Title:
Field Measurements of Prestress Losses in
External Tendons
Author(s):
Carin L. Roberts-Wollmann, Jose A. Arrellaga, John E. Breen, and Michael E. Kreger
Publication:
Structural Journal
Volume:
93
Issue:
5
Appears on pages(s):
595-601
Keywords:
external tendons; field measurements; prestress loss; seg-mental
bridges.
DOI:
10.14359/9718
Date:
10/1/1996
Abstract:
This paper presents the results of a field study of losses in external post-tensioning tendons. An innovative measurement system was developed to measure strains in external tendon bundles. The system was installed on a total of 16 tendons in an urban viaduct of segmental post-tensioned box girders. Measurements were taken to study initial prestress losses, such as losses through stressing hardware, friction losses, seating losses, and elastic shortening losses. Measurements continued for over a year to study time-dependent losses. Recommendations are presented for modifications to the current methods for calculating prestress losses in external tendons pre-sented in the AASHTO Guide Specification for the Design and Construc-tion of Segmental Concrete Bridges.