Solved: The Mystery of Ancient Roman Concrete

Wednesday July 19, 2017 Written by Genevieve

Roman concrete

Just in case you missed the memo, the ancient Romans were a clever bunch.

Building on the ideological and technological foundations laid by other great peoples before them (namely the Greeks), the Romans developed the materials and techniques to better all kinds of machinery, infrastructure and systems. Sewers, roads and ducts were just some of the significant innovations they improved while generating a whole heap of their own original inventions such as plumbing, surgery tools and floor heating.

And while humanity has certainly refined those inventions over time, there is one area of Roman ingenuity that we’ve been unable to better, or even replicate, until only recently: concrete.

Today’s concrete is pretty darn reliable, but there’s one thing that seriously challenges our modern mix: seawater. Fiendishly corrosive, seawater eats away at modern concoctions of concrete. While the daily damage might seem minute, the effect over the decades and centuries is disheartening, if not downright dangerous. And yet countless bridges, piers and other kinds of sea-sloshed structures built by the Romans are still standing. Weirder still: they’re actually stronger today than when they were first built.

How? The answer lies in the volcanic ash the Roman’s mixed into their concrete: when the volcanic material comes into contact with seawater, it creates new minerals that further reinforce the concrete. 

Scientists say the discovery could help builders create stronger seaside structures, such as the proposed nine-kilometre-long seawall to be built in Swansea. 

For all the hard facts, check out the below video from the University of Utah.