Experimental Evaluation and Computational Modeling of Non-Uniform Corrosion of Steel Reinforcement in Concrete

Corrosion of steel reinforcement embedded in concrete structures is a very common problem in construction industry particularly in coastal and saline environments.  Modeling of a system from the corrosion process to full system performance has great benefits for infrastructure and asset management with applications both in the defense and civilian sectors.

This paper will outline the overall goals and present some preliminary results of the ongoing research at the University of Akron.  The overall objective of the project is to develop insight into steel corrosion within reinforced concrete through coordinated experiments and computational modeling.  A multi-scale approach is being taken to address the effects of corrosion rate and formation of corrosion products on the degradation process.  The degradation of bond strength (pull-out strength) is evaluated along with the study of the influence of non-uniform corrosion on the stresses and strains within the concrete surrounding the corroding steel reinforcement.  Carefully designed experiments are being conducted to develop non-uniform corrosion of steel to simulate practical conditions.  The stress condition, crack patterns and rate of crack development, controlled corrosion product growth within the concrete test specimens, and the degradation and failure modes will be studied.

Pull-out tests will be conducted to determine the degradation of bond strength and residual strength.  Computational modeling is being done using the FE models developed with ANSYS.  These models will include the extent and the growth rate of corrosion products, and the non-uniformity of corrosion.  The test results will be correlated with the results obtained from FE analysis to determine the realistic rate and extent of degradation.  The long term goals of the project are to predict the degradation of reinforced concrete structures due to non-uniform corrosion of the embedded steel reinforcement, prediction of the residual strength, and the determination of the remaining life of deteriorating structures.