介绍:
In 1982 the ground beneath the Italian port town港口 of Pozzuoli, near Naples, began to swell膨胀. In the next two years, the town rose more than six feet. Rocks underground cracked under the strain压力, sparking引发 tiny earthquakes. And some 40,000 residents were forced to evacuate撤离. Tiziana Vanorio was one of them.
"We were scared, not because of the earthquakes but because of the fear that an eruption爆发 was about to come."
But that eruption never came. And Vanorio, who's now a geophysicist at Stanford University, wanted to find out how the rock endured忍受 the strain压力. So she and a postdoctoral博士后的 student obtained rock cores from the Campi Flegrei Caldera, the volcanic area underlying Pozzuoli, taken just before the swelling in 1982. They discovered a layer of what’s called caprock, almost like a lid盖子, that sealed off隔开 the caldera below. And the caprock's microstructure was an intricate错综复杂的 network of mineral fibers—the key, she says, to its strength, and ability to flex收缩 under pressure. The findings are in the journal Science. [Tiziana Vanorio and Waruntorn Kanitpanyacharoen, Rock physics of fibrous rocks akin to Roman concrete explains uplifts at Campi Flegrei Caldera]
And that fibrous rock structure? Vanorio says it looked familiar—very similar to the famous ancient Roman concrete, used to build aqueducts沟渠 and the Colosseum. And, similarly to concrete production, the caprock probably formed when lime-rich geothermal地热的 fluids percolated扩散 upward, mixing with the volcanic ash.
It's probably no accident the Romans ended up with that same chemical recipe食谱. "They were keen observers, they knew very well that the volcanic ash from that region was very special. And they also shipped运输 the volcanic ash throughout the Mediterranean."
And now that we're discovering these secrets, she says, we might do as the Romans, and emulate模仿 nature once again—to pave the way toward more durable, self-healing复合的 concrete混泥土.
—Christopher Intagliata
[The above text is a transcript of this podcast.]
