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.
François Coignet
Coignet started experimenting with iron-reinforced concrete in 1852 and was the first builder ever to use this technique as a building material. He decided as a publicity stunt, and for promotional purposes of his cement business, to build a house made of "béton armé", a type of reinforced concrete. In 1853 he built the first iron reinforced concrete structure anywhere, a four-story house at 72 rue Charles Michels. This location was near his family cement plant in St. Denis, a commune in the northern suburbs of Paris. The house was designed by local architect Theodore Lachez.