Structural Efficiency of Prestressing for Concrete Bridges in Ultimate Stage

Maged A Hashad, Fathy Fathy A. Saad, Khaled Khaled H. Riad


The codes describe the behavior of the prestressed beams in the ultimate stage as the prestressed concrete beam starts to behave like a reinforced concrete beam when the value of the flexural moment is well beyond the cracking moment and the total service load moment. The ultimate theory in flexure and the principles and concepts underlying it are thus equally applicable to prestressed concrete. The same fundamental format of equations, modified to reflect the characteristics of the different reinforcing materials and the geometry peculiar to prestressed concrete. The code equations aims to calculate the ultimate moment capacity (ultimate moment of resistance) while neglecting the beneficial effect of prestressing normal force and the induced prestressing moment on the ultimate moment then The capacity is compared with the demand at ultimate load considering the corresponding factor of safety. This study presents the beneficial effect of prestressing normal force and the induced moment on the ultimate moment for twenty five internally bonded prestressed beams.

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ACI Committee, American Concrete Institute, & International Organization for Standardization. (2008). Building code requirements for structural concrete (ACI 318-08) and commentary. American Concrete Institute.

AASHTO LRFD “Bridge design specifications” 4th Ed, Washington D.C. (2007).

California department of transportation (Caltrans). (2006).

Eurocode 2 Design of concrete structures - Part 1-1 “General rules and rules for buildings” 2004

Eurocode 2 Design of concrete structures “Concrete bridges - Design and detailing rules” 2005.

Manual for the design of concrete building structures to Eurocode 2 “The institution of structural engineers 2006”.

Janney, J. R., Hognestad, E., & McHenry, D. (1956, February). Ultimate flexural strength of prestressed and conventionally reinforced concrete beams. In ACI Journal Proceedings (Vol. 52, No. 2). ACI.

Baran, E., Schultz, A. E., & French, C. E. (2005). Analysis of the flexural strength of prestressed concrete flanged sections. PCI journal, 50(1), 74-93.



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