Spat, sounds interesting. I've never heard of it. Keep us posted if you find any details..........Now I'm curious, so I'm off to google. Billie

OK here is one formula I found on the web. Not exactly what I have seen but likely the origional base formula.

As a child I visited one of the coastal forts and I think it origionaly had straw in the mix. Was said to absorbe the blows from canon fire. Guess that was a special use mix.
I grew up on the SC coast and there are a lot of modern forms of tabby that is basicly just adding oyster shell to regular cement. When mixed with crushed shell looks descent and over time has a nice old south look. The ones I hate are a regular cement with complete shells mushed in. Not too bad for walls if you add a dark gray color though. But many use the whole shell for side walks. To me that just doesn't work well. Very tuff on bare feet, and also a trip hazard. Guess I will be having an oyster roast this winter! Well thats actually an old tradition, but I usually return the shells to the creek.

Well I am all for trying it!

Step1
Burn a few dry oak logs down to ash.
Step2
Add to the hot embers some oyster shells that have been bleached in the sun.
Step3
Burn the oyster shells down to ash. This mixture of oak and oyster shell ashes makes an old-fashioned form of lime, the binding agent in cement.
Step4
Mix the lime with sand and water. This makes the cement that binds the aggregate together.
Step5
Add to the cement some oyster shells that have been thoroughly washed.
Step6
Cast the concrete in wood forms to create walls, blocks or paving stones.
Step7
Remove the forms when the concrete is set, and scrub the surface to remove the excess cement and expose the shells.