Fibre Mesh vs Welded Wire Mesh
Fibre Mesh vs Welded Wire Mesh
(OP)
We are considering replacing 6x6 6-6 wwm with fibre mesh in an office slab on grade. We are concerned only with crack control. Does anyone have information on the performance of fibre mesh.





RE: Fibre Mesh vs Welded Wire Mesh
WWF ALWAYS ends up on the ground, exactly where it doesn't do any good.
Now on metal deck slabs, we do use it.
RE: Fibre Mesh vs Welded Wire Mesh
RE: Fibre Mesh vs Welded Wire Mesh
The problem was that the slab was used as the floor of a truck dock where large trucks would back into it and heavy forklifts would drive over it. The beams spanned about 26' and were spaced at 11' o.c. The problem was the forklifts created such large deflections in the beams that significant tensile stresses would develop in the slab. We couldn't thicken the slab due to other parameters.
The slab had really cracked up over the years and was replaced once. Our design included adding beams between the existing beams, adding cross support beams below those on new columns, and using a "strange brew" of fibermesh with steel fibers that our rep. had put together for us.
We had analyzed the slab with FEA to ensure that the maximum tensile stress was below fr. The fibers were added just as a second measure to minimize/avoid cracks.
Unbelievably, after all that, the slab still had a few cracks in it.
RE: Fibre Mesh vs Welded Wire Mesh
My main concern is the distribution of fibres through the concrete mix. They can tend to conglomerate and form balls. With mesh at least you can inspect the reinforcement size, spacing and height before the concrete pour.
However, I would consider specifying it to supplement conventional reinforcing where crack control was particularly important, for shotcreting or for non-critical concrete items such as pedestrian paths.