Time-Dependent Analysis of PostTensioned Concrete Structures,
- B. O. Aalami
- Progress in Structural Engineering and Materials,
The total prestress loss for unbonded, low-relaxation tendons is typically 20 percent of the jacking stress. A lump sum stress loss of 30 ksi (14%) was assumed for several years for pretensioned members, since there is no friction loss in pretensioning. The development of lowrelaxation strands and results of subsequent studies prompted a call for more exact estimates. A rigorous evaluation of stress losses is both time consuming and complex, however. Precise calculations for each tendon are not usually warranted in most residential and commercial buildings; studies have indicated that reliable solutions can be obtained with a number of simplifying assumptions.