Cob: roman cement

[crtaylor]

>     Greetings, I've heard several references to  "Roman Cement" . Pray
>tell, what is it and where can I learn more  about it. Also, does the
>addition of builders lime add strength to cob? And  Finally, how can I
>access the archives? I wish I could contribute more answers  to the
>cobbers , but I always seem to have more questions than answers. Thanks
>to those who know.



A purist will tell you not to add lime to cob, it isn't needed.
 But lime stabilizes any subsoil  and clays and makes it heave less, swell
less, etc, so on sticky gumbo soils it is excellent to use.

Roman cement is simply clay (from burned bricks or volcanic ash) mixed with
lime to form cement. All clay has property to harden, even mildly, to  a
weak cement, but fired/baked clays give the best reaction..this is called
pozzolanic, after Pozouli, a town in Italy where the volcanic ash makes
fine Roman cement used
2,000+ years ago.

Charmaine R. Taylor
Taylor Publishing 1-888-441-1632 9-2PST
PO Box 6985,Eureka CA 95502
http://www.northcoast.com/~tms