Re: Hypertufa (aka hyper-tuffa)
- --- In SBfirstname.lastname@example.org, Norbert Senf <mheat@...> wrote:
>the density at 50 pcf +/- 25%.
> At 04:06 PM 2/28/2006 -0500, Rob Tom wrote:
> >Has anyone here made items out of hypertufa ?
> >(Sand + Portland cement + peat moss)
> Hi Rob: I've only fooled with it on a very limited scale. I'd guess
>Thanks for that MeatHook.
> Not all that much different from vermiculite/portland,
The +/- 25% is interesting, especially the possibility of -25%.
I was thinking that it might be necessary to use a lightweight
aggregate in place of sand if further lightening were desired but at a
mere (possible) 25 pcf, it wouldn't be.
From the bits I've been able to find on-line about hypertufa, I get
the impression that the strength of the material increases with the
increase of the peat portion in the mix .
(ie more peat = less sand = stronger material = lighter material)
Would that impression be accurate ? (Seems too good to be true)
- --- In SBemail@example.com, some arithmetically-challenged dodo
> The +/- 25% is interesting, especially the possibility of -25%.-25% of 50 pcf, you dodo.
> at a mere (possible) 25 pcf, [further lightening] wouldn't be.
Not 25 pcf.
Geeze. Some people's kids. Eh ?
Sorry about that MeatHook.
- At 11:16 PM 3/1/2006 +0000, RT wrote:
>(snip)Don't know, I've never done any tests with it.
> From the bits I've been able to find on-line about hypertufa, I get
>the impression that the strength of the material increases with the
>increase of the peat portion in the mix .
>(ie more peat = less sand = stronger material = lighter material)
>Would that impression be accurate ? (Seems too good to be true)
I'd guess if the peat actually has fibrous qualities, it could add some
tensile strength. I wouldn't think that you'd be gaining much from the
We cast a fair number of vermiculite concrete
slab pieces, and have used different types
("concrete aggregate" ,"plaster aggregate",
"block and cavity fill"), mainly based on
availability. We tried adding sand but it just
made the pieces heavier. The mixing method
has a big effect, as a lot of shear will break
down the aggregate. Peat moss might behave
in a similar fashion.
Like a lot of the other non-standard materials
like clay and lime plasters, I don't
think you can avoid making a number of test mixes
and adjusting as you go to get the
properties that you want / avoid the properties
you don't want. There are more than a few
scrap slabs in our landfill from when materials
changed, shop person changed, etc.
We have to be pretty rigorous about documenting
successful procedures, as reinventing everything from scratch
would be a big job, and it makes it much easier
to train a new person, or refresh somebody
who hasn't done it for awhile.
Norbert Senf---------- mheat(at)mha-net.org
Masonry Stove Builders
RR 5, Shawville------- www.heatkit.com
Québec J0X 2Y0-------- fax:-----819.647.6082