Visiting the Pantheon, one of Rome’s premier tourist sites, it’s hard not be humbled by the knowledge that this building has lasted 1900 years and still stands as the world’s largest unreinforced concrete dome, while modern concrete structures deteriorate. Take a look at the magnificence of the Pantheon.
Photo credit: CC BY-SA 4.0 license
Photo credit: Macrons CC BY-SA 4.0 license
Photo credit: Anthony Majanlahti CC BY 2.0 license
The Romans’ concrete technology was lost for almost a millennium as the Dark Ages unfolded, and Europe regressed technologically and economically. The discovery of Roman manuscripts on making concrete in 1414 sparked gradual reintroduction of concrete as a building material, eventually including the use of reinforcing materials like iron bars that enabled feats that the Romans could not accomplish.
Yet for all our scientific and technical sophistication, Roman concrete resisted cracking and eventually crumbling far better than ours.
Now, as MIT News reports, scientists from MIT, Harvard, and 2 European research institutes have discovered the secret to Rome’s concrete recipe. We may finally be ending the Dark Ages for concrete. David L. Chandler writes:
The findings are published today in the journal Science Advances, in a paper by MIT professor of civil and environmental engineering Admir Masic, former doctoral student Linda Seymour ’14, PhD ’21, and four others.
The Romans used:
…volcanic ash from the area of Pozzuoli, on the Bay of Naples. This specific kind of ash was even shipped all across the vast Roman empire to be used in construction, and was described as a key ingredient for concrete in accounts by architects and historians at the time.
But moderns disregarded the presence in Roman concrete of:
