Is there a need for an MPCP (a mostly printed concrete printer)

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Because the subject on the “Neat” thread was just getting interesting and threatening to hijack the thread entirely - I thought I’d start another.

Basically I contend that the concrete printer is a solution looking for a problem. There are plenty of these in the world, but this one keeps getting legs because it’s an emotional hook.

Warning - I am almost completely one-eyed on this, so see it as your opportunity to change my mind- full on argument is completely fine and I promise I won’t get hurt so go hard! :wink:

My initial points are:
Pros - it’s cool (I have built two CNC machines and a laser engraver because of that)

Cons:

  1. the material is anachronistic and something the industry should be moving away from - it’s a bit akin to developing a new kind of engine that runs on more fossil fuel and has no advantage but is really novel.

  2. Logistically it makes no sense to transport large temporary items that need to be carefully erected and removed as well as all raw material.

  3. The most economical and efficient form of building is by building indoors - it can be fully mechanised and work 24/7 delivering only prefabricated “kit” parts to a site.

  4. had the process been derived from the need to find a way of using material that has a benefit to mankind (recycled plastic bubbles) perhaps I’d listen harder!

I have much more to say, but this is a starter - hit me! (I havent’ even mentioned bed levelling!!) :rofl: :rofl:

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Maybe in the context of an extremely poor and/or disaster stricken area it makes more sense? I could see an aid agency coming in to build housing with one of these. Replaces an entire crew of masons and shipping in dry mix rather than block would be more efficient possibly. Set up a track and have the carpenters follow it down the line.

For a developed nation, kind of a novelty. Still cool though. Sign me up for a MPCP-CP-DOG-HOUSE!

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Yeah the XYZ aspect is easy, at any size. The material pump is a new one to me, and will a slicer scale this easily?

I would love to print a BBQ Island or a shed out of mud, or anything else we could knock down reuse and try again.

3D print a fire pit and chairs. Lots of fun outdoor stuff we could make while testing!

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A smoking pit for the father’s day BBQ

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Personally, I don’t see a problem with the material. Even if it’s “anachronistic” any material that can be made to flow through a tube and harden into a usable structure could easily be substituted. Out of curiosity, what would you consider to be a more modern building material?

Also, presently, concrete is still one of the most useful and versatile building materials out there. Humans use a lot of concrete still, it’s the primary resource for multi-family residences and commercial buildings. We dont have much in the way of economical replacements. It’s environmentally sound and doesn’t have terrible waste products or generate problematic detritus. (You don’t hear about people talking about micro-concrete pollution, for example.)

Maybe some day humanity will learn to produce some miracle material that is stronger, lighter and cheaper than concrete. I would wager that concrete will still be around in common use until at least 2 of those can be achieved, and that “cheaper” must be one of them.

For the wisdom/utility of print in place versus pre-fab, it will depend on the application.

I would see something like building a condo tower. Say 20-30 floors. Start with a steel superstructure and a poured floor. The “printer” could climb the superstructure and lay out identical (or not, as desired) floor plans time and time again. The floors themselves may not be printable, but the walls would be, and could include curves and specialized shapes. Some spots could have “infill” type features currently not possible.

The present concrete printers are at the level of the old impractical toy 3D printers from 10-15 years ago. Functional but not very practical. I can see this going places…

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Disclaimer here - I am not an expert by any means, and have been retired from the industry for more than fifteen years so am well behind the bleeding edge as well, while I don’t wish to broadcast my personal CV here - oddly enough a lot of my life has been involved with innovative methods of concrete construction. From 40 story buildings to 35square metre houses in developing countries. It’s a vexed question and one that gets no coverage in the popular press - if you search you’ll find articles like this one - some not so well balanced.

The old hippie in me says, we can recycle pretty much anything into fibreboard which can be made relatively fireproof, is great at insulating and needs covering to maintain waterproofing. I think the same can be done with many plastics if we had the will.

Check out hempcrete as an alternative.

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I don’t want to be Mr Grump on this and I think at that scale it could work - but apart from the “cool” factor, why?

You can easily do that without the complexity.

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It really could be a solution looking for a problem. The other admittance is that I am not familiar with all of the steps to make a house from the minimum amount of wood. It seems like there are a lot of difficult steps, like building to code, or doing stress calculations on a design, getting the right material, or getting the builders to actually follow the instructions. Because of that blind spot. i may be biased toward replacing that part of the process with software and a robot.

The thing that gets missed is that you’re not thinking outside the box.

You don’t have to make condos where each floor has a similar floorplan. You don’t have to make rectangles. Curves or stars or a natural looking cave are all the same cost as straight lines.

Additionally, anything you can solve in software becomes essentially free at scale. It is very hard to solve some problems. But once you have the solution in software it can be copied and pasted for free. That is also true for traditional bespoke buildings. But they still have to communicate the design to builders. In this system, the software controls the builder so it should be even more effective.

Plastic molding has been around for 150 years. But we still enjoy 3D printing. Why? Because it is completely custom and scaled through software. You can spend some brain power and come up with something that is only interesting to you. You could have made it in wood or in a metal shop. But the price means you can now adapt anything to anything else.

How can you use that kind of flexability in building? I don’t know. But I am optimistic that this kind of power and flexability will get people away from building boxes and filling them with paint and caulk.

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Dont know how sustainable it is but they ground up a shopping mall here abd used it as agitate for the new walls very noisy and dusty and left over mesh rebar

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Nice try, but no - in those situations you need shelter quickly - a factory built prefab that can be assembled in hours will win that race any day. In poor areas, labour is never a problem (in my limited experience) but highly skilled engineers required to operate machinery like this have all buggered off to well paying jobs in the nearest capital. :face_with_hand_over_mouth:

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Yeah. Cement is very heavy on energy usage to create. I am also not an expert but it only makes sense if the building lasts a lot longer than a more sustainable method.

I mentioned it in the other thread because I can imagine having a permanent steel/concrete substructure, and a more temporary above ground structure (I am imagining the mud and straw construction). If you understood that the house would get completely demolished and rebuilt every 25 years, you could maybe make an ecosystem where you would buy a pad in an area you wanted a building and then compost the whole thing and print a new restaurant/bar/gym/makerspace/house. That kind of lifespan seems wrong for concrete. But fine for sustainable materials.

Of course. The devil is in the details and stuff like drywall, plumbing and paint are not compostable.

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Nice try! (and I assume “you’re” is a generic term) but having spent a lifetime thinking outside lots of boxes I can say that that is exactly what the proponents of 3d printed concrete are not doing! I will bore you now point by point - hopefully not in an argumentative way, but just to fill in some of the gaps.

Many techniques come and go because they seemed like a good idea at the time - concrete igloos were a fad (very futuristic) in the sixties the future was curves, Bucky Fuller led the geodesic revolution, currently container homes are a thing, (just add insulation, weathering, windows, services and then it’s not a container any more).

To an extent this is true, and there are “many example of this in the wild”. For instance (forgive me it was almost 50 years ago!) I designed a pair of 38 story buildings in 1976 with five different floor layouts and 182 apartments in each. This is an enormously complex undertaking when you start to understand that services, like plumbing and ventilation do have to be in identical locations in order for the err…waste to flow

No indeed you don’t have to make rectangles, but remember, fridges and drawers and sheets of glass and bookshelves and beds generally don’t come in curves. Neither do simple things like flashings to stop window leaks (ask any Frank Gehry customer about that). These were all things that prevented the geodesic dome movement from flourishing - and of course the lack of curved motor cars to go in the curved garages!

I’ve said it above I think - no, the software only controls the layout of the walls, it doesn’t place services. These days good building CAD systems can control every aspect of the job including material handling.

I agree, but concrete “printing” is not doing that - it is merely laying walls on a foundation that must be manually created (no bed levelling here!) It’s actually not doing anything that could not be done more efficiently using traditional methods IMHO, and It requires a huge amount of overhead and no flexibility during construction.

Sorry if this appears too much of a rant!! I think the tech is great, I just wish someone could find a more positive way of applying it.

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Oh and this is weird - since my time zone has shifted by ten hours, I’m way out of sync with who is answering and when! I’m on Fabien and Phillipe time now, but it’s quite disconcerting not knowing who’s awake and who’s not!! :rofl:

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Physics does, in fact, enforce the idiom that :poop: flows downhill, and no amount of creative architecture can get around that. Multi-level buildings for any use will always be beholden to working around “stacks” of utilities moving vertically. Maybe not always for things like data and electricity, but for plumbing and HVAC (and people, of course). PEX and its ilk make it easier for smaller buildings to de-centralize their plumbing, but that’s just the input, the output still needs big, relatively straight pipes.

This is what I meant by the infrastructure also needs to cross a design horizon. Until we can seamlessly integrate everything else into the construction, it’s a novelty at best, and a nuisance or even a hazard at worst. And no, we don’t need to have bizarro-world appliances or flexy cars, but the design (and more importantly, manufacturing) language needs to evolve to the point where we aren’t forcing square pegs into round holes at every turn, and we can break free of standardized shapes and sizes.

I agree with Peter here. I don’t think there is any compelling reason for large-scale 3D printing. I will concede that it may be possible to concoct a niche scenario where it would be the appropriate solution, but I don’t see it as more than a novelty for a long time to come.

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This is a case where I was truly hoping that there was a flaw in my arguments - I would love for this to be made to work and some of the completed projects look very very nice for what they are.

Some will weather well enough, some will look very ratty in a short time, will leak and cost a lot to maintain. This is why I have been an advocate for prohibiting entries into architecture awards until they have been standing for a minimum of ten years and why I don’t have many architect friends. :rofl: :rofl: :rofl:

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idk environmentally because there’s way too many factors. Shipping, machining, life expectancy, etc.

But the 3d printed homes brings a few things to the table that I think, maybe why it’s here to stay.

The biggest thing it brings is a strong home. Now most places do not need stucco/concrete/masonry homes. But extremely humid, and areas that are prone to severe weather need stronger homes that can take the beating and resist the rot and decay that wood poses.

Now would a metal manufactured home work in this environment? It could but they quickly lose their economic feature as not only does the metal cost more but making metallic “LEGO” pieces per say also cost more, and again it needs to be strong connections for this to work.

But again this can be kind of a minuet problem as this is probably ~10% of homes that need to be constructed this way and of that how many would be concrete printed homes :person_shrugging:

One of the other things this brings to the market, and again this is niche too, bunkers. Now that again brings all kinds of issues to the table, but I could definitely see a use to create what I call “excavated” bunkers (bunkers that are dug, poured/built, then buried).

Now there’s another reason I’m going to say these will stay around. And it’s one of those possibility reasons. They will easily be able to adapt this into an environmentally stable material. Concretes biggest issues are the process of grinding, transporting, and the fact that most is simply tossed vs sent to recycling plants. There are ways to make concrete more eco friendly. One of those ways is already being solved which is the drive away from fossil fuels. The other way is the introduction to the rediscovered Roman concrete which can self heal making it live longer and weight more on the outlasts it carbon footprint. The other thing that could be introduced is recycled waste added to the concrete base (look for MIT plastic reinforced concrete)

I do think the MPCP have a place and/or places they can be utilized in outside of the cool factor. But will they? :person_shrugging: I think they will but only time will tell us

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Having watched a block house go up down the street from us in florida. Concrete block houses are still faster to build than a 3d printed concrete house.

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Thay is absolutely epic. Your points are well stated. The infrastructure stacks do need to line up and I’m sure there was a lot of clever design that went into a project like that.

Absolutely. We need yo fix this too. :slight_smile:

Those are still pretty much one shape. Same with the container houses. They are too inflexible, not incredibly more flexible.

I look in my neighborhood and I see about 6 floorplans. Small, medium, large and their mirror.

What if you wanted to live in a suburb, but wanted a house like this?

1080×1080 166 KB

Or this?

1440×810 136 KB

Or this?

1500×1000 138 KB

Why couldn’t a 3D printed structure make this kind of flexibility more accessible?

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That is the crux of the issue right there I think. I presume that by “more accessible” you mean “less costly” and the short answer is that you are creating walls which by the nature of the process and the material used requires a good deal of fitting and fiddling (or plastering) adding to the total labour cost rather than subtracting from it - even if the wall system could compete with a traditional unfinished wall, which it can’t, the need to fair and make good before fitting things will remain. This is not a software issue, think of it like cleaning up a place print after after breaking away supports that got a bit messy.

You choice of photos is interesting, but since you’ve asked - my view is as follows- Note again I am not trying to shoot you down, simply point out why I don’t think printing is the solution.

House 1 - think about how this could be constructed of concrete and how little of its character relates to the external walls and how much relies on fenestration and detailing. Ironically perhaps, of the three it is perhaps the easiest to adapt but you would need to print the basement, dismantle everything and pour a floor, print the ground floor walls, dismantle everything and pour the next floor, then print the top floor.

Only the walls which are currently siding could be printed, and then you would enter a world of hurt trying to attach all the windows, balconies and fenestration, because there is no simple way of creating a flashing or waterproof junction between the two materials.

Option 2 Eat first glance this looks like an obvious candidate, but based on this one photo only - is it possible to print holes (under extrusion effect)? I think not because the material is fluid so it can’t bridge. So the curved screen wall would not look like that.

Once again you would have to print up to the slab level, pour a floor, reassemble all the gear and print the top level, except that presumably you’d have to leave block-outs to pour the spiral ramp later.

Look carefully at the roof on the left hand side and note that all of the external walls are glass so there’s nothing to be gained or lost there.

Option 3 - To me this one makes no sense at all - to create all those arched heads you would need formwork - it’s the classic form follows function conundrum - built in masonry, minimal formwork is required for a short period while the arch is constructed, then moved on to the next arch as the masonry is self supporting. A concrete solution would require all of the arches to be formed and supported for perhaps weeks while the concrete reached a working strength.

I haven’t really mentioned logistics - concrete is heavy stuff, the further away from the source it is pumped the greater the total mass of the line. The real economy in building comes from using less material and doing so in fewer man-hours. The larger the sheet/block/tile, the fewer man-hours will be needed (with in reason) to build the end product. I can only imagine the complexity of dismantling and reassembling a printer rig heavy enough to carry concrete, but I’ll bet it’s more than borrowing a few bricks to a building perimeter.

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An idea I have thought about for a while is customized “cinder blocks” where each block can be different. They might not end up looking much like cinder blocks but that’s the nearest thing. Since they are hollow, they can be more material-efficient for a given structural strength. You might make the ones near the ground with thicker, walls more similar to existing cinder blocks, while the ones near the top have thinner walls. If each block can be unique, they can have features built in like holes for electrical work or whatever. And of course they can be trapezoids or curves or other shapes.

Even so, I think it is a solution in search of a problem, and that will at least find niche applications, like that CNC stone a little while ago. But for widespread adoption, it’s a much taller order.

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