Are you picking or do you really want to know- let me share how it is
that I know all this -6 years ago when I decided to use the building
of our B&B www.evesgarden.org to showcase papercrete as a super
material , there seemed to be two particular points of concern
-problem one was that the use of portland cement in the world is a
cheif contributor to the Carbon Dioxide levels in the
atmosphere-problem two was that too little cement use left the
papercrete incendiary (a very serious concern for firefighters - To
address these concerns ,and others, I began what eventually became 700
tests, attempting to understand what does what- as you pointed out it
is not easy communicating these factors due to changes in
nomenclature- I had to learn to adapt to the industry standard of
measure, the cubic yard-for instance my paper comes from Houston,
Texas at 80% humidity, yet I am in the desert at 15%-another problem
is if you pour one of my 6 cu.ft bags of perlite into another
container it will measure 8 cu.ft, until it settles - what all this
addes uo to is bad measureing on all of our parts. So, I will try
again--- I use perlite as an aggregate to extend the cement
paste(trying to lessen the portland),and to control shrinkage ( as
there is less water to drain. Because the perlite is a good insulator
itself, I dont think we lose r-value. I use a 4/1 perlite cement ratio
as the experts recommend when you want a stronger finished cement
paste ( the 8/1 ratio is only used when forming large billets that do
not require much strength) half of the mix is by volume perlite as
measured by the manufacturer- there are 14 cubic feet in 1/2 yard so
I use 3.5 sacks of cement ( this cement is by weight made up of 17.5%
metakaolin pozzolan to ameliorate the excess lime from the portland
reaction) the cement paste packs within the perlite for a yeild of 1/2
Yard- to this I add 85 lbs of hammermilled newsprint and maybe 120
gallons of water ( this makes a half yard of pulp)So I am at 50%
lightweight cement or Concrete and 50% paper ( for the brick). For
plaster I simply use half as much paper and water and for finish coats
you can use as little as 5% paper- I hope that I have been more clear
- The brick mix dries at less than 18 pounds per cu.ft. with
reasonable enough strength the plaster much stronger. - Clyde--- In
papercreters@yahoogroups.com, sire@... wrote:
>
> Clyde writes: "I use perlite at a 4 to 1 ratio to cement as it
gives a more solid
> block"
> More solid than what? Is the ratio based on volume or weight?
>
> "I use perlite as 50% of the total mix"
> Again what is this based on and how does it relate to the above ratio?
>
> "greater levels of cement and aggregate do not seem to affect the
flow of heat until the material would be so dense as to conduct from
particle to particle...Probally in excess of 80%"
> Greater amounts of cement and aggregate will definitely decrease the
R-factor. What does 80% mean?
>
> "-even with all the perlite I still dont get the strength I need
till I have at least 3.5 sacks of cement?
> Perlite will not give you strength, so that is to be expected, and
that is not why it should be used. Cement gives you strength,
perlite gives you lightweight insulation and fireproofing.
>
> curious that is also when I gain fire resistance-
> Again it is to be expected that perlite gives fire resistance, and
so does cement for that matter, so this makes no sense. I will post
a table of cement to perlite ratios today.
>
> Neal
>
> -------------- Original message --------------
> From: "clydetcurry" <clyde@...>
> I use perlite at a 4 to 1 ratio to cement as it gives a more solid
> block - I use perlite as 50% of the total mix - greater levels of
> cement and aggregate do not seem to affect the flow of heat until the
> material would be so dense as to conduct from particle to particle
> Probally in excess of 80% -even with all the perlite I still dont get
> the strength I need till I have at least 3.5 sacks of cement? yard -
> curious that is also when I gain fire resistance- ever made an omelot
> without eggs- use enough cement- Clyde--- In
> papercreters@yahoogroups.com, sire@ wrote:
> >
> > It would be good to have a source for these numbers. I believe
> Judith is using less cement than that in her latest fire test.
> >
> > I have been looking at Perlite instead/in addition to paper. If
> fire prevention is your concern, perlite is the answer. You can use
> 6 to 8 cubic feet of perlite per 1 sack of cement, which is not only
> easy on your pocketbook but kind to the environment. Also, the less
> cement you use the greater insulation value you get.
> >
> > Neal
> >
> > -------------- Original message --------------
> > From: "clydetcurry" <clyde@>
> > as a dry weight ratio a yard of finished papercrete requires at
> least 85 lbs.of paper -fire resistance requires at least 3 1/2 sacks
> of cement@ 94 lbs each or 330 lbs - so that is like 4 lbs sof cement
> per 1 lb. of paper- not the other way around - folks are way to cheap
> with the portland- carefull -Clyde---
> > In papercreters@yahoogroups.com,
> > "Ernie Phelps" <eepjr24@> wrote:
> > >
> > > --- In papercreters@yahoogroups.com, "gmkdart" <gkrautha@> wrote:
> > > >
> > > > However, I am concerned about flammability-- it seems the
> general rule is a 4:1 mix of portland cement to paper. My question is,
> are these dry weights?
> > >
> > > I would look at your source for the 4:1 ratio to answer that
> question. Everyone on the list has slightly different mixes they use
> in different situations. I don't need mine to be fireproof at the
> moment, but I need it to stand up to weather. So I use about 3:1 wet
> pulp to dry portland by volume. For fireproofing, I would probably be
> inclined to up the inerts by adding lime, portland or sand.
> > >
> > > - Ernie
> > >
> >
>
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