Frequently Asked Questions
- Is welded wire reinforcement a new product?
- Why have I never heard of welded wire reinforcement?
- Is welded wire reinforcement supported by the American Concrete Institute 318 Building Code?
- Is designing in welded wire reinforcement difficult and time consuming?
- Conventional reinforcing bars have standard sizes (#3, #4, #5, #6, #7, etc.). Does welded wire reinforcement have standard sizes?
- What is the difference between grade 60 and grade 80 steel?
- Why would I want to use grade 80 steel in lieu of grade 60 steel?
- How do you convert from grade 60 steel to grade 80 steel?
- What type of projects are good candidates for welded wire reinforcement?
- Can you bend welded wire reinforcement into a column cage?
- What are the production limitations of welded wire reinforcement sheets (length, width, area of steel)?
- Are there standard sheets of welded wire reinforcement or is everything custom made?
- I have a project that bids in three weeks. I would like an alternate price using grade 80 welded wire reinforcement. Do I need to redesign my project?
- What does 10x18 D20 / D11 stand for?
1) Is welded wire reinforcement a new product?
No. Welded wire reinforcement has been around since 1901 when John Perry invented a machine to weld wires into large sheets. Initially John was looking for a way to make fencing, but in 1906 he was advertising these sheets as reinforcement for concrete.
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2) Why have I never heard of welded wire reinforcement?
In 1884, two German engineers, Wayss and Buchinger, published a paper on steel reinforcement and launched the idea of reinforcing concrete with steel. Since then, the focus of engineering students studying reinforced concrete has been on using conventional reinforcing bars in concrete.
Back in the early 1900's, welded wire reinforcement was in its infancy. Welding and rolling technology limited welded wire reinforcement applications to light gage material used in highways and slabs. Engineers designing reinforced concrete structures gravitated towards conventional rebar because the technology was readily available. Designing reinforced concrete structures with welded wire reinforcement was impractical in the early 1900's. This forced designers to use conventional rebar, which then became the established form of reinforcement in the industry.
It wasn't until the aftermath of World War II that welded wire reinforcement became more acceptable in the engineering community. After World War II, Europe, with a depleted labor force, needed to rebuild its devastated infrastructure in a very short time. Welded wire reinforcement was the perfect reinforcing material to help Europe rebuild because it required less labor to install and a reduction in the time of construction. Because of the success of the post-war reconstruction effort, European builders, architects and engineers started to realize welded wire reinforcement's potential.
Welded wire reinforcement remains extremely popular in Europe; accounting for over 50% of all reinforcing in concrete projects. In comparison, less than 10% of reinforced concrete projects in the United States uses welded wire reinforcement.
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3) Is welded wire reinforcement supported by the American Concrete Institute 318 Building Code?
Yes. The American Concrete Institute regards deformed welded wire reinforcement equivalent to conventional reinforcing bars per Section 3.5.3 of ACI 318 Building Code for Structural Concrete and Commentary.
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4) Is designing in welded wire reinforcement difficult and time consuming?
No. The design process is relatively the same as designing with conventional rebar. The difference in designing in welded wire reinforcement takes place after the design engineer calculates the required areas of steel and before the area of steels is converted into conventional reinforcing bars (#3, #4, #5, #6, #7, etc.). At this point , the required areas of steel are converted into the spacing and wire sizes used in a welded wire reinforcement sheet. For example, an engineer designs a structural slab and calculates an area of steel of the primary reinforcement to be 0.26 in2 per linear foot and 0.13 in2 per linear foot for temperature reinforcement. The welded wire sheet would be 12"x12" D26/D13 or 4"x4" D8.7/D4.3 (note the area of steel per linear foot remains the same). For more information on designing in WWR - Please see the WWR Website for Engineering Resources and Design Aids.
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5) Conventional reinforcing bars have standard sizes (#3, #4, #5, #6, #7, etc.). Does welded wire reinforcement have standard sizes?
No. Ivy Steel & Wire has the flexibility to produce any area of steel from 0.014 in2 to 0.45 in2 in increments of 0.001 in2.
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6) What is the difference between grade 60 and grade 80 steel?
The difference between grade 60 and grade 80 steel is yield strength of the steel. Grade 60 steel has a yield strength of 60,000 psi and grade 80 steel has a yield strength of 80,0000 psi. As the illustration indicates a grade 60 steel bar with an area of steel of one square inch can hold a 60,000-pound elephant. Likewise a grade 80 steel bar with the same area of steel can hold an 80,000-pound elephant.
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7) Why would I want to use grade 80 steel in lieu of grade 60 steel?
Converting from grade 60 steel to grade 80 steel will save you or your client time and money. Converting conventional grade 60 rebar into high yield grade 80 welded wire reinforcement allows the designer to reduce the area of steel by 25%. A grade 60 #9 bar has an area of steel of 1 in2. The same load carried by the #9 bar can be transferred to a 3/4 in2 grade 80 bar. Thereby, reducing the area of steel by 25%. Reducing the area of steel by 25% reduces the weight by 25% and results in a reduction of cost.
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8) How do you convert from grade 60 steel to grade 80 steel?
Converting from grade 60 steel to grade 80 steel is a simple process. In the previous question (What is the difference between grade 60 and grade 80 steel?) a grade 60 steel bar with an area of steel of one square inch carries the weight of a 60,000 pound elephant. The following example illustrates how to determine the area of steel necessary to carry the same 60,000 pound elephant using grade 80 steel.
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9) What type of projects are good candidates for welded wire reinforcement?
There are many types of projects that would be good candidates for welded wire reinforcement. The most common type of project would involve the following construction elements: walls, slabs, footers, and columns. The types of projects listed below are examples of good candidates for welded wire reinforcement.
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10) Can you bend welded wire reinforcement into a column cage?
Yes. Bending welded wire reinforcement into column cages as confinement steel is one of the great advantages of welded wire reinforcement. Welded wire reinforcement column cages can save on installation time and labor by as much as 75%.
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11) What are the production limitations of welded wire reinforcement sheets (length, width, area of steel)?
Welded wire reinforcement sheets can be produced in a variety of lengths, widths and wire sizes. Each Ivy Steel & Wire facility has their own limitations based on their manufacturing equipment. The following is a list of general parameters used in producing Welded Wire Reinforcement sheets.
» Maximum Length: 45'-0"
» Maximum Width: 11'-6"
» Wire Size: 0.014 in2 to 0.45in2
» Wire Spacing: 2" to 48"
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12) Are there standard sheets of welded wire reinforcement or is everything custom made?
Some Ivy Steel & Wire facilities have standard sheets but most projects are designed with custom sheets. The technology used in producing welded wire reinforcement lends itself to custom sheets. Therefore, designers are not limited to a standard sheet size or wire size and can allow the design of the project determine the design of the welded wire reinforcement sheet, not the other way around.
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13) I have a project that bids in three weeks. I would like an alternate price using grade 80 welded wire reinforcement. Do I need to redesign my project?
No. Place a statement in the bidding documents and on the contract drawings indicating an alternate for welded wire reinforcement. Ivy Steel & Wire’s engineering staff can convert the conventional reinforcing steel into grade 80 welded wire reinforcement.
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14) What does 10x18 D20 / D11 stand for?
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