Structural Efficiency of Prestressing for Concrete Bridges in Ultimate

The main objective of this study is to present the effect of prestressing force and induced prestressing moment on the ultimate moment capacity for the structurally determinate and indeterminate prestressed beams. An analytical study was carried out for 33 structurally determinate internally bonded prestressed beams and 21 structurally determinate unbonded prestressed beams with different concrete compressive strength and different reinforcement ratios to determine the ultimate moment capacity. A numerical study included non linear finite element modeling using ¿Tno-Dianä software was used to solve 5 statically determinate prestressed beams, which were previously tested experimentally. These models were used as a calibration models for the program also 60 statically indeterminate prestressed beams were solved using ¿Tno-Dianä program and ultimate moment capacity, ultimate deflection, ultimate concrete strain, ultimate prestressing steel strain and load deflection curves were determined.