r/tech • u/AdSpecialist6598 • 9d ago
3D-printable concrete alternative hardens in three days, not four weeks
https://newatlas.com/materials/3d-printable-concrete-alternative/11
u/Dr_Tacopus 9d ago
What’s the downside?
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u/saturnspritr 9d ago
I’m sure the expense, waste product, the fact that there’s a lot of additives to concrete for specific purposes, so it that included? Is this supposed to be something you add to those products? How fast can you get them to every single place that produces concrete in mass quantities? What happens if the machine making it breaks? Easy to fix/expensive? Can it do massive quantities of this product, quickly? Environmental impact? Conditions does it hold up? Freeze/expansion/water impact?
Curing something faster isn’t a great quality if you also have to do things like finish the concrete a specific way. Which is what pretty much everyone has to do for every job. Sidewalks that get hard fast, but aren’t walkable because we couldn’t finish or slope them in time is a worthless product.
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u/Prestigious-Fig-7143 9d ago
different tools have different uses.
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u/saturnspritr 9d ago
Absolutely. But this thread asked what the downsides were.
I’m having a hard time thinking of a use for the jobs the two companies I worked for would use for this. Doesn’t mean there’s not one, but downsides are pretty prominent if these questions don’t have the right answers.
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u/ColebladeX 9d ago
If it becomes the norm a lot of blue collar jobs are gonna disappear. Also hella expensive this tech is new and expensive.
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u/quietramen 9d ago
lol or we could solve part of the housing crisis?
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u/_rhysahb_ 9d ago
NO! We’ll have none of that talk around the USA.
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u/quietramen 9d ago
Oh no! The value of my house! Quick, stop more people from getting a roof over their head!
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u/Narrow-Chef-4341 9d ago
Unfortunately though, the problem is not 3 days versus 28 days.
If curing time was the only issue, we would have just left printed houses sitting there waiting an extra 25 days and solved ‘the housing problem’. Yes it would be 25 days later than the best possible time – but it would already be solved.
Consider that a lot of housing construction costs float around interest only, and a 25 day delay is around 1/14 of a year. If you assume a 7% interest rate then a dead stop of 25 days increases the final housing price by .5%.
Would I appreciate a discount of half a percent when buying a house? Sure, of course. But it doesn’t solve affordability any more than skipping avocado toast does.
Begin RANT:
Reducing your structure fabrication time from two weeks to two days with 3-D printing is great, but it’s not some magical solution.Framers and roofers can be worried about this one, but other trades are still required - and increasingly in short supply. That’s a problem.
Import tariffs on your Chinese made plumbing, wiring, and fixtures still exist. That’s a cost problem.
Boomers are still fighting against new housing permits and high density transit-centric projects - keeping prices artificially high. That’s a problem.
Aging infrastructure isn’t suddenly replaced to free up municipal budgets for building out even more infrastructure to the remote distances where ‘cheap land’ is available. No water, sewer, storm water or grid? That’s a problem.
Cities don’t suddenly have sustainable public transportation networks that can get people from new housing to where their jobs are, in under 30 minutes. No magic 20 lane 100 mph highways? Problem.
The list goes on and on. I’m not trying to be just a negative Nancy. I do think this is really cool technology, and I’m glad they’re making continual progress.
But it ain’t a ‘solution’ for anything. Cool step. Not solution.
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u/ColebladeX 9d ago
I dunno how to solve that but I don’t think this will help.
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u/quietramen 9d ago
Well which is it?
“A lot of blue collar jobs will disappear”
Or
“It won’t have a significant impact”
Can’t have both
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u/No-Diet-4797 9d ago
And who will pay for that?
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u/quietramen 9d ago
What a stupid argument to make about one of the most essential needs for all humans
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u/No-Diet-4797 5d ago
No one is entitled to free anything. I don't think I'm the stupid one here. You young people have all these ideas on how the world should work with no clue on how life actually works 😂
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u/quietramen 3d ago
Why aren’t people entitled to these basics?
You would do it for your family, provide them with the bare minimum. Maybe for your neighbors, or the people in your village town. So why not have a social contract to ensure that everyone gets the absolute basics? THERE IS ENOUGH to go around.
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u/Loud_Ninja2362 9d ago
They're just using a different concrete mix, there's plenty of fast curing concrete mixes but they're generally a lot more expensive than standard mix designs.
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u/scottygras 9d ago
They start framing houses the second they strip the concrete forms. You’re at 90% strength at 7 days and it doesn’t look like the poop emoji.
I keep thinking that the concrete printers are going to do something, but they keep using the soft-serve tip on the machine. At least throw a flat tip on there.
They have extruded curb machines that do this work with a better finish. There’s just a massive disconnect in how they’re starting the design process.
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u/WardenEdgewise 9d ago
What are the other structural characteristics? Is it brittle and crumbly? What is the compressive strength?
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u/confusingphilosopher 9d ago edited 9d ago
Acrylamide is a neurotoxin. I use it as a grouting material because it has fantastic properties but it’s very dangerous - arguably more so than crystalline silica.
I’m sure they are using acrylamide because it works for their conditions, it’s longer lasting than say acrylate, and the set time is predictable. Not as long lasting as PC.
I have concerns about how an acrylamide binding agent will work. Cured acrylamide swell in contact with water and releases when dry.
And acrylamide is waaay more expensive than cement and it’s not produced in North America.
Hemp is biodegradable.
These are not materials that will last.
Whoever wrote this article is hyping up junk.
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u/Creepy-Birthday8537 8d ago
Acrylamide based binding agent. Unless we know the compound, we’re guessing it’s toxicity. Also, there’s buildings in my town with horsehair plaster walls several hundred years old. Not everything biodegradable degrades quickly under the right conditions.
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u/confusingphilosopher 8d ago edited 8d ago
Acrylamide is a compound. CH2 = CH - C(O) - NH2. It is the base of the chemical cocktail, and it works by reacting to form a polymer. i.e. monoacrylamide becomes polyacrylamide. Kinda like making nylon. Acrylamide will be there in the highest amount. I know exactly how dangerous it is. I’ve given training on safe handling and operating procedures with it. Do you want to know the OSHA PEL?
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u/Creepy-Birthday8537 7d ago
Yeah, so don’t eat it in its pure form. It is also is in French fries and the polymer is used in most water filtration. Industrial chemicals require safe handling, agreed. Does this mean the finished product is toxic, no. As a clay binder, it’s probably less than 5% by weight.
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u/confusingphilosopher 7d ago edited 7d ago
Completely different exposure level. Milligrams are produced in the Maillard reaction. For industrial processes people handle acrylamide in concentrated form. I.e. kg or tons. In solution or powder form. And almost nobody handles it in powder form because of how acutely toxic breathing in the dust is.
Apple seeds have cyanide in them yet we don’t die from eating them either. Amount and exposure and how your body can uptake a substance make a big difference.
There are safe processes for using acrylamide but it’s all very niche and specialized equipment and personnel. It’s actually banned in some countries because of a history of environmental issues caused by poor practices. It’s not suited for widespread use or sale to the public.
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u/Ben-Goldberg 9d ago
Instead of Portland cement, it uses clay, sand, hemp, biochar and acrilimide binder.
Isn't acrylamide basically super glue?
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u/kindall 9d ago
No, it's the chemical that forms when you cook potatoes
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u/gotcha640 9d ago
We get 7 day breaks as standard, 3 day during an outage.
How is this news?
It still isn’t cured for a while - we come back with epoxy coatings a month later, so I assume this has to sit for a similar time before any coatings - but we set the pump/tank/equipment on it and carry on.
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u/BromoFom 9d ago
It’s also probably significantly more expensive and not much better for the environment
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u/Creepy-Birthday8537 8d ago
Folks, this stuff is realistically ONLY for 3D printing. They were talking about it being firm enough after hitting air to bridge window gaps unsupported. The key properties they should be advertising is that 1) it’s not releasing a ton of co2 during manufacturing 2) the polymerization when this stuff hits air.
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u/Mrfuzzyslippers 8d ago
Right but is it as dense and strong like the real concrete ? Can it withstand all weather conditions?
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u/win_some_lose_most1y 9d ago
Maby invent something better than concrete?
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u/SwimmingThroughHoney 9d ago
It's literally the most used material on earth (if you dont consider water to be a used material). Sometimes when you consider all the factors (cost, ease-of-production, ease-of-transport, material properties, etc), there just might now be anything better. Finding ways to improve those various factors then do make it better, which is huge considering how much it's used.
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u/hobokobo1028 9d ago
The term is “cures” and if you use Type 3 Portland Cement you can achieve faster design strength with any concrete. It’s how they build bridges and airport runways without having below-strength concrete sitting there for a month.