Rob & Barb Furlong on tue 18 jan 00
>hi,
I am hoping to make an armature out of poured concrete. The shape is
relatively simple - a turtle shell- about the size of a two and a half by
three foot oval. It will have clay tiles and shapes made by small children
glued and then grouted to its back. The piece will be placed outside and
have to withstand cold temperatures and small children climbing on the
figure. I have a recipe for concrete using portland cement, perlite, peat
moss, and fibermesh that I hope will create a strong durable shell. I plan
to support the turtle underneath with a metal post from the ground to a
fitting mounted in the cement.
Could anyone recommend any concrete mixtures that would serve this purpose
or any other advice for this project? Any input would be greatly
appreciated.
>
> Thanks,
>
> Barbara Drosse-Furlong
Nikom Chimnok on wed 19 jan 00
Hi,
I hope this starts a thread, as I'd like to learn a lot more about
this topic myself. The company I work for supports me and about 40 other
people by making about half ceramics and half cast "sandstone", which is
really a sand and white cement mix that is acid washed to eat the cement and
expose the sand. Living in Thailand, it is not important that it be
frostproof, but now that we are exporting, customers ask. I tell them no.
Not that I have any direct experience, but I have measured the water
absorption at 9% in the 24 hour absorption test, and if it were clay, it
certainly wouldn't be frostproof.
I don't think any normal concrete is frostproof--that's why there's
Thompson's Waterseal. I once talked to an engineer on a dam building project
and learned that he was adding sodium silicate to the mix to make the
concrete how waterproof I don't know, but that's why he was adding it.
Further, I would guess that a lightweight mix like you are proposing
would REALLY soak up the water, besides being less strong than ordinary
concrete. But perhaps you can fix the absorption problem by using frostproof
tiles and a waterproof grout. So far as strength, a turtle shell is a
naturally geometrically strong shape, so you might get away with it.
Fiberglass is very strong--I was once present at the building of a
fiberglass and foam airplane, and was astonished to see that the wings were
connected to the fuselage by 4 stainless steel bolts. If they had your
project here they would use ordinary concrete about 2-3 inches thick with
steel reinforcement and weld the mounting flanges to the steel. Maybe that's
overkill.
Please regard my remarks as the beginning of a discussion. I myself
work in the pottery division, and always wondered if they know what they're
doing in the "sandstone" works. Any concrete experts out there?
Regards,
Nikom
***************************************************************
At 09:40 18/1/00 EST, you wrote:
>----------------------------Original message----------------------------
>>hi,
> I am hoping to make an armature out of poured concrete. The shape is
>relatively simple - a turtle shell- about the size of a two and a half by
>three foot oval. It will have clay tiles and shapes made by small children
>glued and then grouted to its back. The piece will be placed outside and
>have to withstand cold temperatures and small children climbing on the
>figure. I have a recipe for concrete using portland cement, perlite, peat
>moss, and fibermesh that I hope will create a strong durable shell. I plan
>to support the turtle underneath with a metal post from the ground to a
>fitting mounted in the cement.
>
> Could anyone recommend any concrete mixtures that would serve this purpose
>or any other advice for this project? Any input would be greatly
>appreciated.
>>
>> Thanks,
>>
>> Barbara
Drosse-Furlong
>
>
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