Long-Term Behavior of a Prestressed I-Girder Highway Bridge in Champaign County, Illinois

Gamble, W.L.

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https://hdl.handle.net/2142/14077 Copy

Description

Title

Long-Term Behavior of a Prestressed I-Girder Highway Bridge in Champaign County, Illinois

Author(s)

Gamble, W.L.

Issue Date

1979-12

Keyword(s)

• highway bridges
• Prestressed concrete
• Reinforced concrete
• Concrete -- Creep

Abstract

This report describes the measured long-term behavior of a small prestressed concrete highway bridge. The three spans of about 46 ft (14.0 m) each were made with precast pretensioned I-section girders and a cast-in-place deck. Strains and camber were measured in the two instrumented girders for a period of 1067 days after transfer of prestress. The measured camber remained small, with values between 0.25 and 0.30 in. (6 to 8 mm) at the last reading. When corrected for the effects of initial temperature gradients, the camber is about 0.1 in (2.5 mm), while the predicted final camber is about 14 in. (3.5 mm). The concrete strains remained relatively small, since the girders in the bridge were not heavily prestressed. The measured strains were in relatively good agreement with strains computed using an analysis that took into account the measured creep and shrinkage properties of the girder and deck concretes. The same analysis indicates that the prestressing force after losses is somewhat lower than the designer assumed, largely as a result of not obtaining the desired initial forces in the prestressing bed. Creep and shrinkage specimens of both girder and deck concrete were· stored outdoors in the same environment the bridge was subjected to and in a controlled environment laboratory.

Publisher

University of Illinois Engineering Experiment Station. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Civil Engineering Studies SRS-470

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/14077

Sponsor(s)/Grant Number(s)

• State of Illinois Department of Transportation
• U.S. Department of Transportation. Federal Highway Administration

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