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.
Structural clay tile
Clay tile in different capacities has been used for thousands of years. The Romans were among the first to use clay tile in construction by building clay pots to lighten vaulting loads. However the first recorded structural use of terra-cotta forms was in sixth-century Italy in the dome of the Church of San Vitale in Ravenna. Clay pots lined with plaster of paris lightened the load of the dome in a similar way to earlier Roman construction.