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Concretely
Building Cities from Cities: Alfonso Paradinas Aguilera, Holcim, on Recycled Cement Paste
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Cement causes 8% of global CO2 emissions — and fly ash and slag, the industry's usual fixes, are running out as coal plants and blast furnaces disappear. Alfonso Paradinas Aguilera, Global Chief Marketing & Innovation Officer at Holcim, explains how construction demolition materials become a clinker substitute: smart crushing separates cement paste from aggregate, carbonation turns the fines into a carbon sink, and performance-based specification makes it viable for exposed infrastructure. We also cover Zurich's recycled-content procurement rules, Holcim's EcoPlanet and EcoCycle platforms, and CPC — a carbon-fiber-reinforced concrete used in five prefabricated bridges this year.
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Welcome to Concretely. I'm your host Johannes Lohne and I talk with experts about how to make our infrastructure last longer, durable, economical, and sustainable. Today we talked to Alfonso Paradinas Aguilera. I hope I pronounced this correctly. He is the chief marketing and innovation officer at Holzsim of the Holzsim group. So we have here a very high guest today. And we talk about sustainability. We talk about construction demolition materials and how they can be recycled into paste. So we talk about supplementary subtitles materials. I'm sure you all heard of it. It's what we do to reduce the clinker content in concrete. And my first uh starting
Introduction and the European heat wave
SPEAKER_02question, Alfonso, is how how did you spend the last week during the heat wave? How was it for you?
SPEAKER_00Challenging. I was actually well, anyway, thank you very much for having me on the podcast. I mean, I think it's uh um it's an honor for me to have uh, as I was telling you before, and it's an honor to talk about concrete. I I really enjoy anything related to concrete. I'm a civil engineer and I've worked very close to this material for I mean 25 plus years. And uh yeah, thanks a lot for having me. So, how did I spend uh my last couple of weeks was actually traveling? I traveled to six different countries in the last couple of weeks uh visiting uh sites and connecting with uh with our troops in the different countries. And I must say, I mean, especially in London and Paris a couple of weeks ago, it was it was tough. I mean, I'm a runner myself, and I and I actually I arrived into Paris a couple of Thursdays ago and I wanted to go on a run. Uh it was like 7 p.m. or so. And I even got changed uh my running gear and I went uh went downstairs in the hotel lobby, and when I actually exited the the building, I had to go back in. It was impossible for me to for me to go for a run. So yeah, I mean managed as as best as I could.
SPEAKER_02I have to say, my in my office it had more than 30 degrees, and on Sunday I signed up for a triathlon in Zurich and I almost died at the last part during the running. It was so hot I jumped with the shoes into the water afterwards. Um why I asked this Alfonso is as we all know, uh climate change and the main reason for it uh CO2 in the atmosphere that accelerates the heating more than it should and also creates these strong uh weather extremes, which uh maybe in a few years we will look back and think that that was harmless. Um, but it's really a big problem. And as we know, concrete or cement especially is 8% uh responsible of the global CO2 uh release. Um, so it's really a main part when you look at the other segments, uh the concrete place here. Um so I think it's a very important topic today, and I think uh also especially interesting for my guests will be uh how to apply this cement reduced concrete more in their everyday life, in their specifications in their projects, uh, and also a bit how we look at the durability part of it. Um, but what's especially interesting uh is what Holzim is doing here with construction demolition materials. I mean, I I learned about it already in university. Uh I know in Switzerland we are quite advanced, uh, especially for the aggregate part. So aggregates uh can be made out of old concrete, demolished concrete. But what's especially interesting is the cement part. Um, and this I think uh it would be interesting to go into today. Um, maybe to start with uh this uh SEMs, supplementary uh cementitious materials, which would also be a part of the what paste
Why fly ash and slag are hitting limits
SPEAKER_02cement recycled cement paste become. Today you they use more fly ash and slack, which comes from the steel production or from the coal production. Um they're already used uh quite a lot. Uh, they are in the standards. Um but maybe can you say what what's the limitation today? Why is it a good new approach to also use this uh recycled cement paste?
SPEAKER_00No, indeed. I mean, so so in the last um um few years, Holseim has really um pushed circularity to um to higher limits. And I I think we we will have the time later to discuss a little bit with a little bit more detail what what we're doing in terms of uh of circular construction at Holzim. But maybe to uh to set the scene and and to frame uh the circular construction approach at Holzim. Um indeed coal power plants and and steel industry have been primary levers for clinker factor reduction, facilitating the industry shift from SEM1 uh cements to low carbon SEM2, sem three's uh systems and beyond. But there is a bottleneck, especially as coal power plants are phasing out globally and steel production shifts away from blast furnaces towards uh newer and green steel architectures. So this is where wholesome comes in, and uh we are looking at new approaches in order to decouple the cement production from this uh fossil fuels byproducts while maintaining our very um ambitious clinker reduction targets. Our industry uh must develop new generation SCMs. And and utilizing widely available circular materials, um, the topic of today is talking a little bit more about construction demolition materials, but also we're looking at calcine clay and other SCMs that are becoming um uh more available as as we develop new uh innovation initiatives.
SPEAKER_02Oh, it's uh interesting. Um I also heard that for instance, uh, since Japan has very good steel production, they have also, therefore, very good slack, and then this slack is transported from Japan all over the world, which is also not very sustainable. Um let's come to the construction demolition materials, CDMs, uh, before we then go to the application durability side. Um next to my office, there is a house that's being demolished. Uh I took a look as always on construction sites, and there's a bunch of materials,
What construction demolition materials include
SPEAKER_02of course, bricks, concrete, glass. Uh so maybe to start with, uh what are the materials that are being used for concrete recycling? What can be used?
SPEAKER_00So, indeed, when when we talk about construction demolition materials, I think it's very important that we define what actually includes concrete and demolition materials and includes a diverse range of secondary materials under the CDM umbrella. And as you said, it extends from bricks to masonry and glass to excavation soils, asphalt, or even mineral wool.
SPEAKER_02Okay, then it's usually being uh downcycled, no? So usually they are used then for roadbeds, um, but this is actually quite cheap material. And now your approach is as I understood is to upcycle it, to usually use it as concrete again. Uh, what is the process uh that needs to be done for this?
SPEAKER_00So, I mean, what one thing that's uh also very important um for our for our audience to know is that uh Holzim has invested heavily in circular construction in the last few years. This means that we have opened quite a significant amount of circular hubs very close to what we call the urban mines. Urban mines defined as uh as cities where we're actually getting our sourcing. Our sourcing meaning uh demolition materials, but it also means excavation soils and and so on and so forth. So the way the process um uh works is that we are very close to those sources. So we collect um the materials from an excavation or uh demolition site, we bring them to our well, we sort them, normally they're on-site or off-site, and then we bring them to our circular hubs, our recycle centers. And and then what we do is we we we do a uh a process of recycling, meaning that we crush um we take it in into crushing stages, and um what basically uh you know if you look at the concrete is structurally composed of roughly 80% of aggregate, this means sand and gravel, and 20% of cement paste. This is this is cement and water. And rather than downcycling this mix into low-grade road paste, advanced technology and innovation breaks it down to high value competence. On one
Smart crushing: separating aggregate and cement paste
SPEAKER_00hand, you have the coarse and fine aggregates, this advanced crushing strips, attach the attached pore cement paste from the rock matrix producing clean coarse aggregates and circular sand, and are then fed directly back into high performance structural concrete and mortar. Now, on the other hand, you've got the cement paste, this the the cement fines uh through advanced earth separation and high frequency screening, we isolate the fine, the cement enriched mineral fractions, particles that are below um 0.25 millimeters up to um 125 microns, and these chemically avail uh valuable fractions are redirected to the cement plant to act as a clinker rum mix substitute, ARM, or a high value mineral component, what we called uh internally at wholesome mineral components in new cement formulations.
SPEAKER_02So you could call it SEM, no, in the end? It's clinker reduction.
SPEAKER_00Yes, uh MIC is is it's it's SEM. MIC is more an internal uh wholesome language.
SPEAKER_02Okay. Yeah, I think that's also the interesting part because uh replacing the cement again is is very sustainable uh and helps us with the CO2 release. Um but as I understood, um then there's more to be done with these fine particles that you said are below 0.25 millimeters. Um that there is part of there's carbonation done in the Yeah, so I think uh I think uh maybe maybe a step back.
SPEAKER_00I think what's what's very important is uh for our audience is also to understand um how are we um incorporating innovation uh within our within our circular construction. So if you look at uh conventional aggregate crushing, it does rely on high pressure crossing. I mean, through um traditional jaw or impact crushers that actually cracks the rock matrix without debonding the pores attached to the cement paste. And this results in in fractured, low-quality recycled aggregates with high water absorption, which dramatically increases the cement paste and it makes your demand in fresh concrete, ultimately driving the cost uh and and ultimately the carbon emission. So, what we have done at Wholesim in the recent years is really look at smart crushing efficiencies. I mean, through smart processing, such as selective attrition milling or wholesome proprietary smart crushing prototype. In fact, we just um commissioned one in uh in in Switzerland, not far from Zurich, they utilize mechanical grinding and friction to smoothly strip away and liberate the attached cement paste from the aggregate. So the way we normally describe wholesome is that uh this this um high-tech um crushing devices that it massages the rocks or the concrete, the aggregate themselves, allowing for that cement paste to be released from the rock itself, from the from the concrete itself. And uh as a as a result of that, this optimizes two crucial metrics. One of them is it's uh minimizes the water absorption, and then it maximizes the aggregate packing density uh to rival primary virgin stone um quality. So so smart processing at the end of the day fits perfectly into wholesome's metropolitan operations via our localized urban hubs or or or circular hubs because it provides high sky scalability by deploying um mobile processing setups close to the what we call the urban mines. And basically this recovered finds, and I think I I mentioned earlier, are directly integrated back into the existing cement
Carbonation as a permanent carbon sink
SPEAKER_00kill um architectures. And either by thermal activation, as as as you said, inside the clinker or inside the clinker um cooler, or um or via carbonation using the kill, the kilns uh hot flue gases.
SPEAKER_02Okay. So the carbonation also uh it's um like a carbon capturing almost that uh it it indeed.
SPEAKER_00I mean what what we do what the factor what we do is is carbon capture. I mean, instead of uh releasing the flue gases from uh from you know from the um uh cement manufacturing process, what we do is we we uh run it past those cement fines. These cement fines are basically sponges. So what it does is it they literally um capture the CO2 and permanently stores it. So the fact that what you have is an SCM uh that can replace clinker, but at the same time it's a carbon sink. So it it um it replaces clinker, which is by the way the most expensive part of the um of the cement manufacturing process. Uh but at the same time you have a product that um can substitute clinker and uh and become a carbon sick.
SPEAKER_02So it it's about making not only the recycling part, uh but it's also about then the quality of the new concrete. That you have something that needs consistent water, uh no high varieties, otherwise you will have sometimes harder, sometimes softer concrete. Um then also replacing clinker, it must act like a nucleation surface, so where other particles build a bond on these small substances. Um then it also must also somehow in a bit increase the strength of the cement, right?
SPEAKER_00But I think uh maybe I'll explain a little bit more what uh what is the chemistry behind this um this approach. So if you look at the old cement paste, it's it's actually very rich in calcium hydroxide and calcium silicate hydrates. And when they are exposed to to the CO2 from the flue gases, a rapid mineral carbonation reactive reaction occurs. This means that that the paste absorbs the CO2 like a sponge, as I said, turning it into stable calcium carbonate and silica gel, which is reactive. So that basically this translates in a double win because on one hand, uh uh the fact that you're basically capturing carbon and it permanently sequesters the plant's own scope one CO2 emissions directly into the recycled material. But the second, uh, even more important, it creates a decarbonated or even a carbon neutral SEM. Because this carbonated paste is now reactive, high-value supplementary cement tissue material. And you can basically the factor use it to substitute virgin clinker, and this dramatically drops the clinker factor. Clinker factor meaning the the amount of clinker within within the cement composition. And um just to give you a um maybe a um you know a big peace of mind, um Holzim is targeting 65% reduction um by 2030. So um so this means that the uh this means that the carbon footprint of the new cement will will dramatically be reduced by 2030 in the next in the next four or five years. Yes.
SPEAKER_0265% reduction for for what kind of uh cement classes?
SPEAKER_00So I mean what what we are doing, um it in fact, in in the last few years we have dramatically reduced the amount of the percentage of sem one that we manufacture and sell. I mean, I think uh now the sem one percentage uh um in Europe uh we're talking uh less than 10%. And I mean the idea is that we go to a sem 2, a sem three, sem 2A, sem 2b, uh, sem three, sem 4 uh by using alternative SEMs, yes.
SPEAKER_02Okay. Well, that that's fantastic. Um many of my listeners are in the infrastructure uh area where we talk often about exposed concrete, so free saw cycles, carbonation, chloride exposure. So it's a bit of a special case of concrete use, so you need high resistance. So I was wondering a bit uh about the application um or the durability also.
Durability and performance-based specification
SPEAKER_02When would you use uh this uh clinker-reduced uh cements coming from CDMs, construction demolished materials, or this paste? Uh or how you call it in the end, uh the cement.
SPEAKER_00I the well, I mean it's it's a cement, uh low-carbon cement. I mean, I think what what we I mean, this is where my marketing hat comes in. And I mean, we have uh what we call Eco Planet that we launched uh five years ago now. And in fact, now uh year to date we have sold out of the total net sales of uh of cement in the group, we are at 36% of low carbon, um low carbon cement offering. This means that uh our ecoplanet um it's it's it's close to or will finish the year with close to uh three billion plus net sales. And the aim is to reach 50% of our net sales coming from uh coming from Eco Planet. Now, um to follow up with your question.
SPEAKER_02Includes all SEMs. Fly ish.
SPEAKER_00Yes, yes, ecoplanet. I mean the definition of ecoplanet is 30% uh 30% below um the um the um an average CO2 uh footprint of uh of uh of uh of a cement within a market. So we're able to achieve, I mean, in order to have an ecoplanet brand, uh branded product, we need to have 30% below, at least 30% below an average uh CO2 footprint of um within within a market that we operate.
SPEAKER_02From which year?
SPEAKER_00Uh no, that's that's it's a rolling, it's uh it's on a yearly basis. So yeah, this is get uh recalculated. So um and just to follow up with your questions, I mean when you talk when you talk about uh durability acceptance and quality proof of this uh low carbon cements, I think um often engineering concerns include um they're worried about uh the carbonation resistance, they're worrying about um faster uh portlandite depletion, reduced uh pH um buffering, alkanility of uh over time, um, variations in early strength development, uh maybe talking about uh workability retention. And and I think what's what's important is that uh you know we you know we move away for from prescriptive minimum cement contents or strict uh clinker factors. This means that specify direct performance-based criteria. So we have to look at uh when we are selling this low-carbon cement, we have to look at um at um at performance-based targets. I mean, pair the concrete design specific carbonation resistance directly with corresponding concrete cover steps to safe uh safeguard and reinforcement. I mean, we also need to prioritize strict validation of the water to cement ratio, and that ensures disciplined curing practices and use uh real-time digital monitoring sensors. And we have at Holseim, we have developed SmartCast, Smart Therm to track on-site strength development and internal uh temperature differentials during mass pores. I think it's also important to um to have warranty inspections. So we conduct standardized depth uh of carbonation testing and and surface durability, logging to confirm the execution quality matched to the asset long-term service life performance requirements. So I think um in order to reduce the concerns of uh of engineers, construction companies, it's important that uh we perform those tests, but also we um we we talk about um um specific uh design uh carbonation resistance and performance-based criteria. So all in all, uh our low carbon cements, they have um they behave from a structural standpoint, um from uh carbonation resistance, uh, from an early strength development, from a workability retention um um standpoint, uh equally if not better than than uh to traditional SEM1.
SPEAKER_02So you would say that uh engineers could specify also for exposed structures like uh bridge?
SPEAKER_00Absolutely, yes. And the fact that ecoplanet is used in structural um concretes all the time these days. I mean this is it's not really um it's not really affecting the durability, it's not affecting the uh uh you know exposure, um uh you know, carbonation resistance, it's not affecting the workability. So so the fact that this ecoplanets are specified in um in structural elements, it's specified in uh um infrastructure projects, in residential and industrial um setup. So there's I mean absolute no problem.
SPEAKER_02And uh can you highlight again this uh performance-based approach? What exactly do you mean with that?
SPEAKER_00So I I think um one thing that we are doing uh, especially more these days at wholesome is really we're going up the value chain. And what we are um we're doing is it's it's really focusing early stages in a project and specifying our low carbon solutions, our system selling approach, um, just by uh co designing um a structure or a project uh with Architect with the engineer that's specifying those solutions. So I think it's it's the this um partnership with uh designers and specifiers that is uh giving us also that competitive edge because we have the technology, we have the know-how to be able to specify um our cements, our concrete uh products uh in a way that uh that there's no compromise on quality, there's no compromise on on performance, there's no compromise on strength and durability.
SPEAKER_02And so with performance-based, do you mean uh a bit going away from these classical exposure classes like XC3 or XD, uh, and defining more exactly
Standards: EN 197-5, EN 197-6, EU Circular Economy Act
SPEAKER_02specific performance characteristics like uh carbonation resistance, chloride content. Exactly. And uh but today there are no standards for this, no?
SPEAKER_00Or is there well I uh that's that's also it's very interesting that you point this out. I mean, uh what's also very important for us is is that we sit down with um standardization bodies. Uh and this this this is not just for the low carbon cements, for the low carbon concretes, for the low carbon products in general, but also from a circularity standpoint. Uh, I think what's very, very important is that we partner up. We have this public-private uh partnerships and and and partnerships with um with standardization bodies in order to in order to to uh change some of the standards, to evolve those standards and those norms to allow for lower uh carbon footprint within our within products, within uh projects, but also to increase the recycle content uh within the standards. So uh and and and yes, of course, I mean I think it's important that we evolve those norms. Um, we need to make sure that the testing uh it's it's um it's it's carried out uh before we change those standards, and this is done uh in conjunction with the standardization bodies, and we're working um hand in hand to make this uh a reality.
SPEAKER_02What's your experience here? Is this a slow process?
SPEAKER_00Uh do you see uh things changing? I mean, I think uh uh I'm uh for for sure. I mean, uh things are things are changing. I mean, what's already on the way, I mean, if you look at the regulatory landscape, is actually moving faster than expected in Europe. You have the this new EN uh 1975 established uh multi-component low clinker formulations. We have the EN 1976 that officially opened the door for cements containing up to 35% of recycled uh concrete fines. We have additionally also the the EU Circular Um Economy Act and the revised uh waste uh framework directive are targeting uh they're actually targeting EU-wide um end-of-waste criteria for mineral demolition fractions. And while the the EU ETS officially recognized carbon mineralization into products as a permanent uh carbon removal lever. So things are things are moving in the right direction. And and to be fair, although yeah, sometimes it's slow, but um, but what we're observing is that uh really the the the normalization bodies are rolling up their sleeves and uh and um and things are things are things are moving. So but but I think it's very important that we have this uh partnership approach. Because I think it's it's uh it's a win-win situation on both sides.
SPEAKER_02And the European Union works here together. It's not the countries are not doing their individual things.
SPEAKER_00Uh so what you what what's important is that so you have the the the EN, the European directives, and then what we do also at a local level, we we have um we have teams that are basically partnering
Zurich's recycled-content procurement rules
SPEAKER_00up also with uh local bodies in order to accelerate this um this transformation. So I think the the lobbying exercise, the advocacy exercise, needs to happen at all levels, both at a I mean in this case at a European level, but also at a country level. And this not not just for low carbon formulations, but also for the recycled uh content within it, within the our products.
SPEAKER_02I I think also the local bodies uh might be interesting uh because uh of of the uh dumping cost of construction demolition materials, no. Um because today it's cheap to just put it away in the ground. Um but I think local authorities would be helpful if if they'd increase the cost. Um so these materials are being recycled and reused, no?
SPEAKER_00So absolutely. I mean, this is this is very close to my heart. I mean, I I joined Holzim three and a half years ago, and I was one of the the first tasks that I got given was really to push our circular construction strategy. And um and what I always say is is we do have Zurich as our North Star. So if you look at the city of Zurich, I mean, both from a uh from a CO2 footprint reduction as well as from a recycled uh content um increase, they have really set the bar, meaning that uh for every for any public uh work, any uh public uh procruitment forces you to have a um reduction in your CO2 footprint of any product, any solution, any system that you supply. Uh, but at the same time, it requires to have a minimum percentage of recycled content within any material that you uh that you want to supply. So I think what's crucial in order for us to um advance our circular construction strategy in order to reduce waste uh and to and to reutilize waste is is to have um uh stricter landfill regulation in place. And and again, Zurich is our no-star. And what we're doing, um we're partnering up with municipalities. And this is not just uh to um to know, let's say to co-develop um stricter landfill regulation, but also to um for us to take um municipal waste because the big advantage that we have as a cement manufacturer is that we can take anything, we can take any waste. I mean, what we're trying to do is is is we we are we're trying to through advanced processing technologies to reuse as much as possible. But if there's anything that uh we cannot uh really use, we can we can use it in our combustion process. So so we have a company called Geocycle within within our group uh that what it uh what it does is basically looks for alternative um alternative fuels. So we are partnering up with municipalities, we're partnering up with private companies that have um byproducts uh that we can actually use uh as our combustion process to dramatically reduce the exposure to fossil fuels. And uh what I can tell you is that in in some of our some of our European plants, especially in Eastern Europe, we are achieving uh close to uh 90 to 100 percent of uh what we call thermal substitution rate. It means that we are not using any fossil fuels to uh combust for our combustion process in those plants. And and in fact, in some of these plants, our energy costs are negative. Because um this is also very important for our um recycle business or for our uh CDM businesses in order when when the landfill regulation becomes stricter and you have actors within uh within the the construction um business that they are excavating to build a new residential um block, uh housing block, or they are building a new um data center, or they're demolishing a building to build a new one, or they are refurbishing and they're getting rid of some of the construction demolition waste or material. Um they because the landfill is is uh not allowed in in the likes of Switzerland and so on, UK, Belgium. We take the material, we take the their byproduct, their waste, we're getting paid for it, and then we bring it to our circular hubs, uh, in the case of CDM materials, or we bring it directly to our um geocycle plant, which is the the plant that we have in order to uh process um alternative fuels and to fuel our kilns.
SPEAKER_02But to to create uh clinker, you have to heat up uh limestone, uh gypsum and so on to uh something around 1300, 400 degrees?
SPEAKER_00Yes, around 1400 degrees, yes.
SPEAKER_02It's not uh easy to do with recycled uh well.
SPEAKER_00I mean, uh it indeed is not easy, but uh but we have um I mean we have very, very different types of uh waste streams, and we're using I mean anything that we could get our hands on. I mean, it that that's the beauty and that's the competitive advantage that uh that Holzim has, that we can actually process any waste. And indeed, yes, of course. I mean, the calorifical the calorific content of the different waste streams uh varies. So uh but
EcoCycle, circular hubs, and M&A
SPEAKER_00but uh but but um by having this partnership with municipal municipal um entities and also with private companies, we're able to fulfill uh the needs of uh of some of our cement plants. So this means that again, we're not using fossil fuels for our for our combustion process in some of the plants where we operate. And by the way, again we're using organic waste, we're using, I mean, you name it. I mean, we we can use de facto anything that we can get our hands on.
SPEAKER_02All right. Um one question I had uh uh do you know by any chance the percentage of minimum recycled content that Zurich requires?
SPEAKER_00Yes, between 25 and 30 percent.
SPEAKER_02Oh wow, yeah, it's not bad. But uh significant. The government doesn't do it, only the municipalities and so it depends.
SPEAKER_00I mean, you know, in Switzerland it depends. I mean, it's it's uh it's driven uh at a canto level, right? So definitely the uh the the most advanced in this case is the canton of Zurich, where this uh this recycled cont minimum recycled content is is is imposed. In other cantons it's lower, and in in other in some cantons there's still they're still drafting uh new um uh recycled content laws, but uh, but this is this is in the making.
SPEAKER_02Um what I wanted to touch on is I'm also a bit big fan of UHP FRC. We had a few episodes on this. Uh I know Horzim is also uh producing one. Um and I think especially infrastructure it's very durable, um watertight, um, you can make much leaner uh structures, less weight. So I think there is definitely a place for it. Um I wanted to understand a bit from your approach. When would you say such materials make sense that they have much more cement, uh, but they are much more durable and and more efficient, and you save on volume, or or you use the uh ecoplanet products?
SPEAKER_00Yeah, so absolutely. I mean, we have um high performance materials that we have within our product portfolio. We're talking about a product called Dubtau. Um, I mean, it's true that it's it's not uh it's not for every use. Indeed, it's it's the cement uh content, it's much higher. Um but uh having said that having said that, I think uh specified uh for high low distributions. Um they have lean, you can make lean, slim elements. Uh for infrastructure retrofits, for example, we're using ductile quite a lot. Um exposed structural applications like rope bridges, thin facades, um, even overlay waterproofing, we're using we're using ductile. And this this actually minimizes the the the sheer volume of uh material needed on site and dramatically extends the infrastructure's full service life and structural durability. Um maybe also important or interesting for you to know that we also have a product uh where we have um full IP um
UHPFRC and carbon-prestressed concrete (CPC)
SPEAKER_00ownership called uh CPC, which is carbon pre-stressed concrete. And actually, I was visiting our facilities, our manufacturing facilities in in um in Germany yesterday, and this is a revolutionary product. I mean, and and what it uh what you can do is we have embedded um fibers, um carbon fibers within uh within uh concrete um slab. And this this production process allows you to have very, very high strength, um, very very good durability, with a very, very thin layer or slap, concrete slap because of this pre-stressed um carbon fibers. And and this we're using actually in in balconies in Switzerland, we're using in Germany. We are um this year we have um already sold um five full um bridges, pre-uh fabricated bridges with uh with this uh structure elements. It's a very special way of um casting and it's controlled to the millimeter because they have very, very thin uh pre-stressed carbon fibers that are embedded into the into the concrete. And because of this very, very thin um carbon fiber embedded into the concrete, we can have very, very strong concrete um with very high strength with very very thin layers. So this is very interesting. I mean, and and and this is starting to really uh uh to to really kick off, and and we are getting a lot of traction with this with this product. It was actually invented in uh in uh at Sangalen University by by two professors.
SPEAKER_02Not DTH or MPA. Um but the fibers are like distributed everywhere or are these cables?
SPEAKER_00Fiber uh very, very thin cables. And they're there then you pour the concrete and you and and basically you pre-stress them and then you pour the concrete.
SPEAKER_02And you have the advantage of not using steel, so you don't have corrosion.
SPEAKER_00Exactly. There's no corrosion, you can you can very you can have very, very thin slabs.
SPEAKER_02Yeah. I'm generally a fan of fibers because you have uh in all this concrete uh minimum rebars, even if you don't need them structurally to to distribute the cracking from from the shrinkage tracks. And uh I think that's an old approach because the steel can corrode and um doesn't make it durable, and with fibers you can uh make it durable and with the same strength uh compared to the minimum rebar. Right. Do you uh promote this too?
SPEAKER_00Or yeah, no, absolutely I've I fully agree. I mean, again, I mean we we are we're using fibers in a lot of our uh concrete products for sure, and and emphasizing as well the um this uh C CPC CPC product because I think it's uh it's a fantastic product that uh needs recognition. And of course, I again I put my marketing hat on uh and uh encourage you to start promoting our our CPC technology.
SPEAKER_02Okay, Alfonso.
Holcim's Approach
SPEAKER_02Let's go a bit back. Um, I think you mentioned already some of uh uh Holzim's approaches um that you have these circular hubs where you also take care of the recycling part. So you I think you invested even in recycling uh companies, so you have the full cycle value chain uh in in this area. Um then you of course the Eco Planet products. Uh, I think you have even a platform. Uh can you elaborate?
SPEAKER_00Ecocycle. Yeah, yeah, absolutely. I mean, we we we often used to say uh that um at wholesim we're building cities from from cities. So I think what we have demonstrated in the last few years is that uh our circular construction is paying off and it's driving profitable growth at Wholesim. And indeed, we we launched uh two and a half years ago Ecocycle, which is our wholesim global technology platform and a brand for circular construction. And the way it functions is the circular label across our aggregates, our cement, our concrete, um, our mortars, and it guarantees that any labeled product contains a minimum of 10% and up to 100% of recycled CDM by weight without compromising our quality or performance. So as you mentioned um earlier, so Holzim is actually extending our network of circular hubs. So we are um pre-closing of Sela, we were at 109 uh local circular construction hubs that are locally um located in major metropolitan areas and close to our production facility. So that this gives us a um fantastic um value chain competitive advantage because we are very close to the sources as we call them. So very close to the demolition sites, to the excavation sites, because our circular hubs are close to what we call the urban mines. But at the same time, we're very close to our operations. These circular hubs are located relatively close to our cement plants, they're relatively close to our concrete operations, our pre-cast uh manufacturing plants, our our mortar plants, et cetera, et cetera. So so we are we control the entire value chain. And that gives us really a very uh interesting competitive advantage. And just to build up on what you said, we are growing these hubs uh organically. So by applying for recycled permits, that allows us then to build a recycle center close to a city. But at the same time, in countries where um the market is very consolidated, we're also taking advantage of value creative MAs. So in the last three years, we have managed to um acquire 10 companies in the UK, in Belgium, in France, in Germany, in Switzerland, and and what uh what this these companies are obviously adding value to us. We're talking uh in some cases over 30% of EBIT margins. And and this this model, this business uh business model works. Of course, there's an incentive in in cities like Zurich because there is a minimum requirement uh to use recycled content within any public uh procurement. It uh obviously facilitates the price premium to go up.
SPEAKER_02Yeah, I have to say you're uh much more advanced
Closing call to action
SPEAKER_02than I would have thought. We started a conversation focusing on this uh cement-based recycling, which is I think very interesting. You went into detail here. I think it's uh also creates a bit of trust that this is something solid. Um, I really like the case that you mentioned a lot uh in Zurich. I think it's really a good example for other places, other countries. Um, also that Holzim is already scaling up uh this approach with EcoCycling Ecoplanet uh shows that the technology is really here and it's more now on the side of municipalities, uh local authorities, uh governments to tighten the regulations with this recycled content. Maybe also for specify engineers, I think it's good to understand that Holtzim gives support for the specifications. If if there are some concerns about some durability issues or so, you help them specify in a way that this shouldn't be a problem. So this is really a big step forward for sustainability. So I thank you very much for explaining all of this today. Is there something you would uh finish with?
SPEAKER_00Um, I mean, maybe maybe I can I can uh just finalize on on maybe like taking the opportunity that I have with you to to have like a little bit of a call for action, call to action. I think what's important, I mean, maybe uh just focusing on four uh very quick points. I mean, I think it's important that we rewrite specifications. I think the we need to strike for prescriptive prescriptive minimum clinker cement constraints from building locks and replace them with uh performance-based durability specifications. I mean, uh number two, maybe mandate circular content. Uh very important that we integrate strict minimum recycled content uh thresholds, let's say 10% up to 30%, directly into public and private procurement rules to simulate uh a stable market pool. Uh, maybe number three, it's enforced carbon transparency. I mean, I think demanding digital, third-party verified, on-demand EPDs at the bidding stage to drive data-driven low-carbon material optimization. And then last but not least, I mean, really um focus on innovation. I think optimize structural design, partner closely with uh building solution teams early in the design loop to utilize alternative materials and shape optimized systems. We're talking about uh 3D printing and high performance overlays, uh, ensuring that uh uh concrete is um is only poured exactly uh where the load distributions dictate. And maybe one last point um it's on the landfill regulation. I think, I mean, Holzim is taking the lead here. Uh, we are um really partnering up at a municipality level to really push for stricter landfill regulations. And by the way, this is not just a European game. Uh, we have examples in other countries. We're talking, uh we have a pilot project uh within the municipality of Casablanca, we have another pilot project uh within the municipality of Mexico City. And what we're doing is really partnering up with the municipalities in order to create and shape uh circular um norms and standards uh to demand for land stricter landfill regulations because there's a win-win on both sides. I mean, for a municipality to to um to incentivize construction companies to uh really um streamline their waste and to create an ecosystem for um for uh companies like Holzim but uh recycled uh uh companies to uh to to really create an ecosystem uh for for recycled uh materials, it's it's uh, as I said, a win-win on on all sides.
SPEAKER_02Yeah, that's a great summary and call to action. From from my point, uh I just want to repeat the performance-based specification, which I think is critical because we have to all work together and uh speed this up, because this is a really big thing to change. Uh, but I think it's it's really necessary and uh uh up to date to do that, to really specify concrete uh how it makes sense. Uh no, Generally was uh super cool and to hear your approach. Um I think it was really good, very honest, and uh wish you good luck with with your future works at Holzim. And see you soon, maybe. Thank you.
SPEAKER_00Thank you very much, Johannes, for the opportunity, and uh really it was a pleasure to discuss concrete. As I said, I'm a concrete lover, so any time.
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