Service Life Predicted of RC Structure Deterioration Subjected to Chloride with Probability

Abstract

In this research, two different diffusion models were employed to calculate the probability of the time to initial corrosion (TCo) of rebar and the time to initial crack (TCr) of reinforced concrete using Monte Carlo simulation. The first model assumed a constant chloride diffusion coefficient (DCC) over time, while the second model allowed for a variable chloride diffusion coefficient (DCV). The results from both models were compared to determine the effect of assuming DCV on the predicted corrosion and crack initiation times. The research employed an efficient method for reducing the number of iterations, including the calculation of the harmonic mean of the median of prior results and the splitting of these results into two groups, with the harmonic mean being calculated at the end of each iteration when the iteration number exceeded 1,000. The simulation was halted when the harmonic mean was less than 0.001, thus improving the overall efficiency of the study. The analysis showed that at a 10% probability, the TCo and the TCr for the DCC model were 4.00 years and 4.03 years, respectively, while for the DCV model, the TCo and the TCr were 4.05 years and 4.11 years, respectively. At 50% probability, the TCo and the TCr for the DCC model were 6.01 years and 6.31 years, respectively, while for the DCV model, the TCo and the TCr were 11.58 years and 12.18 years, respectively. These results suggest that assuming a variable diffusion coefficient leads to a significant increase in the predicted TCo and TCr