Concrete Beams

If you want to save steel, speed construction and meet tighter placing tolerances, use Welded Wire Reinforcement in your next beam project.

The primary use of Welded Wire Reinforcement in beams is in the form of stirrups for shear. The spacing and size of the wire is determined from engineering drawings. As an engineer you can specify a mesh pattern for the stirrups that gives you the required area of steel, but be aware that the WWR producer may be able to give you the proper area of steel with a different pattern. The type of equipment varies around the country, and you may find a more economical solution by the producer, depending on his equipment. Ivy Steel can provide wire of larger diameter and higher yield strength in most of our plants. By providing a large wire at a higher yield strength, the spacing of the wires can be greater. This is important in facilitating concrete placement in beams with heavy shear requirements.

The advantages of using stirrups made from WWR include:

• Much faster placing time. The handling of many small size rebars and tying them into the proper  location in a beam form, is replaced by simply dropping a pre-bent cage of stirrups held at the proper spacing by holding wires welded by electrical resistance welding.
  
  
• The accuracy of the bends is greatly improved by bending all the stirrups at the same time on a mesh bender.
  
  
• The stirrups are assured of being in the proper location by the way the mesh pattern is laid out on the mesh welder and then welded rigidly in place. This provides a stirrup cage of WWR containing the exact amount of reinforcing at the precise location with tight bending tolerances.

The ACI Building Code provides details of the anchorage requirements for stirrups and eliminates the requirements of wire spacing of 12 or 16 inches for shear reinforcement. The stirrup may be bent out 90 degrees to provide anchorage, or have two wires at least two inches apart at the end of the stirrup.