Hi everybody, nice question folks. A good method in concrete mixing to obtain consistency is the slump test whereby a prismatic shape tin container without a bottom is filled with the concrete/pc mix. The tin is then removed upwards and the height of the material that it has slumped to is measured. This is then recorded and compared to the height of the tin as a percentage including the details of this particular mix i.e. cement type and brand and possible batch # in one column with amount used by volume or weight. The next column contains type of sand/paper used and preferably weighed dry. Record the amount of water used because too much water weakens the strength of the concrete/pc. I have the details somewhere and will post it as soon as I have found it, but the point is that even if there is no current standards for pc you can record your own slump heights results for own use. The point of the exercise is to obtain consistency and being able to record your experiments with various mixes for different applications.
Just another point of interest is that the addition of slaked lime (not agricultural lime) will give the mix a nice buttery working consistency and it will strengthen the material more over a longer period after the cement has reached it full strength.
Slag cement also increases strength after Portland cement has stopped but for all these additives you must remember it does not reach its maximum strength as fast as when you did not use it. It needs time as in years to develop full strength.
When concrete is mixed in a drum mixer, the stone is added first, then follows some of the measured amount of water just to coat the stone followed by the cement and then only the sand and final water left over. I would assume that the dry paper is shredded first followed by some water, then the cement followed by final water allocated for the mix. Please inform me if it is different. Finally I apologies for any incorrect English since it is not my home language.
Regards
Johan Van Tonder
From: papercreters@yahoogroups.com [mailto:papercreters@yahoogroups.com] On Behalf Of JackC
Sent: Thursday, June 02, 2011 5:51 PM
To: papercreters@yahoogroups.com
Subject: [papercreters] Re: Papercrete mix desgn
I think the question was to know the 'mix design', not 'mixer design'.
A mix design in concrete is typically the number of pounds of Portland cement, to pounds of dry sand, to pounds of rock/aggregate (and size of aggregate), to pounds of water. Other things could be included like flyash, crushed slag, and other additives. But everything is done by weight. Then knowing how much of the mix makes a cubic yard. All this helps re-compute the amount of components to be able to get the amount of concrete you want all mixed right. Often concrete is mixed in a small batch to make a 'standard cylinder' that it put through a crush test to compare mix designs. So keeping track of mix designs allows you to make the 'same concrete' the same way each time. Kind of required when putting in highways or big buildings. Yes, the old 3-2-1 plus enough water to make it pourable mix works, it is just not consistent (3 shovels of rock, 2 of sand, 1 of cement). This is kind of the general concrete mix many folks use all over the world, just not high tech!
Papercrete can be calculated the same way.
BTW, water is 8lbs / gallon, and rock is about 64lbs/cubic foot, and a cubic yard is 27 cubic feet. Getting a good scale that will measure 150+ lbs that is good for 'outside use' (like at the mix site) is great to help make good concrete.
I would like to know good mix designs for papercrete too!
--- In papercreters@yahoogroups.com, Glenneth Lambert <glenneth@...> wrote:
>
> Plans for mixers can be gotten @ livinginpaper.com
>
> Sir Glenneth - from " the land of Cobb "
>
> http://www.TheFINE-ARTcafe.org/glenneth
> On Oct 4, 2007, at 6:36 PM, achmad basuki wrote:
>
> > Hi, I am intersted to know papercrete and I want to use it to my house
> > building. But I am not sure about papercrete mix design. Who knows
> > papercrete mix desisn? Please send me information abaout it. Thank you
> > before.
> >
> > Achmad Basuki
> > Solo-Indonesia
> >
> > Moody friends. Drama queens. Your life? Nope! - their life, your story.
> > Play Sims Stories at Yahoo! Games.
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