Yep, it’s the he lime. And: “ The team is now working on commercializing their concrete as a more environmentally friendly alternative to current concretes.”
Comment on We Finally Know How Ancient Roman Concrete Was Able to Last Thousands of Years
BlueEther@no.lastname.nz 8 months ago
let me guess, the didn’t fill it with iron that would corrode and expand and blow out the concrete? or the fact that it has an excess of fired lime that re-seals cracks?
Jakdracula@lemmy.world 8 months ago
BlueEther@no.lastname.nz 8 months ago
Quick lime as a ‘concrete’ is nothing new, or newly rediscovered though… The story seems to come up every few years, and anyone that has used a fluidised lime boiler knows how good quick lime is at forming concrete.
Brcht@lemmy.world 8 months ago
And, coincidentally, every time the story comes up there’s a company ready to sell you the magic roman concrete.
Deebster@programming.dev 8 months ago
Yeah, I was thinking it’s like the “Voyager Has Left the Solar System” story - we’ve heard that several times over the years, and probably will again.
GreatAlbatross@feddit.uk 8 months ago
To be fair, we keep expanding what we class as the solar system. Poor old voyager keeps getting the goalposts moved!
SoylentBlake@lemm.ee 8 months ago
What is that, like 12 people now?
KpntAutismus@lemmy.world 8 months ago
that’d be great, a lot of buildings are torn down just because the concrete cracks.
i’d be interested in seeing how using better concrete impacts overall costs and of course emissions. because the building ends up standing for a lot longer, the temperature isolation becomes very sub-par over time. that would increase total energy consumption compared to buildings that are frequently rebuilt.
but very promising.
Hyperreality@kbin.social 8 months ago
Meh. Lime mortar absorbs and releases moisture. I wouldn't be surprised that roman concrete is much the same.
Don't get me wrong, I'm a huge fan, but that kind of thing isn't compatible with modern insulation. You end up with damp and mould issues in the walls.
Sure it works great in uninsulated stuff though.
veroxii@aussie.zone 8 months ago
Also we only see the few structures which survived. 99%+ did not make it 2000 years.
grue@lemmy.world 8 months ago
Sure it works great in uninsulated stuff though. But people and governments want every room in a building to be insulated nowadays. The whole one warm room, the rest of the building is cold and you’d better wear a three piece suit or heavy wool jumper thing, is abhorrent to our spoiled western arses.
Spoken like somebody who doesn’t live where rooms would be intolerably hot without insulation most of the year.
KpntAutismus@lemmy.world 8 months ago
the iron is a great way to increase tensile strength, but decreases lifespan, rust free metals would also be much nore expensive.
Thorny_Insight@lemm.ee 8 months ago
Epoxy covered rebar exists as does one made from stainless steel. It’s just quite pricey so it’s rarely used unless absolutely necessary. Rust is generally not an issue as long as the rebar is deep inside the concrete. When it’s close to the surface and gets exposed to elements is when the problems start.
photonic_sorcerer@lemmy.dbzer0.com 8 months ago
Wdym? Just replace the iron rebar with gold
Steve@communick.news 8 months ago
Gold is no where near strong enough.
Titanium would work just as well, and last quite a bit longer.BearOfaTime@lemm.ee 8 months ago
Isn’t titanium too rigid for this application though? I’ve worked with both for a mechanical application, and titanium has no flex, so stresses get passed in to other components.
I don’t know, I’m no civil engineer. Any civvies wanna fill us in?
NaibofTabr@infosec.pub 8 months ago
You do know that rebar frames are completely essential for most concrete construction right? It’s not some conspiracy to induce failure. Concrete by itself can only handle compression forces - the rebar allows it to handle tension, torsion and sheering.
applebusch@lemmy.world 8 months ago
I’m guessing they do, but it does also reduce the life of the concrete. Modern concrete structures would be impossible without rebar, so that makes it a good trade, but it doesn’t change the fact that it’s a trade.
gaifux@lemmy.world 8 months ago
Rebar is a god damn conspiracy against the youth my dude
NaibofTabr@infosec.pub 8 months ago
the youths?