The technology of ancient Roman architectures

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The concrete was a mixture of lime mortar, aggregate, pozzolana, water, and stones, which did a very good job in reinforcing and load bearing. That is why some buildings as Temple of Portunus used Roman concrete as a foundation. The use of concrete also made the architect get rid of the ‘rectilinear building’, but its decorative use was discovered in about 100BC though it was started to be used in about 200BC. But there are two serious problem: easy to be wet and not beautiful enough. So, the clever Romans found a way that they put some stones onto the surface of the concrete before its solidification. After solving this problem, the concrete could be changed into different kinds of rates for different kinds of requirements of mechanic, which could be proved by the ruins of Pompeii. [pic 7]

- Structure mechanic

After material, let’s talk about the breakthroughs in the structure mechanic. There is no doubt that the most important technical breakthrough is the vaults.

- Vaults

The invention of the vaults is a great breakthrough in the structure mechanic, which can turn the tension into pressure effectively. The start of using it was about 4th century BC, when the Romans used it for building sewer. And as time going, it was used in more and more aspects which include almost all the large -scale architecture.

There are three kinds of vaults: the semicircular barrel vault, the groin vault, and the dome. They are difficult to be built with stones, so the development of the vaults improved the development of concrete.

First one, the semicircular barrel vault, is the simplest form. It is just built by widening the half-cylinder and then get a cambered surface, which is easily enough for a slave. If a wider space is needed, there is no need to build a larger vault, just combining several small ones together. [pic 8]

[pic 9]

The groin vault is used in a square space. Two semicircular barrel vaults going across can get a groin vault. It can focus the weight to four corners, which means there is no need to have continuous walls.

The last one is the dome. It can produce a large interior space and is widely used in a number of building types such as temples, thermae, palaces, maosolea. And the other important reason why it is so popular is that it can fit the requirement of Christian architecture. [pic 10]

- Mosaics

There is also another application which is used widely: Mosaics. The Mosaics are a combination of colorful small stones. They are usually used to decorate such as a picture or just putting them on the ground.

- Glass windows

And the last one is glass window. Both the glass and even the transparent glass are not invented by the Romans, but they produced plain glass earliest, which is the material basis for the glass window. So the original window which is a hole in the wall was replaced by the glass window which can not only let the light in but also prevent the wind and the rain.

- Examples

Here are some examples which can prove some technologies above.

- Infrastructures

Firstly, here are some infrastructures.

- Roads

The roads are one of the basics of a city. The ancient Romans put the cuboid bricks into the ground with the small surface upwards and facing down which can effectively increase the load-bearing ability. Nowadays, we can still step on the road of the ancient Rome. [pic 11]

- Aqueducts

Then the aqueducts built by the Romans include kinds of technology. Powered by gravity, they transported large amounts of water efficiently. Parts of them which have depressions deeper than 50m have to be crossed. Because inverted siphons are used to forced water uphill. [pic 12]

- Typical patterns

Then here are some typical patterns of architectures.

- Bathing places

The heating of bathing place is worth to say. In the first place, the warmest possible situation must be selected; that is, one which faces away from the north and northeast. The rooms for the hot and tepid baths should be lighted from the southwest. {3}And the second point is that the way to supply heating is a little similar to some of the ways nowadays, which is quite amazing. Also the ground of the bathing place is used the technology of Mosaics, which are mentioned before.

- Theaters

Then the harmonic of the theater is widely and accurately used. The ancient architects, following in the footsteps of nature, perfected the ascending rows of seats in theaters from their investigations of the ascending voice, and, by means of the canonical theory of the mathematicians and that of the musicians, endeavored to make every voice uttered on the stage come with greater clearness and sweetness to the ears of the audience. {3}And also there are other ways to expand the voice such as burying some bronze vats under the ground. Apart from the harmonic, there is an obvious difference to Greek theaters which are usually built along a hill that though theaters were a common element in Greek and Roman cities, this is the first one that was designed as a freestanding object. {4}[pic 13]

- Real examples

And here are some real examples which can still be seen nowadays. Let’s put them in the order of time.

- Servian wall (378BC)

It was the second wall of Rome, about 11km long, which was built of large blocks of tufa. [pic 14]

- Temple of Portunus (100-80BC)

This temple was mentioned in the above. It is one of the architectures built in the transition period from Greek architectures to Roman architectures. The concrete was used in it, though it was just used as the foundation. And the columns are in the Greek styles. Also not all of the columns are load-bearing ones. Some of them are just used for decoration. The Romans inlaid half of the columns into the walls for decoration but the walls still look smooth. [pic 15]

- Theater of Marcellus (44BC-13or11BC)

Julius Caesar commissioned