The PARC_CL 2.1 Crack Model for NLFEA of Reinforced Concrete Elements Subjected to Corrosion Deterioration

During their service life, existing structures may suffer a combination of ageing and reinforcement corrosion. The corrosion deterioration can significantly affect the durability of reinforced concrete (RC) elements causing premature concrete crushing, size reduction of reinforcement cross-section, degradation of mechanical properties of steel and concrete, and stirrups rupture. One of the main purposes related to durability reduction is the evaluation of the maintenance of adequate safety and residual capacity throughout the life of the structure. For this reason, a non-linear finite element approach (NLFEA), based on multi-layer shell elements and PARC_CL 2.1 crack model has been presented in this paper. The PARC_CL 2.1 model is a fixed crack model developed at the University of Parma and implemented in a subroutine UMAT for ABAQUS that incorporates cyclic constitutive laws of materials and the evolution of corrosion over time. In the present work, the crack model was improved by implementing the effects of exposure to environmental attack. Firstly, the effectiveness of the proposed model has been validated through comparison with experimental data available in literature. The residual capacity of corroded RC panels subjected to cyclic loads was then investigated over time considering different exposure classes. Based on the obtained results, the capacity reduction in terms of maximum shear stress and ductility have been estimated over time.