V. 68, 2015, pp. 211-222. doi: 10.1016/j.cemconres.2014.11.010
15. Shafikhani, M., and Chidiac, S. E., “Quantification of Concrete Chloride Diffusion Coefficient—A Critical Review,” Cement and Concrete Composites, V. 99, 2019, pp. 225-250. doi: 10.1016/j.cemconcomp.2019.03.011
16. Shakouri, M.; Vaddey, N. P.; and Trejo, D., “Effect of Admixed and External Chlorides on Transport of Chlorides in Concrete,” ACI Materials Journal, V. 116, No. 5, Sept. 2019, pp. 119-128. doi: 10.14359/51716833
17. Glass, G. K.; Hassanein, A. M.; and Buenfeld, N. R., “Cathodic Protection Afforded by An Intermittent Current Applied to Reinforced Concrete,” Corrosion Science, V. 43, No. 6, 2001, pp. 1111-1131. doi: 10.1016/S0010-938X(00)00133-5
18. Ann, K. Y.; Jung, M. S.; Shim, H. B.; and Shin, M. C., “Effect of Electrochemical Treatment in Inhibiting Corrosion of Steel in Concrete,” ACI Materials Journal, V. 108, No. 5, Jan.-Feb. 2011, pp. 485-492.
19. Buenfeld, N. R., and Glass, G., Kevin.; Reddy, B.; and Viles, R.F., “Process for The Protection of Reinforcement in Reinforced Concrete,” World Intellectual Property Organization, 2004.
20. Ribeiro, M. S.; Lage, J.; and Goncalves, A., “Chloride Assessment in Structures. Influences of Sampling and Test Location,” Cement and Concrete Research, V. 117, 2019, pp. 82-90. doi: 10.1016/j.cemconres.2019.01.002
21. Arya, C.; Buenfeld, N. R.; and Newman, J. B., “Assessment of Simple Methods of Determining the Free Chloride Content of Cement Paste,” Cement and Concrete Research, V. 17, No. 6, 1987, pp. 907-918. doi: 10.1016/0008-8846(87)90079-2
22. British Standard 8110: Part 1, “Structural Use of Concrete—Code of Practice for Design and Construction,” British Standards Institute, London, UK, 1985.
23. ACI Committee 201, “Guide to Durable Concrete, Manual of Concrete Practice, Part 1 (ACI 201.2R-16),” American Concrete Institute, Farmington Hills, MI, 1994, 7 pp.
24. ACI Committee 357, “Guide for Design and Construction of Fixed Off-Shore Concrete Structures, Manual of Concrete Practice, Part 4 (ACI(space)357R-84),” American Concrete Institute, Farmington Hills, MI, 1994.
25. ACI Committee 222, “Corrosion of Metals in Concrete, Manual of Concrete Practice, Part 3 (ACI 201.2R-16),” American Concrete Institute, Farmington Hills, MI, 1994.
26. Broomfield, J. P.; Rodriguez, J.; Ortega, L. M.; and Garcia, A. M., “Corrosion Rate Measurement and Life Prediction for Reinforced Concrete Structures,” Proceedings of the Structural Faults and Repair, V. 2, University of Edinburgh, Scotland, UK, 1993, pp. 155-164.
27. Chen, J. J.; Sorelli, L.; Vandamme, M.; Ulm, F. J.; and Chanvillard, G., “A Coupled Nanoindentation/Sem‐Eds Study On Low Water/Cement Ratio Portland Cement Paste: Evidence For C–S–H/Ca(Oh)2 Nanocomposites,” Journal of the American Ceramic Society, V. 93, No. 5, 2010,
pp. 1484-1493. doi: 10.1111/j.1551-2916.2009.03599.x
28. Ann, K. Y., “Enhancing the Chloride Threshold Level for Steel Corrosion in Concrete,” PhD thesis, University of London, London, UK, 2005.
29. Song, H. W.; Lee, C. H.; Jung, M. S.; and Ann, K. Y., “Development of Chloride Binding Capacity in Cement Pastes and Influence of The PH of Hydration Products,” Canadian Journal of Civil Engineering, V. 35, No. 12, 2008, pp. 1427-1434. doi: 10.1139/L08-089
30. Gonzalez, J. A., and Andrade, C., “Effect of Carbonation, Chlorides and Relative Ambient Humidity on The Corrosion of Galvanized Rebars Embedded In Concrete,” British Corrosion Journal, V. 17, No. 1, 1982, pp. 21-28. doi: 10.1179/000705982798274589
31. Glass, G. K.; Reddy, B.; and Buenfeld, N. R., “The Participation of Bound Chloride in Passive Film Breakdown on Steel in Concrete,” Corrosion Science, V. 42, No. 11, 2000, pp. 2013-2021. doi: 10.1016/S0010-938X(00)00040-8
32. Ryou, J. S., and Ann, K. Y., “Variation in The Chloride Threshold Level for Steel Corrosion in Concrete Arising from Different Chloride Sources,” Magazine of Concrete Research, V. 60, No. 3, 2008, pp. 177-187. doi: 10.1680/macr.2008.60.3.177
33. Elsener, B.; Molina, M.; and Böhni, H., “The Electrochemical Removal of Chlorides from Reinforced Concrete,” Corrosion Science, V. 35, No. 5-8, 1993, pp. 1563-1570. doi: 10.1016/0010-938X(93)90385-T
34. Miranda, J. M.; Gonzalez, J. A.; Cobo, A.; and Otero, E., “Several Questions About Electrochemical Rehabilitation Methods for Reinforced Concrete Structures,” Corrosion Science, V. 48, No. 8, 2006, pp. 2172-2188. doi: 10.1016/j.corsci.2005.08.014
35. Sanchez, M. J.; Garces, P.; and Climent, M. A., “Electrochemical Extraction of Chlorides from Reinforced Concrete: Variables Affecting Treatment Efficiency,” Materiales de Construcción, V. 56, No. 284, 2006, pp. 17-26. doi: 10.3989/mc.2006.v56.i284.15
36. Toumi, A.; Francois, R.; and Alvarado, O., “Experimental and Numerical Study of Electrochemical Chloride Removal from Brick and Concrete Specimens,” Cement and Concrete Research, V. 37, No. 1, 2007, pp. 54-62. doi: 10.1016/j.cemconres.2006.09.012
37. ASTM C876-09, “Standard Test Method for Half-Cell Potentials of Uncoated Reinforcing Steel in Concrete,” ASTM International, West Conshohocken, PA, 2009.
38. Revie, R. W., Uhlig's Corrosion Handbook, John Wiley & Sons, 2011.
39. Ihekwaba, N. M.; Hope, B. B.; and Hansson, C. M., “Pull-Out and Bond Degradation of Steel Reinforcing Bars in ECE Concrete,” Cement and Concrete Research, V. 26, No. 2, 1996, pp. 267-282. doi: 10.1016/0008-8846(95)00210-3
40. Buenfeld, N. R., and Broomfield, J. P., “Influence of Electrochemical Chloride Extraction on The Bond Between Steel and Concrete,” Magazine of Concrete Research, V. 52, No. 2, 2000, pp. 79-91. doi: 10.1680/macr.2000.52.2.79