Quote:
Originally Posted by Beedok
Roman concrete buildings are still standing while their brick ones are not, so I think that's a point in support concrete.
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there is a difference here that everyone should know, between roman concrete and north american concrete.
Roman concrete uses pumice, or volcanic ash, in the construction. It also does not use rebar. As a result the concrete is eternally curing and actually gives it a lot more strength, flexibility, and the ability to breathe. The coliseum is a building that will remain thousands of years from now, whereas ours won't last past 100 or so years.
We don't use pumice or volcanic ash, and we use rebar, thus when air and water gets into the concrete it makes the bars start to rust, and with expansion and contraction the concrete is unable to breathe and thus starts to break off around the rebar, and that is why the best of ours only lasts like 20-50 years.
The parthenon was attempted to be fixed in athens by placing iron joints in that were not coated - the coating originally had prevented them from rusting, so when they rusted they expanded and cracked the blocks. Now they use titanium as the joints as it will not rust. The parthenon used marble in their construction, thus marble does not breathe - the iron in it oxidizes though which is why marble goes from white to ivory colour over time.
Their connectors looked like I shape metal and were placed in between blocks to connect them together.
We could learn a lot from the romans, but instead we just go with what is cheap and easily replaceable.