The works of the Roman Empire have existed for millennia. It wasn’t just the great architects who made it possible. It is an important component in making your buildings appear timeless. This is the great resistance of Roman cement. What elements does the formula contain? That seems to be the best kept secret of the Roman Empire.
The ancient Romans built sea dikes that withstood the onslaught of waves for twenty-one centuries. They also built bridges, aqueducts, and amphitheaters that still exist today. Geologists and engineers have looked for clues as to the exact composition of the cement used.
The Romans based their territorial expansion on engineering. They went to great lengths to manage their possessions. For this purpose, they created roads with a length of 85,000 kilometers. Bridges, warehouses, ports, aqueducts … To build them, they needed an incredibly tough material: Roman concrete. Historical documents on this material are rare. But it became from 150 BC. Widespread. With the fall of the Roman Empire, the exact recipe was completely lost.
De Architectura It is the greatest architectural treatise from ancient times. Marco Vitruvio Polión, architect of Julius Caesar in his youth, left some clues. He described a ratio of one part of lime to three parts of pozzolana, a type of volcanic sand. For underwater work he specified one part of lime to two parts of pozzolana.
The Lawrence Berkeley National Laboratory in the United States used spectroscopy to analyze this mortar. In fact, the ash from volcanic eruptions crystallized into permanent rock. They also handled a very rare mineral called tobermorite containing aluminum. It was created when sea water seeped through the concrete of breakwaters and piers. It dissolved the volcanic ash. So new minerals could be formed. These reinforced the matrix through chemical reaction with seawater. Amazing.
Learn from the past
Modern concrete structures show signs of wear and tear after 50 years. Nothing compared to some Roman engineering work. The problem is that volcanic ash is not abundant on the planet.
Roman concrete, scientists say, could still be very useful in certain contexts. This has been demonstrated in the thick concrete walls of a Japanese nuclear reactor. The accidental formation of aluminous torbemorite increased the strength of the walls more than three times. Japanese scientists confirmed this in a study published in Materials and design.
The great resistance of Roman cement is just one more example of his quest to transform its capital into the Eternal City.