Also we should be moving away from concrete as a building material where possible because it’s terribly energy intensive to make. Of course we need it for some things but there are better materials for walls in normal residential buildings.
Comment on 3D printing a house
chris@l.roofo.cc@l.roofo.cc 1 week ago
As far as I have seen it’s very finicky. The concrete mixture is very special because normalnconcrete is not made for stacking layers and it’s also very sensitive to the weather. If it’s not exactly right it will start cracking.
I am not sure if anyone could yet demonstrate it at scale while being cheaper than traditional building.
philipp_@discuss.tchncs.de 1 week ago
Rooster326@programming.dev 1 week ago
I agree. We should work on 3d printing wood. Stick houses are superior
Pothetato@lemmy.world 1 week ago
Like chip wood into strands, mix with glue and print it out like one big shape of plywood?
Hueristic_Autistic@lemmy.world 1 week ago
where possible because it’s terribly energy intensive to make
Bruh it takes a mixer and water. The only thing that would get used more than not, is water.
Lumber is stupid expensive, brick homes are labor intensive, you can do mixed substrate horns but that’s expensive too. Glass paneling is usually only for stupid rich people or businesses and metal siding with metal interior and a metal roof, you may as well live in a shipping container.
Emma_Gold_Man@lemmy.dbzer0.com 1 week ago
The energy intensive part is in creating the dry mix. Mostly in creating the lime.
philipp_@discuss.tchncs.de 1 week ago
And electricity is carbon neutral because it comes out of the outlet.
Hueristic_Autistic@lemmy.world 1 week ago
Muh Cynicism: Well once the billionaires charge us a larger premium for nuclear energy maybe science will invent magic, har har har.
Nahhhh but to be honest no one can be happy with anything when it comes to energy: Hydroelectric, the fish. Solar, the agricultural and livestock. Nuclear, land and ocean contamination that can last as long as the US has been around.
3D printing houses that can solve a housing crisis, the process it takes to make the concrete.
Can’t we just shut up and and enjoy scientific advances.
kalpol@lemmy.ca 1 week ago
You are correct. I watched one being built. It is only the walls, for one thing, they still did foundation, roof, interior framing the old-fashioned way. The concrete was trucked in on pallets and mixed on site and it looked like a ton of work, and the machine was always breaking, it looked like.
Honestly don’t know why they don’t print the concrete forms in plastic and inject concrete, injectable cast concrete has been a thing for like a hundred years. You could do your raceways and plumbing runs and all then fill.
That would be a lot of waste plastic. Concrete is very heavy. That means the form hast to be extremely tough. For plastic that means a lot of plastic. At a certain point you won’t win anything there either.
isleepinahammock@lemmy.blahaj.zone 1 week ago
I wouldn’t think so. This may be one of the few cases where recycling plastic is actually practical. Recycling plastic is normally a big problem because it’s a very dirty supply stream. Plastic products often have multiple types of plastic laminated together, often include plastic labeling, etc. Even if you make a plastic consumer good out of a reusable thermoplastic, recycling is still impractical. Plus the main contaminants - food remains, react chemically at the temperatures necessary to remelt the plastic.
But this? You would be printing out huge slabs of solid plastic. Imagine big blocks and slabs of plastic 3"-12" thick. They could be made entirely of a single type of plastic. You use a thermoplastic, one that can be melted and reused repeatedly. Make them with no dyes and a chemistry optimized for maximum recyclability.
The printer prints out big plastic forms. Then the forms are injection-filled with concrete. Workers then pry or chip off the plastic forms and collect the debris for recycling. At the recycling plant, the pieces are given a basic cleaning, but the contaminants are almost entirely bits of concrete. Plastic melts at a temperature far far below the melting or decomposition point of any of concrete’s components. Concrete dust can simply be filtered out from the stream of molten plastic.
And that is a lot of plastic on one job. But because of that, builders would actually be incentivized to recycle it. You’re talking potentially thousands of dollars worth of plastic sitting there.
This wouldn’t be a practical replacement for regular rectangular concrete formwork. If you just want straight vertical walls and floors, since you have to tear-down the dorms afterwards, this isn’t going to be competitive with regular formwork. But what if you want to live in a curvy house? What if you want a more flowing space with continuously varying arches, curves, and vaults? This kind of almost organic home form is not within the budget of the average person. The forms required are just too complex. For this type of organic modern architecture, I could see 3D printing plastic forms being a practical option.
You’re right, it would require a lot of plastic. But existing concrete forms also require a lot of material. We’re just able to reuse the forms many times.
Problem is that plastics do not recycle too well. Every time you melt plastic it degrades. That means you always need new plastic and some gets lost. If you want to use recycled plastic you have to add virgin plastic every time. Also printing such thick plastic will take a long time. I don’t think it scales. If you want concrete forms, then generic preforms made from wood are way more practical.
xav@programming.dev 1 week ago
You think about it the wrong way. Do it progressively : 3d print the thin plastic form 10cm high, then pour the concrete, let it dry, print 10 more cm, pour again … That way you need very few plastic.
walden@wetshav.ing 1 week ago
That would take a very long time.
kalpol@lemmy.ca 1 week ago
That’s kinda my point. It’s really a materials and structure engineering problem. How do you automate house-building? Maybe you don’t need concrete at all, or only in strategic places.
isleepinahammock@lemmy.blahaj.zone 1 week ago
Exactly. Automated house building could take many forms. It could be a big 3D concrete printer on a gantry crane. It could be a crew of humanoid robots using ordinary human power tools. It could be a robot arm on a powered dolly that lifts and nails, glues, or welds panels and beams into place.