A multiscale peridynamic model for simulating the corrosion-induced cracking of concrete cover

Previous numerical models for corrosion-induced cracking (CIC) in concrete primarily describe crack patterns but rarely provide quantitative predictions of crack width. Here, a multiscale peridynamic (PD) model is proposed, which treats concrete as a mesoscopic three-phase composite comprising aggregates, mortar and interfacial transition zones. A generation–placement approach was used to construct concrete mesostructures and three distinct types of PD bonds were assigned in terms of the generated mesoscopic phases. Additionally, a novel method was developed to calculate the corrosion-induced crack widths of a concrete cover. In the proposed method, the crack width is determined by summing the displacement vectors of broken bonds connected to damage nodes; however, precise identification of the crack orientation is not necessarily required. The proposed multiscale PD model and the crack width determination method were validated through comparisons with experimental data. Simulation results showed that the model effectively captures CIC across multiple scales. When the fracture energy of aggregates is more than three times the fracture energy of mortar, the predicted internal crack patterns aligned well with experimental observations. Conversely, a lower aggregate fracture energy resulted in cracks propagating through the aggregates. Moreover, internal crack propagation was significantly hindered when the non-uniformity coefficient was greater than 6.0.