July 4 at 7:00 AM

Two thousand years ago, Roman builders constructed vast sea walls and harbor piers. The concrete they used outlasted the empire — and still holds lessons for modern engineers, scientists say.

A bunch of half-sunken structures off the Italian coast might sound less impressive than a gladiatorial colosseum. But underwater, the marvel is in the material. The harbor concrete, a mixture of volcanic ash and quicklime, has withstood the sea for two millennia and counting. What’s more, it is stronger than when it was first mixed.

The Roman stuff is “an extraordinarily rich material in terms of scientific possibility,” said Philip Brune, a research scientist at DuPont Pioneer who has studied the engineering properties of Roman monuments. “It’s the most durable building material in human history, and I say that as an engineer not prone to hyperbole.”

By contrast, modern concrete exposed to saltwater corrodes within decades.

https://www.washingtonpost.com/news/speaking-of-science/wp/2017/07/04/ancient-romans-made-worlds-most-durable-concrete-we-might-use-it-to-stop-rising-seas/?utm_term=.49f8f902329d


မြောက်ကိုရီးယားနိုင်ငံ တိုက်ချင်းပစ်ဒုံကျည်စမ်းသပ်အောင်မြင်သွားပြီ..။

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