Ancient Roman architecture
Although concrete had been used on a minor scale in Mesopotamia, Roman architects perfected Roman concrete and used it in buildings where it could stand on its own and support a great deal of weight. The first use of concrete by the Romans was in the town of Cosa sometime after 273 BC. Ancient Roman concrete was a mixture of lime mortar, aggregate, pozzolana, water, and stones, and was stronger than previously-used concretes. The ancient builders placed these ingredients in wooden frames where they hardened and bonded to a facing of stones or (more frequently) bricks. The aggregates used were often much larger than in modern concrete, amounting to rubble.
French architecture
The architecture of Ancient Rome at first adopted the external Greek architecture and by the late Republic, the architectural style developed its own highly distinctive style by introducing the previously little-used arches, vaults and domes. A crucial factor in this development, coined the Roman Architectural Revolution, was the invention of concrete. Social elements such as wealth and high population densities in cities forced the ancient Romans to discover new (architectural) solutions of their own. The use of vaults and arches together with a sound knowledge of building materials, for example, enabled them to achieve unprecedented successes in the construction of imposing structures for public use.