Mesoscopic characteristics and spatiotemporal variability of chloride transport in concrete

Abstract

Chloride-induced corrosion is the leading cause of structural performance deterioration and life decay in marine environments. This paper delves into the mesoscopic characteristics and spatiotemporal variability of chloride transport in concrete. We conducted extensive mesoscopic simulations to reveal the effects of ITZ and aggregate volume fraction, morphology, size, and particle quantity on chloride transport. We identified the probability characteristics of chloride concentration and diffusion coefficient based on statistical analysis of the mesoscopic simulation results. We proposed a novel probabilistic framework and predictive model for chloride diffusion coefficients incorporating aggregate parameters like volume fraction and particle size. The findings of this study demonstrate that the chloride transport shows noteworthy spatiotemporal variability; the aggregate size effect, aggregate particle quantity effect, and the local effect of large aggregates are all significant characteristics of the chloride transport in addition to the pre-discovered dilution effect, tortuosity effect, and ITZ effect. The chloride diffusion coefficient approximately follows a log-normal distribution, whereas the chloride concentration roughly follows a normal or log-normal distribution. The findings in this work are instrumental in predicting the probabilistic chloride transport and service life of reinforced concrete structures.