Roman maritime concrete better than modern

[Epictetus]

Apparently Roman concrete is much better than modern Portland-style concrete in a maritime environment. Some researchers at the University of California Berkeley campus are studying it and trying to figure out how to replicate some of its properties.

This is pretty interesting. I knew Roman concrete was good, but I didn't know that by some measures it was an improvement on the modern. So much for technologocial progress.

...modern concrete... within 50 years often shows signs of degradation...

“Roman concrete has remained coherent and well-consolidated for 2,000 years in aggressive maritime environments,” said Marie Jackson, lead author of both papers. “It is one of the most durable construction materials on the planet, and that was no accident. Shipping was the lifeline of political, economic and military stability for the Roman Empire, so constructing harbors that would last was critical.”

To improve today's concrete, do as the Romans did

[PhilusEstilius]

That is very true of all their concrete and indeed so many of their monuments are testament to that, in fact when I worked at Housesteads Fort we had a gang nicknamed the hole in the wall gang.
These guys were there to do small repairs to the wall and each year they found that their concrete could not stand up so well as the Roman, they set up various strains to test them over the years but they found they could not match the long lasting stuff the Romans had put there all those years ago.
The wall being 55 degrees north and many of the savage winters have ruined the modern stuff so much more than the wall itself.

[Vindex]

I concur with Brian.

I have some small fragments from my excavations on the wall at West Denton in the late 80s, and it is amazing stuff!

[Timianus]

Someone should contact Abby on NCIS and have her run a sample through her mass spectrometer, so we know exactly what it is made of

[M. Demetrius]

Aw heck. Abby could tell you what it was made of, whether his wife was left-handed and what he had for lunch on the day he mixed the slurry. Give her some credit, Tim! :lol:

[M. Demetrius]

Just the fact that those pilings and bridge footings are still being used a couple thousand years later should tell us their concrete was better than ours. We often have to replace bridge pilings after just 50 or 100 years due to breakdown of the concrete.

[caiusbeerquitius]

Not really "news". There have been several investigations already over here, in the context of sustainability research for modern buildings. A lot published on this...

[Epictetus]

I had heard that concrete gets harder with time, and that our modern practice of reinforcing concrete actually shortens its life, because exposed rebar can rust and introduce instability, but I didn't know the actual composition of ancient concrete was better than what we use today.

[M. Demetrius]

I'm not an expert in this sort of thing, but concrete doesn't really "dry" as if it were water-based paint by the water evaporating. It is a thermochemical reaction that starts out hot, then gradually slows down. Somewhere I read that the curing process takes many years when there is much concrete involved. The Hoover Dam is still going through the reaction, for example, and still is generating heat. Exothermic the big brains call it.

The metal is to hold the whole block of concrete together in the event a stress is applied to it: helps prevent cracking in the first place, and holds the mass together in the event that it does crack, or at least that's the plan. I don't think the ancients used metal reinforcing, yet their concrete seems to hold together, lending some credence to the idea that it was a different formulation.

[M. Demetrius]

This just in, and quite appropriate!
http://www.livescience.com/37237-what-an...pid=527271