Shear behavior of prestressed decked bulb t beams reinforced with CFCC stirrups

Carbon fiber composite cable (CFCC) reinforcement has been broadly accepted as a non-corrosive alternative to the conventional steel reinforcement in bridge construction. Although the flexural behavior of beams prestressed with CFCC strands has been thoroughly examined, their shear behavior when steel stirrups are replaced with CFCC stirrups remains uncertain. This study outlines an extensive research program conducted to evaluate the shear behavior of prestressed decked bulb T beams with CFCC stirrups. The investigation addresses the effect of the shear-span-to-depth (a/d) ratio and the type of transverse reinforcement on the shear carrying capacity. Four 9.45-m-long beams reinforced and prestressed with CFCC reinforcement were constructed and tested under shear loading to failure. Half of the span of each test beam was reinforced with CFCC stirrups and the other half was reinforced with steel stirrups. To assess the performance of CFCC stirrups versus that of steel stirrups, both ends of each beam were tested under identical shear load. The obtained experimental results were compared with developed finite element (FE) models to validate the results. Beam ends with CFCC stirrups failed due to either concrete web crushing or top concrete compression failure, while beam ends with steel stirrups failed in shear tension mode due to yielding of stirrups. The developed FE models predicted the shear behavior and capacity of the test beams with a difference of less than 10%. This investigation demonstrates that CFCC stirrups can be regarded as a non-corrosive alternative to steel stirrups in highway bridge girders.