Accelerated Corrosion of Steel Reinforcement in Concrete: Experimental Tests and Numerical 3D FE Analysis

Abstract

Chloride-induced corrosion of steel reinforcement in concrete is one of the major causes for deterioration of reinforced concrete (RC) structures. RC structures exposed to aggressive environmental conditions, such as structures close to the sea or highway bridges and garages exposed to de-icing salts, very often exhibit damage due to corrosion. Therefore, to predict durability of RC structure it is important to have a numerical tool, which is able to predict corrosion processes and their consequences for the structural safety. In order to speed up corrosion of reinforcement in concrete the experimental tests are almost always accelerated by imposing external electric potential and by adding chlorides to concrete mix. Therefore, the corrosion rate becomes much faster than the fastest corrosion rate in the nature, which can have significant consequences on the non-mechanical and mechanical processes related to the corrosion of reinforcement, i.e. the experimental results can lead to unrealistic conclusions. In the present paper recently performed experiments under accelerated conditions are simulated and compared with corrosion process that approximately corresponds to natural conditions. For the investigated geometry and environmental conditions it is shown that accelerated corrosion rate, which is approximately 20 times faster than corrosion rate under natural conditions, leads to corrosion induced damage of concrete, which is similar to the damage predicted assuming natural conditions.