Unification of the infrastructure networks management is one central concern of the European commission for the next decades. Today, the assessment procedures, e.g. of bridges and their conditions differ all over Europe. The Integrated Project Sustainable Bridges focuses on finding optimum procedures to assess and strengthen the existing railway bridge stock. One of the workpackages concentrates on the integration of Non-Destructive testing into a proposal for a unified condition assessment procedure. To give Non-destructive testing a higher priority means the reduction of uncertainties, which are often included in the calculation of existing structures as safety margin. The non-destructive testing of reinforced or prestressed concrete bridges, made of heterogeneous materials in combination with steel comprises a challenge in data acquisition and data processing. A new developed automated scanning system, especially for concrete bridges, includes advanced equipment components and the feasibility for the variation of sensors with high precise geometrical correlation. Data images obtained with radar measurement can be refined in a second measurement, using two additional methods simultaneously: an ultrasonic-echo array with point-contact for better coupling to the swirl surface and an impact echo-sensor. The images, recorded from radiated and reflected acoustic waves in the heterogeneous solid, can be processed with a Synthetic Aperture Focussing Technique (SAFT-reconstruction). As a result, slices parallel or perpendicular to the surface are visualized in 2D-images or even as 3D-demonstrations. The results are used to verify construction plans and the inner structures of the bridge. Both, bad workmanship or in-service damages, which arose during their service life, can be investigated.