RELATIVE EFFICIENCY OF EXTERNAL PRESTRESSING

In this paper, the efficiency of tendon profiles is examined for the i nternal and external prestressing of statically indeterminate structur es. The statically indeterminate component of the total prestressing m oment is shown to be significant for both parabolic and linear tendon profiles. However, although linear profiles are more effective in coun teracting gravity moments in support regions, their efficiency within the spans can be significantly reduced. Therefore, for these profiles, it is more difficult to optimize the effective eccentricity of the pr estressing force all along the members. On the other hand, internal pr estressing with parabolic tendons offers a more uniform efficiency thr oughout the structure. Recommendations indicate how localized linear t endons can improve the efficiency of external prestressing.