The huge structures of ancient Rome have survived for thousands of years—a testament to the abilities and wisdom of Roman engineers, who perfected the use of concrete. But how did their construction materials help keep grand buildings like the Pantheon(万神殿) (which has the world's largest unreinforced dome)and the Colosseum(斗兽场)standing for more than 2,000 years?
Roman concrete, in many cases, has proven to be longer-lasting than modern concrete, which can worsen within decades. Now, scientists behind a new study say they have uncovered the mystery ingredient that allowed the Romans to make their construction material so durable and build splendid structures in challenging places such as docks, sewers and earthquake zones.
The study team, including researchers from the United States, Italy and Switzerland, analyzed 2,000-year-old concrete samples that were taken from a city wall at the archaeological site of Privernum, in central Italy, and are similar in composition to other concrete found throughout the Roman Empire.
They found that white chunks(块)in the concrete, referred to as lime clasts(石灰碎屑),gave the concrete the ability to heal cracks that formed over time. The white chunks previously had been overlooked as evidence of careless mixing or poor-quality raw material.
The new finding could help make manufacturing today's concrete more sustainable, potentially shaking up society as the Romans once did. "Conerete allowed the Romans to have an architectural revolution,"Masic said,"Romans were able to create and turn the cities into something that is extraordinary and beautiful to live in. And that revolution basically changed completely the way humans live. "
