Durability assessment of reinforced concrete structures due to chloride ingress up and beyond induction period

Abstract

<p>Chloride ingress in reinforced concrete structures is the main cause for the corrosion of reinforcing steel. This paper presents a new chemo-mechanical model up and beyond induction period, taking into account concrete mix design, supplementary cementitious materials, concrete cover, effect of cracking, and environmental conditions. The 1D model of transient problem of chloride ingress is extended for crack effects, which accelerates propagation. Fracture–plastic constitutive model is used for the modelling of externally induced cracks. The influence of cracks is large, e.g. crack width 0.3 mm decreases the induction time approximately five times when compared to intact concrete. Once the end of induction period is reached, progressive corrosion stage takes place. The corrosion current density<i>i</i>corr is used for calculating the time of concrete spalling for chlorides. After concrete spalling, reinforcement is subjected to corrosion without any protection. The models are validated using two practical cases; the Nougawa bridge from Japan and a strut of a concrete bridge from the Czech Republic.</p>