Modern high performance concretes (HPCs) are well characterized by their materials, compositions, and other characteristics, and usually documented by ‘test samples’ from laboratory specimens and trial castings. The characteristics are applied for construction design and estimations of service life time. However, in these young constructions, the internal structure of the HPC often reveals serious differences from that of the ‘test sample concrete’. Accordingly, the characteristics of the constructional concrete may be dramatically different from the expectations, often leading to increased rate of deterioration. A series of examples of such failures in the internal structures from major European HPC civil engineering constructions are presented. A test method is presented for the evaluation of the internal structure of the concrete as it exists in the actual structure. This test method is based on reground vacuum impregnated full sections of concrete core samples, cored from the construction at the moment of stripping the form work. Thus it is made possible to assess the structure during production. The cost of applying the test method approximates 0.1 % of the concrete value.