Several questions about electrochemical rehabilitation methods for reinforced concrete structures

Abstract Electrochemical realkalisation (ERA) and electrochemical chloride removal (ECR) have shown their capacity to eliminate, in just a few weeks, the causes of corrosion in reinforced concrete structures (RCS), and for this reason are currently receiving very special attention. Nevertheless, the present state of the art has not progressed enough to dissipate doubts about the efficiency of ERA and ECR as electrochemical rehabilitation methods (ERM) for corroding RCS. A series of highly important questions persist, and continue to be cause of controversy among specialists in the construction sector, which can be summed up in one all-encompassing question, namely: • Is removing the sources of corrosion in RCS sufficient to stop rusting? To obtain a response to this capital question, electrochemical corrosion analysis techniques are used to study the responses of clean and precorroded steel electrodes embedded in small mortar specimens without chloride additions and large mortar slabs with and without chloride contamination. According to the results obtained, ERM are efficient in delaying the start of corrosion if used preventively. However, if applied too late they do not assure the repassivation of rebars with high precorrosion levels and consequently are not useful.

[1]  Howard W. Pickering,et al.  Interpretation of impedance data for reinforcing steel in alkaline solution containing chlorides and acetates , 1998 .

[2]  Jose Gonzalez,et al.  Electrochemical chloride removal from reinforced concrete structures and its ability to repassivate prerusted steel surfaces , 2001 .

[3]  C. Page,et al.  Aspects of the electrochemistry of steel in concrete , 1982, Nature.

[4]  Carolyn M. Hansson,et al.  The effect of the electrochemical chloride extraction treatment on steel-reinforced mortar Part I: Electrochemical measurements , 1999 .

[5]  G. Arliguie,et al.  ELECTROCHEMICAL CHLORIDE EXTRACTION: EFFICIENCY AND SIDE EFFECTS , 2004 .

[6]  J. M. Miranda,et al.  Considerations on reproducibility of potential and corrosion rate measurements in reinforced concrete , 2004 .

[7]  B. S. Wyatt,et al.  A review of cathodic protection of reinforced concrete , 1987 .

[8]  J. Mietz Electrochemical realkalisation for rehabilitation of reinforced concrete structures , 1995 .

[9]  G. Glass,et al.  A Mathematical Model for Electrochemical Removal of Chloride from Concrete Structures , 1998 .

[10]  A. P. Crane Corrosion of reinforcement in concrete construction , 1983 .

[11]  C. Andrade,et al.  Some questions on the corrosion of steel in concrete. Part II: Corrosion mechanism and monitoring, service life prediction and protection methods , 1996 .

[12]  M. Stern,et al.  Electrochemical Polarization I . A Theoretical Analysis of the Shape of Polarization Curves , 1957 .

[13]  C. M. Rangel,et al.  Electrochemical behaviour of steel rebars in concrete: influence of environmental factors and cement chemistry , 2001 .

[14]  Carolyn M. Hansson,et al.  The effect of the electrochemical chloride extraction treatment on steel-reinforced mortar Part II: Microstructural characterization , 1999 .

[15]  V. Feliu,et al.  Determining polarization resistance in reinforced concrete slabs , 1989 .

[16]  Josefa González,et al.  On the effectiveness of realkalisation as a rehabilitation method for corroded reinforced concrete structures , 2000 .

[17]  J. Lyness,et al.  Change of pore size in concrete due to electrochemical chloride extraction and possible implications for the migration of ions , 2003 .

[18]  Jose Gonzalez,et al.  On the mechanism of steel corrosion in concrete: the role of oxygen diffusion , 1990 .

[19]  Bernhard Elsener,et al.  The electrochemical removal of chlorides from reinforced concrete , 1993 .

[20]  V. Feliu,et al.  Polarization resistance measurements in large concrete specimens: mathematical solution for a unidirectional current distribution , 1989 .