Head of the project: Ing. Kraľovanec Jakub, PhD.

Research team: prof. Ing. Moravčík Martin, PhD., Ing. Bujňáková Petra, PhD.

Duration: September 2023 – August 2026

The basic input data for the analysis and evaluation of the load-carrying capacity of prestressed concrete bridges or other prestressed concrete structures which could have been in operation for several decades is the correct determination of the residual prestressing force value. The absence of appropriate methods and the underestimation of risk in the reliability assessment were one of the main factors that contributed to the fact that accidents of prestressed concrete bridges were not prevented only in our country, but also abroad. We will mention only some cases from the recent past. For example, in 2020, the failures of the bridges in Trstená, Spišská Nová Ves and Veľká Lodina. Moreover, some examples can be illustrated from abroad. In 2017, the failure of a prestressed concrete footbridge in Prague occurred. Similarly, in 2018, the collapse of a bridge in Genoa caught the public attention. Experience shows that a rapid loss of prestressing in a very short time (just a few years or just months) can be observed. These additional prestress losses can lead to the situation that the structure is not able to deal with its self-weight and subsequently it collapses. The main cause of this condition is insufficient protection of prestressing steel and anchoring, the development of corrosion of prestressing steel, as well as enormous loads from heavy traffic. When analysing the current level of prestressing in the structure, we plan to use modern theoretical-experimental techniques based on "Structural Response Methods" or "Stress Release Methods". Individual methods are supposed to be verified both experimentally on prestressed bridges in situ, as well as on laboratory specimens. The research assumes the application of obtained results in practice. The outputs from this research can be used in various situations both by bridge designers and by administrative organizations such as the National Highway Company (NDS), Slovak Road Administration (SSC), Slovak Railways (ŽSR), etc. The research results will be published in high-quality databases such as Scopus and Web of Science. Moreover, they will be shared in the scientific community via the ResearchGate, ORCID and other platforms.