ABSTRACT
The problem of durability of reinforced concrete (RC) elements, exposed to both physical and chemical actions, represents an evolving research topic in the assessment of existing structures: actually, due to aggressive environments and poor construction, nowadays an increasing number of existing RC constructions exhibit high levels of deterioration. The corrosion of reinforcing bars is one of the most important and widely encountered causes of degradation, which can lead to serious structural consequences, as loss of serviceability and load carrying capacity. The corrosion of steel reinforcement in concrete may also influence the seismic response of the RC structures, leading to a more brittle behavior and to a loss of ductility, particularly required in seismic conditions. In recent years, a number of models have been proposed to study of the local effects of corrosion, but relatively little attention has been paid on the assessment of the performance of corroded RC elements. In this work, a numerical model based on damage mechanics, e.g. Saetta et al 1999, is presented and applied to simulate the structural response of RC columns subject to different level of corrosion. In particular, the concrete is modelled with an isotropic coupled environmentalmechanical damage model, whose mechanical feature has been based on the work of Faria (Faria et al. 1998) and then extended to environmental damage by one of the authors, e.g. (Saetta et al 1999, Berto et al. 2013). Then, all the main local effects of corrosion are included in the proposed model, i.e. the reduction of cross sectional area of the corroded reinforcements, the change of the mechanical properties of
both steel and concrete materials, the cracking and the spalling of the concrete cover. In this way the actual behaviour of both sound and corroded RC elements can be profitably modelled.
