TESTS TO DETERMINE PERFORMANCE OF DEFORMED WELDED WIRE FABRIC STIRRUPS

Two full-scale beams with cold-rolled, Grade 500 (Grade 75, ksi), deformed welded wire fabric U-stirrups were tested to assess the service and ultimate load performance of the welded wire fabric as shear reinforcement. By comparing the responses of these beams with two companion beams, reinforced with hot-rolled, Grade 400 (Grade 60, ksi) stirrups, it was demonstrated that the use of welded wire fabric resulted in better diagonal crack control and enabled large strains to be developed in the stirrups. These rests demonstrated that the full yield stress of Grade 500 reinforcement can be developed in the stirrups. The predicted shear capacities of these beams, computed using the 1989 ACI Building Code expression, underestimated the actual strengths. The modified compression field theory provided a more accurate prediction of their capacities.