Semi-probabilistic methods for existing concrete structures under climate change: Review

The assessment of the residual performance of existing structures over their life cycle usually involves a wider spectrum of uncertainties compared to a standard approach for designing new structures. The differences are related to the uncertainties linked to the time-variant aging and deterioration processes, as well as concerning the different lifetime considered in the assessment with respect to the design stage. Additionally, climate change has a significant impact on this evolution. In order to account for these aspects, full-probabilistic approaches are often employed for assessing existing structural systems. However, these methodologies are time-consuming and may require significant knowledge and expertise for numerical implementation. Therefore, the development of semi-probabilistic methodologies for existing structures considering the impact of climate change, including proper validation and calibration for incorporation in design codes and standards, is nowadays of the essence. This paper aims at providing a review of recent accomplishments and available literature regarding semi-probabilistic methodologies for the assessment of existing reinforced concrete (RC) structures, focusing on different steps of the calibration process, highlighting research contributions that proposed the integration of climate change effects on these methodologies, and discussing the benefits, limitations, and research gaps of the reviewed approaches.