Greetings,
I am new to this group. I saw the styrocrete question and felt
I had to join in. I don't have practical experience, equipment,
capital or land. What I do have is interest, some small background
in engineering, (okay, a degree), and some of the mathematics of
Peter Pearse.
I guess I'm one of those guys who want to see it tried, wants to
know how it works out, but doesn't have the resources to do it.
Pearse showed that three-dimensional space could be filled by
multiple, continuous periodic matrices. I don't know how much detail
to go into here on this topic, as it is difficult to explain in plain
text, but I'll try to give you a little to go on.
There are basically four to six general types of continuous,
periodic, space-filling matrices: tetrahedral, cubic, rhombic
dodecahedral, truncated octahedral, octet truss, and non-symmetrical
or irregular types that approximate the foregoing. Multiple matrices
that simultaneously fill the same space are complementary, for
example: a rhombic dodecahedral matrix interspersed with an octet
truss, or a couple of interspersed cubic matrices. Ball bearings of
uniform size will arrange themselves in a rhombic dodecahedral
matrix, (what mathematicians call a "closest packing array"). Living
cells often form a sort of truncated octahedral matrix, (Kelvin
Tetrakaidecahedral minimal surface encapsulation). Natural and
artificial foams form non-symmetrical or irregular patterns, even if
all of the bubbles are of the same volume.
The strongest of these are the triangulated trusses. These are
the shapes you typically can't get, the patterns formed in space by
connecting the centers of the bubbles of the foam. The matrix you
get from open-cell foam is spongy and weak, mostly tetrahedral.
That, I suspect, is what most fiberfoamcrete has been so far.
What does this all mean? I think it means that if you want
strength, yours should be mostly a closed-cell structure. If you're
making StyroCrete, by all means include some fiber for strength, but
don't aerate it! Don't whip it into a foam! The air you want to
have in it is encapsulated in the styrofoam already. You don't want
flakes or plates of extruded foam, like fast-food containers, egg
cartons or styrofoam plates; leave those for others to melt down into
something else. You want spherical, expanded styrofoam beads of
uniform size. Actual size of the beads doesn't matter much if
they're uniform, as long as your paper fibers aren't too short. As
hard as it may be to believe, the weight savings will be about the
same. Sonic or ultrasonic vibration may be useful to help drive out
the air during mixing, or to help things pack and settle after the
pour.
If memory serves, in theory you could get over seventy percent
of your volume replaced by styrofoam beads with minimal or no loss of
rigidity compared to normal concrete!
This is one I'd like to see tried and tested. Theory predicts a
star performer. Please post results.
Theo.
--- In papercreters@yahoogroups.com, "slurryguy" <slurryguy@...>
wrote:
>
> In some ways Clyde Curry's perlite enhanced mix might be somewhat
> similar. Check his posting last week.
>
> Keep in mind that styrofoam (Expanded polystyrene, EPS) is open
celled
> and will take on some moisture. Extruded polystyrene, XPS, is
closed
> cell, denser, and handles moisture better. This does not make one
> material better than the other, just different.
>
> If I remember correctly, Steve Kornher uses something like what you
> suggest for his lightweight roofing structures. I don't remember
where
> I read that. Possibly on FEN. Check the Papercreters links under
the
> non-papercrete but cool folder for "Flying Concrete". You'll see
some
> of his amazing work.
>
> --- In papercreters@yahoogroups.com, "Robert Deutsch" <robdeutsch@>
> wrote:
> >
> > Dear Builders,
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