Field Investigation of a Prestressed Concrete Highway Bridge Located in Douglas County, Illinois

Houdeshell, D.M.; Anderson, T.C.; Gamble, W.L.

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https://hdl.handle.net/2142/14408 Copy

Description

Title

Field Investigation of a Prestressed Concrete Highway Bridge Located in Douglas County, Illinois

Author(s)

• Houdeshell, D.M.
• Anderson, T.C.
• Gamble, W.L.

Issue Date

1972-02

Keyword(s)

• Prestressed concrete construction
• Highway bridge -- Illinois -- Douglas County

Abstract

Camber, strain, creep, and shrinkage measurements were made over a period of two years on a three-span prestressed concrete highway bridge and concrete specimens. The precast I-section girders 72 ft. 9 in. long were made continuous for live-load force by reinforcement cast in the deck. The construction of the bridge is described, as is the instrumentation used. Although the most important changes in camber of the beams occurred within the first 200 days after release of prestress, measurable movements were still occurring after m ore than two years. The strain measurements exhibited annual cyclical expansions and contractions, probably due to changes in average relative humidity at different times of the year. Measurable shortening of the bottom fiber of the girders occurred for more than two years after release of the prestressing force, but was obscured by the large cyclical variations. The major portion of the loss of prestress occurred during the first few weeks after release, but the losses continued at a slow rate throughout the test period. The creep and shrinkage measurements show that the shrinkage in the field was much less than in the laboratory, but that the creep values were comparable in the two environments. Further work is required to define the magnitude of creep of concrete subjected to variable environmental conditions as most accepted present concepts are not adequate.

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-375

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/14408

Sponsor(s)/Grant Number(s)

project IHR-93; illinois Cooperative Highway Research Program Phase I

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