Why we need a high strength concrete in prestressing

There is another aspect to why we need a high strength concrete in prestressing. Prestressed concrete is subjected to high values of compressive, tensile. shear. bond and bearing stresses. In the case of post-tensioned concrete. anchorages occupy a little cross-sectional area of concrete at the ends. Through these small areas, the prestressing force of a high magnitude is transferred to the concrete member. If the strength of concrete is not adequate, the anchorages may locally damage the end portion of concrete member and may punch inside concrete. If this happens, a major portion of tendon stresses may get lost.