Design of Prestressed Concrete Beams for Specific Performance

Mapping Intimacies ◽

10.31224/osf.io/ygwns ◽

2020 ◽

Author(s):

Farshad Haddadi

Keyword(s):

Prestressed Concrete ◽

Failure Load ◽

Concrete Beams ◽

Design Procedure ◽

Live Load ◽

Dead Load ◽

Curvature Analysis ◽

Total Length ◽

Specific Performance ◽

Prestressing Strands

The Florida International University's 2020 Big Beam Team greatly appreciated the opportunity to participate in this competition. The presented report is a step by step design procedure for designing prestressed concrete beams which is expected to perform and fail in a predefined load. The chosen design was a I‐shaped member composed of four straight prestressing strands, and incorporating two compression longitudinal bars. The beam was designed supported span of 18 ft., center-to-center of bearing, and a total length of 19 ft. The loading consists of two point loads as live load and the beam self-weight as dead load. The beam is designed to remain uncracked under the unfactored live load of 20 kips (10 kips at each point) and have capacity of more than factored live load of 32 kips. The final capacity should be less than 40 kips. The team predicted the cracking load, failure load, and ultimate deflection of the beam using a moment‐curvature analysis.

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An approximate nonlinear design procedure for partially prestressed concrete beams

Computers & Structures ◽

10.1016/0045-7949(83)90017-2 ◽

1983 ◽

Vol 17 (2) ◽

pp. 287-299 ◽

Cited By ~ 9

Author(s):

Antoine E. Naaman

Keyword(s):

Prestressed Concrete ◽

Concrete Beams ◽

Design Procedure ◽

Nonlinear Design

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Load Rating of Prestressed Concrete Girder Bridges

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105192800106 ◽

2005 ◽

Vol 1928 (1) ◽

pp. 53-63 ◽

Cited By ~ 1

Author(s):

Brandy J. Rogers ◽

David V. Jáuregui

Keyword(s):

New Mexico ◽

Prestressed Concrete ◽

Resistance Factor ◽

Live Load ◽

Dead Load ◽

Girder Bridges ◽

Load Effects ◽

The Dead ◽

Load And Resistance Factor ◽

Concrete Girder

In light of the adoption of the load and resistance factor design (LRFD) philosophy by the AASHTO Subcommittee on Bridges and Structures, research efforts are under way to facilitate the transition from load factor rating (LFR) to load and resistance factor rating (LRFR) in New Mexico. Five prestressed concrete girder bridges, courtesy of the New Mexico bridge inventory, were rated with the BRASS-GIRDER and BRASS-GIRDER (LRFD) structural software. The objectives for this study were to evaluate and verify the BRASS (bridge rating and analysis of structural systems) software, to identify the source of dissension between LFR and LRFR rating factors, and to examine any trends in the rating factors as affected by bridge geometry. The comparison of LFR and LRFR focused on both flexure and shear for the strength limit state. The LRFR method generally yielded lower rating factors for flexure, with the longer-span bridges demonstrating a larger deviation between LFR and LRFR. The live load effects were identified as the major factor contributing to the difference in flexure ratings; the dead load effects and flexural resistance had little effect. The LRFR rating factors for shear also were generally lower than those produced by LFR. The discrepancy in the shear ratings was caused by both the live load effects and shear resistance. The dead load effects contributed little to the variation in LFR and LRFR rating factors for shear. Overall, the shear ratings controlled over those based on flexure.

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