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Comment by hh3k0 | Hacker News Reader

I wonder, aren't virtually all "easily" available resources already dried up to such a degree that highly advanced/specialized equipment would be needed to extract whatever is left?

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After an apocalypse, if you survive and society has collapsed, resources will be abundant.

You will just have to strip materials from cars and buildings instead of digging them out of the ground.

Better hop to it, that steel isn't going to last forever.

I sure hope that the steel in skyscrapers and stuff is going to last a long freaking time though.

Steel does have a major use in your skyscraper but concrete is perhaps the main player.

Conc is a wonderful and bloody complicated material and so is steel.

Steel is basically iron+(stuff) - Fe 'n' that. If you add small amounts of carbon to iron you get steel and depending on how you do it you transform iron (brittle, hard etc) to a material that is "tough". Tough generally means that it will resist stress/strain more and will fail gradually rather than catastrophically quickly. If you add some other elements, such as chromium you get stainless steel. I can't precis a three year degree into a paragraph but this gets you started!

Conc is a remarkable material, which we think was invented by the Romans. It sets and cures rather than "dries" so will will quite happily work underwater - provided you stop the constituents being carried away by currents. Setting conc involves an exothermic reaction so it heats up - too much in one pour can set itself on fire!

Add steel in the form of "rebar" to conc and you have a material that is nigh on magic in its properties but you do need to know what you are doing. You can simply put C section steel plates in your beams or run FeCr rod through and tension the nuts (lol)

Conc n steel are the modern building blocks of the modern world. I'd like to see a lot more wood ...

This was super interesting. Any book recs with a similar flavor?

I could try to dig out my college reading list (it was actually Plymouth Polytechnic - that's Plymouth, Devon, UK) but it was 30 odd years ago. Things have moved on a bit but not too much.

Do you have a general interest in Civil Engineering or a particular project in mind?

Digging through your stuff would be a bridge too far :) My interest was bc this is a field that I know absolutely nothing about, and so the examples you give were suggestive of an exotic world. If there was something that could sketch out that world in the manner you did, it would be mind-expanding.

I like things that give me a look into a proximate universe that I'd never otherwise pursue, e.g., if I could read a really interesting piece about botany, or modern dance, or challenges in agriculture, or the Michael Jordan of show horses, or the world's most controversial geologist ...

OK, then get your search engine out:

- "Tacoma Narrows bridge failure" - "Roman concrete" - "Millenium bridge London" - "Concrete cancer" - "Gabions" - "3,2,1 concrete mix"

The last two are useful for DIY. That lot is just concrete. Geotechnics and hydrology are also fascinating.

When I studied this stuff we had a class where we grabbed some time to use the Poly's (Polytechnic - a bit like a second tier University back in the day - UK) electron microscope. I over focussed on our sample and vapourised it! We were studying "concrete cancer" which is a bit of a problem in maritime towns because salt in the air is one of the components needed.

I went to Plymouth (Devon, UK) Poly, which is famously a sea town and so we saw a lot of conc cancer, eg the Drake Circus multi story car park.

When you're done with concrete cancer then why not investigate how a building in Florida can collapse - ie this horror: https://www.bbc.co.uk/news/world-us-canada-57631698

Cheers Jon

Thank you for the curated journey!

Folks interested in such material science topics should definitely read about Wootz steel[1] (Damascus steel[0]) and roman concrete [3]. Its very hard [2] to concoct a high fidelity version of these today, mainly because it is hard to get the trace constituents right.

[0] https://en.wikipedia.org/wiki/Damascus_steel

[1] https://en.wikipedia.org/wiki/Wootz_steel

[2] https://en.wikipedia.org/wiki/Wootz_steel#Reproduction_resea...

[3] https://en.wikipedia.org/wiki/Roman_concrete

> You can simply put C section steel plates in your beams or run FeCr rod through and tension the nuts (lol)

"You can't simply...", right? (The "lol" kind of gave it away.)

Too bad, I thought that was about it.

The Miami apartment building collapse has shown us, probably not long enough in some cases.

Parent post is probably referring more to energy resources. Gas and diesel degrade fairly quickly and unless you live in the middle east, aren't just flowing out of the ground anymore. Solar + BEVs might be an option, but only if the apocalypse scenario didn't involve an EMP, otherwise you better know your way around diesel engines and making biodiesel + live close to a hydroelectric plant.

Almost all power is generated by heating water into steam, which can still be done by burning almost anything. It won't be very efficient, but you can do it - so traveling to the nearest coal mine/plant may be an effective energy source.

The most easiest thing, so, would be a Sterling engine then. Something I have to read up again, I'd love to build one with my kids. After all, it was the machinery we did hand-drawn technical 2D drawings for back at university before we moved to CAD.

Hydro, wind, and solar-thermal power is 100% renewable and can be made with 19th-century technology once you've worked out how to build a dynamo. There are some geographic restrictions but one of those power sources should be available in most regions. Plus most of the population has died off in a post-apocalyptic world, so your generators don't need to be nearly as big.

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