[Stoves] calcium aluminate cement

[Norbert Senf]

Andrew Heggie wrote:


> That puts it in its place, so are firebricks a special clay?
>

yes, fireclay. Low in iron (hence the light yellow color), low in fluxing
elements (which lower
the melting point) and preferably high alumina/silica ratio.

> For high stess pieces, we will incorporate some reinforcement such as
> steel
> > diamond
> > lath, used for plastering.
>
> How does that fair once it all gets hot?
>

Good, in our specific application, based on experience and testing.
Refractory engineers will often tell you that this will not work.
In our application (a horizontal 2.5" thick bakeoven floor sitting
immediately above the fire
and spanning 27 inches) the temperatures are relatively low, for a castable
or a firebrick. The
main issues are thermal shock,  thermal cycling and low strength in the
castable
because of the "twilight zone" issue.

In a firebox application, we have the same issues, but more so. Low duty
firebricks often last longer than high duty. High duty are designed for
high temperatures,
but usually not for rapid cycling.

-
Norbert Senf
Masonry Stove Builders
25 Brouse Road, RR 5
Shawville Québec J0X 2Y0
819.647.5092
www.heatkit.com
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