Uncovering Ancient Roman Building Secrets: Pompeii Site Reveals 2,000-Year-Old Construction Techniques

Archaeologists in Southern Italy have uncovered new insights into the unparalleled durability of Ancient Roman buildings like the Colosseum and Pantheon.

A dig into the ruins of a nearly 2,000-year-old construction site in Pompeii shed light on intriguing details about how these buildings were crafted.

The ongoing excavations, originally aimed at managing the area's water systems, revealed an entire block that was once a hive of construction activity, Italy's Culture Ministry said in a press release recently.

"The excavations underway in Pompeii offer the possibility of observing almost directly how an ancient building site functioned," said Gabriel Zuchtriegel, director of the Archaeological Park of Pompeii.

The presence of tools, stacks of bricks and piles of lime suggest the building process at the site was abruptly halted by the eruption of Mount Vesuvius in the year 79 A.D., according to archaeologists.

"Particularly numerous is the evidence of the work in progress in the house with the Rustio Vero bakery, where a still life with the depiction of a focaccia and a glass of wine has already been documented in recent months," the culture ministry said in the translated statement.

Markings on walls, possibly tallies left by the ancient construction crew, offer clues about how builders worked, and the materials found suggest the Romans used a method of mixing quicklime with sand to speed up construction.

“It is a further example of how the small city of Pompeii makes us understand many things about the great Roman Empire, not least the use of cement works," Zuchtriegel said. "Without cement we would have neither the Colosseum, nor the Pantheon, nor the Baths of Caracalla."

Quicklime is typically immersed in water long before use, and sand is mixed in just before application to produce mortar or cement. However, at the Pompeii construction site, this process appeared to be reversed: experts said quicklime was initially mixed only with pozzolanic sand and water was added in just before walls were installed.

"This means that, during the construction of the wall, the mixture of lime, pozzolanic sand and stones was still hot due to the ongoing thermal reaction and consequently dried more quickly, shortening the construction time of the entire construction," Italy's Culture Ministry said. "Differently, when it came to plastering the walls, it seems that the lime was first slaked and then mixed with the aggregates to then be spread, as is still done today."

Zuchtriegel believes these ancient techniques can be applied to boost the sustainability of modern-day building practices.

"Now we network between research institutions to study the construction know-how of the ancient Romans: perhaps we can learn from them, let's think about sustainability and the reuse of materials," he said.

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In January, reports found the Ancient Roman "hot-mixing" method for developing concrete enabled unique chemical reactions and faster construction, giving the material a "self-healing" capability.

The research centered around bright white mineral chunks in ancient Roman concretes called "lime clasts," which originated from lime. Based on high-resolution imaging and chemical mapping techniques, the study found that at "extreme temperatures," the lime clasts allowed cracks in the concrete to "automatically heal before they spread," a team of scientists from the Massachusetts Institute of Technology (MIT) wrote in a paper published by the journal Science Advances.

The Romans, known for their engineering prowess, constructed expansive networks of roads, aqueducts, ports and colossal buildings.

Many of these structures have remained intact for more than 2,000 years, making them exponentially longer-lasting than modern-day concrete constructions that deteriorate within a few decades.

The Pantheon, for example, has stood the test of time despite its concrete dome lacking reinforcement, and some ancient aqueducts still deliver water to Rome to this day.