Hi, I'm I Refledo, and you're listening to Science Friday. If you've listened to the show for a while,

you know that one of my favorite topics is concrete, really. And some of my favorite examples of the

long-term durability of concrete are from the Romans. Take the Pantheon and all those famous aqueducts

built thousands of years ago and still standing. But how exactly was this concrete made?

And what ingredients went into the cement? That knowledge hasn't been very solid. Well,

late last year, scientists discovered an actual

cement mixing site in Pompeii, preserved in the volcanic ash, and it might hold clues to how we

can improve our concrete today. Here to uncover those secrets is Dr. Admir Mashich, Associate Professor of Civil and Environmental Engineering

at MIT, and one of the co-authors on that study. Dr. Mashich, welcome to Science Friday.

Thank you for having me. Nice to have you. So you go to Pompeii and you make a discovery there

that changes about how they made their concrete?

Yeah, so the context of Pompeii is fascinating.

If you think about a city that 2,000 years ago was literally frozen in time by this eruption of Mont Vesuvius and then stayed preserved

till we excavated it, offers an incredible snapshot of what they were up to.

And interestingly, a year ago, archaeologists excavated an construction site, including very well-organized

construction materials like roof tiles or bricks and tools. So imagine literally an active construction

site that allowed us to walk through and understand from the

raw materials how they were mixed and prepared to be then used in construction. So imagine

people were building a house at the moment of eruption and literally stopped the operations and froze that

scene.

Then it felt literally like entering into Pompeii, 2000.

So it was for me, a time travel, literally.

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