Title:
Experimental Investigation of Prestress Losses in Full-Scale Bridge Girders
Author(s):
David B. Garber, José M. Gallardo, Dean J. Deschenes, and Oguzhan Bayrak
Publication:
Structural Journal
Volume:
112
Issue:
5
Appears on pages(s):
553-564
Keywords:
prestress loss; prestressed bridge girder; pretensioned concrete
DOI:
10.14359/51687909
Date:
9/1/2015
Abstract:
An experimental study was conducted in which 30 full-scale,
precast, pretensioned bridge girders were constructed and instrumented with the intention of investigating prestress loss. Several different precast beam fabrication plants were used to investigate the influence of different concrete materials and construction techniques. The constructed girders were conditioned in several different climates for up to 3 years. During this period, prestress loss was measured by using vibrating wire gauges (VWG) embedded in test specimens. Following the conditioning period, the girders were flexural service load-tested to quantify the prestress loss at the time of testing and in turn verify the losses measured using VWGs. Prestress losses were found to be heavily influenced by concrete stiffness, which was dependent on coarse aggregate
type and quantity. The measured short- and long-term prestress losses were compared to those determined using several different estimation procedures, suggested by ACI Committee 423.