Cob Lime dust

[Ecoarcht at aol.com]

In a message dated 7/21/98 3:41:57 PM, you wrote:

<<Does anyone have information or experience with adding Limestone dust to
concrete, mortar or cob? It is a bit like gravel and can be had for pennies
here in southern Indiana. We are thinking that it could add strength to the
concrete and some water resistance.
Adding it to cob seems more problematic. It might continue to expand and
contract if it absorbs water. Is it more like the clay or the sand?>>

Jeanne,
The limestone fines do very well added to the cob, they are more akin to the
sand providing compressive strength. Clay is particles under .003 inch.
~~howard