And thank you to give the opportunity to speak about this specific aspect, because I think it's very critical for the 3D printed concrete technology. So we work on several aspects, material aspects, mechanical, and neurological aspects.

But also, of course, construction aspects, and specifically about reinforcement because we think it's very important. So it's not a new problem. And I think that researchers like us today will think about that during the

previous century, and it exists a lot of solutions. And we saw this morning a lot of adaptations of these solutions with steel concrete, with steel rebars, and so on, and very interesting things. And perhaps we can find some ideas in

these past actions. And I like this one. I love this one.

Because it's very, I think it's very close from what we want to do with 3D printing. We have no formworks, so it's the works of Pierre Louchey-Arvin, and we have no formworks, and we have very distributed reinforcement. So it's something we try to mimic.

Because we think that it's a very good way to think again about concrete construction. And we propose

Sorry for that. So we have in this direction, we have really a material vision, I think. I'm not sure where to place this approach into the three categories. Norman first presented after

several of you present. Perhaps the third one, but it's not really incremental or simultaneous. We want really to reinforce the material and not the structure. So we call it anisotropic concrete because the result is

obviously something very anisotropic, which we want to to insert fibers on multiple continuous yarns. Sorry to interrupt you. In the chat, we have several comments that we are still at the first picture. Is that correct?

The video seemed to be frozen. You are the first picture? We see the person that controls. Okay. Yes. Yes, but maybe you know, it's not it's not normal. Okay.

Sorry, I also have your slides here in case because yes, I sent, I sent to them. Can you see something now? But perhaps not the presentation, but just the. Yeah, we don't see it in present as mode, but we see your slide layout on the

left side. We can see the slides one to always the same. Now you would see the changes. Yeah, and now it's proceeding. Yeah. Yes. Perhaps we can works like that. No. Yes, I'm sorry, because I don't know it's very Webex appears as very complex for me. I never

use the Webex and I have a lot of problems. I don't know why we can zoom in or. It's okay. That's good. Okay. I can and. How can I do. No, I don't know. I'll say try again.

It's better. No, is it better? It's still reversed. So we have, we see your presenter mode now. Yes. And I have a lot of I don't know the message. I added. It's not clear. Okay. So I.

That is working leave it like it is a little bit. I think we will say that. So, I, I said before that there are a lot of example in the, in the previous century about reinforcement and with I saw this morning, a lot of adaptations of of these technologies.

And 1 of them is especially interesting for us. It's the ferro cement from because it use no form works.

1st of all, and he use a very well distributed. Reinforcement steel, reinforcement, very thin. Greeds, so it's a very, very interesting, very interesting at this time. He has, he had very skilled workers because it's very

complex structures to to build and unfortunately, we, we, we haven't a lot of very skilled workers, but we have the robotics. So, it's something very interesting to think again with on you a new way to, to, to build them, especially robotics.

And what we propose is really a matter your reinforcement strategy. We, we want to reinforce the concrete and the mortar itself with multiple. Continuous try to achieve I ratio we, we, we try 10% in the latest

direction and we hope with this solution to add more to and higher strength of course. So, we call it anisotropic concrete because my, my 1st, the researcher about composite materials, and I don't know if you know this reference, but from the professor in Japan, but we want to.

I think about this, like, if composite materials. Why not taking sequences and so on? So it's a very matter your vision. I'm not sure where. I can put it on the normal categories. Perhaps the last 1, but it's not really incremental. It's more simultaneous. So, for instance, it's to put the right reinforcement in the

right direction. Of course. And perhaps this structure we made a few years ago without fibers can take benefits of such a strategy.

So, 1st, double it from a kind of historical aspect. We, we try without. Robotics to to see if our ID. Ideas is working and so we made. Benchtop extruder, and we impregnate some long fibers with the same material. We, we, we print with and we can.

Here see the improvement for the mortar if we introduce here, it's 6%.

In volume ratio, 6% of long fibers in our. 10 size specimens, and you can see that the blue 1 without specimen, of course, it's it's not as good as the specimens we made with 6%. Of long fibers, we can achieve higher strength. Of course, we are 20.

Almost 25 and we have and we have a duty that we obtain thanks to distributed micro cracking. So it works. We try also some in situ microscopic observation and and also pull out to testing.

And we can see it's interesting in the, in these pictures, you can see the fibers. It's here is glass fibers and more.

And you can see that you have a kind of good link between the 2 of them, even impregnation, because you can see some cement. Inside the yarns of glass fibers and here. We have, you can see in red, it's the stiffness of the fibers and in blue, the stiffness of the set of

1 fibers invented in concrete. And here you start to damage the interface. And after that, you have the same stiffness and.

Then the fiber, so it works not so bad. And so we, we decide to go further and to, to be the process that we called flow based. Why flow based? Because the flow. Of concrete is able to pull the fibers. So, without motorization, without complex disposal, we just have the mortar.

Uh, able to to pull the fibers in the, in the lace, so I have to mention that we work with 2 K system. Uh, from extreme, so it's convenient because we have a very, very liquid.

Very, very, very quick paste, so it's a good point to impregnate and thanks to the addition of entities, we have very quickly something sufficiently stiff to pull the fibers.

So, uh, another interesting point is that we obtain low flexural stiffness yarn. So we are able to, uh. To to to to print even a very sharp. The curvatures and we have a good impregnation as I show you before.

Okay, so we made the proof of concept. Uh, we've different, um. Different systems with 5, Bobby, and we have 5 boobies. Well, it's not the. The presentation, so I can, I can't show the 2.

Together here you have to we, we try different mortars and different fibers because the influence of this combination is very important, like in a composite materials and we, we are able to.

Insert until up to 2% of of long fibers in our in our structure. A very interesting point is that's what you see here. Is the of the fresh lace actually. Go, I can show you this spot, but.

It's much interesting for end of of the video here. You can see the lace with some fibers inside. It's really not the same behavior that without fibers without fibers. I think, you know, now we have no fibers and you can have. You can see that we have a classic classical dropped.

Drops of of cement, but we have fibers, it's very, very different matter. You're very. An opportunity for the process itself to perhaps for continuous situation. So I, I think it's a. Unexpected aspect of our proposal, but very interesting.

So, after that, we make some characterization. So, 10, since 10 side specimens and also. Bending specimens and in direct tensions here, you can see.

The force and reinforcement specimen. We've few percent of fibers 0.8%. We have something not very efficient. We have very quickly the localization of of of the cracking and not really a ductility.

But if we go up to 3%, we have. Something really better, and we can issue a multi cracking. So, we have a utility you can see here. It's a 2% of strengths.

So, until 1% of of strengths, we have something. Acceptable it's a very, very interesting. We have the same aspect in bending, so you can see the different.

Cracking we have so very small 1, we need the digital. Image correlation to to see if it's cracking. And finally, we have, of course, a localized record name, a localized localization of 1 of the crack.

And the final eruption, so. And a big area under the curve, so. An interesting utility for the material itself. We try also, we make a 1st try for a structural element. So, we, we propose this TV, but it's inverse TV where we put fibers.

In the of of the beam, so it's. Among 2.5% of fibers. And we, we've made some 4 point. Bending test for and reinforced, you can see that it's very.

Fragile of course, and we have only 4 for. For the strength and we've reinforced. It's here, it's carbon fibers. To to to. To precise, so we have the elastic phase, and after we have a multi cracking with

a high level of utility, and if we make some cycles, we have something quite stable. And we have the new stiffness for the structure, so a very convenient to where.

It's it's very interesting to to to manage structures. After that, we have the final rupture due to sheer. So our fibers. Don't works for this. So, you see this.

Okay, okay, so. Just yeah, you can see the introduced with a 10 seal cracks on the introduce of my beam. So very well distributed micro cracking.

So, like, we've actually so it's very interesting and here you can see the sheer tracks failure just under the loading. So, it's the final rupture in yellow here correspond to this mechanism. Okay, so the perspectives, it's an industrial development that we, we try with each 3 company. We have a common PhD.

And as, as I saw you before we can, we've even for the process, having some long fibers in the, in the core in the lace is very interesting because you can accept very high level of, for instance, county level situations.

Yeah, you can see laces with carbon fibers. And I think I have yes, I have. A small video with the last 2 prototypes we developed with extremes with more.

Bobins, but now we try to put the buttons elsewhere because we, it's very limited limit. It's a very high level of limitation to. Have the bobbins on the end, of course, because you cannot achieve very.

Long structures, and it's a weight load. Introducing a lot of problems. Okay, and so so to 2 perspective 1 for fresh fiber mortar.

As I said, I have consistency new process opportunities. And then fiber mortar, of course, with properties and new structural opportunities. I think it's really a way to to build differently with concrete. So, thank you for your attention.