Temporal analysis of an underground RC tank performance considering the uniform corrosion of steel reinforcement

It is demonstrated that the increase in atmospheric CO2, due to climate change and urbanization, threatens the sustainability of RC structures by accelerating carbonation and corrosion of reinforcement, which reduces structural strength. This study proposes an analysis of the durability of an underground RC water tank, whose space above the dome has been converted into a parking area. A deterministic approach, based on the loss of reinforcement section, is used to quantify uniform corrosion of top ring beam steels. Three carbonation models are compared to evaluate the carbonation progression, and two corrosion current models are applied to analyze the residual area of steel cross-section. A uniform corrosion model is developed to determine the evolution in time of the reinforcements section in different environments. Several parameters influencing corrosion are taken into account. The study concludes that an increase of 10 mm of coating extends the service life by about 20 years, while a higher CO2 concentration accelerates corrosion.