• TheGrandNagus@lemmy.world
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    9 months ago

    Every year we seem to get an article about how we’ve finally discovered how Romans had really good concrete, as if we’ve not already known for ages.

    The issue has always been about logistics, cost, time to produce, etc — not because we had no idea how the Romans did it.

    • player2@lemmy.dbzer0.com
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      9 months ago

      This plus extreme selection bias. There’s plenty of concrete that did not last for thousands of years.

      • TimeSquirrel@kbin.social
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        9 months ago

        “They don’t make things like they used to. See that tube radio over there? It’s 75 years old and still working! A rare find!”

        • jj4211@lemmy.world
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          9 months ago

          But in their defense, not a single thing on Earth made in the last decade has lasted 75 years. Check mate.

    • JayObey711@lemmy.world
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      9 months ago

      And also fucking 16 wheelers. Romans did not drive 80 ton (made up number. I don’t know how heavy big trucks are. But I’m Shure they are lighter than ancient wagons. To be honest I just hate cars and I want to use a scientific discussion to push my personal political view.) vehicles.

  • BlueÆther@no.lastname.nz
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    9 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?

    • NaibofTabr@infosec.pub
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      9 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
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        9 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.

    • Jakdracula@lemmy.world
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      9 months ago

      Yep, it’s the the lime. And: “ The team is now working on commercializing their concrete as a more environmentally friendly alternative to current concretes.”

      • BlueÆther@no.lastname.nz
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        9 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
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          9 months ago

          And, coincidentally, every time the story comes up there’s a company ready to sell you the magic roman concrete.

      • KptnAutismus@lemmy.world
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        9 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
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          9 months ago

          Meh. Lime mortar absorbs and releases moisture. IRC “Roman” lime 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. 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.

          Also: the Romans didn’t build their buildings that high. AFAIK Lime concrete has lower tensile and compressive strength, which is an issue with high rise buildings.

          • grue@lemmy.world
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            9 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.