The effects of transverse prestressing on the shear and bond behaviors of R/C columns

Experiments and 3-D FEM analyses were performed on reinforced concrete columns laterally prestressedby the shear reinforcement to study the influence of the active confinement upon shear crack behaviors and bond splitting strength. Many strain gauges were attached to main bars and hoops, and the width of each crack over transverse hoops was measured by a digital microscope. Transverse prestressing increases the bond splitting strength as well as the shear capacity at first cracking and the ultimate shear strength, and decreases the width values of cracks. The FEM analyses can evaluate the shear capacity at first cracking, ultimate shear strength and the bond splitting strength with a fair degree of precision, and provide valuable information about the effect of the active confinement on shear and bond behaviors by evaluating the intensity of confinement in tri-axial state of stress with minimum principal stress and equivalent confining pressure.