On the robustness to damage in the life-cyle assessment (LCA) of deteriorating bridges

In this paper, the susceptibility of reinforced concrete structures to corrosion using a robustnessbased framework is presented. Robustness is regarded as a structural property related with the tolerance to damage and it is measured by the average performance considering all possible damage scenarios. In this case, structural performance is measured through the reliability index and damage is considered to result from reinforcement corrosion. The proposed methodology is oriented towards structural management and maintenance, as it can be used to classify structures regarding their susceptibility to the effects of corrosion, and help in prioritizing maintenance actions in a more consistent manner. The methodology described is applied to a reinforced concrete bridge demolished due to the concerning signs of advanced deterioration. The structure is analyzed using a non-linear finite element model, explicitly considering the reduction in cross area of reinforcement bars and the loss of bond between concrete and steel, as a result of corrosion. First Order Reliability Method (FORM) combined with the response surface method is used to assess the bridge deck reliability using a non-linear finite element model. Bridge robustness is then assessed using the proposed methodology. Finally, and based on the obtained results and on the visible signs of advanced deterioration, the bridge tolerance to corrosion and the effect of different effects of corrosion are discussed.