Characteristics and Mechanism of Corrosion of Re-bar in Concrete Induced by an Environment Containing Chloride
JI Yong-sheng
YUAN Ying-shu
GENG Ou
JIANG Jian-hua
Abstract：A large number of specimens of concrete containing corroded re-bar were examined by destroying them. The appearance of the re-bar was recorded. Fundamental electrochemical principles were used to analyze the corrosion currents along the circumference of the steel bar. The results were verified experimentally. The corrosion characteristics of the bar depend upon the state of the re-bar surface (activated or passivated) and the macro-corrosion current, I_g, that develops between the interior and the exterior of the bar. I_g both accelerates the corrosion of the outside surface of the bar and forms a cathodic protection to the inside of the bar. Thus corrosion occurs mainly on the side of the bar facing the concrete while no corrosion occurs on the side farthest from the concrete. Macrocell corrosion co-exists with microcell corrosion and the total corrosion could be understimated if either is overlooked. The total corrosion current is the sum of the microcell current, I_(corr2), of the activated steel and the anodic dissolution current, I_(corrA), caused by I_g.
Keywords：chloride contaminatedsteel corrosion characteristicsmacrocellmicrocell
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 309-315 )