Safety assessment of ageing infrastructure exposed to chloride-induced corrosion considering uncertainties in temperature climate change models
Jahangir Alam, Hao Zhang, Luís Neves, Nandini Ramesh, Daniel Dias‐da‐Costa
Abstract
This paper proposes a framework for mixed uncertainty quantification in the remaining service life assessment of existing deteriorated reinforced concrete (RC) bridges under temperature climate changes . The probability bound analysis (PBA) is deployed for quantifying mixed uncertainty. The epistemic uncertainty in climate change is modelled using a distribution-free p-box in the PBA framework. An extension of Chebyshev’s inequality is proposed to construct a parametric distribution-free probability-box (p-box) under a specific confidence interval. This ensures consistency with the distributional p-box, constructed based on the uncertainty in distribution parameters . The proposed method can account for parametric uncertainties for variables with known or unknown distribution types with a specified confidence level and provides narrower bounds than other approaches. The types and sources of uncertainty associated with assessing an existing bridge are thoroughly investigated as an application example. An insight into how epistemic uncertainty governs corrosion initiation and propagation in service life prediction is provided. Results show that the epistemic uncertainty in the diffusion coefficient is most critical in the probabilities of corrosion initiation and damage, followed by the epistemic uncertainty in temperature projections.