Torsion structural behavior of external prestressed circular segments with dry joints. In the tower construction of wind power plants concrete or hybrid towers are established, especially for high towers, they have replaced the traditional steel towers due to better transportability. The needed joints for the prefabricated construction method leads to problems, which are not satisfactorily resolved by the current models and calculation approaches. In the case of the formation of dry joints (horizontal joints) between the segments, the force transmission of the lateral forces and torsion moments take place exclusively through the friction in the joint, the external prestressing and the coefficient of friction generate the frictional resistance. The capacity of lateral force between the joints should be calculate by a linear calculation approach, that the permissible transverse force corresponds to the prestressing force multiplied by the coefficient of friction. For the transmission of the torsional moments, the calculation is carried out according to the known torsion theories of Bredt and Saint-Venant, as long as the joints are overpressed, they can transmit a very high torsional moment. However, in the ultimate limit state, if the joint begin to open, the permissible torsional moment drops immediately to a very small value and thus becoming a critical criterion for the tower. According to recent investigations, these approaches witch describe the bearing and deformation behavior of such a joints are incorrect, results in an uncertainty range and a very large unused potential.