Overview
- An unfinished 79 CE construction site in Pompeii preserved premixed dry piles, intact quicklime fragments, tools and work notes, offering direct evidence of Roman building practice.
- Microscopy, stable isotope measurements and Raman spectroscopy identified fractured lime clasts, calcium‑rich reaction rims and mineral transformations diagnostic of hot‑mixing.
- Lime clasts function as calcium reservoirs that dissolve and recrystallize or react with pozzolans to seal cracks, explaining Roman concrete’s long-term self‑healing.
- The findings contradict a literal reading of Vitruvius’ slaked‑lime instructions, which scholars now say may describe a different method or reflect later misinterpretation.
- Authors highlight applications for conservation and for designing more durable, lower‑carbon modern concretes, with the research led by MIT’s Admir Masic and published on December 9.