Title:
Oxygen Transport and Corrosion of Steel in Concrete under Varying Concrete Cover, w/c, and Moisture
Author(s):
Raja Rizwan Hussain, Tetsuya Ishida, and Muhammad Wasim
Publication:
Materials Journal
Volume:
109
Issue:
1
Appears on pages(s):
3-10
Keywords:
corrosion; model verification; moisture; oxygen; reinforced concrete
DOI:
10.14359/51683565
Date:
1/1/2012
Abstract:
This study aims to verify the detailed experimentation and electrochemical mass balance modeling of corrosion in reinforced concrete under the effect of varying oxygen concentrations. Various concrete corrosion cells with different compositions under four different environmental conditions (air dry, submerged, 95% relative humidity [RH], and alternate wetting and drying) were investigated under controlled laboratory conditions. Using the results (half-cell potential and gravimetric corrosion mass loss) of these laboratory tests and a constitutive equivalent electrochemical circuit model based on mass and energy transfer through the porous media for the corrosion process, it was possible to predict the influence of oxygen concentration on the corrosion rate of the reinforcement under various defined conditions. The variation in oxygen concentration available for the corrosion reaction was taken into account, simulating the actual field conditions, such as varying the concrete cover depth, RH, and water-cement ratio (w/c). The modeling task was incorporated by the use of the concrete durability model as a finite element computational approach for the effect of oxygen on corrosion in relation to the w/c, concrete cover, chloride concentration, and various environmental humidity conditions. This comprehensive modeling and experimental investigation involving a variety of materials and environmental variables will help in the understanding of oxygen-controlled corrosion reaction in reinforced concrete structures and will provide significant future research prospects in the field of oxygen-limiting corrosion modeling of steel-reinforced concrete.