Particle.news
Download on the App Store

Pompeii ‘Time Capsule’ Confirms Romans Made Self-Healing Concrete With Hot-Mixing

Analyses of intact construction materials identified reactive quicklime clasts that drive long-term crack repair.

Overview

  • Nature Communications published the findings on December 9, reporting direct evidence from an unfinished 79 C.E. construction site with raw material piles, tools, and walls at different stages.
  • Researchers conclude that builders dry-mixed quicklime with volcanic ash and other ingredients before adding water, triggering exothermic reactions that created the durable binding matrix.
  • Stable-isotope and mineralogical tests, including analyses of pumice, traced reaction pathways and distinguished hot-mixed quicklime from slaked lime described in traditional accounts.
  • Lime clasts observed in the samples dissolve and recrystallize to fill cracks over time, explaining the material’s longevity in marine, seismic, and volcanic environments.
  • The work challenges long-held interpretations of Vitruvius’ recipe and informs efforts to design more durable, lower-carbon cements, with lead author Admir Masic founding DMAT to pursue applications.