The fiber reinforced concrete is stronger than standard concrete and
probably eliminates the need for a wire grid, but that's not the
reason you don't need rebar in a patio slab. Concrete has high
compression strength but very little tension strength. Rebar provides
the tension strength. A patio slab experiences mostly compression
force and barely any tension force so the rebar is not necessary.
A pier tower base, on the other hand, will have both high tension and
high compression forces so rebar is absolutely required.
On 1/23/06, Eg9k@aol.com <Eg9k@aol.com> wrote:
> Hi all - This past summer I had a 24' x 30' slab poured 4" thick with a 3'
> x 4' by 16' deep at one corner to build a barbecue on it. I was surprised
> when I noticed they weren't using any rebar or heavy wire.
> The concrete man explained that the rebar wasn't necessary with the new
> type concrete with the reinforcing fibers in it. He stated he would put in
> rebar / wire if I wanted it, but it just be a extra expense. I explained to
> him that I had put in several pier type tower bases over the years and had
> the rebar. His answer to me was he didn't think the rebar would be needed
> with the new type concrete, maybe the heavy grid wire but not the rebar. I
> figure there is some merit to what he's telling me because he's been in the
> concrete business for over 20 years. Something to think about 73's
A.J. Farmer, AJ3U
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