An Extended Procedure of Controlling Frictional Losses of Prestress in Post4ensioned Tendons.

摘要

While a simple checking by means of the force-elongation relationship will in most cases be sufficient, it is occasionally necessary to extend this control for better information about the magnitude of friction and its distribution along the tendon. In such a case a newly developed testing procedure - the so-called reversal method - will be very help ful1 where tensioning and temporary releasing of the tendon is accompanied by refined measurements only taken at the active jack. The paper describes the basic idea of the method, reports on the experimental results of laboratory and field tests showing the variability of the method and gives numerous hints for the correct execution of the procedure on sites.