Effects of Friction and Slip-Back on Stresses in Post-Tensioning Tendons

摘要

In post-tension ed systems, friction during stressing and slip-back due to setting the wedge anchors cause loss of prestress. If the tendon is long or contains sharp curvatures, these losses can be significant. This paper summarizes methods for calculating the losses and provides an evaluation of the numerical coefficients suggested by ACI 318-05 forfriction. Equations are provided where closed form methods are possible, and numerical methods are outlined for othercases.