Study on Shear Strength of Prestressed and Non-Prestressed Reinforced Concrete Beams

It’s commonly believed that the shear contribution from concrete consists of shear crack interlocking, concrete in compression zone and dowel action. However , there is still controversial about the major part of shear contribution from concrete. ACI 318-14 considers the major shear resistant from concrete is shear crack interlocking. So there is a specific restriction about the yielding strength of shear stirrup in ACI 318-14. Hsu et al. proposed two equations for predicting shear strength of PC beam and RC beam at 2010 and 2014 respectively. Hsu et al. considered the major shear resistant from concrete is concrete in compression zone. This research tested 8 I beams and 8 rectangular beams. By varying the effective pre-stress force on the specimens, this research want to clarify the effect of pre-stressed force on the shear strength. Also the effect of flange of I beam on the shear strength is investigated. According to the test results of this research and the existing finding from literature, this research concludes that the major shear resistant from concrete is concrete in compression zone and pre-stressed force does increase the shear strength. Also the flange of I beam can increase the shear strength of beam by providing well confinement to the compression zone. Finally this research proposes a new equation that can be used for both RC Beam and PC Beam for shear strength prediction.