ABSTRACT
Strengthening/ retrofitting of structures and infrastructures is a challenging and extremely relevant topic. One of the key tasks in the decision process over strengthening/ retrofitting or demolishing an existing infrastructure is its condition assessment and checking against expected performance rules, usually established in technical codes. However, the problem of performance evaluation of existing reinforced concrete structures is quite distinct from design of new ones. A question arises on the statistics of the concrete compressive strength to be used in the calibration of semi-probabilistic codes for existing structures. In this paper, Monte Carlo simulation is used in the determination of the probabilities of failure (and corresponding reliability indexes) associated to axially-loaded columns. Different scenarios are considered for the compound coefficient of variation, i.e. the one including statistical errors, size effects for the extracted cores, etc. The resulting safety levels for existing axially-loaded reinforced columns, assessed via ACI 562 Repair Code, are obtained and discussed.
