Projection of the Carbonation Depths and its Probability of Corrosion Initiation for the Uncracked and Cracked Concrete

This research aims to investigate the impact of different relative humidity on the carbonation depth by using various mathematical models for the carbonation-induced corrosion at different Representative Concentration Pathways (RCPs) of CO2 concentrations. Additionally, the carbonation depth values were conducted for the uncracked and cracked concrete at various RCPs in the future, considering the impact of the relative humidity. Moreover, the probability of corrosion initiation was investigated using the Monte Carlo Simulation method at different percentages of either high or low calcium fly ash ranging from (5% FA to 30% FA) used as Supplementary Cementing Material (SCM) in the concrete mix for RC bridge decks at different concrete covers. Results show that the carbonation depths for the cracked concrete with a crack width of 0.20 mm are higher than that of the uncracked concrete by 126% at various percentages of either high or low calcium fly ash used as SCM in concrete mixes in year 100. The carbonation depths for concrete mix, including 30% of low calcium fly ash, increased by 78.6% compared to a concrete mix with zero percent of the low calcium fly ash, for the unc and cracked concrete with a crack width of 0.2 mm, in year 100. Finally, the probabilities of corrosion initiation values for uncracked concrete are almost constant (approximately equal to zero values) versus various percentages of either high or low calcium fly ash utilized as SCM in the concrete mix for RC bridge decks having a concrete cover of 50 mm in year 100.