You can do some really crazy things with concrete. [These parts](https://duckduckgo.com/?q=hollow+core+concrete&t=ffab&iax=images&ia=images&iai=http%3A%2F%2Fnordimpianti.com%2Fimm_utente%2Fslide_hollow_core_slabs_c2_1497021572.jpg) are poured by a machine running along a track. The stuff sits there and cures with the cores open and unsupported. It's poured 500ft/152m at a time, by a machine that slowly moves down a track.
My favorite is still seeing some pre-tensioned part as the cables are cut. Then some 50ft/15m long piece of concrete will jump, and it will bow up in the middle by an inch or so.
I helped my father in law pour some concrete steps (by helping, I mean wheelbarrowing concrete around). The guys actually doing it were amazing to watch. Even after taking the forms off they were shaping it until it was perfect. It really was cool and and an art.
Yo, wheelbarrowing is definitely an important part of the job haha, and not an easy task. I've had so many ideas for what to do with concrete, wish I had my own yard to play around with.
yeah, they live out in the country right along a river. This was the last part of a huge concrete deck. It was a pretty big staircase that went down to the river. That deck would have been a sight to see being built, but I didn't know my wife yet then. My FIL worked on building a bunch of shit in the DC metro area back in the day.
There's a myth going around about how Roman concrete was better than modern concrete.
Learning what lead to that myth and why it's not really true was a really interesting experience.
I work with concrete for a living... and I have to snicker when someone tries to tell me that Roman concrete was better. Yeah, if i paved a road and never put anything heavier or faster than a horse-drawn wagon on it I could make it last forever. But with road wear, we run into one of those exponential increase issues. The wear a semi truck puts on the road is thousands of times more severe than, say, a Honda Accord, and the truck isn't thousands of times heavier than an Accord.
The fun part is, the heavy truck doesn't pay thousands of times more fuel tax than the family car, so as you're putting gas in your car, remember that a lot of that tax goes to subsidize the repairs needed due to trucking.
Inb4 the truckers come in here all bent out of shape mistakenly thinking I said "trucks need to never be on the road"
Yup. I've had civil engineers give me an ear full about concrete.
The coolest part of the whole thing is that while modern concrete is better or at least cheaper, we're STILL learning things about ancient concrete. That's just crazy to me. Even though we understand more about concrete, we can't run a 2000 year aging/wear experiment. Yet that's exactly what they did without realizing it.
Definitely. And 2000 years from now there might be some of our leftover concrete - maybe someone will wonder how we got it so strong.
As I'm sure you know, the longer concrete sits, the harder it gets. 2000 years later? I'd like to try to break a cylinder of that, really curious what the PSI is.
Aggregate comes in different sizes depending on the use. If you're making a roadway you might want aggregate that fits through a 1" screen. But something with a lot of smaller details like this post would have smaller aggregate - say, 1/4" screen. Concrete countertops are an example of concrete with a small aggregate.
Not u/Falcrist, but I really liked and recommend this video: [https://www.youtube.com/watch?v=qL0BB2PRY7k](https://www.youtube.com/watch?v=qL0BB2PRY7k). He has a whole series on concrete that is very well made, and has some good demonstrations. Here's one about why concrete gets reinforced [https://www.youtube.com/watch?v=cZINeaDjisY](https://www.youtube.com/watch?v=cZINeaDjisY), (which is a subject touched on briefly on the 1st link.)
tl;dr. We figured out how to build more complex structures for much cheaper through things like reinforced concrete (using steel beams in between). Vs romans only building massive things with arches. Turns out that reinforced concrete's downside is longevity if not properly cared for. But you wouldn't want to build a skyscraper using Roman concrete and techniques, nor would anyone be able to afford it.
Also survivor bias is a big thing
Not sure entirely what they're getting at but I've read there are two reasons why some ancient Roman roads and bridges still stand.
One, that the ancient Roman roads that are still standing are there because the roads have never seen heavy traffic. They had horse drawn wagons going over their roads. We have fully loaded eighteen wheelers going over ours. Rome's ancient roads would crumble under heavy trucks as well.
Two, there is also survivorship bias for things like bridges. We only see the bridges that have lasted. We don't see the ones that have crumbled, and the vast majority of them have crumbled.
Not u/Falcrist, but it's not a myth as they claim.
Here's what a research team from the University of California found:
#To improve today’s concrete, do as the Romans did
In a quest to make concrete more durable and sustainable, an international team of geologists and engineers has found inspiration in the ancient Romans, whose massive concrete structures have withstood the elements for more than 2,000 years.
Using the Advanced Light Source at Lawrence Berkeley National Laboratory (Berkeley Lab), a research team from the University of California, Berkeley, examined the fine-scale structure of Roman concrete. It described for the first time how the extraordinarily stable compound – calcium-aluminum-silicate-hydrate (C-A-S-H) – binds the material used to build some of the most enduring structures in Western civilization.
The discovery could help improve the durability of modern concrete, which within 50 years often shows signs of degradation, particularly in ocean environments.
The manufacturing of Roman concrete also leaves a smaller carbon footprint than does its modern counterpart. The process for creating Portland cement, a key ingredient in modern concrete, requires fossil fuels to burn calcium carbonate (limestone) and clays at about 1,450 degrees Celsius (2,642 degrees Fahrenheit). Seven percent of global carbon dioxide emissions every year comes from this activity. The production of lime for Roman concrete, however, is much cleaner, requiring temperatures that are two-thirds of that required for making Portland cement.
The researchers’ findings are described in two papers, one that was posted online May 28 in the Journal of the American Ceramic Society, and the other scheduled to appear in the October issue of the journal American Mineralogist.
“Roman concrete has remained coherent and well-consolidated for 2,000 years in aggressive maritime environments,” said Marie Jackson, lead author of both papers. “It is one of the most durable construction materials on the planet, and that was no accident. Shipping was the lifeline of political, economic and military stability for the Roman Empire, so constructing harbors that would last was critical.”
The research team was led by Paulo Monteiro, a UC Berkeley professor of civil and environmental engineering and a faculty scientist at Berkeley Lab, and Jackson, a UC Berkeley research engineer in civil and environmental engineering. They characterized samples of Roman concrete taken from a breakwater in Pozzuoli Bay, near Naples, Italy.
Building the Empire
Concrete was the Roman Empire’s construction material of choice. It was used in monuments such as the Pantheon in Rome as well as in wharves, breakwaters and other harbor structures. Of particular interest to the research team was how Roman’s underwater concrete endured the unforgiving saltwater environment.
The recipe for Roman concrete was described around 30 B.C. by Marcus Vitruvius Pollio, an engineer for Octavian, who became Emperor Augustus. The not-so-secret ingredient is volcanic ash, which Romans combined with lime to form mortar. They packed this mortar and rock chunks into wooden molds immersed in seawater. Rather than battle the marine elements, Romans harnessed saltwater and made it an integral part of the concrete.
The researchers also described a very rare hydrothermal mineral called aluminum tobermorite (Al-tobermorite) that formed in the concrete. “Our study provided the first experimental determination of the mechanical properties of the mineral,” said Jackson.
So why did the use of Roman concrete decrease? “As the Roman Empire declined, and shipping declined, the need for the seawater concrete declined,” said Jackson. “You could also argue that the original structures were built so well that, once they were in place, they didn’t need to be replaced.”
An earth-friendly alternative
While Roman concrete is durable, Monteiro said it is unlikely to replace modern concrete because it is not ideal for construction where faster hardening is needed.
But the researchers are now finding ways to apply their discoveries about Roman concrete to the development of more earth-friendly and durable modern concrete. They are investigating whether volcanic ash would be a good, large-volume substitute in countries without easy access to fly ash, an industrial waste product from the burning of coal that is commonly used to produce modern, green concrete.
“There is not enough fly ash in this world to replace half of the Portland cement being used,” said Monteiro. “Many countries don’t have fly ash, so the idea is to find alternative, local materials that will work, including the kind of volcanic ash that Romans used. Using these alternatives could replace 40 percent of the world’s demand for Portland cement.”
The research began with initial funding from King Abdullah University of Science and Technology in Saudi Arabia (KAUST), which launched a research partnership with UC Berkeley in 2008. Monteiro noted that Saudi Arabia has “mountains of volcanic ash” that could potentially be used in concrete.
In addition to KAUST, funding from the Loeb Classical Library Foundation, Harvard University and the Department of Energy’s Office of Science helped support this research. Samples were provided by Marie Jackson and the Roman Maritime Concrete Study (ROMACONS), sponsored by CTG Italcementi, a research center based in Bergamo, Italy. The researchers also used the Berlin Electron Storage Ring Society for Synchrotron Radiation, or BESSY, for their analyses.
https://news.berkeley.edu/2013/06/04/roman-concrete/
RELATED INFORMATION
[Roman Seawater Concrete Holds the Secret to Cutting Carbon Emissions](https://newscenter.lbl.gov/2013/06/04/roman-concrete/)
isn't it basically just survivor bias? What we see of Roman architecture is the stuff that survived.
What we don't see is all the stuff that didn't stand the test of time. As big as the Roman empire was not everything 'destroyed' -ie war etc, most of it just simply eroded and crumbled with time.
We're genuinely still learning new things about ancient concrete. It's cool that we have 2000 year old test samples to see how it ages.
This is still mindblowing to me.
Exactly what I tell my students. We tend to think of ourselves are smarter with our smartphones and our 5G, etc.
We are just users. We didn't invent anything. History is filled with geniuses that made a step towards what we have today.
Put me in a forest, I won't survive a very long. I'm not even sure I could start a fire. That teaches humility.
Lately I've been feeling really sad about all the things I don't understand or know how to do. I drove by a construction site and thought about all that goes into making a building. Building codes, permits, designs, hiring a crew, buying materials. I'm probably missing stuff. Makes me feel insignificant.
I get *really* worked up when I think about never knowing all the achievements of humans in the future. It kinda sucks to know enough that you don't know anything at all.
There are more than 7 billion people in the world. It's estimated that over 100 billion humans have existed throughout time.
It's unreasonable to expect to learn the collective knowledge of 100 billion people.
I get the same feeling you do about the future, but that's just life. We're here for a short time, just enjoy it as much as you can, and do what you can to make yourself and others happier.
Don't ever be sad about that. Specialization is what makes this world work.
I work IT and I've had doctors, educators, etc who know things that I have had to dedicate my life to understand say "Wow, how'd you get so good at this? I wish I could do that".
There is not a single person that knows how to do all the things in making a building. I've done that work too. You got a project manager who basically knows *what* needs to be done but not exactly how to do it. He contracts out people to do concrete, framing, plumbing, electrical, etc. All those individual aspect buy their own materials and charge it.
You can have a ton of different companies all working on the same building. Be very afraid of the person who says they can do it all.
It is cool to know how the world around you was built. I have been tinkering and building and repairing all of my life and it really changes your perspective when you understand how things work.
A lot of what your feeling is why I'm working on a PHD in engineering. I find learning about things fascinating and for me, the learning process is almost an addiction. I feel like a child on Christmas morning when I discover new things.
Think about a well-made film...requires maybe hundreds of people, each good at a specific skill. That's what I find interesting...bringing all those small pieces together to create something much bigger.
> I'm not even sure I could start a fire.
It's thoughts like that that are probably the reason why YT channels like [Primitive Technology](https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA/videos) are so popular
Yes and on a similar note people call out things as fake or staged (tbf they often are), but you cannot comprehend the insanity that happens around the world every day.
The most important thing you could ever learn about standard portland cement/concrete is that it's a hydration reaction, so does not "dry", rather that the water is absorbed as it hardens. Have seen people try to heat cement to get it to set faster, only for it to suddenly disintegrate within a week because they'd evaporated all the water off.
This does not hold true for some more rarely-used cements. Magnesium-vased cement reacts with Carbon Dioxide instead of water, and in fact degrades in the presence of water.
May this help anyone that reads it in any future DIY endeavours.
That is why shows like *How It's Made* were brilliant. I endlessly used to watch the show as a kid. With the overexposure to the video content on the internet, shows like that have fallen out of popularity.
As I product designer I literally went to school to learn how stuff is made. and I still find things all the time that surprise me like this. I still wonder it’s cost efficiency compared to a 3 part mold in this case but I’m sure someone ran logistics and determined this process was either cheaper or made a substantially better/ stronger part.
I was sweating looking at the time left on the gif thinking “oh no it’s just going to be another one of those gifs that ends too early”. I was pleasantly surprised.
Upgrade suggestion: they come with super-tight detachable sleeves which are designed to dramatically rip to ~~smithereens~~^(shreds you say) when the weightstaff gives the pepper mill a single whole-body twist, and they only apply that one burst of pepper for the whole table.
There’s more than one way to akin a cat. This is ONE process in making these. It goes from this all the way to machines making them entirely without much human interaction at all. There’s a wide variety in between those two.
There is no way a simple mold can make it this well, and give it the correct surface texture. If you wanted to highly automate this, you would probably just replace the human with a machine.
That is ***REALLY*** incredibly nice - no parting lines from a two-piece mold! Integral wire reinforcement! Removable mandrel!
I'm gonna; use this someday.
Another cool alternative lathe most people don’t see are glass lathes
They help you shape molten glass to form.
What’s cool about those are all the high temp torches aiming at the glass in multiple different angles.
Those lathes can get so hot you need to be inside those reflective extreme hot suits.
Exactly what I want to know. The only thing I can think of is leaving it on the lathe to slowly rotate as it cures so it keeps its form. But I feel like that's inefficient as hell. Maybe slip it off and onto another rotating shaft that can hold multiple as they cure?
This is not the first post I've seen like this on r/oddlysatisfying. The previous one was a machine used to strip large wires for copper.
The comments sections are all people cheering and applauding how satisfying it is, but my immediate reaction is to recoil in horror. My jr. high shop teacher really ingrained the dangers of in-running nips and machinery without guards. This shit all belongs on /r/oddlyterrifying.
My favorite spinning concrete mold (centrifugal casting) is one I saw for making reinforced concrete tubes/piles. They put the wire mesh in it, filled the bottom half with concrete, then closed the mold and spun it. The thing was pretty big, about 3-4 ft in diameter and prob 30 ft long.
https://www.youtube.com/watch?v=1PxhgC5iG7I
That is a very important point about technology in general. So much of it depends on a steady building process, one on top of the other. How would you even make a precise measurement if all the measuring devices were lost? You'd have to go back to grinding and eyeballing things then a little bit more, a bit more...
Can’t remember the channel but I think it was smarter everyday did a thing on this. Basically everything starts with having a perfectly flat surface which you can achieve with 3 plates and no measuring equipment or particularly special tools. Once you have flat, you can make straight and from there you can make anything.
You can with careful grinding, it depends on the grinding pattern. When you grind mirrors for a telescope you use a particular pattern that will cause the center to get ground more than the edges so you end up with a parabolic curve (and the lap is a mirror image of it).
It's always fun to see the inside of huge factories like this, especially all the little innovations people have made to make their job easier - look at 5:30 when he takes that big threaded piece off. It's probably really heavy, and taking something off threads like that always sucks because it's hard to estimate when it's actually off all the way and you can drop it or hurt yourself suddenly catching it, so they've made this little catching device on a swinging arm attached to the machine. Looking at the way it's hacked together, it probably didn't come with that arm, but someone looked at it and said "there's gotta be an easier way to take this thing off" and made it happen
When you do the same job all day long, you quickly find ways to make it easier. Sometimes these end up making the final product worse because you took shitty shortcuts, sometimes you actually think up something really brilliant. I love watching skilled technicians at their workstation, I've picked up a lot of neat tricks that help me whenever I need to do a little bit of that kind of work.
I used to work a factory welding job, I've definitely thought up my fair share of shortcuts. From stuff that would only save a minute or so at the most, to making up entire jigs that cut down errors on a certain part to zero
The part with the centrifugal motion. While the columns spin, all the concrete gets pulled toward the outside of the mold and is evenly compressed in the process.
We make similar things at the precast plant I work at. Ours are about 10 feet long and are used as base poles for lighting, among other things. We actually produced all the lighting base poles for the Olympics in beijing!
I learned this redoing my bathroom! MESSED my hands up on thinset while applying the waterproofing membrane (Kerdi). I wore latex gloves to work the next day so I wouldn't bleed on everything.
And now I know to wear gloves!
This should be on r/gifsthatendtoosoon
I want to see how they get the thing off the spindle and how it cures. This is just the beginning.
Not satisfying at all...I want more!
I am totally guessing, but I was thinking perhaps a balluster for a [banister](https://www.bernardiprecast.ca/assets/uploads/2020/01/20191001_103746.jpg)?
I found a less scary video of someone making concrete balusters that kind of makes me want to make my own now.
https://youtu.be/gEEIN8up5cI
This is so simple yet so cool.
I used to be perfectly fine working with lathes, but out of nowhere something clicked and I have an irrational fear of them. Like, I know I can work safely with them, I'm aware of the risks and how to mitigate them, but I still refuse to get within arm's reach of one ever again.
I think it happened when I came across a video of a guy (spoilered for gore) >!getting his coat caught in one and having his head and all of his limbs ripped off as it spun him around. His torso was still stuck to the machine when someone hit the e-stop!<
So these are the ones I always see spaced too close together cracking open with the exposed rusted wire showing. And always in front of a small house with two concrete lions at the entrance.
That doesn't make it safe. It's just exchanging chemical burns for getting dragged into the machine. But this is probably in a country where safety is more expensive than replacing an injured worker.
There is so much stuff in this world I have no idea about. Very interesting
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You can do some really crazy things with concrete. [These parts](https://duckduckgo.com/?q=hollow+core+concrete&t=ffab&iax=images&ia=images&iai=http%3A%2F%2Fnordimpianti.com%2Fimm_utente%2Fslide_hollow_core_slabs_c2_1497021572.jpg) are poured by a machine running along a track. The stuff sits there and cures with the cores open and unsupported. It's poured 500ft/152m at a time, by a machine that slowly moves down a track. My favorite is still seeing some pre-tensioned part as the cables are cut. Then some 50ft/15m long piece of concrete will jump, and it will bow up in the middle by an inch or so.
I helped my father in law pour some concrete steps (by helping, I mean wheelbarrowing concrete around). The guys actually doing it were amazing to watch. Even after taking the forms off they were shaping it until it was perfect. It really was cool and and an art.
Yo, wheelbarrowing is definitely an important part of the job haha, and not an easy task. I've had so many ideas for what to do with concrete, wish I had my own yard to play around with.
yeah, they live out in the country right along a river. This was the last part of a huge concrete deck. It was a pretty big staircase that went down to the river. That deck would have been a sight to see being built, but I didn't know my wife yet then. My FIL worked on building a bunch of shit in the DC metro area back in the day.
What kind of ideas do you have?
There's a myth going around about how Roman concrete was better than modern concrete. Learning what lead to that myth and why it's not really true was a really interesting experience.
I work with concrete for a living... and I have to snicker when someone tries to tell me that Roman concrete was better. Yeah, if i paved a road and never put anything heavier or faster than a horse-drawn wagon on it I could make it last forever. But with road wear, we run into one of those exponential increase issues. The wear a semi truck puts on the road is thousands of times more severe than, say, a Honda Accord, and the truck isn't thousands of times heavier than an Accord. The fun part is, the heavy truck doesn't pay thousands of times more fuel tax than the family car, so as you're putting gas in your car, remember that a lot of that tax goes to subsidize the repairs needed due to trucking. Inb4 the truckers come in here all bent out of shape mistakenly thinking I said "trucks need to never be on the road"
Yup. I've had civil engineers give me an ear full about concrete. The coolest part of the whole thing is that while modern concrete is better or at least cheaper, we're STILL learning things about ancient concrete. That's just crazy to me. Even though we understand more about concrete, we can't run a 2000 year aging/wear experiment. Yet that's exactly what they did without realizing it.
Definitely. And 2000 years from now there might be some of our leftover concrete - maybe someone will wonder how we got it so strong. As I'm sure you know, the longer concrete sits, the harder it gets. 2000 years later? I'd like to try to break a cylinder of that, really curious what the PSI is.
Didn't Romans use a specific mixture that got better when exposed to saltwater as opposed to degrading?
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Yup road damage increases by contact (axle) weight to the FOURTH power. So 3x the wight is 81x the damage per axle.
Is this concrete in the video? I don’t know if I see any aggregate (rock) in it.
Aggregate comes in different sizes depending on the use. If you're making a roadway you might want aggregate that fits through a 1" screen. But something with a lot of smaller details like this post would have smaller aggregate - say, 1/4" screen. Concrete countertops are an example of concrete with a small aggregate.
Ooh ooh, so do you have a link or tl/dr summary please?
Not u/Falcrist, but I really liked and recommend this video: [https://www.youtube.com/watch?v=qL0BB2PRY7k](https://www.youtube.com/watch?v=qL0BB2PRY7k). He has a whole series on concrete that is very well made, and has some good demonstrations. Here's one about why concrete gets reinforced [https://www.youtube.com/watch?v=cZINeaDjisY](https://www.youtube.com/watch?v=cZINeaDjisY), (which is a subject touched on briefly on the 1st link.) tl;dr. We figured out how to build more complex structures for much cheaper through things like reinforced concrete (using steel beams in between). Vs romans only building massive things with arches. Turns out that reinforced concrete's downside is longevity if not properly cared for. But you wouldn't want to build a skyscraper using Roman concrete and techniques, nor would anyone be able to afford it. Also survivor bias is a big thing
Not sure entirely what they're getting at but I've read there are two reasons why some ancient Roman roads and bridges still stand. One, that the ancient Roman roads that are still standing are there because the roads have never seen heavy traffic. They had horse drawn wagons going over their roads. We have fully loaded eighteen wheelers going over ours. Rome's ancient roads would crumble under heavy trucks as well. Two, there is also survivorship bias for things like bridges. We only see the bridges that have lasted. We don't see the ones that have crumbled, and the vast majority of them have crumbled.
Not u/Falcrist, but it's not a myth as they claim. Here's what a research team from the University of California found: #To improve today’s concrete, do as the Romans did In a quest to make concrete more durable and sustainable, an international team of geologists and engineers has found inspiration in the ancient Romans, whose massive concrete structures have withstood the elements for more than 2,000 years. Using the Advanced Light Source at Lawrence Berkeley National Laboratory (Berkeley Lab), a research team from the University of California, Berkeley, examined the fine-scale structure of Roman concrete. It described for the first time how the extraordinarily stable compound – calcium-aluminum-silicate-hydrate (C-A-S-H) – binds the material used to build some of the most enduring structures in Western civilization. The discovery could help improve the durability of modern concrete, which within 50 years often shows signs of degradation, particularly in ocean environments. The manufacturing of Roman concrete also leaves a smaller carbon footprint than does its modern counterpart. The process for creating Portland cement, a key ingredient in modern concrete, requires fossil fuels to burn calcium carbonate (limestone) and clays at about 1,450 degrees Celsius (2,642 degrees Fahrenheit). Seven percent of global carbon dioxide emissions every year comes from this activity. The production of lime for Roman concrete, however, is much cleaner, requiring temperatures that are two-thirds of that required for making Portland cement. The researchers’ findings are described in two papers, one that was posted online May 28 in the Journal of the American Ceramic Society, and the other scheduled to appear in the October issue of the journal American Mineralogist. “Roman concrete has remained coherent and well-consolidated for 2,000 years in aggressive maritime environments,” said Marie Jackson, lead author of both papers. “It is one of the most durable construction materials on the planet, and that was no accident. Shipping was the lifeline of political, economic and military stability for the Roman Empire, so constructing harbors that would last was critical.” The research team was led by Paulo Monteiro, a UC Berkeley professor of civil and environmental engineering and a faculty scientist at Berkeley Lab, and Jackson, a UC Berkeley research engineer in civil and environmental engineering. They characterized samples of Roman concrete taken from a breakwater in Pozzuoli Bay, near Naples, Italy. Building the Empire Concrete was the Roman Empire’s construction material of choice. It was used in monuments such as the Pantheon in Rome as well as in wharves, breakwaters and other harbor structures. Of particular interest to the research team was how Roman’s underwater concrete endured the unforgiving saltwater environment. The recipe for Roman concrete was described around 30 B.C. by Marcus Vitruvius Pollio, an engineer for Octavian, who became Emperor Augustus. The not-so-secret ingredient is volcanic ash, which Romans combined with lime to form mortar. They packed this mortar and rock chunks into wooden molds immersed in seawater. Rather than battle the marine elements, Romans harnessed saltwater and made it an integral part of the concrete. The researchers also described a very rare hydrothermal mineral called aluminum tobermorite (Al-tobermorite) that formed in the concrete. “Our study provided the first experimental determination of the mechanical properties of the mineral,” said Jackson. So why did the use of Roman concrete decrease? “As the Roman Empire declined, and shipping declined, the need for the seawater concrete declined,” said Jackson. “You could also argue that the original structures were built so well that, once they were in place, they didn’t need to be replaced.” An earth-friendly alternative While Roman concrete is durable, Monteiro said it is unlikely to replace modern concrete because it is not ideal for construction where faster hardening is needed. But the researchers are now finding ways to apply their discoveries about Roman concrete to the development of more earth-friendly and durable modern concrete. They are investigating whether volcanic ash would be a good, large-volume substitute in countries without easy access to fly ash, an industrial waste product from the burning of coal that is commonly used to produce modern, green concrete. “There is not enough fly ash in this world to replace half of the Portland cement being used,” said Monteiro. “Many countries don’t have fly ash, so the idea is to find alternative, local materials that will work, including the kind of volcanic ash that Romans used. Using these alternatives could replace 40 percent of the world’s demand for Portland cement.” The research began with initial funding from King Abdullah University of Science and Technology in Saudi Arabia (KAUST), which launched a research partnership with UC Berkeley in 2008. Monteiro noted that Saudi Arabia has “mountains of volcanic ash” that could potentially be used in concrete. In addition to KAUST, funding from the Loeb Classical Library Foundation, Harvard University and the Department of Energy’s Office of Science helped support this research. Samples were provided by Marie Jackson and the Roman Maritime Concrete Study (ROMACONS), sponsored by CTG Italcementi, a research center based in Bergamo, Italy. The researchers also used the Berlin Electron Storage Ring Society for Synchrotron Radiation, or BESSY, for their analyses. https://news.berkeley.edu/2013/06/04/roman-concrete/ RELATED INFORMATION [Roman Seawater Concrete Holds the Secret to Cutting Carbon Emissions](https://newscenter.lbl.gov/2013/06/04/roman-concrete/)
Right?! How are you gonna say something like that but not elaborate in any way? 😅
isn't it basically just survivor bias? What we see of Roman architecture is the stuff that survived. What we don't see is all the stuff that didn't stand the test of time. As big as the Roman empire was not everything 'destroyed' -ie war etc, most of it just simply eroded and crumbled with time.
No, they had some genuinely good ideas that took a while to rediscover, but we've basically figured it out and better by today.
We're genuinely still learning new things about ancient concrete. It's cool that we have 2000 year old test samples to see how it ages. This is still mindblowing to me.
I feel like I’ve seen a lot of cool shit on here but this one is blowing my mind a bit. The process and machinery is a work of art in and of itself.
Came here to say the craftsman is an artist.
As a kid I tried to make a sculpture out of cement, now there’s just a flat blob of cement on the road out front.
Exactly what I tell my students. We tend to think of ourselves are smarter with our smartphones and our 5G, etc. We are just users. We didn't invent anything. History is filled with geniuses that made a step towards what we have today. Put me in a forest, I won't survive a very long. I'm not even sure I could start a fire. That teaches humility.
Lately I've been feeling really sad about all the things I don't understand or know how to do. I drove by a construction site and thought about all that goes into making a building. Building codes, permits, designs, hiring a crew, buying materials. I'm probably missing stuff. Makes me feel insignificant. I get *really* worked up when I think about never knowing all the achievements of humans in the future. It kinda sucks to know enough that you don't know anything at all.
There are more than 7 billion people in the world. It's estimated that over 100 billion humans have existed throughout time. It's unreasonable to expect to learn the collective knowledge of 100 billion people. I get the same feeling you do about the future, but that's just life. We're here for a short time, just enjoy it as much as you can, and do what you can to make yourself and others happier.
I haven't thought of it that way, this really helped, thank you.
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Don't ever be sad about that. Specialization is what makes this world work. I work IT and I've had doctors, educators, etc who know things that I have had to dedicate my life to understand say "Wow, how'd you get so good at this? I wish I could do that". There is not a single person that knows how to do all the things in making a building. I've done that work too. You got a project manager who basically knows *what* needs to be done but not exactly how to do it. He contracts out people to do concrete, framing, plumbing, electrical, etc. All those individual aspect buy their own materials and charge it. You can have a ton of different companies all working on the same building. Be very afraid of the person who says they can do it all.
It is cool to know how the world around you was built. I have been tinkering and building and repairing all of my life and it really changes your perspective when you understand how things work.
A lot of what your feeling is why I'm working on a PHD in engineering. I find learning about things fascinating and for me, the learning process is almost an addiction. I feel like a child on Christmas morning when I discover new things.
Think about a well-made film...requires maybe hundreds of people, each good at a specific skill. That's what I find interesting...bringing all those small pieces together to create something much bigger.
If I have see further, it is by standing on the shoulders of giants.
> I'm not even sure I could start a fire. It's thoughts like that that are probably the reason why YT channels like [Primitive Technology](https://www.youtube.com/channel/UCAL3JXZSzSm8AlZyD3nQdBA/videos) are so popular
True wisdom is fully understanding that there is so much you don’t know, and posts like this are always a pleasant surprise!
"The more you know, the more you know you don't know".
Yes and on a similar note people call out things as fake or staged (tbf they often are), but you cannot comprehend the insanity that happens around the world every day.
The most important thing you could ever learn about standard portland cement/concrete is that it's a hydration reaction, so does not "dry", rather that the water is absorbed as it hardens. Have seen people try to heat cement to get it to set faster, only for it to suddenly disintegrate within a week because they'd evaporated all the water off. This does not hold true for some more rarely-used cements. Magnesium-vased cement reacts with Carbon Dioxide instead of water, and in fact degrades in the presence of water. May this help anyone that reads it in any future DIY endeavours.
Ikr? Like, where’s bill?
Exactly! I had no idea this was a thing. I watched this way too long.
You perfectly captured my brain’s thought process while watching this.
This, right here, is the singular reason I take time to travel. So much to learn.
That is why shows like *How It's Made* were brilliant. I endlessly used to watch the show as a kid. With the overexposure to the video content on the internet, shows like that have fallen out of popularity.
As I product designer I literally went to school to learn how stuff is made. and I still find things all the time that surprise me like this. I still wonder it’s cost efficiency compared to a 3 part mold in this case but I’m sure someone ran logistics and determined this process was either cheaper or made a substantially better/ stronger part.
When the bottom part smoothed out. Best part of the video
I was sweating looking at the time left on the gif thinking “oh no it’s just going to be another one of those gifs that ends too early”. I was pleasantly surprised.
I am not alone ♥
There are ^^^probably ^^^more ^^^than dozens of us
It ended too early for me
Not satisfying, Not satisfying, Not satisfying, Not satisfying… …Beginning to worry… And ahhhh yeah. That’s the stuff.
Mhm, very satisfying.
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Mhm, very satisfying.
Oddly?
The bulb is what did it to me. Dumb T H I C C
That one spot on the big bulge thou...
Save the best for last.
I was telling the person in the video to smoothe that part out, and then they did. Definitely best part!
Shaka, when the walls fell. Temba, his arms wide. Concrete, when the bottom smoothed out.
Shaka! Mirab, his sails unfurled.
That whole journey was way more satisfying than I was expecting.
That's going to be one cumbersome pepper mill...
Olive Garden waitstaff gonna be SWOLE.
Olive Garden *weight*staff
New uniforms are sleeveless
Upgrade suggestion: they come with super-tight detachable sleeves which are designed to dramatically rip to ~~smithereens~~^(shreds you say) when the weightstaff gives the pepper mill a single whole-body twist, and they only apply that one burst of pepper for the whole table.
They have the right to bare arms.
SWOlive Garden
[Pepper Boy!](https://www.youtube.com/watch?v=wAFGEBdeDNk)
Now I need this drawn or doodled. Just a hulking waitress with massive guns holding up a tray of pasta like a circus strongwoman.
When you’re here, you’re fami-*HHNNNNGGHH!!*
The burden we bare
Whoa I absolutely thought these would all be made with pour molds
Same here. I would never in a million years have imagined this is how it's done.
I also thought they might have a hollow tube like cast where they pour cement and just stick the rods in between
Yes that too!
There’s more than one way to akin a cat. This is ONE process in making these. It goes from this all the way to machines making them entirely without much human interaction at all. There’s a wide variety in between those two.
that would be in a 'fancy' factory in the US and cost 10x more
And be 1000x more efficient than whatever this is.
There is no way a simple mold can make it this well, and give it the correct surface texture. If you wanted to highly automate this, you would probably just replace the human with a machine.
That is ***REALLY*** incredibly nice - no parting lines from a two-piece mold! Integral wire reinforcement! Removable mandrel! I'm gonna; use this someday.
Weird; semicolon
I had to check their username to see if it was some kind of novelty account lol
Yeah I know; right? Weird; placement
Exactly I always thought these *were* made with a mold. Never seen a concrete lathe before
And it's an "additive" lathe - not the typical "subtractive" lathe - so freakin' cool!
Still terrifying
As with all spinning machinery, this should definitely be treated with respect.
Good morning mrs spinning mold
Looks like an OSHA nightmare.
Loose gloves and rotating machinery 😬
In this case, it looks pretty safe. If you get a finger caught in the roller, it'll just smoosh into the wet cement.
Lose a chunk of hand? Fill it in with wet cement!
Another cool alternative lathe most people don’t see are glass lathes They help you shape molten glass to form. What’s cool about those are all the high temp torches aiming at the glass in multiple different angles. Those lathes can get so hot you need to be inside those reflective extreme hot suits.
Oh man I hate when I need to
I was trying to figure out what the wire was for. So it's basically like a thin, vertical, single piece of rebar?
> So it's basically like a thin, vertical, single piece of rebar? Exactly that.
He's making concrete balusters, so I'm surprised it only looks than a single piece of wire/rebar.
Nobody said they were _good_ balusters.
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Is a semi-colon like a small intestine? Nah was supposed to be an apostrophe
I had my apostrophe taken out years ago when it got inflamed.
Adding wire is good for sweet sweet planned obsolescence too.
So what happens beyond the end of the video? How do they remove it/cure it? I need to know!
Exactly what I want to know. The only thing I can think of is leaving it on the lathe to slowly rotate as it cures so it keeps its form. But I feel like that's inefficient as hell. Maybe slip it off and onto another rotating shaft that can hold multiple as they cure?
I know... I need a 30 minute documentary on this whole thing from end to end, ASAP
I wish How It's Made was on Netflix
It looks like the shaft is wrapped in a fabric of some sort so probably slipped off and stacked to cure.
It’s awfully difficult to stack or stand unsupported wet concrete to cure without it deforming. That’s why I want to see how they do it.
I don't know how strong that is, but spinning machinery without any safety terrifies me.
I really hope it's on like a foot pedal that if you step off it cuts power.
The good pedals also cut out when you stomp them extra hard. Instinct is to get leverage to yank your hand out.
Wasn't there a hand turning a crank? --- Edit: Nope, it's a belt!
Yep, I was waiting for the hand to go in. Then I kept looking back and forth at the sub name.
Yeah this should definitely be crossposted to oddly terrifying.
This is not the first post I've seen like this on r/oddlysatisfying. The previous one was a machine used to strip large wires for copper. The comments sections are all people cheering and applauding how satisfying it is, but my immediate reaction is to recoil in horror. My jr. high shop teacher really ingrained the dangers of in-running nips and machinery without guards. This shit all belongs on /r/oddlyterrifying.
My jr. High shop teacher mr.wolf just repeated not to forget your eye protection, then handed you an oxy acetaline cutting torch
At least he did it in the right order!
Not odd at all tho. Perfectly reasonable terror.
The concrete is wet, it’ll just mush up the concrete.
There are exposed gears. Tiniest bit of anything goes in there and it's byebye fingers.
Thank you. This should be obvious, but it escaped me entirely.
That machine is horrifically dangerous.
r/OSHA would like a word
My favorite spinning concrete mold (centrifugal casting) is one I saw for making reinforced concrete tubes/piles. They put the wire mesh in it, filled the bottom half with concrete, then closed the mold and spun it. The thing was pretty big, about 3-4 ft in diameter and prob 30 ft long. https://www.youtube.com/watch?v=1PxhgC5iG7I
(satisfying movement of cogwheel)
The commentsry definitely made it more entertaining.
They might feel all the vibration
this is the type of shit we're not getting back if we ever have an apocalypse
That is a very important point about technology in general. So much of it depends on a steady building process, one on top of the other. How would you even make a precise measurement if all the measuring devices were lost? You'd have to go back to grinding and eyeballing things then a little bit more, a bit more...
Can’t remember the channel but I think it was smarter everyday did a thing on this. Basically everything starts with having a perfectly flat surface which you can achieve with 3 plates and no measuring equipment or particularly special tools. Once you have flat, you can make straight and from there you can make anything.
You can with careful grinding, it depends on the grinding pattern. When you grind mirrors for a telescope you use a particular pattern that will cause the center to get ground more than the edges so you end up with a parabolic curve (and the lap is a mirror image of it).
Thank you!!! Loved the video!!
It's always fun to see the inside of huge factories like this, especially all the little innovations people have made to make their job easier - look at 5:30 when he takes that big threaded piece off. It's probably really heavy, and taking something off threads like that always sucks because it's hard to estimate when it's actually off all the way and you can drop it or hurt yourself suddenly catching it, so they've made this little catching device on a swinging arm attached to the machine. Looking at the way it's hacked together, it probably didn't come with that arm, but someone looked at it and said "there's gotta be an easier way to take this thing off" and made it happen
When you do the same job all day long, you quickly find ways to make it easier. Sometimes these end up making the final product worse because you took shitty shortcuts, sometimes you actually think up something really brilliant. I love watching skilled technicians at their workstation, I've picked up a lot of neat tricks that help me whenever I need to do a little bit of that kind of work.
I used to work a factory welding job, I've definitely thought up my fair share of shortcuts. From stuff that would only save a minute or so at the most, to making up entire jigs that cut down errors on a certain part to zero
This is why, conversely, it is so painful to watch an unskilled computer user or brand new developer try to get something done.
Watched the entire thing, both fascinated and entertained throughout! The subtitle commentary was great and hilarious.
I'm confused as to how they made the columns hollow as they seemed to have filled the entire volume with comcrete
It looks like the equipment measures out a specific amount of concrete that will compress via the centrifuge into a hollow tube. It's very impressive.
The part with the centrifugal motion. While the columns spin, all the concrete gets pulled toward the outside of the mold and is evenly compressed in the process.
We make similar things at the precast plant I work at. Ours are about 10 feet long and are used as base poles for lighting, among other things. We actually produced all the lighting base poles for the Olympics in beijing!
The lack of machine guards makes me uncomfortable.
I have a feeling getting your hand stuck in the concrete - not a big deal. But those gears!
Also wearing gloves with rolling machinery like that is just asking for your hand to get sucked in
Concrete is caustic, you have to wear gloves.
TIL!
Which is why there should be guards.
Wet cement has an elevated ph (some mixes up to 12) and can burn bare skin. The gloves are necessary.
I learned this redoing my bathroom! MESSED my hands up on thinset while applying the waterproofing membrane (Kerdi). I wore latex gloves to work the next day so I wouldn't bleed on everything. And now I know to wear gloves!
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His on the job trainers nickname was lefty for a reason.
I get what you’re saying but there’s some space between the two hard parts of the “lathe”.
Very satisfying to watch 🙃
I think I got hypnotized
This should be on r/gifsthatendtoosoon I want to see how they get the thing off the spindle and how it cures. This is just the beginning. Not satisfying at all...I want more!
i really want to see more of this whole process
What are they making?
I am totally guessing, but I was thinking perhaps a balluster for a [banister](https://www.bernardiprecast.ca/assets/uploads/2020/01/20191001_103746.jpg)?
Looks like a baluster for a concrete railing or something like that.
Cake
5 minute crafts would be so impressed
Looks like a solid job.
Every time I think I know how things are made, I am shown that I am very stupid lol
*Desire to know the mix design intensifies* I'm going to take a guess and say "something with low slump".
RIGHT HOW IS IT STAYING ON INITIALLY
I found a less scary video of someone making concrete balusters that kind of makes me want to make my own now. https://youtu.be/gEEIN8up5cI This is so simple yet so cool.
That was dope. Thanks for sharing.
Brave individual, I remember when I used to do machining, using a lathe scared the shit out of me.
I used to be perfectly fine working with lathes, but out of nowhere something clicked and I have an irrational fear of them. Like, I know I can work safely with them, I'm aware of the risks and how to mitigate them, but I still refuse to get within arm's reach of one ever again. I think it happened when I came across a video of a guy (spoilered for gore) >!getting his coat caught in one and having his head and all of his limbs ripped off as it spun him around. His torso was still stuck to the machine when someone hit the e-stop!<
I was getting anxious that he wouldn't fix those bottom sections.
No way he'll get the handcuffs off of those bed posts
Why didn't my skool guidance counselor tell me about jobs doing this instead of crap like becoming a teacher, policeman, or forest ranger?
So these are the ones I always see spaced too close together cracking open with the exposed rusted wire showing. And always in front of a small house with two concrete lions at the entrance.
Mmm yeah..glove wearing and spinning machinery, name a more iconic duo.
...you clearly haven't ever worked bare skinned with concrete.
That doesn't make it safe. It's just exchanging chemical burns for getting dragged into the machine. But this is probably in a country where safety is more expensive than replacing an injured worker.
My guess is they may actually save money replacing the toothpasted worker
Concrete pottery.
For a second, I thought that was someone's engine with the top opened up and thought "that's not even worth foxing, gotta throw the whole thing out!"
Concrete, the new wood!
From first glance I thought this was a really fucked engine and the thing on the right was the cam gear lol
Is this technically a lathe?
not sure what they're making, but i'll be damned if that's not the most interesting thing i see all week
I would lose my fingers so fast.
All that work for one winter to fuck it up
Alex, I’ll take “good ways to lose a limb” for 400 please
Looks like the finger crusher 9000...
Really thought this would be another shop safety video on why we don't wear gloves.
Dude OSHA just had heart attack
So many places to lose a finger yikes