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Well to be fair, most Roman stuff didn't survive, and plenty of non-steel-reinforced concrete things will last just as long as the Roman stuff. Often times bui

Well to be fair, most Roman stuff didn't survive, and plenty of non-steel-reinforced concrete things will last just as long as the Roman stuff. Often times buildings are disappointingly short lived, but I think sometimes people lament it a little too much. If we need a different building there 50 years later, and we built it to last 200 years, then a lot of material and effort was wasted. There's often a lot of good that comes from knocking a building down and using the limited space for something more useful.

Jaruzel 9y ago
I think you've hit the nail on the head there. Back in Roman times, there were about ~300m people in the known world. That's lots of space to settle into, with a view that you and your descendants will be there for a very long time. They built stuff to _last_, because as far as they were concerned, the Roman Empire was unbeatable, and their dynasties would go on forever. These days, we're so crammed in where ever there are usable resources, that the moment we die, or move on, someone claims the space and adapts it to their needs. Space is at such a premium that it's illogical to lock it out as one particular usage for centuries.
- tomrod 9y ago
  This is true in cities perhaps, but there are many lonely places still.
  - bronson 9y ago
    The building (& concrete) is in the cities, not the lonely places.
kobeya 9y ago
> and plenty of non-steel-reinforced concrete things will last just as long as the Roman stuff Not as long as you would think. Non-reinforced concrete only lasts a few generations, whereas there are Roman concrete roads still in (mild, rural) use today. We actually know why too. Recent science shows that Roman concrete used a slightly different formula that took much longer to set -- weeks or maybe months rather than days. They didn't know how to make fast-setting concrete like we have today. But the length of time also made the structure stronger. We could build that way, if we wanted. But we don't.
- DoubleCribble 9y ago
  Indeed. One need only look at a few DIY sidewalk repair jobs to see what happens to unreinforced concrete in relatively short order. This article doesn't mention what the usable cure time is, but the magic of Roman cement is that it continues to get harder over centuries.[1] [1]http://www.sciencemag.org/news/2017/07/why-modern-mortar-crumbles-roman-concrete-lasts-millennia http://www.sciencemag.org/news/2017/07/why-modern-mortar-cru...
  - lostlogin 9y ago
    Pour it thicker and it lasts one hell of a lot longer. Cheaping out on the volume is a huge part of paths breaking up.
- wlesieutre 9y ago
  Recent research on Roman concrete, particularly in constructions exposed to seawater: https://phys.org/news/2017-07-ancient-concrete-romans.html https://phys.org/news/2017-07-ancient-concrete-romans.html
- sgc 9y ago
  We do for niche uses. Runways, bunkers, etc can have even 2 year curing times to make "hardened concrete", which is up to 7x stronger than the same formulation allowed to dry out instead of keeping it wet for extended curing.
deleted 9y ago
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Jaruzel 9y ago

I think you've hit the nail on the head there. Back in Roman times, there were about ~300m people in the known world. That's lots of space to settle into, with a view that you and your descendants will be there for a very long time. They built stuff to _last_, because as far as they were concerned, the Roman Empire was unbeatable, and their dynasties would go on forever. These days, we're so crammed in where ever there are usable resources, that the moment we die, or move on, someone claims the space and adapts it to their needs. Space is at such a premium that it's illogical to lock it out as one particular usage for centuries.

tomrod 9y ago
This is true in cities perhaps, but there are many lonely places still.
- bronson 9y ago
  The building (& concrete) is in the cities, not the lonely places.

kobeya 9y ago

> and plenty of non-steel-reinforced concrete things will last just as long as the Roman stuff Not as long as you would think. Non-reinforced concrete only lasts a few generations, whereas there are Roman concrete roads still in (mild, rural) use today. We actually know why too. Recent science shows that Roman concrete used a slightly different formula that took much longer to set -- weeks or maybe months rather than days. They didn't know how to make fast-setting concrete like we have today. But the length of time also made the structure stronger. We could build that way, if we wanted. But we don't.

DoubleCribble 9y ago
Indeed. One need only look at a few DIY sidewalk repair jobs to see what happens to unreinforced concrete in relatively short order. This article doesn't mention what the usable cure time is, but the magic of Roman cement is that it continues to get harder over centuries.[1] [1]http://www.sciencemag.org/news/2017/07/why-modern-mortar-crumbles-roman-concrete-lasts-millennia http://www.sciencemag.org/news/2017/07/why-modern-mortar-cru...
- lostlogin 9y ago
  Pour it thicker and it lasts one hell of a lot longer. Cheaping out on the volume is a huge part of paths breaking up.
wlesieutre 9y ago
Recent research on Roman concrete, particularly in constructions exposed to seawater: https://phys.org/news/2017-07-ancient-concrete-romans.html https://phys.org/news/2017-07-ancient-concrete-romans.html
sgc 9y ago
We do for niche uses. Runways, bunkers, etc can have even 2 year curing times to make "hardened concrete", which is up to 7x stronger than the same formulation allowed to dry out instead of keeping it wet for extended curing.

deleted 9y ago

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