Fiber-reinforced rocks discovered at the site of Italy's dormant Campi Flegrei volcano are similar to a wonder-material used by the ancients to construct enduring structures such as the Pantheon, and may lead to improved construction materials.
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Once again, the drill cores provided the crucial clue. The samples showed that the deep basement of the caldera—the "wall" of the bowl-like depression—consisted of carbonate-bearing rocks similar to limestone, and that interspersed within the carbonate rocks was a needle-shaped mineral called actinolite."The actinolite was the key to understanding all of the other chemical reactions that had to take place to form the natural cement at Campi Flegrei," said Kanitpanyacharoen, who is now at Chulalongkorn University in Thailand.
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Pozzuoli was the main commercial and military port for the Roman Empire, and it was common for ships to use pozzolana as ballast while trading grain from the eastern Mediterranean. As a result of this practice, volcanic ash from Campi Flegrei-and the use of Roman concrete-spread across the ancient world. Archeologists have recently found that piers in Alexandria, Caesarea, and Cyprus are all made from Roman concrete and have pozzolana as a primary ingredient.
Interesting stuff, and somewhat reminiscent of the discovery that Damascus steel was so strong because the process created carbon nanotubes.
Non-javascript version of the story is available at: http://news.stanford.edu/news/2015/july/concrete-roman-volcano-071015.html
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The story of concrete is so ancient that we don't even know when and where it begins. It is a story of discovery, experimentation, and mystery. Emperors and kings became legends for erecting great concrete structures, some of which are still a mystery to engineers today. Many of history's most skilled architects found inspiration in slabs of the gray building material. Common bricklayers advanced the technology, and a con man played a crucial role in the development of concrete recipes.
Today, the world is literally filled with concrete, from roads and sidewalks to bridges and dams. The word itself has become a synonym for something that is real and tangible. Press your handprints into the sidewalk and sign your name to history. This is the story of concrete.
[...] Let's get this out of the way right here: cement and concrete are not the same thing. Cement, a mixture of powdered limestone and clay, is an ingredient in concrete along with water, sand, and gravel.
So ubiquitous and fundamental, that nobody thinks about it. Its inventor is unknown, but that person changed history.
Related: Volcanic Rocks Resembling Roman Concrete Explain Record Uplift in Italian Caldera
Roman Concrete Explained
(Score: 2) by jcross on Monday July 13 2015, @01:47AM
"the deep basement of the caldera-the "wall" of the bowl-like depression-consisted of carbonate-bearing rocks similar to limestone"
Em dashes and hyphens are not the same thing at all. Even in plain old ASCII it's nice to use two dashes to indicate the em dash.
(Score: 2) by martyb on Monday July 13 2015, @01:57AM
Yes—you are right—they are not the same. Thank-you for pointing that out--kindly and politely--as it has now been corrected.
Wit is intellect, dancing.
(Score: 0) by Anonymous Coward on Monday July 13 2015, @08:20PM
I always understood the correct usage to be separating the em-dash with spaces on either side - like this - while hyphenating words in-line like-so.
(Score: 2) by gidds on Wednesday July 15 2015, @01:04PM
Me too — and I'm generally quite fussy about my typography.
I don't understand why more people don't do that. It's much clearer: it separates the words on either side, rather than joining them like a hyphen.
[sig redacted]
(Score: 3, Informative) by mendax on Monday July 13 2015, @01:48AM
Actually, it was Misenum (modern day Miseno) that was the main military port. The city was built solely for the purpose of supporting the Roman navy base there. Pozzuoli is nearby.
It's really quite a simple choice: Life, Death, or Los Angeles.
(Score: 1) by khallow on Monday July 13 2015, @01:51AM
(Score: 3, Informative) by purpleland on Monday July 13 2015, @02:01AM
When I first skimmed through the article I wondered why the concrete rocks looked more like limestone (sedimentary), rather than like the more crystalline granite as you might expect with molten conditions. Reason is that the concrete formed after the molten volcanic activity, and is a result of chemical reactions (video has some nice animations explaining the process).