Distribution of Post-Tensioning Forces Prior to Grouting Tendons

The objective of this study was to evaluate the simplification of design procedures for continuous post-tensioned memebers using an average-tendon stress as opposed to the current-design procedure of using a variable-tendon stress at different design control points along the length of a tendon profile.

This report evaluates the tendon stress distribution due to frictional effects during jacking and seating of several tendon profiles. Measured strand stress values along the tendon profile are compared to predicted theoretical stress values. After seating, the redistribution of strand stresses was observed to determine the magnitude of tendon stress equalization and the necessary time period for redistribution to occur. The results of laboratory and field experimental studies are summarized in this report.