EXPERIMENTAL STUDY ON SHEAR PERFORMANCE AND BEARING CAPACITY OF PRESTRESSED CONCRETE T-BEAMS

Abstract

Prestressed concrete t-beams have complex shear mechanism, and their shear performance is influenced by various factors, such as flange width and prestress. The shear performance of prestressed concrete t-beams has not been solved completely. This study designed and established nine prestressed concrete t-beams and one ordinary reinforced concrete t-beam to investigate the influence of flange width and the number and bending angle of prestressed tendons on the shear bearing capacity of concrete t-beams. The crack development, failure form, mid-span deflection, and concrete strain of the prestressed concrete t-beams were measured to analyze the load–deflection relationship; the concrete strain in the compressive zone; and the shear bearing capacity under different flange widths, reinforcement ratios of prestressed tendons, and bending angles. Experimental results were verified by the outputs of the bearing capacity calculation formula specified in China, America, Canada, and Europe. The results demonstrate that the increase in flange width, bending angle, and number of prestressed tendons can improve the internal force and shear bearing capacity of t-beams significantly. However, the flange width has less evident influence on the shear bearing capacity. The positive effect of the flange is evident under a specific flange width. For example, when the ratio of the flange width to the web width is greater than 4. The shear bearing capacity of the prestressed concrete t-beams is large when the reinforcement ratio and bending angle of the prestressed tendons are great. This study has reference values for revealing the shear failure mechanism of prestressed concrete t-beams under concentrated loads and provides a basis for engineering design. Keywords: Prestressed concrete; T-beam;Shear bearing; Experimental study