ABSTRACT
ABSTRACT: The effects of prestressing on a structure are closely bound with the redundancy of a structural system. Imposed deformations due to the prestressing are restrained by hyper static restraints, which lead to the development of additional reactions. Those reactions, may significantly influence the internal forces in a structure. They are called secondary effects of prestressing. Regarding the above mentioned principle, there is a question of what will happen with those effects after changing the structural system e.g. due to development of plastic hinge or after development of a kinematic mechanism. This paper deals with investigation of behavior of post-tensioned beams with significant secondary effects of prestressing subjected to the ultimate load. Six two span beams prestressed by two single strand tendons were subjected to external load that has changed the structural system up to the kinematic mechanism. Results have shown that secondary effects did not disappear and they represent permanent part of the beam action.
