Time-dependent reliability of deteriorating structural elements

In order to assess the reliability of planned or existing constructions, effects of deterioration that may diminish their ability to withstand future operating conditions, as well as extreme accidental conditions, must be taken into account. In fact, age-related deterioration of structures has the potential to increase the risk to public health and safety, if its effects are not controlled. A probabilistic procedure for the reliability assessment of structural elements subject to deterioration over time has been developed and presented in previous papers. The assumption has been made that the structural element deteriorates because of the effects of two different sets of phenomena: the first, denoted by ageing, manifest their effects on a substantially continuous basis during the structural lifetime; the others, denoted by shocks, have effects that superimpose only occasionally to the first ones. In this paper the procedure is briefly discussed, and illustrated with reference to a realistic example: a reinforced concrete slab subject to deterioration due to carbonation of concrete and corrosion of reinforcement.