Suitability of assessment methods for identifying active and passive zones in reinforced concrete

Journal Article · Wed Feb 01 00:00:00 EST 1995 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3293586· OSTI ID:6768657

Gonzalez, J A; Benito, M; Feliu, S ^[1]; Rodriguez, P ^[2]; Andrade, C ^[3]

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1. Centro Nacional de Investigaciones Metallurgicas del Consejo Superior de Investigaciones Cientificas, Madrid (Spain)
2. Univ. Nacional Autonoma de Mexico, Mexico City (Mexico)
3. Inst. de Ciencias de la Construccion Eduardo Torroja, Madrid (Spain)

The ability of various electrochemical techniques to differentiate between areas of reinforcing steel (rebar) with high and low corrosion activity and to define the boundary between such areas was studied. These techniques are based on determining the corrosion potential (E[sub corr]), the galvanic current between an external stainless steel (SS) sensor and the bar (I[sub g]), the apparent polarization resistance (R[sub p][sup ap]), or the polarization resistance (R[sub p]) under electric confinement conditions. Values of E[sub corr] and I[sub g] (the current flowing between a SS counter electrode [CE] and the rebars) were shown to distinguish active areas from passive ones very well when the areas were isolated electrically, but with difficulty when the areas were in electric contact, which is usually the case. Values of R[sub p][sup ap] or i[sub corr] (both calculated using the Stern-Geary equation) were shown to define areas of high corrosion rates in a structure where passivity prevailed much better. However, excessive i[sub corr] values were estimated because the polarized area of the rebar (especially with passive rebars) was much greater than the CE area. Finally, the confinement of signal distribution permitted definition of the exact boundary between active and passive areas, regardless of whether they were isolated or interconnected. In addition, i[sub corr] values obtained with this technique were shown to provide a reliable quantitative index of the damage rate in reinforced concrete structures.

• OSTI ID: 6768657
• Journal Information: Corrosion (Houston); (United States), Vol. 51:2; ISSN 0010-9312
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
REINFORCED CONCRETE
ELECTROCHEMICAL CORROSION
EVALUATION
MEASURING METHODS
NONDESTRUCTIVE ANALYSIS
STEELS
ALLOYS
BUILDING MATERIALS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COMPOSITE MATERIALS
CONCRETES
CORROSION
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
REINFORCED MATERIALS
360105* - Metals & Alloys- Corrosion & Erosion
360604 - Materials- Corrosion
Erosion
& Degradation