What Was the Secret Behind the Ancient Roman Concrete That Lasted Millennia?

One of the most fascinating aspects of ancient Roman engineering is the durability of their concrete, which has withstood the test of time far better than many modern concrete mixtures. Roman concrete, known as opus caementicium, was made using volcanic ash, lime, and seawater, creating a chemical reaction that produced a sturdy material resistant to cracking. This unique formulation allowed structures such as the Pantheon and aqueducts to endure for nearly two thousand years, showcasing not only the Romans' advanced understanding of materials but also their innovative construction techniques. Recent studies have revealed that the volcanic ash used in their concrete improved its longevity and resilience against environmental factors, hinting at a lost technology that modern engineers are now striving to replicate for sustainable infrastructure.