New research in Pompeii supports the theory of the use of hot lime

Rome - A new archaeological research in the southern Italian city of Pompeii has supported the assumptions about the use of hot lime in the construction of buildings in ancient Rome. This was stated by the archaeological park that manages the site of the city destroyed by the eruption of Vesuvius in 79 AD. According to some experts, the use of hot lime is one of the reasons why many structures from ancient Rome have withstood wear and the ravages of time so well.

The new archaeological research in Pompeii focused on several houses that were being reconstructed at the time of the eruption. This allowed researchers to familiarize themselves with a number of tools and construction techniques common in the first century in southern Italy and likely also in ancient Rome. The research also involved experts from the Massachusetts Institute of Technology (MIT).

According to the research, stonemasons in Pompeii first mixed lime with volcanic ash and then poured water into the mixture. As a result of chemical reactions, the lime was hot during construction. Researchers believe that the so-called hot lime mixing was commonly used in Pompeii. For plaster, slaked lime was used instead. "The results derived from the survey indicate the use of unslaked lime in the construction of walls," said Gabriel Zuchtriegel, the head of the archaeological park. According to him, this technique significantly accelerated construction.

The use of unslaked lime and the so-called hot mixing of building materials had already been pointed out by research from the Massachusetts Institute of Technology (MIT), Harvard University, and research centers in Italy and Switzerland in January of last year. The high-temperature mixing created large particles of limestone, known as clasts. According to the authors of the research, these have a specific structure, allowing the mortar and concrete to possess self-healing abilities. This led to the structures demonstrating good resistance to wear.