http://www.rsc.org/images/Construction_tcm18-114530.pdf

Humans have been using concrete
in their pioneering architectural
feats for millennia. The basic
ingredients – sand and gravel
(aggregate), a cement-like binder,
and water – were being mixed at
least as far back as Egyptian times.
The Romans are well-documented
masters of the material, using it to
create such wonders as the Pantheon
in Rome, topped with its gravitydefying
43.3-metre-diameter
concrete dome: now over 2000 years
old but still the world’s largest nonreinforced
concrete dome.
With the loss of Roman concrete
expertise as the Empire fell into
decline, concrete’s secrets didn’t
re-emerge until just 200 years ago.

—-

What did the Romans know 2,000 years ago that disappeard for 1,800 years?

test

Humans have been using concrete
in their pioneering architectural
feats for millennia. The basic
ingredients – sand and gravel
(aggregate), a cement-like binder,
and water – were being mixed at
least as far back as Egyptian times.
The Romans are well-documented
masters of the material, using it to
create such wonders as the Pantheon
in Rome, topped with its gravitydefying
43.3-metre-diameter
concrete dome: now over 2000 years
old but still the world’s largest nonreinforced
concrete dome.
With the loss of Roman concrete
expertise as the Empire fell into
decline, concrete’s secrets didn’t
re-emerge until just 200 years ago.

With the loss of Roman concrete
expertise as the Empire fell into
decline, concrete’s secrets didn’t
re-emerge until just 200 years ago.

—-

Why would it take more than a thousand years for the secrets of concrete to re-emerge?

where quotes come from…

http://www.rsc.org/images/Construction_tcm18-114530.pdf

brett said:

With the loss of Roman concrete
expertise as the Empire fell into
decline, concrete’s secrets didn’t
re-emerge until just 200 years ago.

—-

Why would it take more than a thousand years for the secrets of concrete to re-emerge?

Roman concrete was different from what we use today. The chemistry of modern cement was investigated and refined by Le Chatelier, the same Frenchman after whom Le Chatelier’s Principle is named. That would have been about 200 years ago.

such wonders as the Pantheon
in Rome, topped with its gravitydefying
43.3-metre-diameter
concrete dome: now over 2000 years
old but still the world’s largest nonreinforced
concrete dome.

—-

Their is some impressive knowledge there that hasn’t been superceded.

brett said:

Their is some impressive knowledge there that hasn’t been superceded.

I like historical gear,.Rome would have been cool, to our eyes very familiar I think. At the time it was full of bunting, fluttering standards, advertisements and graffiti, and painted public features and statues. Colourful and chaotic in that organised way of big enterprises or citys. I can imagine the traffic jams of the night traffic when the merchants were supplied during the night, because large vehicles banned during the day.

I can imagine the traffic jams of the night traffic when the merchants were supplied during the night, because large vehicles banned during the day.

——

pfft, they were rushing to the first stone mason meetings.

different aggregate i think

the greeks were using concrete before the romans

phillips round building uses concrete at delphi as i remember

they definitely use concrete at olympia – you can see seashells in the mix and the finish is rough as its degraded over the centuries.

the romans must have modified the mix they learnt from other people

they didn’t have stuff like silastic so the mortar they used had to be watertight.

the romans allowed the concrete to cure for much longer before pouring/building upon it in the next stage, nowadays new concrete might be built upon after days of pouring, you’ll take samples to test for strength but even if they dont come up as any good the building will continue, its too expensive to do anything else.

morrie said:

brett said:

With the loss of Roman concrete
expertise as the Empire fell into
decline, concrete’s secrets didn’t
re-emerge until just 200 years ago.

—-

Why would it take more than a thousand years for the secrets of concrete to re-emerge?

Roman concrete was different from what we use today. The chemistry of modern cement was investigated and refined by Le Chatelier, the same Frenchman after whom Le Chatelier’s Principle is named. That would have been about 200 years ago.

Rome was lucky in that Italy was “blessed” with volcanoes like Vesuvius that chucked out the right volcanic ash for making pozzolanic cement. Other parts of Europe were not so blessed, so with the fall of the Roman Empire to ‘outsiders’ (who tended to build less permanent buildings), the knowledge of the pozzolanic concrete technology faded away.

Puts me in mind of the nutter in Toowoomba who was, for years, “building” an underground bunker on a block of land at the Range end of Margaret Street. Whenever the Council had a go at him about actually finishing it off, he’d reply that he was waiting for someone to rediscover the secret of Roman cement. I often wonder if he ever sat at the front of his block and watched the big semi-trailer loads of pozzolanic cement go past.

i like the idea of an underground bunker

the practicality of it is another thing

you’d probably have damp and ventilation problems

would you build open cut and then fill in or dig down and along (assuming its deep)?

as i understood it underground bunkers were banned by the council generally

The forum poster known as joey lived in a cut-and-cover underground house for many years.