Service life simulation of RC structures under chloride ingress based on measured corrosion potential and Monte-Carlo simulation

Determining an allowable chloride concentration is crucial for assessing durability and service life of reinforced concrete (RC) structures exposed to chloride attack. This study measured corrosion potential and current density in embedded steel within cement mortar mixed with chloride ions and several mineral admixtures. Corrosion potential was quantified across a range of initial chloride concentrations (0.0% to 0.8% of binder wt.), and corrosion probability was calculated using Monte Carlo simulation. With a 10% coefficient of variation, corrosion probability ranged from 0.0002% to 0.91% with increasing chloride concentration. Relationships between changing corrosion potential, corrosion probability, and service life were plotted against increasing chloride concentration. Higher ground granulated blast furnace slag and fly ash replacement ratios, coupled with reduced chloride concentration, led to reduced corrosion potential and extended service life. A proposed critical chloride concentration of 0.4% of binder mass was conservative, with service life extending to 120% ~ 12% when increased to 0.8%.