Concept of load balancing
In above cases of concentric and eccentric pre-stressing, straight tendon profiles (or tendon shapes) along the beam span have been considered. If a tendon is provided a curved profile along the span, transverse component of pre-stressing force resists the external loads depending on the tendon force and inclination of tendon. It is possible to select an appropriate value of prestressing force and provide a suitable cable profile in a pre-stressed concrete member so as to result in the most desirable system of forces in concrete.