Semi-probabilistic methods for the assessment of existing concrete structures: An overview

Life-cycle assessment of the residual performance of existing structures usually involves a wider spectrum of uncertainties compared to a standard approach for designing new structures. The main differences are related to the modification of structural capacity and demand in time, f.i. due to aging and structural deterioration processes. Furthermore, climate change has a significant impact on this evolution. In order to account for these aspects, full probabilistic approaches are often exploited 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 essence. This paper provides an overview of recent accomplishments and available literature regarding semiprobabilistic code formats for the assessment of existing reinforced concrete structures, including insights on how to incorporate climate change effects on these methodologies.