AAC block/hebel block use as low mass insulative refractory

[raymilosh]

Hi all,

I am considering using AAC block (autoclaved aerated concrete) also called hebel block for the burn tunnel and heat riser.  I built my garage with hebel, so I have some around.  It is easy to cut and may be an excellent highly insulative, low mass refractory.

When I put an oxyacetylene torch against it, after a while, a spot right in the flame melted a little to a glassy substance... meaning I think it can take the heat.  I'm not sure if it will last, though.  Anyone have experience with it?

The reason I want to use it is to see if I can get the stove up to temp quickly so it burns cleanly and efficiently quickly. 

Am I correct in my thinking that a low mass burn tube/riser would come to temp quickly and burn cleaner sooner?

[Orange]

yes but normal concrete cracks on high heat and air-concrete cant handle abrasion.