[aiauthoritydev]

The 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.

[Maken]

>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

[throwaway27448]

> 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

[Hugsbox]

We don't build better bridges than we did 200 years ago? Forgive me if I'm wrong, but it seems like we build bridges right now that would have been unthinkable 200 years ago

[matheusmoreira]

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.

[dev_l1x_be]

This is exactly what we did with houses, buildings. We had perfectly functional 100+ years old fully functional, gorgeous buildings and we replaced those with brutalist concrete/glass barely functional garbage.

[otherme123]

In Europe we have plenty of old buildings. The good ones (i.e. made by very wealthy people) tend to be decent, with a skew towards huge living rooms but tiny rooms. The cheaper ones are a mess to mantain: cold in winter, hot in summer, expensive to renovate (it could be more expensive to renovate than to build a new one), bad to no isolation, in my region terribly humid, usually too dark with minuscule windows for modern standards.

With roman buildings that last 2000 thousand years we are looking at survivor bias. Near me there are some roman ruins from a (cheap and small) public bath that are barely distiguishable from a pile of bricks. The are some nearby pre-roman ruins in better shape.

[modo_mario]

>cold in winter >in my region terribly humid

You need to actually reduce draft a bit (often old houses like mine tend to accumulate flaws that the elderly living there before didn't fix anymore.) and use a heating sources that matches.

Having a fireplace is fine. It could overheat the house whilst also keeping air dryer and it's essentially renewable (compared to the alternatives and houses made of more plastic insulation than anything else) if you don't mind air quality dip in winter.

That said i can see how that's no longer an option in places that have drastically increased their population

[jaapz]

Fireplace is extremely inefficient, and really bad for both your (exhaust fumes get into the room anyway), and your neighbors (the smoke doesn't just dissappear) health, though.

I love the heat and smell of a good fire as much as the next guy, I'm just not sure it's worth the risk of cancer and respiratory diseases.

[modo_mario]

If exhaust fumes get into the room too often you're doing it wrong. You shouldn't be able to smell it inside. I've at times made the fire go a little harder to get rid of fumes (kitchen oopsies). My air quality measurer found it remarkably effective.

As for neighbors. That is true but at the same time these things are rather sustainable and from a time when the population density was lower. I think they still have some place outside of cities untill heatpumps come down in price.

[AngryData]

If efficiency is important, like if you are using wood for primary heat, you should at a minimum be using a sealed box stove which should be pretty efficient and have little to no smoke escaping.

Alternatly you could just use an outdoor stove that merely heat exchanges to the inside.

[dev_l1x_be]

The insulation is the easiest to add to old buildings.

Red bricks offer better thermal insulation than dense standard concrete. Because of their porous clay structure, red bricks absorb heat slowly during the day and release it at night.

Solid concrete blocks, conversely, are highly conductive and absorb/transfer heat much faster, usually requiring added insulation.

We could just fix the insulation where it is bad instead of tear down the entire housing unit and rebuild it with concrete / glass / metal.

[wbl]

There are exactly 3 old buildings in Warsaw thanks to the Germans. Brutalism exists because a generation who grew up in rubble wanted solidity.

[ascorbic]

They weren't torn down because there was better technology available. They were torn down because they were falling apart, or were no longer meeting the needs in that location. I love old buildings – my house is 250 years old – but there's no denying that generally they are less suited to current needs than newer buildings.

[benj111]

Older buildings are generally more flexible though.

In the UK, within living memory electricity has become widely available, TV has, gas, internet etc etc. and yet we still build houses without the assumption that some cable isn't going to be modified in the wall some how.

There's fairly modern houses that didnt have the 2 courses of brick added to the loft to allow 300mm of insulation to be installed.

We are now building houses with gas boilers, knowing that they will have to be swapped out probably before the life of the boiler runs out. And I bet the radiators and piping aren't sized to make that possible. That the circuit isn't sized for that.

Yes none of this is easier in a 250 year old house, but it isn't harder and 250 year old houses hadn't really changed appreciably for a few centuries so it isn't as if there would be an expectation that you would be installing new things in the wall every decade.

[ascorbic]

When we bought our house, the only plumbing was in a tiny, asbestos-filled lean-to extension added in the 1940s that contained the kitchen, bathroom and toilet. The way people use houses has changed a lot in the past 100 years

[matheusmoreira]

Those are houses though, private property. Not government infrastructure.

[Zardoz84]

But we are currently doing it when a bridge can't handle modern traffic levels because it was designed thinking in 50's traffic (single lane for each direction without peatón or bicycle ways to 4 or 6 lanes and pedestrian and bicycle ways).

[gus_massa]

Usually you need wider bridges, so the old bridge needs a replacement or a second bridge on the side.

[matheusmoreira]

If the bridge became a bottleneck, then there is an actual reason to replace it. People aren't doing it on a whim because technology changed.

[croes]

Sometimes knowledge gets lost and newer doesn’t automatically mean better

[culi]

In fact, the dominance of concrete is surprisingly political. It has a lot to do with Cold War geopolitics

https://www.listennotes.com/podcasts/the-conversation/keepin...

[hkt]

Case in point, Roman concrete

[culi]

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

[dizhn]

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).