Disrupting concrete construction
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Transkript: Englisch(automatisch erzeugt)
00:00
You are a professor for architecture at Zurich, and I have read that you have also got a Riesler Prize, given to the most promising young professor. What is the most fulfilling part about teaching architecture? The most fulfilling part, yes. So I increasingly actually like to teach architecture.
00:22
I teach in the first year. The first year students I like because they are extremely eager, very open-minded. They're still fresh, they are not yet kind of indoctrinated by typical architecture education. And I think that's an important stage and also an important mindset, because I think increasingly
00:42
we have to be open and rethink everything as architects. But I tend to also not want to talk about architects, so my background is both in architecture but mainly done in structural engineering as well, structural design. And I would prefer to start to get rid of these labels
01:00
that almost force in silo thinking, that force people to kind of move on responsibility, and to think much more integrative. And that is something that I recognize with my first year students. But what I also increasingly recognize is that our students are really questioning why things are done. They want to make a difference, they want to be part of the
01:24
solution, they are extremely critical. And even to the extent that, for example, when I see my architecture students want to connect on LinkedIn as an example, then many of them describe them as architect slash activist. And that is something that I notice and that makes me hopeful.
01:43
And particularly for the field that I teach, which is structural engineering, structural design, I don't want to teach it as a service-providing kind of field, but as an issue, an aspect that needs to be integral to any type of design. Your theme, Jorge, is concrete. You want to reuse
02:01
the material, and there are a lot of opinions about concrete. The most popular one is the one that concrete should not be allowed to be produced due to the environment of waste it creates. Do you have something to advocate for concrete as a material, secondhand and new made? Of course. That's also why I increasingly kind of use concrete explicitly in the titles of all my
02:25
lectures, even though it's only an application, it's a material that we use in the bigger picture. So maybe I'll zoom out quickly first. What we do with the red line through our work is actually to advocate for something that we call strength through geometry. And so through that, we want
02:42
to show that by getting the geometry right, you can save a lot of material. It's not just about the amount of material, but it's also the type of materials that you're using and the impact of those materials. And so what we show is that by reintroducing historic principles of compression, of vaulted architecture, that you can not only save a lot of materials, but that you can also
03:05
use lower-strength, extremely low-carbon footprint materials. And so that's the important aspect. And then increasingly, what we are demonstrating is that if you're disciplined about how you design a structural design, that you can also extend the lifetime of a building, extend the
03:23
lifetime of a component through reuse opportunities, and then ideally indeed not need any virgin materials and keep them eternally in the loop. I just wanted to give that as a background a bit, because that is the background how we approach concrete. We approach concrete as an artificial
03:41
stone, so not reinforced concrete. If you look at it as an artificial stone, a stone is happy in compression, not in tension. So the vaulted geometries of Roman arch bridges, of Gothic cathedrals, are exactly the right geometries for this material. I'll give you an example. We have developed, and we are now close to being able to offer this as a commercial
04:04
system and product, we have developed an alternative of our very common reinforced concrete floor plate. And if you reintroduce these kind of structural geometries, you save 70% of the mass in concrete and 90% of the reinforcement steel. So these are disruptive changes. So this is a huge
04:23
opportunity that one has to do things better. We have to get past a current absurd discussion that is only about materials. That says concrete is bad, period. Wood is good, period. So both statements are entirely absurd. It depends where you built it, where you use these materials. It
04:41
depends more importantly how you use the materials. I gave you an example. Concrete actually per unit mass has a surprisingly extremely low embodied carbon coefficient. So it's quite a good material. But because it's so cheap, we are using it irresponsibly in quantities that are just not justifiable. Additionally, by the way, because the concrete
05:05
industry has been targeted so much. In fact, there is in the West here, certainly in Europe, there is a total concrete shaming going on. Like you say that you're not allowed to use this material, that big clients, governments are asking solutions without concrete. Concrete
05:21
is the taboo, is no longer allowed. The industry is fully aware of that. And it's really taking an ambitious kind of goal to reduce the impact of the material on top of these fundamental changes that we could already offer significant reductions through better design, structural design, right? So what are then opportunities of a material that is getting better and better
05:43
and better? A material that we are now showing that you can reduce the volume that you need from it already by smarter design. If you indeed use this unreinforced concrete only where needed, but you design it such like a masonry structure so that the different elements are nicely
06:02
stable just in compression. You don't need any glues. You don't need any kind of additional mechanical connections and so on. That actually gives you structures that are fully reversible. And so of course, in an outlook of reuse and so on, this is a very powerful kind of concept. One also has to acknowledge that why I also want to clarify a possible route,
06:24
because we need many solutions. The urgency is so important. We have to have solutions now. I'm also a bit sensitive to the reality that we need solutions at scale. So we don't have sustainable farms and forests for trees yet that can offer all the materials that is needed to
06:45
build all over the world. People say about we should also stop building. That's maybe fine where we live, but that is not fine in a developing world that needs to still provide adequate housing and infrastructure for a lot of people that will be more on this planet.
07:02
More than 2 billion more people on this planet. I also want to be pragmatic and realistic. And so this material, again, that is becoming greener and greener and greener because everyone knows how impactful the clinker in the cement in the concrete is. So we have to replace this. So I'm not saying that concrete as we have it, in fact, 10 years ago is the one that we need
07:24
to use. But there is much development that is going on. But it's how we use the material. That is the key thing. And then what you get with materials like concrete or concrete construction is that you have, for example, sufficient thermal mass so that you don't have to over dimension the building systems to compensate for the lack of thermal mass.
07:44
Another opportunity that you could have is that concrete can be crushed, recycled, and eternally kept in the loop. Currently, we are in a situation, again, because of this very placate, very wrong kind of simplification to concrete is bad, wood is good. That means
08:04
that, for example, my colleagues at SOM, they said that a client in China wanted for quite a tall building. It had to be in timber. It had to be in timber because that is the green solution. But if you go to a tall building with long spans, that is not what naturally timber wants
08:22
to do. So maybe it looks green, it has wood on the outside. But it has extremely important steel connections in between steel is a super high embodied carbon coefficient material, you go to highly engineered timbers, where the more you engineer the timber, the less you give it opportunities of reusing of the components later on at the end of life. And again, if you
08:45
approach concrete like we do as an unreinforced artificial stone, we separate materials, we have a clean material that can be recycled easily, low energy, easily recycled all the time, placed only where needed, with connections that are fully reversible so that we can start to reuse
09:03
components. And we have components that become stronger and stronger and stronger because then something, and this is maybe a bit technical, but in concrete, you have long term what is called carbonation, that actually, by the way, also locks in CO2 permanently. But this carbonation
09:20
is something that in typical reinforced concrete structures, you're fighting because this carbonation changes the pH in the material and that causes chemical corrosion of the reinforcement. But if you don't have reinforcements, because you treat it like a masonry system, then you can fully take all the benefits of the carbonation. And an important one is that
09:41
your material becomes stronger, stronger, stronger and stronger. So actually, for an investor, that is good news. Because what you put in your building, your components will become even higher quality after time. And so we can also start to rethink the value of a building rather than after 30, 40 years of building being entirely amortized, valued nothing. In fact, you need to
10:04
put money into it to demolish it. Now you might have a building where you have high value components like Roman arch bridges, right? If these structures were taken down, these elements were used for construction somewhere else. You see it in Naples, you see it in many places
10:21
in Rome, you find traces of this high quality material in new construction as well. Do you already have investors or is it just in planning and just in research? We have finally realized the first project like this with our floor system, so where we span five and a half by five and a half meters with three centimeters of unreinforced low strength,
10:46
almost entirely recycled concrete, right? So that we have a building. And I must say that this building after 10 years of development, after doing a lot of tests, after overcoming skepticism from everyone, every single engineer thought that we were being crazy, that would never happen,
11:03
has nothing to do with modern and so on. We got there and now indeed it is accelerating. So we have projects in the pipeline, but they haven't realized yet. That's by the way, another big challenge of pushing any innovation in the build environment is that the cycles of actually getting something implemented at a meaningful scale are so long. If we are now
11:24
building buildings with the knowledge or ideas of three, four years ago, and it's even worse. I heard from the city of Zurich that for them actually, because there is a required competition phase and so on and so on, that actually the cycles are eight years. Can you imagine that
11:43
we are today building buildings with knowledge and ideas of eight years ago, eight years ago, this urgency, the real ideas, the real innovations were absolutely not on the planet yet. So we are today already kind of causing an accelerated issue that we are trying to fight. This is a sad
12:02
reality, so I cannot say that it's a product yet. What we're trying to do is both. We're trying to actually explain the principles, be very open about it, work with as many architects as possible for competitions. We get a lot of requests, so that is very exciting, but indeed it's a bit of a chicken or the egg. Do we really want to go for this system while it's not already product
12:24
on the market yet and so on? So we're doing a lot of effort there, but at the same time, we're also trying to not like a startup or a spin-off, bottom-up, trying to kind of save the world, but we're teaming up with a really large player, Holzim, to actually globally trying to develop a product. And so in that sense, we're trying to do both because just with activism,
12:46
we're not going to go there. Just with kind of these boutique demonstrators, light-hearted projects, great for teaching, very great for the magazines and so on, but I really want to have impact, and that's why we are doing the two at the same time. I first focus on one aspect. I focus on significantly reducing already the amount of
13:05
material needed, and I offer an outlook for using lower-strength, better materials, already lower-strength concrete. But I do it in concrete because if I would come and I say, we developed a floor that saves x amounts of material, and we build it in mushroom,
13:23
and it works. Believe me, it works. We did all the tests and so on. Of course it works, but the world is not ready for all of these steps at this point. So what I increasingly am doing as a strategy is actually to break it down and to kind of choose what is the best first
13:41
innovation to get acceptance, and then you can push the boundaries, and then you can really go to the Holy Grail. So we want to, of course, go then to concrete-like materials with no clinker anymore. And so then we are at the earthen materials, kind of, right? And so that's where I want to end up.