Shear behavior of continuous reinforced concrete T-beams using wire ropeas internal shear reinforcement

摘要

The use of wire ropes with high-strength and high flexibility as internal shear reinforcement can solve the difficulties encountered in bending higher strength steel bar and can provide a better shear behavior to concrete beams. Three two-span reinforced concrete T-beams were tested to failure in order to examine the possibility of the practical application of wire ropes as shear reinforcement. The measured shear capacities of beams were compared with predictions obtained from equations specified in ACI 318-08 and the mechanism analysis based on the upper-bound theorem of concrete plasticity. Test results showed that using spiral-type wire rope as shear reinforcement is highly favourable for controlling the diagonal crack width and enhancing the ductility of beams failing in shear. In particular, the high-strength of the wire ropes significantly promoted the shear capacity of concrete beams. When a limit stress of 420 MPa for wire ropes is employed, ACI 318-08 is highly conservative in beams with spiral-type wire ropes compared with the control beams with closed stirrups. In addition, ACI 318-08 is still conservative when using the equivalent yield strength of wire ropes. On the other hand, the predictions obtained from the mechanism analysis are in good agreement with test results, regardless of the type of shear reinforcement.