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Within a recently finished funded FFG-project the load carrying behaviour of thrust rings for the transfer of axial loads from the penstock to the rock was studied. On the one hand tests were carriedoutTwo "full tests", comprising of a pipe with a thrust ring and the surrounding cylindrical concrete block, with two border cases for the slenderness of the rectangular thrust ring (very stocky, very slender) were performed. In addition 12 plane tests of pipe segments were carried out. The latter ones were carried out, because due to the axial load in the pipe the stresses in the thrust ring along the circumference are constant. Within these tests the slenderness of the thrust ring, the amount and position of the reinforcement in the concrete and the thickness of the pipe were varied. Additionally every test was simulated through numerical FEM- calculations. The results of all tests were used to calibrate the accompanying FEM model. Based on all results - tests and FEM- calculations - the fundamentals for a design model were developed. This paper gives an overview of the project, showing the test setup and the main results. To get realistic FEM- results, the material model for concrete (CDP - Concrete Damaged Plasticity Model in ABAQUS) has to be modified. A short overview of the improved parameters is given. Finally the new insights in the load carrying behaviour of thrust rings are shown and the basics for a design model in practice are presented.