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2444222 No.2444222 [Reply] [Original] [archived.moe]

Why don't engineers bite the bullet and use stainless for things like bridges? Buy once, cry once

>> No.2444227

Aside from the cost of stainless, the difficulty working with it, the fact that its physical properties aren't always a benefit to the application, and it's ability to still corrode under the right conditions, it's not always best to engineer things to last hundreds of years. Even if you could build a bridge that would last for a couple of centuries, at some point it's going to get taken down and rebuilt because it no longer serves modern purposes. Look at how many rail crossings that go over roads and were built in the early 1900's create problems now because two vehicles can't fit side by side under them or box trucks are too tall to pass.

>> No.2444254

>>2444222
>Why don't engineers bite the bullet and use stainless for things like bridges? Buy once, cry once
anything you don't understand must be:
easy
better
cheap

>> No.2444263
File: 30 KB, 480x620, fllhhfz7clo81.jpg [View same] [iqdb] [saucenao] [google]
2444263

>>2444222
Checked.
Well, not bridges, but for example busses. Many wicked smaht manufacturers have started using stainless steels and more expensive materials in their frames for key benefits such as
>Durability and longer lifespan
>Higher tensile strength leading to structural rigidity leading to decreased weight
>Availability from suppliers
There isn't significant added costs to handling stainless steels and your storage solutions are less dependent on optimizing climate and you can get away with cheaper or nonexistant coatings.

>> No.2444265

>>2444263
>There isn't significant added costs to handling stainless steels and your storage solutions are less dependent on optimizing climate and you can get away with cheaper or nonexistant coatings.
then why do stainless steel appliances cost so god damn much?

>> No.2444271
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2444271

>>2444265
Purely coincidental

>> No.2444272
File: 152 KB, 525x350, img_2479.jpg [View same] [iqdb] [saucenao] [google]
2444272

>>2444222
Gosh, that's a real puzzler...

https://structurae.net/en/structures/bridges/stainless-steel-bridges

https://www.stainless-structurals.com/blog/structural-stainless-steel-in-bridges/

https://www.shortspansteelbridges.org/stainless-steel-bridges/

https://www.constructionspecifier.com/duplex-bridges/

>> No.2444283

>>2444265
The kitchen market is inflated by modern Western "women" and their Instagram photos, ironic since most of them will never touch the kitchen aside from using the microwave to reheat Ubereats.

>> No.2444304

>>2444222
The true Roman chad didn't have or need to use metallic reinforcing bars to accomplish what they did and their architecture had stood the test of time. Modern engineers are so cucked by expectations of concrete construction that they are forced to impregnate their designs with the ticking time bombs that are rebar which are destined to fail by corrosion within a century. Stainless could work but the funding entities will balk at the cost (Fun Fact: Roads are constructed by rhe lowest bidder). Someone did come up with carbon fiber strand rebar that did work quite well on a smaller bridge but the issue with epoxy material is the concrete just doesn't bond well enough to it, also fabricating a custom bar bend in the field just isn't practical. Modern construction is shit, the workers in charge of mixing and curing concrete properly generally tend to be huge retards and don't understand the effects of excess water in the mix or how concrete develops its strength so the engineers just add more time bombs to their design to cope.

t. bridge construction inspector

>> No.2444332

>>2444265
Your paying more cause it looks pretty and housewives are female and care about things that look pretty.

>> No.2444340

>>2444283
stainless steel appliances have been expensive LONG before cell phones.

>> No.2444362

>>2444265
He said there's isn't significant added costs to handling stainless steels. He didn't say stainless costs the same. He's saying it costs the same to drill holes in it, or to bend it, or to weld it.

>> No.2444364

>>2444222
>Why don't engineers bite the bullet and use stainless for things like bridges? Buy once, cry once
Because engineering design for cost first, and everything else second.

>> No.2444367

>>2444227
Modern people should stop being so fucking fat and driving such unnecessarily large vehicles then

>> No.2444378

>>2444364
/thread
well, at least in north america

>>2444222
You want to change this, OP? You're going to have to change the entire culture of how we build things. Provided you're American or Canadian, our entire culture around city infrastructure is "lowest bidder." In fact, it's difficult to find a municipality here that doesn't have a lowest bidder policy in place.

And no, I don't agree with it. The city I live in is made of cheap, crumbling concrete and rusting low grade metal structures. Most of those structures aren't even a decade old. But the city refuses even to repair them before an engineer deems them "unsafe" because they're too cheap. About 50% of my town's population are self-described "fiscal conservatives," but that really just means they'd rather save $250/year in taxes than live in a city free of potholes and broken watermains. So it's impossible to elect a city council that will, god for-fucking-bid, spend money on solving problems.

>> No.2444387

>>2444340
>>2444362
see>>2444332

>> No.2444389

>>2444222
I have no problem designing stuff from stainless but it's the client that rejects this shit because of $$$
Too many decisions are made by bean counters. I would consider it based on the cost difference for my own applications that is was paying for
t. Structural engineer

Industrial/mining/process clients are the biggest jews of them all.

>> No.2444392

>>2444304
What about that fiberglass rebar they have now?

>> No.2444398

>>2444222
those are some serious digits

>> No.2444399

>>2444304
>Roman chad
I'm seriously interested in their construction practices, but every book I've found focuses on art rather than engineering. Describing how pretty domes and arches are does absolutely fucking nothing to help me understand the composition and shape of the bricks or the way they handled large concrete pours in terms of stress gaps and whatnot.

>> No.2444400

>>2444304
>Roman architecture stood the test of time
Now drive cars over the roman architecture and make it bear loads, let's see how long it stands.

>> No.2444409

>>2444392
glass gets corroded by the concrete

>> No.2444413

>>2444362
>He said there's isn't significant added costs to handling stainless steels. He didn't say stainless costs the same. He's saying it costs the same to drill holes in it, or to bend it, or to weld it.

That's not "handling" it's fabrication, and there absoluty is a difference in costs to fabricate things in stainless steel alloys using those procedures over more typical steel.
Handling is the process of moving materials and products to where they need to be and in usable condition that isn't strictly shipping- filling the order, packaging, palletizing, wrapping, moving to and from a truck or plane or train or ship and offloading it at the end user's location.
In that sense there's virtually no difference between regular steel and stainless steel unless the stainless has a special finish that takes more care to protect during handling.
When a TV ad says some magic cooking tool or flashlight is "$19.99 plus shipping and handling" they aren't talking about drilling or bending or welding it.

>> No.2444415
File: 52 KB, 550x412, 8e89c288591cfff1d2ef7d6784043438.jpg [View same] [iqdb] [saucenao] [google]
2444415

>>2444400
Yeah

>> No.2444417

>>2444222
The advantage of having something affordable now far outweighs the reduced maintenance cost over the expected lifespan.

>> No.2444419

>>2444413
You do not drill holes in or weld bridge rebar. Ever.

>> No.2444423

>>2444367
LOL, bait.

>> No.2444426

>>2444304
Dude you just want us to sacrifice more bulls to make Roman ready mix.

>> No.2444431

>>2444419
I am pretty sure this is not true. I am in a growing area and we had multiple bridge fires due to welders not being on the buddy system. Concrete forms caught fire while the welders were doing their job solo. The local papers said rebar welding each time, but journalists hop back and forth between working fast food and writing news articles. So it is entirely possible the journalists were just filling the page. And the wielders weren't welding rebar but something else within the form?

>> No.2444432

>>2444419
Who said anything about rebar?
Steel reinforced concrete is concrete.
Metal bridges are metal bridges and almost always include drilled holes and welding at some point in their fabrication.

>> No.2444434

>>2444304
Can carbon fiber rope, stiffened with Portland cement, without epoxy resin, be employed as debar?

>> No.2444442

>>2444431
There are stay in place metal concrete forms that get welded to tabs cast along the beams, but no you don't ever weld the rebar, improper heat treatment creates a weak point in the bar

>> No.2444443

>>2444415
Roquefavour was made in the 19th century and doesn't carry traffic. You're full of shit.

>> No.2444447

>>2444434
Possible, would require a degree of tensioning in the forms before concrete is cast and afterwards as well for a span to be supported by a small arch under extreme tensile pressure. Again, you are relying on the field guys to not fuck this up and is best done in a controlled setting

>> No.2444701

>>2444400
Have you ever been to Spain, Italy or Greece?

>> No.2444706

>>2444378
Poor anon. You think $250/year would fix the problem? Remember how shittt gov’t is. If you need $250 in funding from the gov’t to complete a project, they’re going to need to collect like $1500 in taxes. Then $1250 of that $1500 is wasted on absolute bullshit before the necessary $250 gets to work. And the resulting project will be shitty anyway.

This is why people hate throwing their money away on taxes.

>> No.2444708

>>2444443
multilane traffic, a bit of water, really whats the difference?

>> No.2444709

>>2444378
its not the culture of how we build - it sall you bitches saying gov is trash i hate muh socialism dont tax the rich "le lowerst bidder"
you guys stop progress, and you elect people that stop progress

>> No.2444747

>>2444701
Yeah

>> No.2444830

Anyone ITT actually made anything out of stainless?
Compared to regular carbon steel it is a royal pain in the ass. Drills go blunt quicker, taps snap off randomly for no fucking reason, abraisive cut-off wheels heat up and glaze over quicker. Everyting about it is more difficult and annoying. That and whenever you try to bend it, it just springs back to it's original shape. You have to over-bend the shit out of it.

>> No.2444845

>>2444830
Eww, rusty shit. Get better tools and calculate your process. Order lasercuts where possible if you can't afford correct tooling.

>> No.2444859

>>2444222
It's brittle.

>> No.2445185

>>2444830
The Chad stainless vs the virgin carbon steel

>> No.2445202

>>2444222
Stainless steel is fucking weak, that's why.

>> No.2445212

>>2444222
The same reason idiots don't use a search engine and want spoonfeed.

>> No.2445242

>>2444378
Let’s be honest. If you’ve ever designed ANYTHING in construction, it is either:
A) under detailed
B) under specified
C) “value engineered” to oblivion

Problem starts at the top, and if architects and designers weren’t armchair experts, things might end up nicer.

>> No.2445268

>>2444222

There is literally not enough readily-available chromium to do this.

>> No.2445269

The engineer doesn't pay for it. You do.

>> No.2445283

>>2444708
>whats the difference?
Weight distribution, total weight, vibration, and more.

>> No.2445322

>>2445283
hey look how well engineers get sarcasm

>> No.2445382

>>2444222
All these replies and no mentions of sacrificial anodes

>> No.2445390

>>2444423
He's right though. Maybe the modern world should adapt to historical structures. Stop being so arrogant.

>> No.2445400

>>2444340
CONSOOOOMER appliances were status symbols before cell phones or personal computers existed. People used to just brag right to their neighbor's face instead of spewing their mental feces onto Twitter 24/7.

>> No.2445415

>>2445400
Remember when people still had the "good china"? You know, the plates that sat in a cabinet at the end of the dining room and were never used? That was a weird way for bitches to brag.

>> No.2445429

>>2444222
If engineers had their way the world would be built with titanium.
Ask why won't the Jews let us do it.

>> No.2445448

>>2445400
my grandpa was big into meme appliances

electric can opener
a little trash compactor in the kitchen
electric cheese grater
electric carving knife
I'm sure there was others

>> No.2445452

>>2444830

lrn2fab noob

To stop stainless killing your bits, lower speed, more feed, keep your bits properly sharp. Heat causes that initial hardening, coolant won't help that. For your taps, that's galling, use a high sulfur lube like chainsaw bar oil, keep your taps sharp. A light stone on the cutting edge with an abrasive sounding rod/dremel stone will fix it. Bending, that's as much bend radius as material, try actually measuring the spring back and accounting for it, that's how I bend. Plus welding stainless is better than blowing a load.

>> No.2445529

>>2444222
Probably because there are cheaper alternatives that work just as well.
https://en.wikipedia.org/wiki/Weathering_steel

>> No.2445913

>>2444442
Weldable rebar is real.

https://precast.org/2017/09/practice-preach-tips-welding-rebar/

https://www.totalmateria.com/page.aspx?ID=CheckArticle&site=kts&NM=189

>> No.2446045

>>2444709
100%. The fuckers on this board constantly lamenting the symptoms of capitalism, then sprinting in the other direction to blindly sing its praises never gets old.

>> No.2446075

>>2444222
and give all welders in the world cancer from hexavalent chromium

>> No.2446304

>>2444222
more like bite the BILLET, amirite?

>> No.2446475

>>2446304
I'd rather not get curb-stomped at the steel rack, thanks.

>> No.2446490

>>2444399

It's a couple things, but none of them revolutionary or unknown. The ash they used as fill instead of sand is a great choice because it's porous, lightening the concrete, and has sharp edges for good grip within the concrete to help strengthen the mix. The cement is 100% lime cement, which takes forever to cure, but cures softer and more flexible then modern cement. Finally, with no rebar or computer engineering, everything was massively overbuilt to compensate.

>> No.2446592

Because engineers don't write the contracts.

>t. engineer

>> No.2446594

>>2444222
your provincialism is inaccurate
maintainance is an always kind of thing, especially for say a bridge - something involving life and limb. so there isnt really any crying. keep it up and fix when fixes are needed. its really - just dont fuck up like that SF building tiliting.

>> No.2447253

>>2444706
What is your solution then
Live like a bunch of Hatians while everything crumbles around us?

Town forums are almost never useful because you go there to sperg out and not actually follow procedure.

Yes the procedure is there to be dickballs for the sake of it but read the theory on what rules are followed and when the cunt nugget at the top says no eiether grow a pair and run against him or egg on the #2 to fix take his place by getting enough local interests to properly feed to your point.

>> No.2447254

>>2445429
Titanium blows unless you want a metal that is better for thermal cycling with sapphire than aluminum or steel.

>> No.2447852

>>2446490
>more flexible then modern cement
So no expanstion joints?
That explains a lot.

>> No.2447911

>>2444222
Fuck stainless, just use Hastelloy for everything.

>> No.2447958

>>2444222
because part of engineering is understanding you cant just make everything out f diamonds and carbon fiber

>> No.2448176

>>2444265
>>2444362
>>2444413
kitchen appliance stainless is not even real stainless.

>> No.2449745

>>2444399
Try Vitruvius - its dry but covers architectural methods of the time.
Its the second time ive shilled it today, someone on /a/ was asking about learning architecture....

>> No.2449754

>>2448176
It might not be the highest grade but if it doesn't rust when I put water on it every day, then it's fucking stainless

>> No.2449896

>>2449745
Thank (you)

>> No.2450067

>>2444304
Roads are built by the contractor who isn’t going to say lol let’s spend 3x more and upgrade to stainless bar so the state gives us a pat on the back. Blame the government being cheap.

Also mfw hosing down a bridge deck with water when the inspector looks away

>> No.2450285

>>2444227
The golden gate bridge is perpetually being painted. The crew never stops they just move from place to place on it.

That sort of expense is expensive.

>> No.2450295

>>2444222
Reinforced concrete and its consequences have been a disaster for the human race

>> No.2450887

>>2450295
Only for autspergies. Otherwise utility is magnificent. All things are transient therefore disposable.

>> No.2451041

>>2444222
Because stainless steel is more like "stain-resistant" steel. It will still have spots of oxidization develop, especially when exposed to salt water. Try leaving your stainless cookware in saltwater overnight and see what happens.

>> No.2451069

>>2444265
Because you're willing to pay for it

>> No.2451080

>>2445452
Nobody asked bro

>> No.2451093 [DELETED] 
File: 57 KB, 984x315, top_match_prpl.png [View same] [iqdb] [saucenao] [google]
2451093

well at least memory foam mattress stock holders also know the struggle

>> No.2451102

>>2451041
There's different grades of stainless. Most 300 series won't oxidize at all except under high heat, some 400 series can develop rust spots but nothing beyond that.

Another topic I didn't see mentioned at all in this thread is that stainless tends to be heavier than regular mild steel and also can be considerably weaker in tensile and sheer strength depending on the chemistry.

>> No.2451156

>>2451102
316 steel is the highest rated against corrosion and even that will get messed up by salt water.
https://www.youtube.com/watch?v=NQk1LJYe3K4

>> No.2451177
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2451177

>>2446045
>government projects in the USA are shit because "capitalism"
Oh boy, you should see the infrastructure in communist countries.

>> No.2451281

>>2451156
>316 steel is the highest rated against corrosion

No, it is not. 1.4529 or 1.4539 are fit for permanent use in seawater, whatever name/number they may bear in the US. I´m a hundred percent sure you hve these too over there, because they are important for offshore oil stuff.

>> No.2451288

>>2444222
Boats or dump truck bodies should be stainless. The dump bodies should be lined with it at least.

>> No.2451311

>>2450285
Why build things to last when you can keep the money flowing endlessly?
That said, huge bridges like that will need constant maintenance anyway.

>> No.2451314
File: 2.37 MB, 2240x1260, untitled-design-24[1].png [View same] [iqdb] [saucenao] [google]
2451314

>>2444265
Because its purely cosmetic and wont affect its function in any way. The only time I would care would be a stainless kettle electric over something made from plastic.

>> No.2451546

>>2451102
Austenitic stainless steels work hardens to a much higher degree than mild steel. Stress can transform some of the austenite into martensite.

>> No.2451550

Seismic concerns (stainless is more brittle)

And we need to save the nickel for electric cars, if that makes you feel better

>> No.2453338

>>2451288
Someone doesn't understand dump truck economics and why beds are made as they are. Why do you permit yourself an opinion when you don't understand the subject?

Stainless in that thickness is a waste of money and effort because dump beds usually don't rust to destruction. They wear, crack and bend instead making the best material carbon steels for most use cases.

Easy field repair, not autism, is the goal when designing such high wear expendable items. They exist to make profit and by the time the truck is done the bed is often also ready for scrapping.

>> No.2453472

>>2450285
the same for the harbour Bridge in Sydney, Australia

>> No.2453584

>>2444442
>you don't ever weld the rebar
There are special grades that allow welding, but of course the welder must know what he's doing, and indeed there's rarely a good reason to weld rebar on site because the connection is not structural after concrete sets and is only needed to hold the rods in place until the pour is done, so wire or cable ties are perfectly adequate in most cases. I believe welding is most often used in making reinforcement rebar mesh, but those are factory made and welded by a machine.

>> No.2453657

>>2444222
>Why don't engineers bite the bullet and use stainless for things like bridges? Buy once, cry once

Engineers don't make design choices. They're given a set of requirements and they design within them. Why don't planners bite the bullet and require bridges be made from stainless, is a valid question. The answer is always cost. Aside from the materials cost difference, there's a design difference required. Stainless is stainless because it has chromium or sometimes nitrogen in solution in the steel. It has to be heat treated a very specific way to to leave the chromium in solution instead of creating chromium carbides that lead to embrittlement. This adds to materials cost and another thing that must be inspected. Either way no matter which flavor of stainless you use it has a different young's modulus and must be designed significantly different in order to apply forces in a way that doesn't exceed the yield points for it. The reason that bridges are built the way they are is because it's been a race to the bottom of the "good enough"/"cheap enough" ratio. Municipalities don't have to build or rebuild a bridge. They have to build or rebuild 10 or 50 bridges. They have shrinking budgets and are stretching maintenance intervals to the limits.

>> No.2454461

>>2450887
>Muh buddha
>Therefore fuck future generations

>> No.2454469
File: 598 KB, 1200x707, I-came-to-laff-at-you.jpg [View same] [iqdb] [saucenao] [google]
2454469

>>2454461
Sounds pretty based to me

>> No.2454485

>>2444444

>> No.2454518

>>2444304
What about fiber glass shavings to prevent cracking? What's your take on that?

>> No.2454535

>>2444222
In my case the issue is in the supply side.
If there was stainless steel in my local hardware store I'd buy it in a heartbeat, it would make it much easier to make mechanisms.

>> No.2455901

>>2454535
In that case consider buying your own bench stock like any shop does. I get all my metals from industrial suppliers and cut out the high markup retailer. Hardware store metal prices are high because they have a captive audience.

I buy all the hardware I can manage online too and treat it as I would commercial supply management. Stainless is often cheap via Ebay.

>> No.2456082

>>2444304
> Modern construction is shit, the workers in charge of mixing and curing concrete properly generally tend to be huge retards and don't understand the effects of excess water in the mix or how concrete develops its strength
What kind of shithole are you from? The municipal/city authorities in the towns in my area always, always, ALWAYS require a concrete PSI/pressure test when the concrete truck arrives before the pour.

>> No.2456413

>>2450285
>Paint in a marine environment, on metal, that moves.
>For some unnatural reason, doesn't last.
Clearly, the paint company is ripping them off.

>> No.2456465

>>2444265
I had to get a new fridge last month, and wanted it white to match the kitchen. Shit was more expensive than the stainless version, yet they had it available for delivery the next day and stainless would.have been 2 months out.

>> No.2456703

>>2455901
>Stainless is often cheap via Ebay.
Probably because it's shipped in from fuck-knows-where and it isn't actually stainless.

>> No.2456715

>>2456703
But people online are not allowed to lie abut things.

>>
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