Nowadays, most of the historical bridges (Amsterdam, 2019) of Amsterdam do not meet the load-bearing criteria of the current design code (Eurocode: 2012). This has several reasons. It comes partly because of the overdue of the maintenance (Amsterdam, 2019) but also because the traffic load for which the bridge has been designed, is lower than the present traffic load (Amsterdam, 2019). The current Eurocode 4 does not guarantee the safety of this type of bridge decks. To guarantee the safety and the remaining service life of the historical bridges in Amsterdam, the municipality has started an investigation on historical steel-concrete-composite-bridge-decks. The focus in this thesis is on historical steel-concrete-composite-bridge-decks (a.k.a. Verbundträger brücken in German) because this type of bridges does not contain shear connectors in their configuration. This leads to the fact that the capacity of the bridge deck is almost not determined in the longitudinal and completely not determined in the transversal direction. The bridge deck in the longitudinal direction satisfies the unity check based on the protocol of the municipality of Amsterdam to check this type of bridges on safety, where they only consider the steel profile to define the capacity of the bridge in this direction. This is very conservative because the concrete is not taken into account during the calculation of the cross-section. In the transverse direction, the bridge deck does not fulfil the necessary unit check limit, because the municipality takes only the shrinkage reinforcement into consideration during their calculations. In addition to this, the state of the bridge decks and relevant research about how the bridge deck is build-up, is investigated. The main conclusion that can be taken from the cross-section of these type of bridge decks is that there is a lot of variation in all the components of the bridge decks. Furthermore, during the investigation of the bridge decks it is decided to choose three typical bridge decks (A, B, C), which will be simulated to gain more insights about the cross-section of these historical bridge decks. The current Eurocode 4, which is implemented to guarantee the safety of the type of cross-section containing steel and concrete, does not provide an answer to calculate the load-bearing capacity of historical steel-concrete-composite-bridge-decks, because of a significant difference between the designed current Eurocode 4 model and the designed cross section of the historical model. The behaviour of the bridge is studied in two directions based on the available literature. In the longitudinal direction, the focus is on the interaction between steel and concrete and how this interaction can be described. In the transverse direction, the aim is to find the relevant failure mechanism and corresponding modelling approach to define the behaviour of the bridge deck in the transverse direction of these bridge decks. The failure mechanisms that were evaluated are: Punching shear failure, compressive membrane action, and failure of concrete strut. The assessment of the aforementioned failure mechanisms is carried out and the most logical model which can be used to validate during the FEA-simulation is the failure of concrete strut which can be modelled by strut and tie model. This model will also be carried out on the other two chosen bridges, next to bridge A on which the in-situ-load-test is done, to validate this model on more than one bridge deck. There was made use of an analytical model based on Eurocode 2, which has been compared the values of the numerical simulations…