In 2016 the Lahntal Viaduct was replaced by a new structure. Before the western superstructure was deconstructed, more than 250 cores and other specimens could be taken from the old structure. The present paper deals with the investigations on compressive strength and tensile splitting strength of the concrete. The test results are evaluated statistically and different populations are tested for the taken sample. The goal is to identify a reasonable subdivision of the sample. Furthermore, the design values according to DIN EN 13791 and Eurocode 0 were calculated and compared with calculated expected values. These investigations are intended to provide insights for the assessment of the strength properties of existing viaducts and to develop a safe and economical investigation methodology from them.