In the scope of this work the questions in the field of concrete technology, based on experimental and numerical investigations, are explored. The concrete samples for the three point bending and the UCS (uniaxial compressive strength) tests were produced at the construction area KAT2 and they were tested in the laboratory of the Montanuniversity in Leoben. The normative basis is the ÖNORM EN 12390. For the determination of the fracture work and the stress-strain behaviour at the post-failure, the available measuring system was expanded with additional sensors. The measured values constitute a basis for further numerical calculations. The Finite Element analysis are subject to the application of the software ABAQUS Version 6.13 of the company Dassault Systemès and the detailed discussion about the used materially nonlinear CDP (Concrete Damaged Plasticity) constitutive law. For the numerical back calculation of the parameters from the three-point bending tests, different approaches are selected and compared to their application.