DIYbanter - View Single Post - concrete driveway: thickness ; mesh or not ?

Goedjn

On Mon, 07 May 2007 14:45:37 -0000, (Chris
Lewis) wrote:

According to Bob Morrison :
The trick to using no rebar in a slab on grade is proper subgrade
preparation. You MUST pour the slab on a properly compacted base. And,
you MUST have a proper layout of crack control joints.

I regularly specify slabs for residential garages and driveways as "5-inch
unreinforced slab on grade on 6" of 3/4" minus compacted gravel base.
Crack control joint every 150 sq.ft."

The only reason to put reinforcing steel in a slab on grade is if the soil
is very poor and cannot be properly compacted.

If the OP thinks he's got a good chance to avoid having to use rebar,
using fiberglass fiber reinforcement works quite well (not as well as
full blown rebar, but...), and is _much_ cheaper than rebar or mesh.
Cheap insurance for marginal situations.

I thought the point of the fiberglass was to limit spalling.
Does it really increase the tensile strength of concrete?