I have been reinforcing slabs-on -grade with minimum reinforcement per ACI
7.12, ie: 0.0018bh. This works out to #4@ 24" o.c. or #3@12" o.c. I have
stayed away from wire mesh due to the placing problems you mention in your
What spacing are your smooth dowels? I use 5/8 dia @ 24" o.c.
In answer to your question:
Questions: Eventhough the tensile capacity of the proposed mesh matches
the current #4 configuration, is the "doweling" action across the sawcut
joints going to be weakend due to the smaller bar diameter?
When the slab cracks completely through the weakened plane we are left with
the reinforcing resisting the shear, neglecting any interlocking of the
concrete. Checking the average shear stress on the dowels versus the #3 mesh
I get a higher shear capacity using the #3 @ 12, 80ksi mesh then I get with
3/4" dowels @ 24" o.c.
Va=A*.45Fy , where A= equivalent area per foot. Fy=80ksi, A=0.11 for #3 and
Fy=36ksi, A=0.22 for 3/4" dowels.
I hope this helps.
Tom Jakaby, SE