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.
Edmond Coignet
Coignet was the son of industrialist François Coignet (1814-1888) and educated at the École Centrale des Arts et Manufactures (École Centrale Paris). He was the inventor of the agglomerated concrete to strengthen the cement with metal inserts. He permanently reoriented the family business to construction. In 1892 he applied his innovative construction methods on the aqueduct of Achères in Paris. Coignet was the first to use reinforced concrete piles and built with the architect Jacques Hermant some of the first Parisian buildings in this material.