Use of Welded Wire Reinforcement as Lateral Reinforcement in Concrete Beams: Part 1-Shear

Reinforced concrete beams are typically reinforced transversely with rectilinear stirrups made from steel reinforcing bars to resist shear. The process of making stirrups requires extended time and considerable labor, and results in relatively large tolerances. This study aims at studying the viability of using welded wire reinforce-ment (WWR), cold-formed into the shape of a closed steel cage to resist the shear load effect. To accomplish the objective of the study, 16 half-scale beams were tested by a universal testing machine under displacement-controlled loading conditions. The study considered different wire diameters (4, 6, and 8 mm [0.16, 0.24, and 0.32 in.]), grid openings (25, 50, and 100 mm [1, 2, and 4 in.]), shear span-to-thickness ratios (2.5 and 3.0), and transverse steel reinforcement ratios (251 and 505 N/mm [1433 and 2884 lb/in.]). A comparison was carried out between the test results of WWR-reinforced beams and corresponding stirrup-reinforced beams in terms of the crack formation characteristics, stiffness, shear strength, residual strength, and ductility. Findings of the study showed that the WWR-reinforced beams possessed 2 to 17% higher shear strength than the corresponding stirrup-reinforced beams, without a compromise in the ductility. The predicted shear strength based on ACI 318 was within 10% of the strength obtained by the experiments.