On May 18, 5:36 pm, "DanG" wrote:
2'x8'x2" will weigh about 400 pounds and will require about 2.66
cubic feet of concrete which will require 5 80 pound sacks of
premixed concrete (make sure you are not pricing or considering
the 40# or 60# bags).

Anything made of concrete that is long and thin will probably
crack.

Rebar should have 1 1/2" of cover. You will have less than 3/4".

Regular sacked concrete is about 2500 # concrete, the minimum
allowed by code for foundations. Prestress concrete runs up
towards 6000#. Most commercial concrete is 3500 with air
entrainment.

There are special processes to create what you are after, but they
require exotic concrete blends, special procedures, and technical
curing. You can probably produce them if you do a bit more
research on what will be required.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)


wrote in message

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I am about to start a project where I plan to cast a number of
large
concrete pavers in a mold for a patio and a walkway. The pavers
will
be 2" thick and vary from 2'x4' to 2x8'. Each paver will have
embedded 3/8" rebar and remesh for reinforcement. I also plan
to use
some synthethic fibers mixed into the concrete as well to
prevent
cracking. I am debating if water reducer would be needed.

I am using the bagged Quikrete you can get at the Home Depot.
My
issue is to whether to use the regular or the high early
concrete.
Faster cure time would help me get the project completed faster.
However, I am worried that the high early, since it cures faster
might
be weaker and more susceptible to cracking. My biggest concern
is that
cosmetically the pavers look good for as long as possible.

Does anyone have any experience with this process, or have any
suggestions that would help produce a casting with maximum
longevity?

Thanks,

Naveen- Hide quoted text -

- Show quoted text -

Thanks for the responses so far. I would not have thought of idea
that I am proposing, other than I have seen this type of work done in
a number of homes here in Los Angeles - albeit expensive ones I have
seen on architectural tours. I could not afford the cost of having
some one else fabricate custom concrete forms and then have them
installed. The only reason I am attempting something like this is
that is looks fantastic when the paver/slabs are in place and some
sort of ornamental grass such as dymondia is alowed to grow in between
the spaces.

Basically the site on which I will be installing these paver/slabs is
very hard clay with little give. I expect there to be normal to light
foot traffic. The idea with the 2" thickness was to limit the weight
so that I could physically install the slab. Additionally, with the
paver/slabs that I have seen, they all appeared to be roughly 2" in
thickness. I actually cast one that was 2' x4' and was able, without
too much trouble to pick it up and move it into place.

I was hoping to solve the potential cracking issue by either adding a
little thickness to the paver/slab, using a littl more rebar, fiber or
simply curing the concrete wet for 30 days.

Naveen