Details:

Creators:
Rizkalla, Sami ; Zia, Paul ; Storm, Tyler
Rizkalla, Sami ; Zia, Paul ; Storm, Tyler Less -
Corporate Creators:
North Carolina State University
Corporate Contributors:
North Carolina. Dept. of Transportation. Research and Analysis Group
Subject/TRT Terms:
[+]
Bridge Members
Curvature
Deflection
Prestressed Concrete
Prestressed Concrete Bridges
Structural Members

Publication/ Report Number:
FHWA/NC/2010-05
Resource Type:
Tech Report
Geographical Coverage:
North Carolina
OCLC Number:
779852628
Edition:
Final report; 8/16/2009-3/31/2011.
Corporate Publisher:
North Carolina State University
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-Bridges and Structures ; NTL-HIGHWAY/ROAD TRANSPORTATION-Construction and Maintenance ; NTL-HIGHWAY/ROAD TRANSPORTATION-Design ; NTL-HIGHWAY/ROAD TRANSPORTATION-Materials ; NTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and Performance ;
Abstract:
Accurate predictions of camber and prestress losses for prestressed concrete bridge girders are essential to minimizing the frequency and cost of construction problems. The time-dependent nature of prestress losses, variable concrete properties, and problems related to production variables make it difficult to predict camber accurately. The recent problems experienced by NCDOT during construction are mainly related to inaccurate prediction of camber. In this report, several factors related to girder production are shown to have a significant impact on the prediction of camber. A detailed method and an approximate method for predicting camber that both utilize adjustments to account for the production factors are proposed. The detailed method uses time-dependent losses calculations and creep factors to predict camber, while the approximate method uses multipliers. The current NCDOT method and the proposed methods are analyzed and compared using an extensive database of field measurements. The proposed methods are shown to provide significant improvements to the camber predictions in comparison to the current NCDOT method. Recommendations for design and production practices are provided.
Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:d2cd4ee53fa0ab28c23fa322576328301325013490b76aad1eb14b23f3afc28b
File Type:

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