Modelling fracture due to corrosion and mechanical loading in reinforced concrete

Corrosion in reinforced concrete is an important feature which can lead to increased deformation and cracking, as well as to premature failure. In the present work, macro-mechanical modelling of corrosion is performed, namely the degradation of bond-slip between concrete and steel. A mixed-mode damage model is adopted, in which the interaction between the bond-slip law and the stress acting in the neighbourhood of the concrete-steel bar interface is taken into account. Bond-slip degradation is modelled using an evolutionary bond-slip relationship, which depends on the level of corrosion. Different relevant loading cases are studied. Special attention is given to the evolution of corrosion in time, under constant load. This is done by adopting a Total Iterative Approach, in which the structure is reevaluated each time step, upon damage increase due to corrosion. Pullout tests are presented to illustrate the performance of the model. Bending tests are also performed to evaluate the influence of corrosion at structural level.