Predicting the impact of water transport on carbonation-induced corrosion in variably saturated reinforced concrete

TL;DR

This paper introduces a comprehensive modeling framework that predicts carbonation-induced corrosion in reinforced concrete, accounting for water transport, carbonation, and wetting-drying cycles, validated against experimental data.

Contribution

It presents a novel integrated model combining water transport, carbonation, and corrosion prediction, with numerical implementation and extensive benchmarking against experiments.

Findings

Cyclic wetting accelerates carbonation progress.

Corrosion current density is highly sensitive to concrete saturation.

Model accurately predicts carbonation and moisture dynamics.

Abstract

A modelling framework for predicting carbonation-induced corrosion in reinforced concrete is presented. The framework constituents include a new model for water transport in cracked concrete, a link between corrosion current density and water saturation, and a theory for characterising concrete carbonation. The theoretical framework is numerically implemented using the finite element method and model predictions are extensively benchmarked against experimental data. The results show that the model is capable of accurately predicting carbonation progress, as well as wetting and drying of cracked and uncracked concrete, revealing a very good agreement with independent experiments from a set of consistent parameters. In addition, insight is gained into the evolution of carbonation penetration and corrosion current density under periodic wetting and drying conditions. Among others, we find that cyclic wetting periods significantly speed up the carbonation progress and that the induced corrosion current density is very sensitive to concrete saturation.