Mechanical Reliability Analysis of an RC Storage Tank Considering Pitting and Uniform Corrosion

The lifetime of a reinforced concrete (RC) storage tank depends strongly on the aggressiveness degree of its environment (presence of chlorides and carbon dioxide). The aggressiveness of these agents leads to corrosion of steel reinforcements. To understand the evolution in time of this corrosion pathology, the engineer uses corrosion models in deterministic calculation of RC structures. However, this deterministic approach, using average values of input variables, leads to an unreliable representation of the reality. Similarly, the loads applied to the structure are not always perfectly known. It is why the civil engineer uses probabilistic analysis to take into account the uncertainties marring these parameters. This paper is dedicated to mechanical reliability analysis of the RC tank upper beam, taking into account pitting corrosion and uniform corrosion of its steel reinforcements. The influence of chloride ion concentration and carbon dioxide content on the evolution of corrosion is studied in order to determine the evolution, as a function of time, of the residual section of its steel reinforcements. The reliability analysis is performed with the Monte Carlo method.