As the bridge stock in many countries is ageing, the topic of bridge assessment is gaining more importance. Bridge load testing is one of the tools that can be used to assess existing bridges. Over the past decade, assessment, and by extent, bridge load testing, have been applied, studied, and improved in various countries. This paper provides an international overview of bridge assessment practices, load testing practices, and recent research insights. Moreover, synergies in the research activities, collaboration efforts via technical committees, and recently published codes and guidelines are highlighted. The major topics of importance identified are linking load testing to global and element structural behaviour, improved on-site sensing techniques, incorporating load testing with structural monitoring, non-destructive evaluation, numerical modelling, probabilistic analysis, and leveraging the use of digital tools for embedding detailed load testing insights into modern bridge management systems. It can be concluded that bridge load testing is a dynamic field of application and research, for which international collaboration and comparing best practices is essential.

In this work, dynamic characterization of a simply supported beam is carried out during different steps in a failure load test. The main goal of this work is to evaluate the evolution of the structural dynamic parameters of the beam with different status of damage. Real-scale prestressed concrete beams are tested to investigate its shear behaviour as a part of a large research program at TU Delft. Four dynamic tests are performed at different damage status of the beam: firstly in the initial or undamaged condition; secondly after the first flexural cracks; then, after shear cracking; and finally in the full damaged condition. The dynamic excitation is performed with an impact load at fixed location on the top of the beam and the vibration data is recorded by three different systems. The first one is a cost-effective and open source monitoring equipment, consisting of seven low-cost accelerometers. The second system is based on five trusted high performance accelerometers. The last one is a commercial alternative consisting of four high accuracy piezoelectric accelerometers. Acceleration data is analysed afterwards using Operational Modal Analysis techniques to obtain modal frequencies, modal shapes and damping of the structure in the different states. The obtained dynamic behaviour of the structure and its results are discussed and compared. It is concluded that a change in the frequency of the first flexural mode is only observed when the damage in the beam is very significant, while no changes are observed with the occurrence of flexural and shear cracks.