For creep and shrinkage investigations, relatively small cylindrical specimens are generally exposed to constant climatic conditions. The derived mainly empirical prediction models are used for the calculation of large engineering structures with massive cross‐sections. In this paper, the expected values of the material models according to fib Model Code 2010 and Eurocode 2 are compared with monitoring data, which were acquired over a period of more than 12 years during a structural health monitoring of a large viaduct. It was found that in addition to the measured continuous increase in the viscous deformations, seasonal fluctuations due to climatic influences could also be detected. The numerical calculations show that the material models differ significantly in their magnitude and time course of the predicted viscous concrete deformations. In comparison with the monitoring data, a good agreement was achieved when using the material models according to Eurocode 2. The models of the fib Model Code 2010, on the other hand, underestimated the deformations of the massive bridge girder.