From the Colosseum to the Pantheon and from the Arch of Titus to the Mausoleum of Hadrian, it is no coincidence that Rome is called … “The Eternal City”.

The imposing, colossal buildings have not only stood the test of time, but are part of its history. It is no coincidence that the entire city was declared a UNESCO World Heritage Site in 1980.

But what made Roman buildings survive for thousands of years?

According to a new study that aims to shed light on the mystery of the longevity of Roman buildings, building materials played a decisive role.

According to CNN, Roman concrete has in many cases proved to be more durable than the concrete used now, as the latter can take decades to wear out.

But in addition to concrete, the scientists behind this new study say they have also discovered a mysterious ingredient that allowed the Romans to make their building material so strong and create complex structures in hard-to-reach places like docks, sewers and earthquake zones.

The Element the Researchers Ignored

For years, researchers believed that volcanic ash from the Pozzuoli region in the Gulf of Naples made Roman concrete so strong.

This type of ash was transported throughout the Roman Empire for use in construction and was described in the reports of architects and historians of the time as a key ingredient in concrete.

Now, however, experts are emphasizing that the way lime was used in the past was not only ignored, but was a very important component.

The research team, which included researchers from the US, Italy and Switzerland, analyzed 2,000-year-old concrete samples taken from the city wall at the Privernum archaeological site in central Italy. The Roman Empire.

The team found that the secret was in the lime used, as it gives concrete the ability to “heal” cracks over time.

Previous studies did not even consider lime, as it was assumed that it had been mixed in by mistake or that the concrete was of poor quality.

“For me, the ancient Romans (engineers) really did a great job of selecting and processing materials,” said study author Admir Masik, an assistant professor of civil and environmental engineering at MIT. “Experts then wrote the exact recipes and implemented them at construction sites (throughout the Roman Empire),” he added.

The new discovery could help make today’s concrete construction more sustainable, the researchers say. “Concrete allowed the Romans to revolutionize architecture,” he says, adding that “the Romans were able to create and transform cities into something unique. This revolution essentially completely changed their way of life.

Studying

In more detail, concrete is a stone or rock formed by mixing cement and a binder, usually limestone, water, sand and gravel.

Upon further study, the researchers concluded that the limestone masses were caused by the use of lime (calcium oxide)—the most reactive and dangerous dry form of limestone—in mixing the concrete.

Further analysis of the concrete showed that another secret was that it got hot. “The benefits of hot mixing materials are twofold,” Masik said and explained:

“Firstly, when the concrete aggregate is heated to high temperatures, it allows the use of chemicals that would not be possible if only slaked lime was used, and not (lime oxide). Secondly, this increased temperature significantly reduces the curing and setting time, as all reactions are accelerated, so the material is made faster,” he added.

The researchers also noted that this ability to “heal” cracks could pave the way for the production of stronger concrete. Finally, the study claims that the production of a new type of concrete will reduce its carbon footprint in the environment, which is up to 8% of global greenhouse gas emissions.

According to CNN