In a second year class I took the prof posed us the question: why don't we do this today? Why is this not part of an ASTM standard?<p>He ended up saying it's too tough to get a hold of proper pozzlanic ash, but I suspect its more a "this is the way we've always done it" difficulty. Does anyone know more to the story?
I must be missing something. I’ve never used scihub before, and I can’t find the link to read the paper. All I see on this link is the name of the paper and the authors.
I am becoming partial to the ancient Egyptian concrete, that they might have used to mold the pyramid blocks <i>in situ</i>.<p>It takes just limestone crumble, clay (which was already in their limestone), natron, and water.<p>It is a fair bet the precursors to the Inka who built with the really big blocks had that, or a similar trick. Local observers report the big blocks do not show embedded marine shells at the surface, unlike native limestone. (I have not had opportunity to verify this.)