Welded Wire Reinforcement Fabrication Has Plain and Deformed Wire Options
Dec. 19, 2019 - Fairfax, VA,
Welded wire reinforcement is fabricated with deformed steel wire, plain/non-deformed wire, or some combination of the two. Each is effective in different project applications.
Deformed wire used for the manufacturing of welded wire reinforcement is an orthogonal arrangement of structural wires of various sizes and spacing but is manufactured with ridges, protrusions or indentations to improve the mechanical interaction with the surrounding hardened concrete. Anchorage is developed along the wire by virtue of both the deformations as well as at the welded intersections.
The design professional is afforded the flexibility of choosing between two deformed wire options to best suit the project-specific application. The actual calculation of development lengths and tension lap splices derived solely from the mechanical bond between the deformed surface and the surrounding concrete is well-defined throughout American Concrete Institute (ACI) 318 and related reference standards, and perhaps, the most familiar to design professionals. These standards also include a second provision that allows development lengths and lap splices of welded deformed wire reinforcement to be calculated based on a combination of mechanical surface bond and the anchorage force that develops at welded intersections.
Welded deformed wire reinforcement mats are available with yield strengths up to 80 ksi, and are commonly used as primary flexural reinforcement and shrinkage-temperature reinforcement in slabs, footings, conventional and tilt-up walls, as well as shear reinforcement and confinement in beam and column-type structural elements.
Welded plain wire reinforcement is similar to welded deformed wire reinforcement in that it, too, is an orthogonal arrangement of structural wires of varying size and spacing. However, wires used in welded plain wire reinforcement have smooth circumferences. In the absence of surface deformations, development lengths and tension lap splices are entirely dependent on the anchorage force that develops as a result of the shear capacity at welded intersections.
Welded plain wire reinforcement is available with yield strengths up to 80 ksi, and is commonly used as shrinkage-temperature reinforcement in slabs-on-ground, as anchored shear reinforcement and confinement in beam and column-type structural elements, and in numerous precast water-conveyance structures such as culverts and manhole risers.
There are several advantages to using WWR. It reduces material requirements, is easier to inspect, and provides higher strength compared to conventional Grade 60 designs.
Welded wire reinforcement has crisscrossed the world in highways, train stations, subways and major airport runways. It was placed in such famous structures as the Anaheim Stadium, Grand Central Station, the Standard Oil Building, Golden Gate Bridge, Empire State Building, the Nabisco Bakery, the World Trade Center Towers, the Empire State Building, Sears Tower-Chicago, the Abu Dhabi Airport and the Volkswagen plant in Pennsylvania..
According to American Concrete Institute, Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318 R-19), WWR is interchangeable with rebar when used as mild reinforcement. The actual design routines and calculations are identical, with concepts including strain compatibility, tension- and compression-controlled limits, application of reduction (phi) factors, and prescriptive spacing limits related to design all remaining familiar to the design professional.
The Wire Reinforcement Institute offers technical information and courses on the subject of WWR.
About the Wire Reinforcement Institute (WRI)
WRI is the world’s leading association of manufacturers, allied industries and professionals engaged in the production and application of structural welded wire reinforcement (WWR) and related concrete reinforcement products. The Institute advances the concrete industry by providing technical, outreach and promotional programs and materials on the applications and benefits of structural WWR. WRI works closely with design firms, universities, owners, contractors and government agencies, to ensure adherence to the most accurate, up-to-date codes, standards, specifications and regulatory requirements. For more information on WRI or WWR, visit www.wirereinforcmentinstitute.org or call 1-860-240-9545.