A diagnostic survey on the precast prestressed bridge Nižná confirmed significant deterioration due to environmental distress. Evidently, decisive failures of the structure have a similar character as in the previous precast prestressed bridge in Podbiel in the northern part of Slovakia. These failures result from the unsuitable concept of the first generation of precast prestressed concrete beams, which was used in the former Czechoslovakia in the second half of the 20th century. Subsequently, experimental verification using the proof-load test was also executed. This bridge was built in 1956, so at the time of testing, it was 60 years old. The paper presents the indirect determination of prestressing level in one precast post-tensioned concrete beam using the saw-cut method. Experimental measurement was executed during the bridge demolition. Subsequently, a 2D numerical model in ATENA 2D Software, with the assumption of nonlinear material behavior for verification of experimental results, was performed. Finally, the residual prestressing force was evaluated and compared with the expected state of prestressing according to Eurocodes after 60 years of service.

Reliability is one of the most significant requirements for structures given in Eurocodes. Thus, the specific level of safety, serviceability, and durability have to be satisfied to fulfill the reliability of structures. In the case of reinforced concrete (RC) members, the corrosion of reinforcement is not assumed in the stage of structure design, which is in contrast with the structures in service, where the corrosion of reinforcement can significantly decrease their diameter ø in time. In these cases, the moment resistance in time M_Rd(t) decreases during the designed lifetime T_d of a structure. The corrosion speed is as a basis for the calculation of moment resistance in time M_Rd(t), i.e., a first-year corrosion rate r_corr and a corrosion model as well. The corrosion itself is a very complicated issue, so the first-year corrosion rate r_corr and also the corrosion model can be different under various conditions in Slovakia. The paper is focused not only to determine the corrosion speed (first-year corrosion rate r_corr and the corrosion model) and parametric study of the moment resistance in time M_Rd(t) under various conditions in Slovakia but also shows an overview on some parameters that may influence the corrosion process.

New segmental concrete bridge has been built near the city Žilina, aligned on European highway corridor E 50. The bridge is composed of the two separate precast prestressed box girder structure constructed by balanced cantilever method. The total length of both structures is 1042 m. The similar superstructure consists of a total of eighteen continuous spans with main spans of 60.5 m. The construction process, load carrying capacity and monitoring of the bridge has been investigated before the opening of the bridge. The paper presents verification of the structural behaviour of the bridge under static load compared to predicted model for both precast prestressed structures.

Large-scale construction of transport infrastructure inevitably includes the construction of new bridges. During the design process, many assumptions and simplifications are taken into account. Therefore, the verification of the structural response of new bridges is necessary. One of the possible tests of structural response is a proof-load test which can detect certain problems of investigated structures. The paper introduces numerical and experimental analysis of the new bridge, which is located on Slovak Highway D1, section Hricovske Podhradie – Lietavska Lucka. The verified bridge is a four-span continuous structure with a total length of 129.4 m. The bridge is a representative of typical precast girder bridges adopted for construction of Slovak highways. The superstructure consists of eight post-tensioned precast I-beams. During a load test, predicted structural response was verified to check for any unusual behaviour. Finally, recorded data was summarised and report was distributed to all subcontractors and bridge owner. This information may help in further bridge management program.