Papercreters: [papercreters] Re: Idea... Gypsum and a box of rocks

Friday, February 4, 2011

[papercreters] Re: Idea... Gypsum and a box of rocks

Well the answer depends on several things...

1) Is it gypsum powder actually cheaper than concrete? I mean cheaper in dollars than concrete?

2) Is gypsum powder powder more green?

By more green I mean is still a plentiful resource and does it's preparation and transport cost less in carbon emissions than concrete?

3) Will the simple pour in place batch based mixture I propose work?

Or would it have too many large air voids or other failure modes?

4) Why would I want to do it at all?

Well as cheap as paper is, it still isn't really free and plenty of places have a ready supply of rocks on site and in such case they really are pretty close to free.

Also there are lots of ways of recycling paper and while I am all for papercrete it is not the only game in town. I would prefer that paper recycling take the most carbon conservative path possible (CO2 emissions wise.) So not knowing that answer off the top of my head I am not going to endorse papercrete based paper recycling over other forms of paper recycling (until I do know the answer.)

5) Why this over papercrete?

Because it would most likely be stronger in terms of compressive strength (to be determined) and because sometimes all you want is thermal mass not insulation and solid rock will beat the heck out of papercrete for that purpose.

Finally, I imagine that if one wanted to do this at all? Most likely it would be as part of a hybrid building system where you add lots of thermal mass to the interior of a building (making heavy high thermal mass floors and walls and such) with this system and you make outer walls out of papercrete.

The best possible system has lots and lot of mass surrounded by lots and lots of insulation.

Thanks: Steve

More thermal mass, gypsum is cheaper than concrete
--- In papercreters@yahoogroups.com, JUDITH WILLIAMS <williams_judith@...> wrote:
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> What is the objective here? To use up some gypsum you have lying around? Why not just use paper? it is free and works great.
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> They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
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> ~ in Memoirs of the Life and Writings of Benjamin Franklin
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> Follow progress on the new project at http://www.papercretebyjudith.com/blog
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> More papercrete info at http://squidoo.com/papercretebyjudith
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> To: papercreters@yahoogroups.com
> From: steven.ivy@...
> Date: Wed, 2 Feb 2011 06:29:53 +0000
> Subject: [papercreters] Idea... Gypsum and a box of rocks
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> What would happen if you packed a form with rocks and then poured in gypsum and let it set?
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> Yes, I know gypsum is pretty soft but in this system it is really only the binder the rocks themselves will be carrying most of the weight and of course you would want to seal the block with a breathable sealer before use to prevent water from perhaps one day entering the gypsum.
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> Advantages...
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> Each big brick could be batch built alone (and would be ready to use 20 minutes after pouring.
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> You set up the form on top of the last poured row of blocks, you fill in the rock, you mix enough gypsum for the one block, you pour it, you wait 20 minutes you break down the form and set it up for the next block.
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> I am pretty sure that gypsum will breath (unlike straight . Is anyone here sure about that?
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> I just wonder how expensive plain dehydrated gypsum is?
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> Another idea...
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> What would happen if you could QUICKLY mix up anhydrous gypsum and a slurry of water and paper fibers?
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> Obviously the setting time and drying time would shrink greatly, but just how strong could the blocks be?
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> Thanks: Steve
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