Quicklime in Roman concrete: hot mixing and self-healing
Cal viva en el hormigón romano: mezcla en caliente y autorreparación
- Date
- 2023 · confidence high
- Place
- Cambridge, Massachusetts, United States
- Credited to
- Admir Masic and the MIT team with Italian collaborators
- Field
- Tools
⚠️ Disputed: the sources disagree.
What was discovered
The white lime clasts in Roman concrete are not mixing flaws but remnants of quicklime mixed hot that, when cracks appear, dissolves with water and recrystallises as calcite, filling them. It would explain the durability of Roman works.
The hot-mixing hypothesis rests on samples from Privernum and contrasts with Vitruvius, who describes slaked lime; some specialists argue the clasts come from incomplete mixing or underburned lime.
What it led to
- self-healing modern concretes using quicklime
- understanding of Roman concrete from Privernum
- lower emissions through greater durability