Half-Cell Potential as an Indicator of Chloride-Induced Rebar Corrosion Initiation in RC
Publication: Journal of Materials in Civil Engineering
Volume 21, Issue 10
Abstract
The results of an experimental study conducted on specimens similar to ASTM G109 made with different types of cement and steel, and varying water/cement (w/c) ratios are reported in this paper. A portion of the top surface of the specimens was subjected to an exposure to 3% sodium chloride solution followed by an exposure to air, in cycles, for a large number of repetitions. Half-cell potential measurements were carried out periodically at the beginning of every exposure to chloride solution and also just prior to exposure to air, until a sudden drop in the potential was noticed. The average half-cell potential value of top steel bar, after sudden drop, is observed to be nearly the same, irrespective of steel, cement, and w/c ratio. However, corresponding free and total chloride concentrations, just after the preceding sudden drop, varied with experimental factors. The aforementioned sudden drop is also accompanied by reversal in the direction of current between top and bottom steel bars, indicated by a sign change in the potential difference. Thus, it is demonstrated that half-cell potential is a stable indicator of rebar corrosion initiation.
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References
Alonso, C., Andrade, C., Castellote, M., and Castro, P. (2000). “Chloride threshold values to depassivate reinforcing bars embedded in a standardized OPC mortar.” Cem. Concr. Res., 30, 1047–1055.
ASTM. (1999). “Standard test method for half-cell potentials of uncoated reinforcing steel in concrete.” C876, ASTM, West Conshohocken, Pa.
ASTM. (2005). “Standard test method for determining the effects of chemical admixtures on the corrosion of embedded steel reinforcement in concrete exposed to chloride environments.” G109, ASTM, West Conshohocken, Pa.
Baessler, R., and Burkert, A. (2001). “Laboratory testing of portable equipment.” Brite/Euram project integrated monitoring system for durability assessment of concrete structures, Federal Institute for Materials and Testing (BAM), Berlin.
Dehwah, H. A. F., Maslehuddin, M., and Austin, S. A. (2002). “Long-term effect of sulfate ions and associated cation type on chloride-induced reinforcement corrosion in Portland cement concretes.” Cem. Concr. Compos., 24, 17–25.
Garces, P., Andrade, M. C., Saez, A., and Alonso, M. C. (2005). “Corrosion of reinforcing steel in neutral and acid solutions simulating the electrolytic environments in the micropores of concrete in the propagation period.” Corros. Sci., 47, 289–306.
Glass, G. K., and Buenfeld, N. R. (1997). “The presentation of the chloride threshold level for corrosion of steel in concrete.” Corros. Sci., 39, 1001–1013.
Hope, B. B., and Lp, A. K. C. (1987). “Chloride corrosion threshold in concrete.” ACI Mater. J., 84, 306–314.
Hussain, S. E., Rasheeduzzafar, Al-Musallam, A., and Al-Gahtani, A. S. (1995). “Factors affecting threshold chloride for reinforcement corrosion in concrete.” Cem. Concr. Res., 25, 1543–1555.
Kapat, C., Pradhan, B., and Bhattacharjee, B. (2006). “Potentiostatic study of reinforcing steel in chloride contaminated concrete powder solution extracts.” Corros. Sci., 48(7), 1757–1769.
Klinghofer, O., Riislund, E., Frolund, T., Elsener, B., Schiegg, Y., and Bohni, H. (1997). “Assessment of reinforcement corrosion by galvanostatic pulse technique.” Proc., Int. Conf. on Repair of Concrete Structures, Norway, 391–400.
Maheswaran, T., and Sanjayan, J. G. (2004). “A semi-closed-form solution for chloride diffusion in concrete with time-varying parameters.” Mag. Concrete Res., 56(6), 359–366.
Montemor, M. F., Simoes, A. M. P., and Ferreira, M. G. S. (2003). “Chloride-induced corrosion on reinforcing steel: From the fundamentals to the monitoring techniques.” Cem. Concr. Compos., 25, 491–502.
Moreno, M., Morris, W., Alvarez, M. G., and Duffo, G. S. (2004). “Corrosion of reinforcing steel in simulated concrete pore solutions—Effect of carbonation and chloride content.” Corros. Sci., 46, 2681–2699.
Oh, B. H., Jang, S. Y., and Shin, Y. S. (2003). “Experimental investigation of the threshold chloride concentration for corrosion initiation in reinforced concrete structures.” Mag. Concrete Res., 55(2), 117–124.
Raupach, M. (1996). “Chloride-induce macrocell corrosion of steel in concrete-theoretical background and practical consequences.” Constr. Build. Mater., 10(5), 329–338.
Saricimen, H., Mohammad, M., Quddus, A., Shameem, M., and Barry, M. S. (2002). “Effectiveness of concrete inhibitors in retarding rebar corrosion.” Cem. Concr. Compos., 24, 89–100.
Trejo, D., and Monteiro, P. J. (2005). “Corrosion performance of conventional (ASTM A615) and low-alloy (ASTM A706) reinforcing bars embedded in concrete and exposed to chloride environments.” Cem. Concr. Res., 35, 562–571.
Trejo, D., and Pillai, R. G. (2003). “Accelerated chloride threshold testing: Part 1—ASTM A615 and A706 reinforcement.” ACI Mater. J., 100, 519–527.
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© 2009 ASCE.
History
Received: Mar 28, 2007
Accepted: Sep 26, 2008
Published online: Sep 15, 2009
Published in print: Oct 2009
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