Enabling sustainable construction with calcined clay: Alejandro Velez, Sika

Thank you, Thomas, and your team for the invitation. Thank you to my local team and Pakawat from Sika Thailand who selected the topic, so thank you very much. And of course, thank you to all of you because during the next 10 minutes, I will be trying not to sell the company, I'm trying to sell the technology. Let's see if we are able to do that. So basically, the idea is how we motivate, how we enable sustainable construction. We have been listening this morning already, the use of SCM. Later on, I will answer Peter's question about recycling concrete and things like that, the use of alternative ideas, new topics. So this is mainly what we wanted to present here.

And my colleagues, when I ask, "Okay, what should be the most interesting topic?" They said, "Why don't we talk a little bit about calcined clays?" We have some experiences from other regions, so I will try to mention a little bit of what we have been able to learn during the last five to six years related to the use of calcined clays, which is a topic clearly very interesting these two days here. First, I will present a little bit shortly, a little bit my company. I thought, no, I don't need to do it. Everybody knows Sika. To my surprise, there was a German guy came to me this morning, "What do you do?

I don't know this company." So at least the first two minutes of these presentations are dedicated to these guests who came this morning and did not know Sika. Then we will talk a little bit about the calcined clay itself, of course, about the solution. We are not going to put the price on the product, but at least to present what is the product able to do, and we will try to present some field test and reference from different companies and regions around the world.

Because of confidentiality reasons, I am not allowed to mention some of the name of the companies, but you will see at least some of the results, and I think to identify the trend is the most important part of the full presentation. So my name is Alejandro Velez. Thank you for the introduction. You can visit us later in the booth if you have any specific question. And one thing is, it's not the person presenting these five or 10 pages. It's a full team behind. It's a dedicated team. We have the local team, the regional team, the corporate team. So this presentation reflects the work of many people behind me. It's not only myself. Okay.

Sika, for the few that do not know it, basically is a chemical producer based in Switzerland. It was found more than 100 years ago, and it's dedicated to the production of products for the bonding and sealing industry. Adhesives is very famous, and we have industry related to waterproofing, even auto industry. So by basically chemical production, and today we are going to talk about the cement additives. Okay. Our company, I don't want to show the numbers and the sales. What I want to mention is basically what makes us very different. We are present in more than 100 countries, and this give us the opportunity to take ideas from one country and try to move it and spread it to the other ones.

So we have a big network, and this give us the possibility to collect information, examples to improve our chemistry because some of the products that I will bring from Switzerland will not work here. The raw materials are completely different. Maybe the expectations are different. But based on the experience from other regions, we are able to adapt, we call it in Sika, to localize the solution and make the most of it. Also, one person asked me this week, "Okay, so you are sending the product from Switzerland?" No, no, no. We are sending you the idea, the formulation from Switzerland, but mainly the scope of Sika is to produce the product locally.

It's not worth that you are trying to reduce the CO2, and we're bringing all these products with the airplane from Switzerland. So basically, the products and the full business approach and the full idea has to be developed locally and trying to fulfill the local expectations. Okay. Concrete, because you mentioned also, Peter, at the end, we talk about cement solutions, but we have to take considerations that it does not affect the concrete. Basically, it's important that at the end you are able to build the house or the bridge or whatever you are having.

Of course, sometimes depending on the topic and considering the calcined clay, you will see in the last example, some of the markets are oriented to bag cement, and then the expectations should fulfill the expectations of this, let's say, market. Okay. From the technologies that we are going to talk, we call this in Sika, SikaGrind. This is a product, let's say, the cement additives. It's not a grinding aid any longer. I will show that later on. And basically from the approach, because we are based in Switzerland, but basically we have technology centers in each region which are able to take the information and transform it and translate it to the different teams.

So the good thing is we have know-how from different parts of the world. We want to bring it to the different specific projects, and this makes us, let's say, a good solution when we are talking about that. So now clinker reduction and the raw materials. There have been many nice presentations telling there are different types of SCMs, different expectations, not enough for everybody. But today we will focus how we can use the calcined clay to reduce the clinker factor. Okay. Here it's clear, and this information is well known. Last year, almost 4,000 million tons of cement produced. The 7 or 8%, this is still a topic. Everybody tries to reduce the The CO2 footprint.

And independent which company you will find, depending on the region, you will say, "No, in my country it's a little bit less. My company, we do a little bit less than 650 kilograms CO2 per ton of cement." It's clear that the trend has to go down. So sustainability is a big topic for everybody. We see that as a chemical company in every request that we get. Five years ago, 10 years ago, was completely different. Now the people say, "Look, we really have to be more sustainable." There is, of course, the challenge of the raw materials. Raw materials are getting scarce. Sometimes it's difficult to get them. Sometimes you don't even find the container.

In other regions of the world, Peter already mentioned, Europeans are taking some of them. If you go to Latin America, they say, "Look, I would like to have a little bit of s**g too, so please." So basically, the challenge is becoming huge, and the more you try to reduce the amount of clinker, you have big challenges with the water demand. It's clear that most of these SCMs, when we talk about natural pozzolans or especially calcined clay, the water demand becomes huge. The workability will be affected, and what is already mentioned, the early strength will be a big issue. So considering these challenges, we have to work with the chemistry.

It's not just reduce clinker, put a little bit of calcined clay, and hope that it work. No. Unfortunately for you, fortunately for Sika, you have to use the chemistry to compensate the performance. So this is a graphic that shows, let's say, a trend of the CO2 depending on the type of cement. It's clear that we have to go into the LC3 solutions, calcined clay. But on the right-hand side, this is a very famous graphic from the Polytechnique Lausanne in Switzerland, and they mention there is not enough material for everybody. Peter already presented that. There are some natural pozzolanas, a little bit, or let's say, complicated. If you have them, you will use them.

I was in a conference in Peru, and the guy told me, "Look, as long as I have my volcano in front of me, I will use the natural pozzolana." But as soon as that is not available, then for sure you have to change. S**g, it has been already commented this morning, there is not enough for everybody. Sometimes the quality is not as you wish. Fly ash. But what we see, and this is clear, limestone, it will be more and more used, and the calcined clay, which is available mostly everywhere in the world. Here, I have to warn you, not all the calcined clays will be working. There have to be a specific analysis. I remember some customers who said, "Look, we have this calcined clay.

How much we can reduce from the clinker?" And when we made the analysis, nothing, because the calcined clay could not be activated. So please pay attention. The expectations cannot be just, "I have clay here, and I want to change everything." There should be a technical analysis behind. So we are going now with these technologies. Somebody mentioned yesterday. Oh, this is just another grinding aid, and this is not the approach any longer. Grinding aid is the product, the liquid product that you put in the ball mill, vertical mill, to improve a little bit the performance during the mill process.

But what we are talking right now is quality improvers of strength enhancers because we are taking and we are reducing the amount of clinker, so we are losing the power, and we have to activate it again or put it more stronger so that we can have the same performance. So chemical producers, not only Sika, also our competitors, to be very fair, we are talking about quality improvers, and this is what we are looking when we need to replace the clinker with the calcined clay. Here we are talking about very complex building blocks, we call it in Sika. It's not just one or two products. And as somebody said yesterday, one visitor, "Ah, it's just water." No, it's not water.

It's really building blocks, complex formulations, mix of different raw materials, and basically, the challenge is that we have to perform, and we have to cover the missing performance from the reduced amount of clinker. Okay. So calcined clay, CC, calcined clay or limestone calcined clay, which is let's say the general name, it's going to help us to reduce emissions, and there are some challenges, and this is what we have to see together. Sika has prepared a product, and this is not just for today. We have been working on this already several years. Basically, because we noticed that there is, let's say, a missing of some performance or some change in the performance.

We have created some chemical products, basically liquid products because it makes them easier to be mixed. And the idea is to continue and maintain the workability, and to keep the durability of the concrete. The tests that we have been able to do in the laboratory and in the field test in the factories, it showed that it does not affect the separators and the traditional cement mills. Okay. And something which is very important, this type of products do not cause any discoloration in the surface of the final concrete. You will ask me, "What's inside?" Yes, building blocks, different materials. It's not just one raw material. It's a mix of several things. Now to the examples.

Without mentioning, this was probably the first field test that we did four years ago. A company in South America, probably the first cement producer producing calcined clay. And in that time, we got some samples. We did some tests in the laboratory. We go from the original, let's say the gray curve, and this is the original flow table. And we noticed that when you start adding the calcined clay, the curve goes immediately down. So the material does not flow because it's soaking a lot of water, so you are losing the workability.

After many tests, we found out that only by using, and we will not mention the name of the product, only by using chemical products, you were able to go back to the almost original line. So we went from the gray one, we went down to the green and the black one, and only by adding the product we were able to go to the yellow back again. So it's clear that you're losing performance, and only if you want to go back to the original with reduced amount of clinker, then you have to use chemistry. On the right-hand side, you have the performance, the strength, and it has been also mentioned, you have the early strength.

Because clinker is not there anymore, calcined clay is not able to react as fast as the clinker. So it's a little bit slower and probably a little bit sleepy. So what we notice is by slow amount of clinker reduction, let's say if you put calcined clay by 10 or 15%, you will not have a very drastic impact on the early strength. But once you start reducing more than 20, in this example, 32% of clinker reduction compared to the original, then you have, let's say, relevant losses in the early strength. For that reason, we had to put, let's say, the blue line and the yellow line, we put a little bit of Sika, and then you were able to increase a little bit.

On the late strength, 28 days, we see that the problem is not as drastic. We see always the issue at the early strength. Unfortunately, not all the cases we were able to increase to the original strength. But please take in consideration that the gray line as a reference has 32% more clinker than the yellow line on the right-hand side. So if we try to compare the same level of clinker, for sure the new product would be better. But it's clear that there is a loss at the beginning of the early strength. Okay. Also, we did some tests with one company in Scandinavian countries. This test was done in concrete because some people said, "No, no, don't go only on cement.

What's happening in the concrete?" So my colleagues from the concrete team, they just took also a reference. This is concrete, the gray one. And once you put the calcined clay, they went again down to the flow table. So only by using specific superplasticizers and ViscoCrete, for the concrete, we call it ViscoCrete, we were able to go back to the original line. So it's possible to go back to the flow, to the workability that you were expecting, but there has to be a chemical treatment. For the concrete, the compressive strength was less impacting like the cement.

We had the reference on the left-hand side in gray, and then by reducing, we were able to even go to the original early strength or even higher with the late strength. So we see internally a bigger impact for the cement, probably not so critical for the concrete industry. And once again, even in the concrete industry, we notice the early strength is hardly affected, the workability remains on topic, and for sure, what everybody's scared, the high water demand. This high water demand will be a topic for the dosage. We are not going to use the cement additives any longer.

Yesterday, somebody mentioned, "Yes, I am using 300, 600 ppms." Unfortunately for this kind of technologies and considering the high water absorption from these products, let's say we cannot go for dosages less than 1,000 ppm. So if one Sika guy or one chemical guy goes to you and offers you that, it's not that we want to have more money, it's technically very difficult to get the performance only by putting 200 or 300 ppm. So don't be scared if the dosages of the product has to go more than 1,000 ppm. It's not just a matter of business and charging you more, but the chemistry needs a little bit. Okay.

One very actual example, this factory had the possibility, and I asked, so I will mention because I asked for permission. I had the possibility to visit this factory in Ghana, which is right now the biggest calcined clay factory in the world. I think more than 400,000 tons calcined clay per year. It belongs to a local company. And basically, it's very interesting because this factory, you would say, look, in Africa. Yes, in Africa, they were able to do that. It's not only Latin America from the first example. Now you have in West Africa people doing that. Why do they need to make calcined clay?

Because they don't produce clinker by themselves, so they have to bring it somewhere from the Mediterranean or from Africa. And basically, they import clinker. Ghana is one of the biggest clinker importers in the world. So they import clinker, and they try to grind it locally with the calcined clay. And calcined clay, they have a lot. So they see it as a business model, bringing clinker, grinding it locally with a lot of calcined clay, and being competitive against all these, let's say, cheap clinker or cement producers that are coming. I think it was the topic yesterday. There is a big wave of cheap materials out there.

So this company, what they had said, and it was mentioned by Peter before, they had to change the rule, the norm, because normally, the norm is not allowed to put the certain amount of calcined clay that they were expecting to be competitive. So they did internal test, and they were able to create an appendix, an annex for the local regulation that allows the use of calcined clay. Right now, I know they have been using up to 35% clinker for the cement that they use in that country. So this is a huge reduction of the amount that they need. For sure, it depends on the local market because maybe they use a lot of bag A business.

So if you are going to use a small road or to build one or two storage houses, you don't need to have the performance if you are making a skyscraper. So they were all able to convince, okay, this is the market that we have to supply. This is the requirement from the local team. They were able to make the annex from the local regulation, and this is how they found out the business case, bringing clinker, mixing it with local calcined clay, and that's the reason why they created or they built this factory, which was inaugurated a few months ago. To the performance, of course, because we want to see what are they doing there. They call it CEM IV with 58% clinker, and now they change it to LC3.

It has a name. I just put LC3, and now they reduced to 43% amount of clinker. I know that they are using also one example with 35% clinker. And basically what you see is on the left-hand side, you have the reference, the original product, and on the right-hand side, you see the new improved product with less amount of clinker, with a lot of calcined clay, and fortunately for us, with a little bit of Sika. On the right-hand side, you see there is a small loss in the performance in the early strength, but consider there is a difference of almost 15 points in the clinker factor. But on the late strength, there is no big issue.

One thing, because I also made the question, "Is that a problem with the one day?" And he said, "No, the requirement of the market, we are caring about the 28 days. For us, it's okay." So this improves their business model. So it's clear that it's possible to reduce. The first example was starting with 20% calcined clay. This one is going higher. You have to adapt it to the local expectations, to the local business case. We see several examples in Africa going on, and I am sure in the Asian market, we will have more and more because of the same reason. You have a lot of clinker available, so what can you do?

Bring the clinker or mix the available clinker and put the local calcined clay that you can produce. This will help to improve the business model, and this will help to reduce the CO2 footprint. But at the end, it's clear that even with the chemical treatment, you are able to more or less identify the same performance as originally. If you ask me here, we don't care about the product name, but the dosage, we are talking by dosage with more than 1,000 ppms of the product that we are using. So it's not possible anymore with just two, 300 ppms, unfortunately. Conclusions, and this is what you have to take, and this is what we want to do, not to tell the people in Africa doing or Latin America.

The message is to tell you it's possible to do it. There are big challenges, but there is also a big opportunity behind, probably even a big necessity. As it has been presented today, if we don't continue moving, somebody will run faster than you. So challenges or let's say opportunities, it's clear that we can reduce the amount of CO2. You can do it. For sure, you will need the help of the chemical product. The material, there is a very nice graphic around the world. Everybody has calcined clay, or let's say clay. You, of course, have to make the calcination. Please pay attention because not all the clay is fitable.

We have done many analysis of the clinker, of the calcine clay that we receive from around the world, and not all of them are performing good. The approach that we do is we start doing the analysis in the laboratory. We do XRF, analytic, microscopic. We check how far we can take, let's say, the power of your clinker, the power of your clay, and based on that, we have to do the chemical treatment. There is also a very nice presentation because some people say, "Look, if you reduce so much clinker, probably this thing will not last forever." There are some scientific papers that show that the durability is not being affected.

I know there is one team in Cuba which put some concrete cubes on the beach in the Caribbean, and after several years, they are still there. So apparently, it's not a big issue. Globally scalable. I show you the first example from Latin America, the second one from Africa. There are many more we could spend here hours talking about that. It's just to highlight it's possible. There is, of course, an initial investment. Of course, as Peter mentioned, in Europe, when you have the CO2 taxes, the business becomes, sorry, the business becomes more interesting. As soon as you have the taxes, you have to pay for the CO2, then it's more attractive. But sooner or later, the solution is important.

Cost-effective, yes, we know that you have to pay a little bit for the chemical treatment, but when you compare with the money that you may be saving by the clinker production, by the money that you are maybe investing to calcine the clay, most of the cases, it's cost feasible. And the good thing, it's ready to be implemented. It's not a technology that you have to wait three or four years. Already, some countries around the world are doing it. So just ask, raise your hand, and then we will be able to send you samples. It's very easy. One bottle, we send it from Switzerland, and as soon as we make some laboratory tests with your local team, we will be able to localize it and start doing it.

So it's feasible. We have created some web pages because one of the scopes of the presentation is not just to promote Sika, it's to promote the technology. We see a big potential there, and you are welcome to visit the web page. But it's not only that, and I have to be fair with the other ones. Calcined clay is one topic, but we still know the people who have slack, they will continue using it. And if you have it, keep it because it's a very good SCM. Some other people will tell me, like in Latin America, "No, we have pozzolana. We will use it until we cannot do it anymore.

We don't want to invest in any calcination plant." And for sure, the use of limestone, which is very established, will remain there. So there is the solution for everybody. We want to promote all of them. We have solutions for all of them. But of course, it's a work together. Before I finish the presentation, I want to answer your question because it's very actual. I had the opportunity to visit last week a very nice example of a ready-mix plant in Switzerland, and what they are promoting, they don't make, "I do cement, I do concrete, I do..." They just do the normal ready-mix business.

They get waste from the city, old concrete waste material, let's say old bricks, old concrete plates, or even some parts of the asphalt. They put it into the process, and what they do is they recycle the materials, used material, they put it as an alternative SCM, and some of these materials, for example, the powder, they sell back to the cement producer. So they try to do a circularity of the process. And what is very impressive, when I was visiting, a ready-mix truck came, and they just put two or three cubic meters there. I said, "What are they doing there?

You cannot just dispose it there." Basically, the disposal goes into a specific area, and it will be reused for the preparation of the new ready mix. So, basically, this is what we want to achieve altogether, with or without Sika, to complete the cycle, to use old materials, maybe to use new SCMs, but maybe to use old things that have been already there. And this is a very good example of how to do it. Moreover, because one thing is not only on your shoulders, the government, the rules in Switzerland say if you are going to sell materials, in this case, ready-mix concrete for the public buildings, you have to use a certain amount of recycled materials.

So it has to be also a regulation support, and it's not just all on your side. Okay, this is what I wanted to present. Thank you very much. If somebody has specific questions, please come to us. Look for the local team. And most important, we believe in the technology. We think it's a game changer. It will not be the only solution. It will be a part of the many solutions. And because we know some people are scared about the cost, even the color will be a topic, is my clay. Don't worry, we will try to find a solution together. Most of the cases, we have been able to find a chemical building block to go where you want to be with the new material. Thank you very much.