BUT it was an 'eq1uivealent' - not the same thing as modern Portland based material.
Which is sufficiently waterproof that you can build boats out of it.
It and steel are the only real advances made in structural materials in the last 150 years. And possibly glass.
Timber bricks tiles and so on are cheap and very suitable. There is no point in trying to beat them. Unless you are an architect with a big ego and as small dick.
The cinder blocks of the 60s from coal ash are now the thermalite blocks
- and even straw bales are viable if you render them. People have always built with what was to hand.