It is known that the constructions erected by the Romans 2000 years ago and more resist the ravages of time extremely well. A team of scientists with Swiss participation has managed to unlock the secret of the longevity of Roman concrete.
The researchers looked at samples of a 2,000-year-old Roman-era concrete wall from the Priverno archaeological site near Rome. The analyzes carried out in particular with X-rays showed that the concrete had been hot mixed with the addition of quicklime.
The result is the presence of large aggregates of lime which, in the presence of water, function as a source of calcium and fill the empty spaces. Calcium also reacts with another additive used by the Romans, pozzolan, a volcanic rock, creating crystalline structures that become harder and harder over time.
Autoguérison
The concrete is thus reinforced. The lime aggregates reacting with the water that infiltrates through any cracks give it a self-healing capacity, and this over millennia, according to the authors, who claim to have developed their own recipe for durable concrete on the basis of this research.
Researchers from the Institute of Mechanics of Materials IMM SA in Grancia (TI) also contributed to this published study in the journal Science Advances.
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