 Good afternoon, everyone, and thank you for sticking around. Let's switch a little bit gears here. I'm very excited to share the research that we are doing under the umbrella of CERC, and the focus of this presentation today is on cement and our concrete, and in particular on decarbonizing cement. And I will focus on the approach that we are taking. It's our view that addressing decarbonation of cement requires geoscience and engineering approach. Indeed, the making of cement in the carbon footprint is without doubt an engineering problem. But as I will show today, the root cause of the carbon footprint of cement falls right into the geosciences disciplines. So, but let's start with what's at stake here. Concrete is one of the most used materials at all times. The first concrete, oh, sorry, the first concrete buildings or structures made of early cementitious materials have a very rich history. Civilization of all times have used cement or whatever precursors. And today, concrete is the most used material. It's second only to water, which means it's the most used man-made material in the world. It's used extensively from buildings to well completion. And just to give you some numbers here, 30 billion tons of concrete is used every, each year, worldwide, which if we look at the problem in terms of per capita basis, this number corresponds to three tons per single person or even three times as much as 40 years ago. In fact, the demand of concrete is growing and it's growing much faster compared to steel and also wood. Such a demand clearly poses a big challenge for sustainability. In fact, the making of cement, so the glue that holds concrete together is responsible for 8, 11% of worldwide CO2 emissions. And the core of the problem is really in the root. It has its root in the geosciences. In fact, to paraphrase the head of CEMEX, the head of R&D, the making of cement and the decarbonation of cement is not rocket science, but actually it's rock science. Why? At least for two reasons. Cement manufacturing really starts with carbonate rocks with limestones, which are made of calcium carbonate or calcite. And the rock is thermally decomposed through a process called calcination to produce lime. Calcination is a high temperature process that requires the use of energy. Generally, the energy comes from fossil fuels. However, the use of the energy from fossil fuels is responsible only for 25%, 30% of the emissions. Here I'm not calculating the emissions that come from the transport. But then it's really true calcination that the molecule of calcite is broken into calcium oxide, also known as quick lime, and then CO2. And it's truly the breaking down of these molecules that contributes to the majority of the CO2. We are talking about 65%, 70% of the emissions. Then calcium oxide is mixed with alumina silicates and sulfur sulfates. And I had to mention that the mining of carbonate rocks for the cement industry is estimated about 2 billion tons of rocks per year, world-wise. This translates into 1,300 megatons of CO2 that is emitted into the atmosphere. And just to give you a sense, this figure corresponds roughly to the amount of cars generated, so the emissions from the cars circulating in the US, clearly with some assumptions here. As I mentioned, calcium oxide's quick lime is then mixed with alumina silicates, can be clay, can be ash, fly ash, or volcanic ash, and then gypsum that act as a moderator, and then altogether forms Portland cement. So the first lesson that we can draw from this is that even though, in the future, more efficient technologies for energy will provide us or will help reduce the amount of emissions that come from the use of energy, searching for alternative raw material that drastically reduces the emissions from the use of limestone rocks, remains absolutely the priority. And finding an alternative earth material means finding a new rock, and so that's why the problem is within the geoscience disciplines. But this is only one part of the problem. Once the lime is produced, so the cement is created, then the cement is mixed with the aggregates, so generally sand size and gravel size materials, then mixed with water, and finally with the reinforcement. And the reinforcement really leads to the second issue. Cement and concrete in general is not good, does not exhibit good tensile stress, and so that's why reinforcement is needed. Stainless steel reinforcement and not only data indicate that the reinforced concrete produces about 15% more carbon emissions compared to the voided concrete system, but then the reinforcement is also one of the reasons why we have corrosion in modern concrete. And that is a very interesting fact to remember, because if we think of ancient concrete, ancient concrete does not have any reinforcement and yet has survived the test of time. Today we know that modern concrete has a relatively, or shows a relatively short lifespan in general, generally speaking, it's around 80 years, which definitely does not bode well for the total carbon footprint of concrete. And today we have applications that require performance in harsh environment, whether it's at sea or adapt in the subsurface. In fact, durability normally is not factor in in the computation of the CO2 emission, and I have to say the durability as ramification that go beyond the simple replacement. In fact, if we think of methane leaks, Naomi this morning showed the number. So some of the methane leaks result from the well bore integrity being compromised, and which is due to the degradation of the well bore cement, whether it's a chemical degradation or also mechanical degradation. So the second lesson learned here is that we definitely need to explore different solutions for increasing the durability of cement and concrete, of course, and also the serviceability, especially for those applications that require performance in harsh environment. And so we need to understand how to include a different type of reinforcement that it's not a large scale reinforcement, for example, from stainless steel. So before focusing on the technology and the research that we are doing, let's also give a look at the current approaches how people are tackling this problem so far. The first approach is carbon upcycling. Carbon upcycling clearly uses or captures the CO2 from the making of the lime, then reject the CO2 into the fresh slurry and transforms supercritical CO2 back into solid carbonate minerals. However, what are the limitations or the problems here? Clearly, the entire manufacturing chain needs to be changed. There are also high costs to change the manufacturing chain. This approach is limited to precast because if you want to inject CO2, you're supercritical CO2, you need vessels, so it's just the precast. But then, and this is something that not many people talk about, and so it's really the perspective from the geoscience, the fact that this solution or this approach creates carbonate minerals, we know that carbonate minerals or calcite in general is a brittle mineral and also very prone to this solution. So this will not really help the durability that the final product. Let's think, for example, we know that shales are more prone to be fracked if more carbonate minerals or calcite is present, so frackability of shales goes up if there are more minerals like carbonates. The second approach that is being considered is making cement blends. Portland cement is very high in calcium content because it comes from the making of lime. But then if you want to reduce the lime, you have to put in new chemicals that form new cementitious materials. One of these are alkaline solutions, which are actually both calcium hydroxide and sodium hydroxides. And this forms really the basis for alkali-activated cements or geopolymers, which are called geopolymers in chemistry. But actually, they resemble, and that's why the use of this name, they resemble very closely the minerals that form in nature. Our technology and our research really sits in the middle between the making of the Portland cement and the making of alkali-activated cement. In particular, we are using a geomimetic approach. As with biomimetics, which are as many transformative materials from Velcro to adhesives that are inspired by the Kegoskin, we are harnessing structures and also processes that mimic how rocks, in particular rock cement, is making. And so this includes a new rock composition that does not, as we will see, does not have the carbon ion and also looking how to reinforce the binder and also the cementitious materials at the nanoscale. So here's the basic concept. Certain rocks are not that different from concrete, including Roman concrete. I must say that I'm always struck by the similarity, at least by looking at the microstructure of certain rocks and ancient concrete, which indeed can be fortuitous. But the question that I always ask myself, how would anyone think of adding litics or rubbles or today they're called aggregates to a fine materials, which is ash and a binder, just to make concrete? So rocks I know that cement, we know they cement naturally and sometimes they exhibit high strength without any reinforcement. What you are looking here are it's basically the cementation of a fault. You can think of earth as a large scale kiln factory. During earthquakes, fault just break rocks and pulverize the rock to the micron or finer scale and then internally channel heat to prime the material, so reduce the material, the minerals to the oxides and make it ready for fluid mediated reaction, which eventually leads to the formation of this concrete-like rock without any apparent reinforcement. But actually, the reinforcement exists. It's just at a scale that is too tiny and so it's not visible to the naked high. In fact, nano many times does not always equate to manufactured. You can think of earth as really an excellent nano technologist that uses only water for its chemistry. What you are looking at here, it's an SEM image of an aluminum silicate cement of a certain rocks and cement here appears as a tangle of nano minerals, which in other times, this nano minerals can be sometimes tangles, sometimes they are very well aligned. And this really represents the nano scale glue of rocks. Why are fibers important? And this is really knowledge that comes from an old knowledge that comes from the engineering. The addition of fibers to materials, we know, increases toughness and stiffness. So you can see here a plot from 1996, just the addition of 3% of carbon fibers to this cement paste, increased the strength but also makes the material more ductile. So you have a transition from a stress strain relationship which goes from brittle behavior to a more ductile behavior, which means the material resists stress while accommodating more strain. And the reason is simple because fibers bridge, serve the purpose of bridging fractures and also deflect the path of the propagation of a crack. So overall, fiber reinforced material can absorb strain energy, preventing what we call it brittle failure. That's great, but what are the limitations? Why we cannot easily add, so simply add fibers to a material or any material. The first limitation here is that from a practical standpoint, there is a limit to which you can add fibers and mix the fibers to a paste. You have to consider that the larger the amount of fibers, indeed, larger is the strength. However, the greater is the viscosity. And so this is a limit to the workability of the paste, poor workability of the paste leads to an heterogeneous distribution of the fibers within the material. So that's a problem. But then there is also a second problem, which is fiber debonding. Fibers normally are simply added to a paste. They do not grow into the cement or the paste as they grow into rocks. Therefore, there is a poor chemical affinity between the matrix and the fabric. And because of this extraneous nature, sheer strength at the matrix fiber interface is low that leads then to poor bonding. And that then is responsible for the failure or performance failure due to fiber debonding. But what if fibers were allowed to grow into the paste as they grow in rocks? And then instead of adding fibers, they're simple inclusions. And then can we control the amount of fibers that we can grow into the paste when the paste looks still a slurry? And then can we control the topological arrangement? Why is the topological arrangement important? I showed in some previous slides that if we look at the cement of rocks, sometimes the fibers of the cementitious material can be entangled and other times the fibers can be very aligned. From a mechanical point of view, they have a completely different response. You can see here, this is a result of a simulation. When the fibers are well aligned, sorry, when the fibers are very entangled and disordered, you have a stress strain relationship that the behavior of the material is more resilient and so as a more ductile behavior. As the fibers become more aligned, strength increases but then the stress strain behavior becomes or favors a brittle failure. So entanglement is a very important parameter here and this is not very surprising. If we want to make a fast rope, we just need to braid the strands or create some knots. And in order to increase the strength of a more ductile behavior, we just need to increase the number of fibers per unit volume. The simulation that I mentioned that I showed here, all the only parameter that is changing is just the entanglement of the fibers and the alignment but then the number of fibers is kept constant. So if you want to increase the strength, you need to increase the number of fibers. So with all this in mind, we are leveraging knowledge from engineering and the geosciences to formulate a new clinker through a geomimetic approach, just looking at rocks. So here I'm showing, we are now focusing on alternative rocks. So it's an alternative raw materials as a binder. We are at the moment also blending different type of rocks. And here in this plot I'm showing the mass loss upon pyro processing the rock. You still have a rock and so you have minerals, you have to reduce the minerals to oxides. And I'm comparing here the mass loss which here I'm considering a proxy of CO2 and the new binder. These are experiments that I did during the pandemic in my garage, I had to say. And so I didn't have a spectrometer but definitely the mass loss, it's very low. So the new rock and the new rock blend actually allows a drastic reduction of CO2 emissions upon calcination. And the reason why this rock is a volcanic rock, so nature has done the job for us, does not have any carbon ion. Then we are using this alternative material to grow fibers in the lab. These are really the first fibers we grew in the lab for a completely different application. Here you can see more SCM images of what we are doing in my lab. And actually I was very excited when I saw this picture because you can see fibers literally sprouting from the binder, from the cementitious materials as it were a living creature. Clearly we're also looking at how to increase the number of fibers. There's two SCM here, the scale is exactly the same but we are exploring ways of increasing the amount of fibers in a short period of time. And clearly we're also looking at the entanglement, how to make fibers long enough so that they resemble more and more as polymers or geopolymers but then how to make them entangled. So in conclusion, I hope that I convince you that the cement decarbonation is as much an engineering as a geoscience challenging. And so this, in my opinion, this partnership is very crucial to start cross-pollinating and also leveraging knowledge across the engineering and also the geoscience community. I'd like to hear a knowledge, my cool copy eyes, Alberto Saleo who is the chair, so material science and also Matteo Cagnelo who is a system professor in chemical engineering. So again, and clearly the students who are working on that that comes from two different disciplines. Here the main take home messages. In my opinion, to abate the CO2 emissions is crucial. We need to rely on different rocks and a rock blend. Because of this partnership, we are used to say it takes two to tango but it's actually in this case it takes two to tango. So as I mentioned, we are relying on a natural rock blend that provides a sustainable binder precursor. We have shown that the CO2 emissions, there is a drastic reduction in CO2 emission. We are using a geomimetic approach that literally draw inspiration from the way earth makes chemistry and how this chemistry contributes to the mechanics of the cementation, the cementation of rocks and then hopefully of concrete. In my opinion, there is a lot to consolidate and cross pollinate between the knowledge of nano minerals and nanotechnology to really understand how to control the growth and also the orientation of mineral fibers to enhance reinforcement at the nanoscale. And with that, I leave you with this quote from Pliny that was always inspired. Nature, we need to look at nature but we also need to look at very small designs. We have now the technology and we can learn and we can look how really earth makes its chemistry. And with that, thank you for your attention and I'm happy to answer any questions you may have. Thank you. Thank you. So this volcanic rock, you didn't tell us what it was. Is it a magnesium silicate or is it more of the magnesium iron version? No, absolutely. So this is a rock that is called a calcalkaline rock. So it contains naturally both the calcium component and the alkaline component. And it's a rock that crops and forms in many places of the world actually are the place where we have subduction zones. So it's clearly, I started from Italy where Roman Concrete and I'm Italian originally. But actually this rocks up crops in any region of the Ring of Fire, so Japan, the Aleatian, and also clear here in the United States and also the Andes, for example. But I'm interested in the chemical composition. So the chemical composition, it's really a long formula that I can tell it's called calcalkaline rocks because it has the two components. So it has magnesium oxide, calcium oxide, sodium silicates, and potassium silicates. In fact, normally the type of volcanism where this rocks is created is referred in our community as ultra-potastic volcanism, which is typical of the subduction zones. Great, thank you. Thank you very much. Andreas Matzakos from Shell. Is this presentation indicating that therefore we could reduce the amount of limestone being used as a raw material and then replaced with other aluminum silicates already found in nature in abundant quantity and therefore they will not require high CO2 chemical emissions and fuel emissions? Yes, and I have to say, if you look at Roman concrete, and so it really was when, actually I started from a rock that I was interested for a completely different reason. It's a rock in a volcanic region in Italy. It's the same region where Roman concrete was engineered. And the rock exhibits high strength, but also is able to withstand high strain. And then from there, I start looking at Roman concrete. If you look at Roman concrete, normally the recipe, at least the one that's been passed on to us, the recipe says mix volcanic ash with a binder, and I will go back to the binder and some rubbles. Then if you look at the binder, today people believe it's limestone because that's what, you know, it's the recipe that has been passed on to us. But if you go back to the ancient texts, actually the Romans or Retrovius, the engineer, was simply say we use white rocks. They didn't say, which then definitely over time has been translated as limestone because limestone is white, but there are many other rocks that are white. So this, I really believe, and so if you look at Roman concrete and the lime relics that still are there, there is a lot of heterogeneity. If you look at Roman concrete, for example, in the Israel region, Caesarea, definitely the lime comes from limestone. You see fossils inside, so it could be just limestone. Besides the composition is pure calcium oxide. But if you look at Roman concrete from the Italian region or also the France region, basically you have a lime that actually could have come from a volcanic rocks. You see minerals that belong to a volcanic rocks, you don't see minerals that. So to answer your question, yes, that rock can serve as binder and it's possible that even the ancient use it. Thank you, and actually one thing I will echo from your presentation is that Romans built and Greeks and whoever built those buildings to last for millennia with the current way of concrete, every 80 years, we have to replace it. Can you imagine the cumulative CO2 emissions from that? And this is why I mentioned, Roman concrete did not use any reinforcement at least at the large scale. What you are seeing here, it's really Roman concrete before and after stressing the concrete. So you see there are no fractures going on at the least of this scale. But then it was really when we look at the micro nano scale that you see a lot of fibers, much more. And those are fibers that are really embedded in the matrix so that clearly they were now added and they are very intertwined. So somehow there is a technology out there that somehow we lost. And so I'm glad today to work with chemical engineers and material scientists to see how can we actually to build upon a technology like that with the tools that we have today. Wonderful, thank you. It looks a little like a plant cell wall. You know the ultra structure of a plant cell wall with all the cellulose and fiber fiber. You know, a club is a very, as the property that has because all the threads are very well intertwined. Yeah, it's great, wonderful. Thanks Tiziana, that's great.