[Strawbale] Chris Green's links to Diato sites

[Chris Green]

Adam wilson wrote:
> The old magnesite decks seemed to weather pretty bad, 
> which may mean that this flooring option requires moderate maintenance.
> Or the stuff really doesn't hold up too well. 
It turns out to be a little better known as "magnesia cement," and was 
developed in the late 19th Century. One name for it is Sorel Cement, and 
there's a Wikipedia stub on it, which I'll quote here:
>
> *Sorel cement* is a hydraulic cement 
> <http://en.wikipedia.org/wiki/Cement> mixture of magnesium 
> <http://en.wikipedia.org/wiki/Magnesium> oxide (burnt magnesia 
> <http://en.wikipedia.org/wiki/Magnesia>) with magnesium chloride 
> together with filler materials like sand or crushed stone. The usual 
> weight ratio 2.5-3.5 parts MgO to one part MgCl_2 . This material is 
> also called *magnesia cement*.
>
> A variant uses zinc <http://en.wikipedia.org/wiki/Zinc> oxide with 
> zinc chloride instead of the magnesium compounds.
>
> Sorel cement was developed since the mid of the 19th century 
> <http://en.wikipedia.org/wiki/19th_century>. It is used for 
> grindstones, tiles, artificial stone (cast stone), cast floors, and 
> even artificial ivory <http://en.wikipedia.org/wiki/Ivory> (e.g. for 
> billiard-balls). Magnesia cement floors are credited a high resistance 
> to wear <http://en.wikipedia.org/wiki/Wear>.
>
> Its chief drawback is its poor resistance to water, making it 
> unsuitable for construction applications.
>
Source of quote:
http://en.wikipedia.org/wiki/Sorel_cement

I presume by the term "construction applications," the author meant 
structural ones like foundations and suspended slabs, etc., especially 
when he states it is credited with a high resistance to wear.

As long as it isn't exposed to much water, which is probable for stairs 
sundecks, etc. Even in sunny California!

The water problem instantly eliminates this as a substitute for Portland 
cement in strawbale construction. At least on the exterior of the building.

At this point, the Eco-cement product from Tasmania, Australia, seems to 
be a proprietary form of this class of cements. I recall reading last 
year that some US Federal government construction contracts specify 
magnesia cements, but don't recall the details.

I'll keep looking into this.

Cheers,

Chris Green.