Meso-scale Fracture Modelling of Concrete Cover Induced by Non-uniform Corrosion of Reinforcing Bar

Corrosion-induced concrete cracking is a significant durability problem for reinforced concrete structures. In practice, critical corrosion degree to surface cracking and crack width evolution are of significance in regards to the assessment of serviceability of reinforced concrete structures. Literature review suggests that, although considerable research has been undertaken on corrosion-induced concrete cracking, little has been focused on non-uniform corrosion of reinforcing bar, especially by considering concrete as a three-phase materials. In this paper, a meso-scale fracture model, consisting of aggregates, cement paste/mortar and ITZ, is established. To simulate arbitrary cracking in concrete, cohesive elements are inserted in the fine meshes and the process is achieved through a script written in Python. It has been found that some microcracks occur before they are connected to form a dominating discrete crack approaching to the surface. The surface crack width is obtained as a function of corrosion degree and verification against experimental results from literature is conducted