Research Activities: 2006

 

Serviceability and Prestress Loss Behavior of SCC Prestressed Concrete Girders Subjected to Increased Compressive Stresses at Release

 

Status

Complete  View Report: PDF
 

Sequential Number

R209
 

Identification Number

00018532
 

Matching Research Agency

Coreslab Structures, Inc, Marshall, MO

 

Principal Investigator

Dr. John Myers, Associate Professor
325 Butler Carlton Hall
Missouri University of Science & Technology
Rolla, MO 65409
p573-341-6618
f573-341-4729
jmyers@mst.edu
 

Student Involvement

One (1) graduate student.
 

Project Objective

This proposal will examine the serviceability and prestress loss behavior of SCC members subjected to increased compressive stresses at release.  The effects of variable stress levels on losses and camber prediction will be investigated both experimentally and analytically.

 

Project Abstract

There are limited measurements documented in the literature related to long-term prestress losses in self consolidated concrete (SCC) members. Recorded test data has shown variations in mechanical property behavior of SCC compared to conventional HSC mixtures in the 8-12 ksi range. Over the past year, precast manufacturers such as Coreslab Structures, Inc., in Marshall, MO have experienced inconsistencies in camber behavior with SCC which may be attributed to mechanical property variations, but variation in stress may also be a contributing factor. Additionally, increasing the allowable fiber stress limit is desired for full utilization of materials and members, as long as structural performance is maintained. Furthermore, accurate prediction of time-dependant prestress losses is essential for determination of the effective prestress force, which effects serviceability prediction and structural performance. Further investigation is required.

 

Task Description

N/A

 

Anticipated Benefits

While the prestressed/precast concrete industry has been growing steadily in the last few decades, limited research has been conducted on the behavior of girders (HPC-PC) consisting of self-consolidating concrete. The work conducted in this study will examine issues related to prestress losses and their serviceability behavior as well as the possibility of increasing the allowable compressive stress limits at release. The wider acceptance for the use of SCC in longer-spanning bridge girders and improved design techniques will enhance the productivity of precast plants by further implementing the use of SCC and result in structural elements with fewer surface defects and improved predicted performance in terms of prestress losses and camber/deflection estimates.

Modal Orientation

N/A
 

Milestones

Project Start Date:9/15/2007
Project End Date:

6/30/2009

 

Relationship to other Research/Projects

N/A
 

Technology Transfer Activities

Technology transfer   will occur through publication(s) submitted to UTC and Coreslab Structures, Inc., in the form of a journal article(s) and/or conference proceeding(s). Results of this study will also be implemented into classroom lecture material in CE-ArchE 328 at MST.
 

Transportation Research Board Keywords

SCC, prestressed concrete, bridges