Title:
Time-Dependent Behavior of Post-Tensioned Slab Bridge
Author(s):
Paul N. Roschke, Kevin R. Pruski, and Narayanna Sripadanna
Publication:
Structural Journal
Volume:
96
Issue:
3
Appears on pages(s):
400-407
Keywords:
deflection; finite element method; post-tensioning; strains; stresses
DOI:
10.14359/674
Date:
5/1/1999
Abstract:
A three-span flat slab bridge is instrumented during its construction and monitored for more than 2 years. The slab is moderately thick and rests directly on columns without bent caps. Post-tensioning is employed in the longitudinal and transverse directions. Longitudinal post-tensioning is uniformly distributed across the width of the bridge; transverse post-tensioning is employed only in column regions. Strains in the field bridge are measured by a large array of gages attached to small reinforcing bars that are embedded in the concrete. Deflection data due to dead load are acquired immediately after placing of concrete, after longitudinal prestressing, and for a period of 2.5 years. Comparisons of deflections and strains are presented for existing simplified analytical methods and actual bridge response. Results indicate that a simplified one-way procedure yields predictions that are not always consistent with experimental measurements for service load conditions.