Opus caementicium

Opus caementicium was the Roman technique of constructing structures using concrete. It was used from the beginning of the Roman republic through the whole history of the Roman empire.

Opus caementicium, like other forms of concrete, is made from a mix of aggregate and a binder which, when mixed with water, hardens over time. In Roman times gypsum and lime were used as binders, but volcanic dusts such as pozzolana were favored where they could be obtained. Reinforcing elements, such as steel rebar, were not used.

In most usage the raw concrete surface was considered unsightly and some sort of facing was applied. Different techniques were characteristic of different periods and included:

*"Opus incertum": small irregular stones
*"Opus reticulatum": small squared blocks laid in a diamond pattern
*"Opus quadratum": regularly laid courses of ashlars
*"Opus latericium": regularly laid courses of brick
*"Opus spicatum": brick laid in a herringbone pattern
*"Opus vittatum": Square Tuff blocks intersected by brick bands at regular and irregular distances.
*"Opus africanum": vertical chains of upright blocks with alternating horizontal blocks
*"Opus testaceum": Think horizontal brick work

See also

*Roman concrete

References

* [http://archserve.id.ucsb.edu/arthistory/152k/concrete.html Roman Concrete]
*Roman Building By Jean-Pierre Adam, Anthony Mathews (1994)

External links

* [http://www.cs.uu.nl/~wilke/aquasite/hulp/tekopusbreed.htm "Opus caementicium "Roman walls]