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can concrete be rotomoulded as you would plastic powder? Answered

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aeray (author)2010-12-14

Maybe, but probably not. A concrete delivery truck is basically a giant mobile rotomold, right? It keeps it from curing.

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Re-design (author)aeray2010-12-14

Movement in the mixer truck does not keep it from curing. Once the water is added the driver has about 45 mins to 1 hour to unload or it sets up in the truck rotating or not.

When conc. companies bid jobs more than 30 min. away they either trade with a competitor close to the job site or set up a small batch plant close to the job.

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caarntedd (author)Re-design2010-12-14

Retardants can be added to extend the workable period. Concrete is pretty high tech these days, with many additives available. Water reducers, retardants, accelerants, waterproofing, plasticisers. Inevitably it all goes off eventually.

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stephen maher (author)Re-design2010-12-14

Quite correct but Ihave found a site where its been done.'michaelsblog'Thanks for answer

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aeray (author)Re-design2010-12-14

I agree. In my area, they sometimes make the run dry and add water at the jobsite. It's hard to hit the slump just right though.

I shouldn't have said "keeps it from curing". But it does delay it.

An anecdote: I have a buddy who spent a whole summer chipping cured concrete out of mix trucks, in the sun, wearing a respirator and full coveralls. He lost about 20 lbs.

Shotcrete is a good idea too.

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stephen maher (author)aeray2010-12-14

I actually found 'michaelsblog' and these guys have done it 7-12-2010.I googled 'concrete rotational moulding'Very interesting.thanks for your quick response .

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aeray (author)stephen maher2010-12-14

I can't seem to find the site you're looking at, but I'm quite interested. Are they using it for ferro-cement boat building? What are you wanting to use it for?

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lemonie (author)2010-12-14

If you are talking about casting concrete-shells in rotary-moulds yes sure. But why?

L

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Re-design (author)2010-12-14

Yes. make a dryish mix with pea gravel and have at it.

If can also be shot from an air gun.  Google "gunite".  It's how they spray swimming pool walls.

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