# How Did Roman Contractors Mix large Volumes of Concrete? **URL:** \ **Category:** Factual Questions\ **Created:** [May 10, 2008, 2:02pm UTC](https://boards.straightdope.com/t/how-did-roman-contractors-mix-large-volumes-of-concrete/448804 "2008-05-10T14:02:56Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [May 10, 2008, 2:02pm UTC](https://boards.straightdope.com/t/how-did-roman-contractors-mix-large-volumes-of-concrete/448804/1 "2008-05-10T14:02:56Z")
Roman concrete is pretty impressive-they made a type of concrete (pozzolana) which is tronger than modern concrete. Only, when you need a lot of it (such as pouring the dome of the Pantheon), how do you mix it? did they have an army of slaves doing this? or did they have some kind of crude mechanical concrete mixer? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 10, 2008, 3:11pm UTC](https://boards.straightdope.com/t/how-did-roman-contractors-mix-large-volumes-of-concrete/448804/2 "2008-05-10T15:11:35Z")
Why, specifically, would you need a “big pour” other than for reasons of economy? Many very large concrete structures are a succession of small pours. ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [May 10, 2008, 4:36pm UTC](https://boards.straightdope.com/t/how-did-roman-contractors-mix-large-volumes-of-concrete/448804/3 "2008-05-10T16:36:16Z")
Info [here](http://www.romanconcrete.com/docs/chapt01/chapt01.htm) on how they constructed the dome of the Pantheon. (Scroll down)