Critical Conditions for Depassivation of Steel in Concrete: Interface Chloride Profiles and Steel Surface Condition
Magazine article, 2012

The composition and macrostructure of the concrete-steel interface and the surface finish of the steel are fundamental for the chloride induced corrosion initiation in reinforced concrete, with direct influence in the chloride threshold values (Cth). In this paper these characteristics were examined for vertically cast samples immersed in salt solution. After depassivation, the specimens were open for visual examination. Corrosion always initiated at the front side and surface defects were found to influence the corrosion onset. Chloride, calcium and iron profiles along the interface were drawn by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and higher chloride contents were measured around active corroding areas.

LA-ICP-MS

elemental distributions

steel surface condition

chloride threshold values

Steel-concrete interface

Author

Nelson Dias Ferreira Da Silva

Chalmers, Civil and Environmental Engineering, Building Technology

Dimitrios Boubitsas

Luping Tang

Chalmers, Civil and Environmental Engineering, Building Technology

Jan Erik Lindqvist

Nordic Concrete Research

0800-6377 (ISSN)

Vol. 45 111-123

Subject Categories

Materials Engineering

Civil Engineering

Areas of Advance

Building Futures

Materials Science