Welded Wire Mesh Fy

[Stenbrook]

I have always acted under the assumption that welded wire mesh was the same strength as rebar (60ksi). It came up recently that welded wire mesh also comes in higher strengths. My question is, what is the most common strength used for welded wire mesh and is it cost effective to go with the higher strength mesh. For reference, I am using a W2.9 x W2.9 4x4 mesh.

 

[WARose]

It depends on the size (and if it's deformed). But for most wire meshes the range will be from about 56 to 70 ksi.

See:

http://wri.support/WWR_500-R-16_Final.pdf

 

[BAretired]

http://www.webcivil.com/usfrmwwf.aspx

BA

 

[hokie66]

Strength is only part of the decision. No matter the yield strength, the elongation under force will be the same. And wire is not as ductile as bars. So a lot depends on the function of the reinforcement.

 

[Stenbrook]

Reinforcement is being used in a thin concrete shell (2 1/2") thick. We want to know if a higher grade steel is more cost effective then using a tighter spaced welded wire mesh. Or if it is even common to order a higher strength mesh.

 

[hokie66]

I see no benefit in the higher yield strength fabric for a thin shell.

Do you mind sharing some more information about your shell?

 

[Stenbrook]

It is sort of a unique design situation where we are using a composite light gauge-concrete panel. Essentially, there are metal studs built compositely with a 2 1/2" concrete shell. This shell is being treated as "sheathing" essentially resisting the load in-plane and spanning from stud to stud. The complicated part in this is that we are using 200 mph wind pressure (ASCE 7-5) to design these panels. In some of the panels we have called for two layers of welded wire mesh which theoretically will fit into the panel, but you have to install it in a specific way in which the layers are overlapping each other. The contractor/owner is having issues with this so wants to utilize carbon fiber reinforced concrete to reduce the amount of strength needed from the welded wire mesh to reduce the layers of mesh down to 1 layer. The engineer they have are using to analyze the carbon fiber concrete with the mesh has indicated to us that the strength between 60 ksi and 75 ksi plays a significant impact on the dosage of the fibers. So hence why I am here, because I wasn't really sure if 75 ksi welded wire mesh was all too common or if it would be cost effective.

 

[TehMightyEngineer]

All of the WWR we order is 70 ksi, and 80 ksi can be had for a reasonably small premium. As small as 2" spacing on wire mesh is common in precast. Reach out to a WWR supplier (we use CRI) and work with them to get an idea of what is a feasible stock wire size/spacing/grade and what would be difficult for them to do. For example, deformed wire diameters greater than 0.558" need to be custom made to order by our supplier and thus we avoid them.

Ian Riley, PE, SE
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

https://www.facebook.com/AmericanConcrete/