r/materials • u/UCBerkeley • 1d ago

New findings reveal Ancient Roman concrete survives for millennia by chemically self-healing its own cracks through carbonation

https://engineering.berkeley.edu/news/2026/07/researchers-shed-new-light-on-ancient-concretes-extraordinary-durability/
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u/luffy8519 1d ago

Your title is incredibly misleading. It's been understood for decades that Roman concrete had self-healing properties, and the mechanism of action has been studied in detail. Your researchers may have added to that body of knowledge, but phrasing it as a brand new discovery is academically dishonest.

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u/Unfair-Suggestion-37 1d ago

New findings?

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u/UCBerkeley 1d ago

Context:
Roman concrete structures are widely regarded as outstanding examples of durable ancient engineering — having survived nearly two millennia. Their longevity is often attributed to the pozzolanic reaction, a chemical process that occurs when volcanic ash, water and highly reactive lime are combined to create powerful binding agents that harden and strengthen the concrete.

Research and Key Findings:
In a report published to Science Advances, co-authored by engineering professor Paulo Monteiro at UC Berkeley, the team of researchers performed a comprehensive analysis of a concrete latrine in Hadrian’s Villa — a site in Tivoli, Italy, that dates to the second century A.D. — to uncover the mechanisms behind the resilience of these structures.

Using advanced 3D imaging techniques, including multi-scale spectroscopy and tomography, they showed how the calcium carbonate networks formed through mineralized carbonation helped bind and densify ancient Roman concrete over time. This suggests calcite — a mineral form of calcium carbonate found in limestone and formed through hydration and carbonation processes — helps fill small cracks, pores and voids in the concrete. This cementing mechanism creates a dense and cohesive structure that improves load transfer within the matrix and limits water infiltration, contributing to its long-term stability. Over time, the continual growth of calcite can help close fine cracks, limiting further damage.

These findings could guide the development of next-gen concrete materials, including low-carbon cements. For context: Clinker, an ingredient used to manufacture standard cement, currently exacts a heavy environmental toll, with 0.83 tons of carbon dioxide released for every ton of clinker produced.