Enduring Roman Concrete

[Serendipity]

Looks like they've found out why Roman concrete lasted so long...

Scientists explain ancient Rome's long-lasting concrete - BBC News

What I don't quite understand is why the knowledge of how to mix Roman concrete was lost in the first place... this could be a good idea for an alternative history story... hm...

 

[The Ace]

Like a lot of other things, the collapse of the Empire led to the process to be lost - it was only rediscovered in the 19th Century.

Even during the empire, the classic Roman helmet was made by a process called, "Spinning," but when such helmets were replaced by cheaper types from the third Century on, the process was lost, only to be rediscovered in the early 20th Century.

We have ballista bolts copied from originals found in peat-bogs - they're area-ruled, despite this being, "Discovered," in the 1950s.

We'll probably never know what was lost in the collapse of civilisation and the destruction of written works after the 5th Century.