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Rebar reinforced concrete rusts. Non-reinforced concrete has to be built bigger, but can last a long time. The coliseum is still up - Hoover Dam will also prob

Rebar reinforced concrete rusts. Non-reinforced concrete has to be built bigger, but can last a long time. The coliseum is still up - Hoover Dam will also probably last awhile. And that's without much maintenance. Smaller non-reinforced structures are harder to build. You have to use the concrete to hold itself up which requires a larger structure. So you're left with reinforcement. There are options for non-rusting rebar, and non-rusting coatings, but I believe they're expensive. Also, any nick or scratch in a coating ruins it. There's also unique and novel research for non-rebar reinforcement - again expensive. Here in US most buildings are built to last X years. So long as the rebar lasts longer than X, they'll use rebar. Increase X via regulations, and the quality (and cost) of the buildings in that area increases. Otherwise the bidder with the lowest cost of materials is most competitive. Anyone know what it's like in China?

aksss 5y ago
Small nit not to take away from your larger point - I'm not sure the colosseum is a good example of a concrete structure for comparison to the concrete buildings of current age being discussed. The colosseum did use concrete for the arches, but was primarily built of limestone block secured with metal clamping. Then plenty of brickwork was used. Concrete was integral to the colosseum, but (I believe) a relative minority of the material on the whole.
- Retric 5y ago
  Skyscrapers use a great deal of steel, but their still reinforced concrete structures.
baybal2 5y ago
> There are options for non-rusting rebar, and non-rusting coatings, but I believe they're expensive. Galvanised rebar is omnipresent around the world. I believe even mandatory in some countries. > Otherwise the bidder with the lowest cost of materials is most competitive. Anyone know what it's like in China? Just as you said. Construction companies save on everything. GFRP rebar got adopted in China not so much because of advantages, but because of code allowing for lower concrete cover with it, as I heard.
- deleted 5y ago
  [deleted]
Haemm0r 5y ago
Carrying strucuture is mainly reinforced steel(classic pillar + concrete floor/ceilings design), walls are usually bricks.

aksss 5y ago

Small nit not to take away from your larger point - I'm not sure the colosseum is a good example of a concrete structure for comparison to the concrete buildings of current age being discussed. The colosseum did use concrete for the arches, but was primarily built of limestone block secured with metal clamping. Then plenty of brickwork was used. Concrete was integral to the colosseum, but (I believe) a relative minority of the material on the whole.

Retric 5y ago
Skyscrapers use a great deal of steel, but their still reinforced concrete structures.

baybal2 5y ago

> There are options for non-rusting rebar, and non-rusting coatings, but I believe they're expensive. Galvanised rebar is omnipresent around the world. I believe even mandatory in some countries. > Otherwise the bidder with the lowest cost of materials is most competitive. Anyone know what it's like in China? Just as you said. Construction companies save on everything. GFRP rebar got adopted in China not so much because of advantages, but because of code allowing for lower concrete cover with it, as I heard.

deleted 5y ago
[deleted]

Haemm0r 5y ago

Carrying strucuture is mainly reinforced steel(classic pillar + concrete floor/ceilings design), walls are usually bricks.