With increasing use of high strength concrete (HSC) in prestressed concrete girders, conditions at transfer often control the level of prestress that can be placed in these girders. This, in turn, controls the maximum span capacity. This paper presents a rational method for design due to forces at the time of prestress transfer. It is equally applicable to both normal and high strength concrete. The need to have a lower strength at transfer is far more important with high strength concrete than it is with conventional strength concrete. It is proposed that flexural design of prestressed concrete members for effects of prestress transfer be based on strength design criteria. The proposed method will frequently allow for higher prestress levels than the current empirical allowable compression stress limits of 0.6 f_(ci)' given in ACI 318-99 Building Code and AASHTO Standard Specifications for Highway Bridges.
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