Calculation of Short-Term and Long-Term Behavior of Prestressed Concrete Box Girders Considering Effect of Shear Lag

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Abstract:

A set of formulae to calculate short-term behavior of simply supported prestressed concrete box girders under dead load and prestress are established based on energy method, in which shear lag and effect of prestressed steel and non-prestressed steel are taken into account. As the time-dependent relationship between stress and strain of concrete, equilibrium of sectional forces and compatibility equation are introduced, a novel approach to analyze long-term behavior of prestressed concrete box girders is presented, and the theoretical formulae considering the synthetic effect of creep and shrinkage of concrete, relaxation of prestressed steel, shear lag and restriction of steels are deduced, which can be used directly to calculate time-dependent deflection of box girder, stresses and strains of concrete and steel at any location at any time. Comparison of theoretical values shows that that the long-term deflection increases by shear lag while distribution of transverse concrete stresses become even by concrete creep and shrinkage.

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Key Engineering Materials (Volumes 400-402)

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943-948

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October 2008

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© 2009 Trans Tech Publications Ltd. All Rights Reserved

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[1] V. Kristek and Z.P. Bažant: Shear Lag Effect and Uncertainty in Concrete Box Girder Creep. Journal of Structural Engineering, ASCE Vol. 113 (1987), pp.557-574.

DOI: 10.1061/(asce)0733-9445(1987)113:3(557)

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[2] W. Peng and G.L. Lu: Shear Lag Effect in Concrete Box Girder Creep. Bridge Construction, Vol. 1 (1988) , pp.28-30.

Google Scholar

[3] Z.P. Bažant: Prediction of Concrete Creep Effects Using Age-adjusted Effective Modulus Method. ACI proceedings Vol. 69 (1972), pp.212-217.

DOI: 10.14359/11265

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[4] E. Reissner: Analysis of Shear Lag in Box Beams by the Principle of Minimum Potential Energy. Quarterly of Applied Mathematics Vol. 4 (1946).

DOI: 10.1090/qam/17176

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