What did roman architecture emphasize?

"margin-bottom:.0001pt;line-height:normal;">The Romans effected

what historians call the Roman architectural revolution or concrete

revolution. This involved the extensive use of concrete, the barrel

(simple) arch and the vaulted arch. These three elements enabled

the Romans to go beyond Greek methods of construction which used

cut-stone and post-and-beam or post-and-lintel structures. They

became essential for large roofs and large buildings, such as

basilicas (public buildings) amphitheatres (arenas), theatres,

baths, domes, forts and fortifications and dams. They also made it

possible to build bridges which were much longer than before and

could cross much wider rivers and valleys.

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"margin-bottom:.0001pt;line-height:normal;">Prior to the Romans

concrete was hardly used. The Romans were the first to made large

scale use of it. They developed a type of concrete (opus

caementicium) which was as resistant as modern concrete. It also

set underwater and therefore could be used to build docks for

ports, dams and bridges. It was less fluid than modern concrete and

had to be layered by hand. It was made by mixing a volcanic rock

called pozzolana (which is named after Pozzuoli, a suburb of

Naples) with lime. The two acted as a binder and rubble from

stones, bricks or pottery shreds were added as aggregates which

added body to it. Concrete had technical and practical advantages.

It was exceptionally strong. it could be moulded and could span

great distances when shaped into arches, vaults and domes. It was

layered into a formwork and it took the shape of its container. It

did not require skilled labour and therefore was cheaper.. It was

much faster for construction than laborious masonry walls. It was

safer because concrete vaulted roofing was fireproof, unlike the

wooden-beamed roofs of traditional post-and-lintel construction

methods.

"margin-bottom:.0001pt;line-height:normal;">

"margin-bottom:.0001pt;line-height:normal;">The potential of the

previously very little used arch and vault, were fully exploited

for the first time. The Romans were the first to fully appreciate

the advantage of these structures and make large scale use of them.

The Etruscans are thought to have invented the simple (barrel)

arch. The oldest example of the vaulted arch has been found in the

Greek city of Pergamon (in western Turkey). The (simple, barrel)

arch has a strong load- bearing capacity and was useful to build

large walls without using the post-and-lintel method and to build

bridges which were much longer than ever before. The vault (vaulted

arch) has an even greater load-bearing capacity and its structure

is suited to support large roofs. Their construction in concrete

made them easier to build and even stronger. This led to the use

larger and monumental arches and vaults on a grand scale. However,

the Romans did not abandon masonry arches and vaults. The vaulted

arch came into two forms: the groin arch is formed by two to four

intersecting barrel (simple) arches and the rib arch, where the

intersecting arches were of different diameter.