Time-Dependent Deflection of Prestressed Concrete Members of any Concrete Compressive Strength

Abstract

The deflection of a member can be determined more accurately from the values of the mean curvatures of a number of sections using simple geometrical deflection-curvature relations taking into account the effect of tension stiffening. Thus, the "The Proposed Mean Curvature" idealization is derived in this work exclusively for prestressed concrete members taking into consideration the effect of cracking of these members. It shows better agreement with experimental data than the conventional models, which are established essentially for normal strength concrete and do not fit higher-strength concrete. The computer program "PPCD" is developed in this work following the proposed model. Immediate and time dependent deflections of prestressed concrete beams can be computed. Concrete compressive strength, tension-stiffening effect, and time-dependent factors are included in this program. This program has been verified once to typical studied example with varying concrete compressive strengths and furthermore to an experimental data.
The results indicate that the accuracy of The Proposed Model in deflection predicting is acceptable for partially prestressed concrete members of any concrete compressive strength.