Blind Predictions and Uncertainty in the Simulation of Reinforced Concrete Structures

Nonlinear analysis of reinforced concrete structures is becoming a standard tool for both the assessment of existing structures and the design of new ones. This trend is supported by new safety formats for nonlinear analysis introduced in the fib Model Code 2010 and incorporated in the new Eurocode (prEN 1992-1-1:2022). A key challenge is the evaluation and management of uncertainties. This paper focuses on the model uncertainty in ultimate and serviceability limit states, including crack width estimation. The significant insights into modeling uncertainty are provided by the recent blind prediction competitions, which offer a practical benchmark for assessing the robustness and reliability of nonlinear models and software tools. This paper highlights the findings from several such competitions. A key limitation is that the material uncertainties are typically neglected, meaning that the most accurate predictions often result from a chance rather than from the consistently reliable modeling.