Simulation of chloride ingress into aging surface-coated concrete

This paper presents a calibration of prediction model for chloride ingress into surface-treated reinforced concrete (RC) structures. Since the research on long-term durability of the coating materials is still limited, the coating degradation model about chloride resistivity is investigated and established from experimental results with accelerated deterioration tests and chloride migration tests (CMT). On the other hand, the results of AgNO3 spray tests for surface-coated concrete specimens exposed to CMT show that chloride ions would penetrate mainly from the defective areas such as cracks and delamination in surfaces. Therefore, two different deterioration models are proposed for the coating system: averaged time-variant diffusivity and increase of local defects in coated surface. The deterioration models are implemented into diffusion analysis based on cellular automata and applied to a coated RC cross-section to investigate the residual lifetime associated with corrosion initiation of steel reinforcement.