University of Michigan researchers make advances in 3D concrete printing
Cathy Shafran: This is 89.1 WEMU. I'm Cathy Shafran. Consider a home built by a 3D printer. It's actually a concept that's been around for a while now. The concept is building a cheaper home and faster with a computer, designing how a machine will lay down layer upon layer of concrete until you A-frame pretty much a nine-foot tall building in some cases. So, as I mentioned, many companies have been doing this for many years. But University of Michigan researchers believe they may have a better method that can make the concrete structure stronger and allow for more creative designing. And one of those U-M researchers is joining us now. Mania Meibodi, thank you so much for being with us.
Mania Meibodi: Thank you, Cathy.
Cathy Shafran: So first, for our listeners, could you paint a word picture of what this 3D concrete printing process actually looks like?
Mania Meibodi: Yeah. Typical 3D concrete printing is a very simple process. You could imagine your toothpaste, hold it in your hand, and then lay the paste. And then, once that first layer is finished, keep going up another layer on top of it, keep going another layer on top of it, and, eventually, you have a wall if your pace cure or set fast. So, that's exactly how a concrete printing works, except the fact that you have a machine that controls the movement of this paste. So, you basically lay material--concrete--layer by layer, and then you vertically go up. But the challenge comes in the fact that, just like in a paste, the toothpaste, that might collapse because the material doesn't set very quickly means they don't dry, for example, very fast. The concrete printing would face the similar problem, the material challenge. You need to make sure your material is designed or your fabrication process is designed in a way that allow your material to set in an appropriate timing, so that you can lay the next layer.
Cathy Shafran: Yeah, I'm just curious. I don't think I've seen or heard of any 3D concrete buildings being built in Michigan. Do you know of any?
Mania Meibodi: Not in Michigan that I know.
Cathy Shafran: There aren't that many in the U.S. Is this more of an international concept now that seems to be coming to the U.S.?
Mania Meibodi: There are some in U.S., I couldn't say. Not many. So, Texas is producing quite a bit of 3D printed house.
Cathy Shafran: In the little research I've done, and I've heard people saying that you could set up the building site in just six or eight hours and that you could actually print a 1900 square foot home in under 48 hours?
Mania Meibodi: Hypothetically, yes.
Cathy Shafran: Hypothetically. And that it could be done for half the cost.
Mania Meibodi: Hypothetically, yes. It's true. The cost will be significantly less than what we have today, because you are cutting off labor, but that's not in a negative way. We will have people doing another kind of job. You will reduce material consumption. You are eliminating the wood form work and the work that goes around it for concrete production. So, you have a machine that doesn't get tired. So, yes.
Cathy Shafran: I understand that it also is better for insulation. It can reduce the amount that we expend in energy to heat our homes. [7.5]
Mania Meibodi: Yes, I mean, generally speaking, 3D printing for construction is a better building, a highly insulated building, because, again, we can really place material where we want. We can imagine that even print insulation as part of printing while we go up.
Cathy Shafran: So, this concept is to do it faster and cheaper. What are the downsides of it then? Why are we not seeing this proliferating?
Mania Meibodi: Yeah. Good point. So, faster, cheaper and better building hopefully. There are many reasons we don't see the fast adaptation by the contractors and builders. One thing is when you print with a special concrete, it's not like printing plastic in your house that you are fully in control of your material. You are outside in the environment, and you need to make sure your concrete stays in the right condition. So, it's a material challenge. It's the skill challenge. If you don't have so many people who know how to use this technology too, I would say it's much easier than the way we do things today. We don't have certifications in place. We don't have a standardization in place. So,one of the reason also that we see a lot of concrete 3D printing happening in Houston and in Austin, in Texas, it's because they don't have to deal with permits as much as we have to do. There are many challenges, but I think less technical challenges, more knowing how much it costs. A builder wants to know how much does it cost for me to adopt a 3D concrete printing technology per linear foot or per square foot. They want to know the price. And there's a lot of unknown because there has been so little experimentation.
Cathy Shafran: Now the work that you're doing is to improve the method.
Mania Meibodi: Right.
Cathy Shafran: That they have already begun. How does your design differ from what has been done up to this point?
Mania Meibodi: Right. So, typically, what you see outside is that you print two layer parallel to each other almost as a stay in place formwork. When you place rebar inside, which is their reinforcement, a cage, and then you would cast concrete in, we first want to use our material efficiently. We don't believe that we need this much concrete. So, we place material only where the structural load is needed. That's one thing. The second thing is these software doesn't really exist out there to push the boundary of that particular printing.
Cathy Shafran: When you say push the boundary, you mean instead of just a square home?
Mania Meibodi: Yeah.
Cathy Shafran: You could create a curved wall.
Mania Meibodi: Yeah. Or even beyond. Like, we see that now. A lot of the printed one have a little bit curve here and there, but the real potential of 3D printing is really into placing material where it's needed. This is the true potential of this technology.
Cathy Shafran: Now we're going to have a link to what the video--what the visual process looks like--on our website, WEMU dot org, so people can go and actually see what you're talking about. But if you could paint, again, word pictures of what this looks like, your method compared to a standard method at this point, what would we be seeing?
Mania Meibodi: Well, imagine a wall where it has to take a load from the second floor everywhere, so it has to be as thick everywhere. And then, if you would be localizing the load saying, like, the forces are in this four point and these four moments in this wall going to carry the load of the second floor. These four areas will be thicker. The in-between would be thinner. So, that would be how you could simplify the process, basically. But it's also more than that. The technology we develop would allow you typical concrete 3D printing with print planar, by which I mean horizontal to the ground. And then, what we've developed is a printing method where you can print nonplanar, meaning every layer doesn't have to be from beginning to the end in the same height. This would also expand not only what we can print. It would allow you to go in a more complex area of design. So, you would see design or complex design that you would never seen before.
Cathy Shafran: Something with more angles perhaps?
Mania Meibodi: Yes, more angles, cantilevers....
Cathy Shafran: Your method, if I understand correctly, also helps with the issue that we're facing, which is a limited supply of concrete.
Mania Meibodi: Yeah, good point.
Cathy Shafran: Raw materials thereof.
Mania Meibodi: Yeah, there's a shortage in sand for instance, that we use in concrete. It's the main ingredient of concrete. What we are doing is we are using concrete in a resourceful manner. We have to reduce our material consumption as we go forward.
Cathy Shafran: And this allows you to do that.
Mania Meibodi: Yes.
Cathy Shafran: You are looking at a future where more people look at 3D concrete printing as the solution to the environment and costs and space.
Mania Meibodi: Yes, it's also...what I'm hoping is we do a lot of 3D construction printing, so we investigate earth printing or dirt printing, we investigate clay printing, we investigate plastic printing for building industry, recyclable plastic printing, alternative materials. So, what we have to know, also, 3D printing opens a new door to construction. We, all of a sudden, can investigate many material we have not thought about before and see what other alternative we have to becoming concrete or if we are using this concrete, what within the mix we can change to have a more sustainable concrete mix.
Cathy Shafran: So, I understand that you have used this method already in a building, at least the bottom of a building in Switzerland, and you are going to be talking about a project in Texas coming up. Do you see this as expanding the way that we in the United States start building our homes--something different in the future? Do you see this as the beginning of a change?
Mania Meibodi: I think it's already changing. If you look at the calls from the United States government and institutions, National Science Foundation, for example, there is so much call around future of manufacturing, or how can we construct waste-free. How can we reduce material? How can we be efficient, but also be frontier of the world. I hope that, by our work here, one day, Michigan, and hopefully Detroit one day, would be part of this change rather than waking up one day and then being surprised by a change because the construction industry is changing. It's changing slowly and silently. And many countries like Germany, Switzerland, the frontiers in the industry, are making that change in their own, disrupting their own current model.
Cathy Shafran: Mania Meibodi from the Taubman College of Architecture and Urban Planning at the University of Michigan, thank you so much for joining us today.
Mania Meibodi: Thank you.
Cathy Shafran: Very interesting conversation. And, again, we will have visuals of the designs that she was talking about on our website, WEMU.org I'm Cathy Shafran, and this is 89.1 WEMU FM, Ypsilanti.
Here is an example of 3D Concrete printing
Here is a link to the UM proposed design.
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