Models Uncertainties Assessment of fib Model Code 2020 and Second-Generation Eurocode 2 Transmission Length Formulations

In this contribution, the model uncertainties of bond formulations in prestressed concrete members are evaluated by investigating the transmission length formulations prescribed in the drafts of the forthcoming fib Model Code 2020 and second-generation Eurocode 2. To this end, the predictions of the aforementioned formulations have been compared with 561 experimental transmission length measurements collected from the scientific literature. From the comparison, samples of the model uncertainties have been obtained and fitted with suitable probability distributions. Then, new probabilistic models are formulated, and probabilistic coefficients are proposed to achieve the target reliability length to be adopted in the main design situations.