alt Hacker NewsThe whole promise of engineering is not to build a bridge that stands but to build a bridge that barely stands. It is not a good idea to build a bridge that last 500 years. You likely destroyed valuable resources to build one. Build a bridge that lasts 100 years and save those resources. In 100 years the technology to build bridges improves so much that it is lot easier to build a new one. At least in most countries like India.
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> In 100 years the technology to build bridges improves so much that it is lot easier to build a new one
This hasn't even been true for 200 years lol
Nobody is going to tear down old bridges and rebuild them at enormous costs just because technology changed. Some things can't or won't be redone and so it's worth it to build it to last and getting it right on the first try.
Modern concrete includes plastic fibers like polypropylene, fly ash (a great source of arsenic, lead, and mercury), silica fume, formaldehyde, and often even PFAS
This type of concrete does not give us any more flexibility in the future to rebuild or upgrade because doing anything to it could turn it into an environmental and public health hazard
Aren't structures like bridges tested to at least 1.5x design parameters? In our field it's usually 2x (pressure and lifting lug strength).
Sometimes knowledge gets lost and newer doesn’t automatically mean better
>It is not a good idea to build a bridge that last 500 years.
Why not? A well-build bridge from 500 years ago is perfectly functional today [1]
[1] https://en.wikipedia.org/wiki/Puente_de_Segovia,_Madrid