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Well also, pre-Roman (or any, really) concrete has to be buried deep in the ground to survive the elements. Concrete is really good for stuff you need to be there for a couple centuries, but millenia will wear it down. In that case monoliths are better. Even if they're stacked on top of each other like a pyramid.
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# ? Mar 5, 2016 10:00 |
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# ? May 15, 2024 03:52 |
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A White Guy posted:Odd as it seems, a lot of other indigenous groups hate the Sami. Of course, this is just... so white of them.
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# ? Mar 5, 2016 13:17 |
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Concrete rules. There's dudes right now making self-healing concrete by infusing it with bacteria that awakens when it comes in contact with water, secreting limestone and patching the damage.
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# ? Mar 5, 2016 22:43 |
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Babe Magnet posted:Concrete rules. There's dudes right now making self-healing concrete by infusing it with bacteria that awakens when it comes in contact with water, secreting limestone and patching the damage. i think we need to expose these covert concrete dudes
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# ? Mar 5, 2016 22:48 |
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Didn't think there was a video but it turns out there is! https://www.youtube.com/watch?v=OXkW1q9HpFA
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# ? Mar 5, 2016 23:06 |
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Egh I tried a search for a fun concrete video in Danish words and it was literally half 911 conspiracies and half nazi hitler wasnt so bad kinda stuff. Concrete is probably alright, but I'm not gonna put that in my interests ever again.
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# ? Mar 5, 2016 23:11 |
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Isn't the original concrete recipe lost in time or some poo poo like that
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# ? Mar 5, 2016 23:46 |
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It isn't set in stone
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# ? Mar 5, 2016 23:52 |
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# ? Mar 6, 2016 00:12 |
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Hogge Wild posted:no Slime posted:You see this kind of thing a lot. There's people who get mad on some ethnic group's behalf, while the ethnic group itself either doesn't care or has the opposite opinion. I think the Sami reaction was that they were just happy to be represented, even if it's not entirely accurate. It's called "finding an excuse to look morally superior to others in front of peers." It's very popular.
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# ? Mar 7, 2016 04:49 |
Nostalgia4Dicks posted:Isn't the original concrete recipe lost in time or some poo poo like that Looking it up, it seems using coal ash is a reasonable substitute for the Roman recipe and would hopefully produce similar results, though of course we won't know for a while, will we?
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# ? Mar 7, 2016 04:54 |
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Concrete is super stable. The problem is reinforced concrete since steel changes size fairly dramatically with temperature which introduces cracks in the concrete. Water gets into those cracks and rusts the steel. That further expands the beams, causing more cracks, causing more water. Eventually the steel has rusted out and is worthless from a stability perspective and the concrete is cracked to poo poo. It gets worse if freezing water is involved.
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# ? Mar 7, 2016 05:44 |
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Shbobdb posted:Concrete is super stable. The problem is reinforced concrete since steel changes size fairly dramatically with temperature which introduces cracks in the concrete. Water gets into those cracks and rusts the steel. That further expands the beams, causing more cracks, causing more water. Eventually the steel has rusted out and is worthless from a stability perspective and the concrete is cracked to poo poo. I thought rebar expanded and contracted at the same rate as concrete.
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# ? Mar 7, 2016 05:48 |
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syscall girl posted:I thought rebar expanded and contracted at the same rate as concrete. If not there's a metallurgy PhD just sitting there for the taking.
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# ? Mar 7, 2016 05:56 |
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It does, the concrete is what cracks. The water getting in then rusts the rebar, destroying its strength. The rebar's job is to keep the slab strong under tension, which concrete by itself is pretty bad at.
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# ? Mar 7, 2016 05:58 |
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PittTheElder posted:It does, the concrete is what cracks. The water getting in then rusts the rebar, destroying its strength. The rebar's job is to keep the slab strong under tension, which concrete by itself is pretty bad at. Yeah, the tensile strength of concrete is ~1/10th it's strength under compression. Until it cracks, which it will. Then it has a tensile strength of zero, and that's bad.
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# ? Mar 7, 2016 06:42 |
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Sucrose posted:It's called "finding an excuse to look morally superior to others in front of peers." It's very popular. When I was a kid, we called it "being snotty." Not quite as exact, but much snappier.
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# ? Mar 7, 2016 07:28 |
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Nessus posted:I think the Romans had some kind of secret sauce that made their concrete real good. Not that ours is bad but you know, there's a lot of Roman concrete actually around still to study, so that's a sign of something. I thought it had to do with shattered pottery that had gotten fire glazed or something. Roman concrete was made with silica ash from all the volcanoes present in the empire. Silica ash, at a microscopic level, is all little flakes that are way harder to pull apart, so Roman concrete constructions have fared many many times better than our modern concrete.
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# ? Mar 8, 2016 08:45 |
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Prokhor Zakharov posted:Roman concrete was made with silica ash from all the volcanoes present in the empire. Silica ash, at a microscopic level, is all little flakes that are way harder to pull apart, so Roman concrete constructions have fared many many times better than our modern concrete. Are there not any modern varieties that use silica ash? I imagine in the age of international worldwide commerce it would be easy enough to get now, let alone artificial methods at making it if that's possible.
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# ? Mar 8, 2016 09:47 |
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RedneckwithGuns posted:Are there not any modern varieties that use silica ash? I imagine in the age of international worldwide commerce it would be easy enough to get now, let alone artificial methods at making it if that's possible. IIRC modern contractors don't use concrete with the intention that it would last 1000+ years.
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# ? Mar 8, 2016 10:00 |
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Tiggum posted:You mean these ones? Nope. Ubiquitous in the big companies' mainline products maybe, but a lot of cans these days don't even have a definite top and bottom so they'll stack nicely.
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# ? Mar 8, 2016 15:42 |
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Canemacar posted:IIRC modern contractors don't use concrete with the intention that it would last 1000+ years. Mainly because until very recently, we couldn't. We only really "Discovered" the secret of Roman cement in the mid 1980's by accident when building a dam that just happened to use a Fly ash filler and new placement techniques, and didn't really solidify what we'd done until 2013. it wasn't just the chemical formula that we were missing (the volcanic ash), but how it was placed (using less water than we would consider normal with portland cement, placed in layers, and packed/pounded into place), that had to be rediscovered. Also, when it comes to using concrete that will last a thousand years, a dam is a pretty good place to use it, IMHO. http://www.romanconcrete.com/docs/spillway/spillway.htm <-- Article I stumbled across years ago that seems to explain the rediscovery work by the BoR. I may be mistaken in a few of the particulars.
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# ? Mar 8, 2016 21:52 |
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Doccers posted:Mainly because until very recently, we couldn't. We only really "Discovered" the secret of Roman cement in the mid 1980's by accident when building a dam that just happened to use a Fly ash filler and new placement techniques, and didn't really solidify what we'd done until 2013. Let's face it: We're gonna find Roman ruins on Mars.
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# ? Mar 16, 2016 07:08 |
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Khazar-khum posted:Let's face it: We're gonna find Roman ruins on Mars. If we do we better find roman martian graffiti to go along with it
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# ? Mar 16, 2016 10:13 |
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Romanus Eunt Martius
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# ? Mar 16, 2016 10:42 |
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Marvin is bald
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# ? Mar 16, 2016 12:00 |
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Prokhor Zakharov posted:If we do we better find roman martian graffiti to go along with it Weep, you girls. My penis has given you up. Now it penetrates Martian behinds. Goodbye, wondrous femininity!
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# ? Mar 16, 2016 21:21 |
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Khazar-khum posted:Let's face it: We're gonna find Romans "There was other life, here. They were annoying."
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# ? Mar 16, 2016 21:59 |
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Gann Jerrod posted:Weep, you girls. My penis has given you up. Now it penetrates Martian behinds. Goodbye, wondrous femininity! Theophilus, don’t perform oral sex on girls against the Olympus Mons like a dog
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# ? Mar 17, 2016 00:44 |
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Whybird posted:Have we done the Reply of the Zaporozhian Cossacks to Sultan Mehmed IV? I'm only on page 8 of this thread, but I legit want a picture of this hanging on my wall. Any clue what it's called?
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# ? Mar 18, 2016 17:37 |
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https://en.wikipedia.org/wiki/Reply_of_the_Zaporozhian_Cossacks
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# ? Mar 18, 2016 17:42 |
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The wry little look of amusement on the scribes face is so loving perfect.
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# ? Mar 18, 2016 18:12 |
When emperor Hirohito released the speech where he said that Japan had surrendered it was the first time that the majority of the population had heard his voice.
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# ? Mar 20, 2016 23:41 |
Alhazred posted:When emperor Hirohito released the speech where he said that Japan had surrendered it was the first time that the majority of the population had heard his voice. Never put the pussy on a pedestal.
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# ? Mar 20, 2016 23:47 |
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Yeah but he was god and you're not really supposed to hear god's voice.
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# ? Mar 21, 2016 00:53 |
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FreudianSlippers posted:Yeah but he was god and you're not really supposed to hear god's voice. Where's Alan Rickman when you need him? Oh yeah
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# ? Mar 21, 2016 01:53 |
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Aphrodite posted:Wait is soup on mashed potatoes really a thing? Campbell's chunky soup has an even sadder suggestion
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# ? Mar 21, 2016 07:04 |
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Alhazred posted:When emperor Hirohito released the speech where he said that Japan had surrendered it was the first time that the majority of the population had heard his voice. Also many of the listeners had no idea what he was saying since his Court Japanese was so different from the modern everyday language
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# ? Mar 21, 2016 08:32 |
FreudianSlippers posted:Yeah but he was god and you're not really supposed to hear god's voice. Speaking of gods and rulers. The reason why the pharaohs had fake beard was that Horus had beard and since the pharaoh was the living embodiment of Horus beard was mandatory. Even Hatshepsut who was a woman had to follow this rule. This was also the reason why the royals was okay with incest, after all Horus married his sister and what's good enough for Horus is good enough for the pharaoh.
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# ? Mar 21, 2016 14:11 |
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# ? May 15, 2024 03:52 |
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Alhazred posted:Speaking of gods and rulers. The reason why the pharaohs had fake beard was that Horus had beard and since the pharaoh was the living embodiment of Horus beard was mandatory. Even Hatshepsut who was a woman had to follow this rule. This was also the reason why the royals was okay with incest, after all Horus married his sister and what's good enough for Horus is good enough for the pharaoh. I remember someone in the Ancient History thread said something like Pharaohs would marry their sister, yeah, but that doesn't mean they'd actually be banging. It was more of a ceremonial marriage than an actual one, with pharaohs knocking up a concubine to get a kid.
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# ? Mar 21, 2016 15:19 |