Skilled Labor Series: Concrete Making
*This episode is part of our Skilled Labor Series hosted by MCJ partner, Yin Lu. This series is focused on amplifying the voices of folks from the skilled labor workforce, including electricians, farmers, ranchers, HVAC installers, and others who are on the front lines of rewiring our infrastructure.
Today’s guest on Yin Lu’s Skilled Labor Series is Alana Guzzetta, a 15-year veteran of the concrete-making business. Alana started as an intern, worked her way up to being a lab technician, and now runs the R&D lab at Vulcan Materials. She has both a bachelor's and master's of civil engineering.
In this episode, Yin and Alana delve into the history of cement and how new technologies are disrupting an industry that dates back to the fourth century BC. They also discuss the environmental impact of cement, which is responsible for approximately 7% of total global CO2 emissions, a staggering number that highlights the significance of concrete as a material in the world and its carbon footprint.
Alana shares her insights on the latest innovations in concrete-making, including the use of alternative materials and carbon capture technologies. She also sheds light on the crucial role that research and development play in the industry, and what her job as an R&D lab manager at Vulcan Materials entails.
Get connected:
Yin’s Twitter / LinkedIn
Alana Guzzetta / Vulcan Materials
MCJ Podcast / Collective
*You can also reach us via email at info@mcjcollective.com, where we encourage you to share your feedback on episodes and suggestions for future topics or guests.
Episode recorded on March 8, 2023.
In this episode, we cover:
[3:06] Alana's academic journey getting into the concrete industry
[7:32] The difference between cement and concrete
[8:57] An overview of concrete and supplementary cementitious materials
[11:22] The carbon-intensive cement-making process
[17:53] Alana's role managing the concrete lab at Vulcan Materials
[19:30] An overview of Vulcan Materials
[23:29] A few example projects Alana has worked on with architects and startups
[25:00] What success looks like for Alana and her team
[29:38] Her experience working with CarbonCure
[32:04] A direct air capture project with Heirloom
[35:54] New technology in the cement industry including zero carbon cement and utilizing waste products
[41:07] Advice for people interested in working in the concrete industry
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Yin Lu (00:00):
Hey, everyone, Yin here. My guest today is Alana Guzetta. Alana is a 15-year veteran of the concrete making business. She started off as an intern, worked her way up to being a lab technician, and now she runs the R&D lab at Vulcan Materials. Alana has both a bachelor's and masters of civil engineering, and in this episode we get into the history of cement and how new technologies are disrupting a thousands of year old industry dating back to the fourth century BC and what the heck a R&D lab manager does at a concrete making company. We learn a lot from Alana, but before we get started-
Cody Simms (00:36):
I'm Cody Simms.
Yin Lu (00:38):
I'm Yin Lu.
Jason Jacobs (00:39):
And I'm Jason Jacobs. And welcome to My Climate Journey.
Yin Lu (00:45):
This show is a growing body of knowledge focused on climate change and potential solutions.
Cody Simms (00:51):
In this podcast, we traverse disciplines, industries, and opinions to better understand and make sense of the formidable problem of climate change and all the ways people like you and I can help.
Yin Lu (01:04):
And with that, Alana, welcome to the show.
Alana Guzetta (01:07):
Thank you.
Yin Lu (01:08):
All right. So the context here for us getting connected is I put an ask out there to Twitter and to our MCJ community to talk to someone who is an expert in concrete and someone who works kind of on about the ground level in a concrete plant. And two community members, Riley O'Hara and Mike Carter-Conneen reached out and said, "If you were going to talk to anyone, you should talk to Alana Guzetta." So overwhelmingly, your name was floated to the top of both of their lists, and so I'm just so excited to learn from you today. Before we get started, we should just set the stage that concrete, if you don't know, is the most consumed man-made material in the world. At the environmental impact of a cement, which is one of the key ingredients in concrete is responsible for about 7% of total global CO2 emissions and that's about three times the emissions of global aviations just to level set on how big concrete is as a material in the world and its carbon footprint.
(02:10):
And you, Alana, have had a decade plus of experience in the business as a lab technician, and then you worked your way up to currently managing Vulcan Materials Research Lab, which is pretty cool. I don't know what the research lab entails in the concrete business, but excited to find out. And your role has expanded my understanding to include kind of exploring technology's help with corporate sustainability goals and you sit in this really unique position to learn and collaborate with new technologies that are coming onto the market. Gosh, just you are going to be full of knowledge that I hopefully will absorb and our listeners will absorb too. And so with that, I'd love to just get into it. Maybe as a starting point before we talk about local materials and the research lab, just tell us about you. What was your academic journey in getting into the concrete business? Did you always know that this was an area that you had interest in and wanted to get into as a professional career?
Alana Guzetta (03:06):
Sure. Well, thank you. Yeah, I'm excited to talk with you today and for me, it's definitely not something I planned out or had vision for prior to college or even during college. As you mentioned, I studied civil engineering at San Jose State. Born and raised in San Jose. I've lived here my whole life. And so when I first started with civil engineering, I did it mainly because I was interested in math and science and I wasn't really sure what career I wanted, but I wanted to do something technical. I thought I was interested in doing structural design or something like that. I really kind of got introduced to concrete, one, because my dad is a civil engineer. He worked for a water utility, but I remember him teaching us that the sidewalk is concrete, not cement. So as a kid, I think it's funny that I learned that and ended up that being a big part of my career.
(03:52):
But then in college, because I lived at home, I was looking to get involved in something that would help me meet people. And I like being competitive. I did sports in high school, so I actually joined the Concrete Canoe team, which is a competition through the American Society of Civil Engineers. I actually originally thought I would do their steel bridge competition because that feels more like structural design. And there were just some really great people at the concrete canoe table who I'm still friends with, and they were like, "Come join us." And so I figured, okay, I'll just try it. I ended up doing it for four years, had a fun time. The competition is basically as students you have to design a concrete mix, build a canoe out of it, and then you take it to your regional competition and race it on a lake against other schools who have built their concrete canoes.
(04:37):
So there's a lot to it in terms of the mixing, the designing, you have to do a presentation, you have to write a technical report, and then there's also the athletic part of having to paddle it and compete. So that was really kind of what brought me into understanding a little bit more about concrete as a material. I had an internship in college with a concrete contractor, so one of my first jobs was getting mixed designs from Central Concrete, which is where I work now. But even then I was not thinking that would be where my career would take me. And then when I was graduating college, looked at kind of a variety of career opportunities and ended up accepting the role within the research lab. At the time it was US Concrete, now our parent company is Vulcan Materials due to the acquisition in 2021. But I've been in the research lab the whole time for the last 12 years or so, and that allowed me to be able to work here and go to grad school at the same time at San Jose State and get my master's in civil engineering. Also work with a professional engineer so I could get my professional engineering license.
(05:39):
Once I had finished all that up, I had still thought that I was going to focus on structural or I did focus on structural engineering when studying my master's. But once I had graduated and finished, I enjoyed studying it, but I didn't think I really wanted to be a structural engineer and I liked the team and the people and the environment here and just chose to stay. So yeah, it was all just sort of pursuing things that I was interested in and just ended up being here and realizing that the concrete material side is a career path for civil engineers, which I think isn't necessarily obvious in school because civil engineering is so broad, there's a lot you could do with it. And concrete materials tends to be a fairly small portion of your overall education.
Yin Lu (06:19):
Within your education path on civil, was there a specialization that you had to do specifically on materials, specifically on concrete, or was it just part of a general curriculum?
Alana Guzetta (06:29):
It's just part of the general curriculum. So yeah, that's why it's not very obvious is that what you pick for the things you're going to... The classes you take that specialize are either transportation or water resources or environmental or geotechnical design or structural. And as I look back, I actually really liked the mechanics of materials class and the introduction to material science, but through that, I didn't necessarily see an obvious career path. But as I look back, I kind of go, "Well, it really makes sense where I ended up because I really liked those classes and I get to use that as a base for what I do here."
Yin Lu (07:04):
Yeah, it's interesting, all these domains of transportation and structural, they share that most of these domains use concrete in allowing them to work.
Alana Guzetta (07:14):
Definitely. Yeah.
Yin Lu (07:15):
Very cool. Okay, I want to take a step back on what your dad explained to you as a child that cement and concrete are different. And so for those of us who use the terms, I mean for me somewhat synonymously until doing further research, what is the difference?
Alana Guzetta (07:32):
Yeah, so concrete is really the final product, and that's the material that the sidewalk is made out of, that your building foundations are made from, that bridges are made from, and cement is really one of the ingredients in concrete. So concrete is made up of, at a very basic level, it's rock, sand, water, and cement, or there are other powders we can put in as well. So cement is basically limestone that's been heated and ground down to a powder. And so in that form, it will react with water through a chemical reaction that we call hydration and that's what makes it go from kind of a fluid state as it's delivered into a truck, and then it's poured and placed. And as it sits there, it gets hard. It's that cement reacting with the water that makes it hard. The rock in the sand that's in the mix, we call those aggregates. So the rock is a coarse aggregate and the sand is a fine aggregate.
Yin Lu (08:24):
Got it. So you have cement, which is crushed lime plus these aggregates, and you add water into the mix, and then it turns from powder to a fluid and then eventually a solid. Maybe if we can break those down a bit, and if you can maybe zoom out and give us a history of just cement, how did it come to be that we're like, "Ooh, yes, let's take limestone and crush it, and let's make cement." And then how did we in our industrial arc figure out like let's turn that into concrete.
Alana Guzetta (08:57):
Sure. Well, I can't get into the details of the history as well as I wish I could, but it's something that goes back thousands of years. We see a lot of articles now that look at the Romans and the structures that they built and the type of concrete that they used. And that concrete is a little different than what we have now, but it's the same similar idea. They were taking powder ingredients, so lime, they were taking ash, it could be volcanic ash, using that, mixing it with aggregates and making a version of concrete. And then Portland cement is really that cement powder ingredient and that... I can't remember now when really the start of that was, but that is kind of what the material that we've had for hundreds of years now that gets used as that powder ingredient for hydration, and that makes the concrete what it is.
(09:50):
So it started with Portland cement, and then a few decades ago, really, we started looking at alternative cementitious materials or what we call supplementary cementitious materials that could be used in addition to that cement, and they really add durability. The cool part is that those actually help us to reduce the carbon of concrete, which we can get into a little bit later in an explanation. But those actually are waste products from other industries such as slag and fly ash, which come from the seal industry and coal firepower plants. And those are waste products that we actually use in concrete that actually result in a lower carbon for the concrete. But originally when they were used, it wasn't for that goal, it was actually because they offer higher strength and better durability, and that's something then that was sort of a progression of concrete`` started with Portland cement, and then we started using these supplementary cementitious materials and expanding the use of them was getting us lower carbon concrete with actually better durability properties.
Yin Lu (10:55):
Why is it called Portland cement?
Alana Guzetta (10:58):
It's basically the region from where it was developed from. So I think it's a region right off of England or that's part of England. And so it was the rock that was used there to create the first Portland cement, and then that's the name that stuck with it because that's really kind of where it originated.
Yin Lu (11:16):
Got it. It's a lime from a specific region near the UK.
Alana Guzetta (11:20):
Limestone.
Yin Lu (11:21):
Limestone. Okay.
Alana Guzetta (11:21):
Yeah.
Yin Lu (11:22):
Yep.
Alana Guzetta (11:22):
Limestone.
Yin Lu (11:22):
Got it. So with the Portland cement, and now over time there's new cementitious materials that you use that reduce carbon. Maybe if we can take a step back and just lay the foundations for why making cement, and then we'll get into concrete, but cement. Why making cement emits so much CO2?
Alana Guzetta (11:41):
Sure. Yeah. So cement is the most carbon intensive ingredient in concrete, and there's two reasons for that. One is you're taking limestone and you're putting it in a kiln and you're heating that kiln to 2,700 degrees. So to get that type of heat, you're using a lot of fossil fuels and there's the CO2 that's associated with that. Then the reason you're heating up the limestone is you're trying to change the chemical state of it. And so that chemistry that changes, a result of that is releasing CO2 from that calcium carbonate form.
(12:15):
That calcium carbonate is the limestone that we're talking about. And so when you take that calcium carbonate and you heat it up, CO2 gets released to then form it into a more reactive form. So part of it is just the chemistry that makes Portland's network so well needs to release the CO2 in that chemistry process. And our company is not a cement producer, but as I understand it from cement producers, the amount that comes from the fossil fuel energy used to heat the kiln is maybe about 40% and about 60% of the CO2 emissions then is from that chemistry reaction.
Yin Lu (12:51):
Got it. For those who are listening who want to have an additional perspective on the science behind carbon emissions for making cement, there's a really good episode that we recently did with Leah Ellis from Sublime System, so I'd encourage giving that one a listen to. So understanding the carbon emissions associated with cement, now's turn it over to concrete. And so you take this powder that is cement and you mix it with aggregates and water. What is the additional carbon footprint added once you turn cement into concrete?
Alana Guzetta (13:27):
Sure. So I think I'll just address that in the context of the carbon footprint of concrete just in general because really our Central Concrete, which is a subsidiary of Vulcan Materials, and that's actually my lab is located at their main office. They really led the way in being able to measure that and quantify that, so we quantify it using something called an environmental product declaration. We call them EPDs for short. An EP D will show you several sustainability metrics that quantify the sustainability of a concrete mix. And the way we get that is by looking at what were the processing emissions of all the ingredients that we use. So the cement, heating it and the kiln grinding it, that chemistry release, but also the aggregates as well to collect and process the aggregates. And then any of the supplementary cementitious materials that we use, what went into making those materials as they are.
(14:21):
Then there's the transportation of those materials to our concrete plants, and so there's emissions that are calculated for that as well. Then at the concrete plant, there are emissions associated with the energy required to store and move all those materials and then put it in a mixer, mix it up and put it in the truck. And so that is the frame that an EPD will show. So typically I've looked at these numbers and kind of broken it down for mixed designs. The cement portion is anywhere from 70 to 90% of the total CO2 emissions of that concrete mix. The plant portion to actually mix it is maybe about 5% of the total CO2 emissions. Usually that's measured in the form of a term called a global warming potential or GWP. That'll be a number that is a kilograms of CO2 equivalent per cubic meter for the mixed design.
Yin Lu (15:17):
Got it. And so it sounds like any optimizations we can make along the way. It sounds like a large part of it is in the cement making process for the carbon footprint and the small portion, but still a non-trivial portion, 5 to 10% as associated with the rest of the process?
Alana Guzetta (15:32):
Yeah, it's really going to be more a function of how we put the materials together, how we use and proportion them in the mix. And that's kind of the benefit of concrete is that we can get all types of different performances out of concrete with the same core ingredients. It just matters how we put them together and how we proportion them in the mix. So we can really do lower carbon concrete by either replacing some of the cement with those supplementary cementitious materials. So the supplementary cementitious materials like slag and fly ash that I mentioned earlier, the reason they reduce the carbon of a concrete mix is that we're actually use them to replace some of the cement and use them as powder instead of a portion of the cement. So when we look at cement being 70 to 90% of the GWP, that does give us a good reduction.
(16:21):
Cement producers are also changing the cement types that they're making and they are making some cement types that are a little lower carbon. And so one example of where that's really happening in the industry right now is going from a cement that meets a certain ASTM standard, which is just a set of criteria that's physical and chemical requirements to comply with. Going from that type of a standard to a different type of a standard that allows you to put more of the raw limestone into the final blend rather than having to do as much limestone that goes through the kiln. And so those are called a Type 1L. There's a few other different types as well, but like a Type 1L cement would be a lower carbon cement. So now the portion of the concrete mix that is attributed to cement now has an eight to 10% reduction of carbon when we're able to use those types of cements.
(17:15):
Then the other piece too, the aggregates, while they are not as carbon intensive, they do make up 60 to 70% of the actual concrete mix of volume. So they significantly contribute to what type of performance you're going to get, and this speaks to what type of cement efficiency you can get. So there's a lot we can do with the aggregates as well in selecting ones with a geology that has a higher strength or where there's shapes that make the mix more workable. And by how we proportion those, by which ones we select, we can also just make it so that the mix needs less cement in order to get to the strength that we need.
Yin Lu (17:53):
Fascinating. I want to double click into both of those areas in terms of new technologies that you're seeing, but maybe before we do that, I'd love to understand your role and welcome materials a bit more. And so can you just give us a high level overview of Vulcan Materials, Central Concrete? You talked about those two organizations, one being the parent company, one being the subsidiary, and then how much does Vulcan Materials kind of produce in the grand scheme of global concrete making? And talk a bit more about your job specifically on a day-to-day basis.
Alana Guzetta (18:27):
Sure. So in terms of my role and what my department does and how that fits into the company, I manage our concrete research lab. So we have various technical teams in the areas that we deliver concrete across the country, and so those are our quality assurance teams. And the quality assurance teams manage putting together all the concrete mixed designs that we have available to sell to customers. They handle the technical questions, they handle testing and data that needs to be produced for those. And my team is the one team that's dedicated to kind of being separate from that everyday production and focusing on the research side of either developing new types of mixes, targeting certain types of performances, but also working with some of the companies that are out there that are developing new materials or new technologies for us to consider using. My team is really the resource that vets that out for our company and then shares that information and works alongside our quality assurance teams to then take solutions that we want to implement and move them forward in that.
(19:30):
So Vulcan Materials is an aggregate concrete and asphalt producer. So we have locations and facilities from California to the East Coast, mainly the southern part of the United States. So that means that Vulcan owns material quarries for that rock and that sand produces that. And then we also have concrete plants in the California area, in the Virginia, DC area, and then also in Texas, and then we have asphalt plants that are scattered throughout the United States as well. Central Concrete is the concrete producer subsidiary that we have specifically in Northern California. So that's pretty much throughout the San Francisco Bay Area and then going up towards Sacramento and Napa markets as well in Northern California.
(20:16):
And so my research lab is actually located in San Jose at Central Concrete's main office. So while I work with all of our various concrete subsidiaries being located, right here with Central means that I usually work most closely with them, and my role here has been not only to really manage the day-to-day operations of the research lab and the projects that we're doing and collaborate with startup companies and other companies that have technologies for us to consider looking at, but to also work with the design community, with architects and engineers. And that's been a really cool way to incorporate my civil engineering background to be able to work alongside of them because in a normal construction sort of setup or structure, we don't usually have direct contact with the architect or the engineer.
(21:04):
You've got the architect and the engineer, you've got a general contractor on the job, then sometimes the subcontractor that's actually placing the concrete and that subcontractor would be buying the concrete from us. Sometimes the general contractor is the one buying the concrete, but everything goes through them. But the designers are the ones that set the specifications for the project and set certain criteria for what the concrete needs to meet. And so our sales team is the one that's interacting with our customers, so those are the contractors. And so there's no real direct interaction with the designers unless we try to do that through my team.
(21:36):
So being here has been really cool because I get to be part of a pretty robust technical team. We've got both myself and Patrick Fraley, our quality assurance director, our professional engineers, and then we also have Juan Gonzalez, who's our sustainability manager, who also has a civil engineering background. And the three of us kind of work as a technical team together in reaching out to architects and engineers, collaborating with them, letting them know what we can do on the concrete material side so that projects can really be set up knowing how they can achieve low carbon or how they can make the most of the concrete for that project.
Yin Lu (22:12):
Hey everyone, I'm Yin a partner at MCJ Collective here to take a quick minute to tell you about our MCJ membership community, which was born out of a collective thirst for peer-to-peer learning and doing that goes beyond just listening to the podcast. We started in 2019 and have grown to thousands of members globally. Each week we're inspired by people who join with different backgrounds and points of view. What we all share is a deep curiosity to learn and a bias to action around ways to accelerate solutions to climate change. Some awesome initiatives have come out of the community.
(22:41):
A number of founding teams have met, several nonprofits have been established, and a bunch of hiring has been done. Many early stage investments have been made as well as ongoing events and programming like monthly Women in Climate meetups, Idea Jam sessions for early stage founders, climate book club workshops and more. Whether you've been in the climate space for a while or just embarking on your journey, having a community to support you is important. If you want to learn more, head over to mcjcollective.com and click on the members tab at the top. Thanks and enjoy the rest of the show.
(23:12):
Can you give a tactical example? I was going to say, can you give a concrete example, but I didn't want to get that, punny.
Alana Guzetta (23:18):
That's okay. I love stuff like that.
Yin Lu (23:21):
So what's an example of a project that you've been working on that involves architects as well as, let's say, startups with new technologies?
Alana Guzetta (23:29):
Yeah. Well, there's been several in terms of projects that we've worked with. There are a lot of engineering firms here who have wanted to be really progressive with how they do their specifications. There's one project in particular that just comes to mind mind because they're going to be getting an award for it at the National Ready Mix Concrete Association event next week where Mar structural was the engineer on the project, and our quality assurance director really worked closely with them on coming up with mixed designs that would be the lowest carbon for that project. That was the... I think it was called the Casa Adelante project. And I can't remember at the moment what city that was in, but that was one where we were able to work with the structural engineer to show them what we could do for the lowest carbon concrete and still meet their structural goals and then work with the contractor on that for being able to make sure that the mixes were ones that they could place and they could use.
(24:27):
And that had, I forget off the top of my head, but I want to say it was like 50 to 60% reduction in embodied carbon for that project. We were able to show it in what we call a project profile, where we put together a document that will show using our EPDs, here's what the carbon is for the concrete, here's how it compares to industry benchmarks. And we're able to do that really on any projects that we're working on that could be helpful at the start with the design team or even later on carrying through the project.
Yin Lu (25:00):
That's so fascinating that you're in this startup within a big company that has existed for many decades working on a material that is so ubiquitous. It's really interesting to see the vantage point that you have and really trying to change up incumbent processes, incumbent materials to help meet sustainability goals and help address climate in a really substantial way. I wonder, is an R&D lab within a concrete materials company? Is that the norm or is that an anomaly that is unique to Central Concrete and Vulcan Materials? And I guess also, what are your OKRs? What does success look like for you and your team in a given let's say year?
Alana Guzetta (25:43):
Sure. I wouldn't say it's the norm from what I've seen. So that is something I'm so grateful to have had this position and to have this opportunity and that it was here, located here where I was going to school. When I started the lab, had only been part of the company for about three or four years, so it's pretty new when I got started. At this point I've been around for over half of its life, so that's been a pretty unique experience. So I would say it's not the norm. A lot of large material producers do have research labs, but a lot of those tend to be international companies. So they'll have a research lab in America, they'll have a research lab elsewhere wherever they're located in the world. But for smaller companies, that's definitely unique and for being just an American based company. We're definitely not the only one out there, but it isn't something that you're going to find all over the place. So that's been really cool.
(26:33):
Oh, and what does success look like? For me, that's one thing that's been just part of career development is trying to figure out what does that success look like for our team and being able to get better at that. I would say the first thing I think of is just making sure that all the testing we do has purpose and has value and gets utilized. So making sure that when we are doing testing, we've got everything logged and recorded because sometimes we don't see the use of it immediately, but I'll have things where people will come to me with questions or What do you think this is going to do? Or how do you think the results would be if we did this? And I can go back to data from four or five years ago and say, "Well, we tried that or we've done a version of that. Let's see. So that way we're not starting from scratch or at ground zero, we've got something to back that up."
(27:22):
So to me, I hate seeing our time in the lab and our testing efforts go to waste. So I like to try to make sure that what we're doing makes sense and that then it's all logged for the future as well, so that way we can just keep building from it and not redoing the same thing over and over just because we haven't remembered it. And then being available to provide technical answers for some of the questions that are out there. So that's kind of the first piece of success that I look at is making sure that we're able to still be a resource that way. But then success also looks like being able to take new technologies and apply them, getting them from the lab stage to the field stage or to like a pilot stage and then out into a production stage.
(28:03):
And that's the part that doesn't necessarily always happen every year. That's the part that can take a long time, and that's the part that can be challenging too, is to figure out how long do you try something before maybe that's not the right answer, and when do you pivot and switch directions? That's something that I think is a challenging part of the job that I'm still learning how to do that well. Then I think also success is just also being a resource to when there are new technologies out there, our company will be asked, "Hey, have you heard of this? What do you think about this?" And so making sure that we are staying up to speed with what are all of those different options available so that way when our sales team or someone within the company gets asked that, they know they can come to me and be like, "Hey, have you heard about this? Have we tested this?" I can either say yes or no and or explain why or just have familiarity with it. And so just being an expert for the industry and for our company to be at the forefront of new technologies and leadership and innovation.
Yin Lu (29:07):
I think being part of Vulcan Materials in such a big company that's existed for many decades, you're uniquely positioned to help take some of the technologies that might be at a lab or pilot stage and really think about the viability at a production or full field stage, which is really, really neat. One of the recent things that you all did in partnership with Heirloom and CarbonCure, can you talk about that a bit more? I don't want to butcher it, and so I'd love to hear what your role was in making that partnership happen.
Alana Guzetta (29:38):
Sure. Yeah, no problem. Well, so I'll start with CarbonCure first because there's really two companies that were involved in that we were working with Heirloom and CarbonCure. CarbonCure is the one that we had a relationship with first. And really when I talked about the ingredients of concrete and the ways we do lower carbon, the CarbonCure technology is really the newest one that we're doing. And so that allows us to put recycled CO2 into concrete as an additional ingredient. So now we not only have powders, rocks, sand, water, we also have recycled CO2 that goes into the concrete mix. So they developed a technology for injecting that CO2 and developed the system that would go at our plant to do that. So we now have CO2 that's taken from emitters and stored as a liquid at our plant, and then it's used as an additional ingredient into our concrete mixes.
(30:30):
Central Concrete has about eight or nine plants with that setup here in the San Francisco Bay Area. They were the first Concrete Ready Mix producer to bring that to the San Francisco Bay Area market. We also have that on the East Coast with our Vulcan concrete supply out in the Virginia, DC area. They were also the first to bring it to that market as well. And now we've implemented it at a plant in Texas as well. So we've been working with them ever since about 2017, and so that started with my team really vetting out that technology. It was a little unique because we couldn't test it out in the lab, so we were doing that in the field at the plant. So in 2017, we were running a lot of pilots and testing defined what was the CO2 doing to confirm the strength boost that we were getting out of it, the right dosages and combinations.
(31:14):
Then in 2018, we signed on as a CarbonCure customer and started permanent plant installations. So since then, CarbonCure has developed a wash water technology. So they've now come up with a way to inject CO2 into recycled water, and this recycled water is something that we have at our plants. We handle it differently at different plants, but there's one plant in San Jose where we have a reclaimer that separates out the aggregate and this pasty water, which would be the recycled water and stores that in a tank that then we can use as batch water. One of the challenges with that and the controls you have to have in place is watching the specific gravity of that water and making sure that we're using a controlled amount in the mix so that we're not going to change the set time or the strength of that concrete mix.
(32:04):
So one thing that CarbonCure is offering is injecting CO2 into that. So now we're going to have the CO2 reacting with the water turning into limestone and becoming permanently sequestered the same way that it does in our concrete mix when we inject it directly in the concrete mix. And it's going to help make that water more consistent and more stable, which is going to be a helpful operational process for us. My understanding is that we're the first one in the US to pilot that technology. So the timing of that was we were getting that all set up to start in January. And then Heirloom is a company that I first got connected to a couple of years ago where they said, "Hey, we've got a way of doing direct air capture CO2." So not necessarily sourcing it from a production emitter, just taking it straight out of the air.
(32:53):
And so I got to meet them and work with them a couple years ago, see their lab scale version of this and kind of help talk through what does our industry look like, what are our needs on that side, how do we use CO2? And through that just kept in touch on trying to figure out what's the best opportunity and how could we use their source of CO2. So then this really just aligned with the greywater demonstration that we were doing where we used their CO2 as the first CO2 within this greywater treatment system.
(33:26):
So on February 1st, we had CO2 from Heirloom that had been produced through their production facility. They have a pilot located in Brisbane. So they brought us that CO2 and we treated the greywater with it, and then we're continuing to move forward in testing out the Carbon Cure greywater system and looking at how to implement that in our operation. But with that February 1st demonstration, that was the first time that direct air capture CO2 was utilized in concrete to my understanding. So that was a pretty cool opportunity we got to bring both of them together and do that.
Yin Lu (34:02):
So just so I have a clear understanding of the partnership, you took direct air capture CO2 from Heirloom, which is awesome because we're an MCJ portfolio company, Shahan and his team are wonderful, and you use that CO2 to put it into the greywater treatment system that CarbonCure has come up with, and then we're able to then use that water, mix it with the cement and the aggregates, the Vulcan mix to make low carbon concrete.
Alana Guzetta (34:33):
And you can do any type of mix. You do any low carbon concrete mix with it, and now you've got less potable water that you've used because you're able to use some of the recycled water and you've got sequestered CO2 in that recycled water now.
Yin Lu (34:47):
And that CO2 is fixed. If I were to use the concrete to build a structure and it gets demolished like 20 years later, what happens to the CO2, if anything?
Alana Guzetta (34:59):
Yeah, it'll stay permanently in there. So it's basically the opposite of what happens when you make cement. You're turning limestone into what we call a clinker, and so you're releasing CO2. So now we're going the other way around, and we're taking those calcium ions that you're getting from cement that's in the water or wherever, you're reacting it with CO2 and you're putting it back as limestone. That's a very stable product that we have to heat to 2,700 degrees to release the CO2. So as long as the concrete isn't being heated that high, that's not going to be released, that's going to stay as limestone. That's a permanent solid in the concrete, like the other ingredients.
Yin Lu (35:40):
Gotcha. Okay. We just deep dove into that one specific example. If we were to zoom out and look at in general, what are the interesting new technology areas that are popping up in cement and concrete? Can you talk to those?
Alana Guzetta (35:54):
Yeah, there's a lot of them out there and some are coming up are startup companies. Some are very established companies that are coming up with new products to use. So I just sort of categorize them in a few different categories. So one I would say is that there's new cements and new cement production processes that are coming out on board that would either give us lower carbon cement or zero carbon cement, potentially even negative carbon cement. There's also new alternative supplementary cementitious materials, and that could mean just looking at... You know, slag and fly ash are not going to be around forever id the quantities we use them in. As I mentioned before, slag comes from steel manufacturing and a lot of the steel manufacturing processes are changing that don't have that same type of waste. And then fly ash comes from burning coal at a power plant, and so that is going to become less and less available.
(36:47):
So looking at what are the other sources such as natural porcelain or other clays, other things that we can use out there to make concrete. There's also sequestering CO2 into an existing material that's used in concrete. So there are some treatment processes, there are ways of making calcium carbonate from CO2 that would either become a new ingredient or could treat the current rock sand cementitious materials that we use. There's also different waste products. Being part of the research lab, I always get samples of certain type of waste products that are like, "Hey, can we use this in concrete?"
(37:24):
And so that's a benefit is that with concrete, you can sometimes use waste products from other industries as another ingredient in concrete. With that, you always want to make sure it's adding some type of value to the concrete, not that we're just putting waste in it. And so there are various new sources of that that we get to take a look at that some have CO2 sequestering properties as a part of them, so they could really lower the carbon of the concrete mix by using them. And others are a useful way of just making sure we're using up waste and conserving natural resources.
Yin Lu (37:58):
Can you elaborate on that a little bit more? What industries are producing these new potential waste products that could get integrated into the concrete making process?
Alana Guzetta (38:05):
So there's a few different that I think of. One is just in the concrete industry, the extra concrete that doesn't get used on projects that could be turned into recycled concrete aggregate. Some of those, there are treatment processes out there where you can actually utilize the carbonation that concrete does. When concrete sits in the environment, it will absorb CO2, and so taking advantage of that through recycled concrete aggregate and sequestering CO2 and using that. Biochar is a big topic as well. Right now there are various sources of biochar, which could come from either wood or wastewater treatment and through the pyrolysis process that there are materials coming through there. I'm aware of products coming from the aviation fuel industry where there are sustainable fuels, but now new waste that come from producing those, so trying to utilize those. Those would be the ones that come to mind at the moment.
Yin Lu (39:03):
Very cool. Okay. It's great to learn about the potential more circularity in the concrete making business. Just curious on, when we think about low carbon concrete, is that something that is still done in the pilot lab phase or is that happening at full production? Yeah, can you speak to that?
Alana Guzetta (39:22):
Sure. Yeah. I would say low carbon concrete is definitely available, and it looks differently though throughout different parts of the country. So that's the important thing to understand is that with concrete, one of the benefits is that it's regionally produced and regionally available, and that makes it an on-demand product that can be ordered to accommodate construction schedules with all types of different properties and performance. But then an important piece to that is that it's very regional, so not every solution is going to be right for each region or for each type of application. So it's important to work with concrete producers on figuring out what is the lowest carbon solution that can be developed for this specific application, needing these specific performances and meeting the contractor's schedule and placement requirements. And so within that, I would say Central Concrete has really led the way in offering low carbon solutions. In the San Francisco Bay Area, low carbon solutions are definitely available out there at full production scale right now.
(40:21):
The newer products that are going to potentially take concrete to zero carbon, that's really what's still at the lab scale right now and at small pilot scale. And so then it's figuring out what are the ways that we get that from the lab and pilot to a production scale that a concrete facility can actually use. Because that can be one of the challenges is making that leap from the lab to concrete production scale. Because as you mentioned earlier, there's a lot of volume of concrete that's used, and a concrete plant needs to be able to handle all of the orders for that day and has limited storage room for all of the different materials. So how do we get a volume of these new products that's going to be able to incorporate into that current concrete production scale?
Yin Lu (41:07):
Gotcha. Super helpful. I want to be mindful of your time. Thank you so much for coming onto the show. I have one last question, which is the genesis of why we're doing this series is to help more people understand and realize the career paths within the climate economy. So as we're thinking about a climate economy in the future, I think concrete is a material that is going to continue to be ubiquitous in our lives, and we need more people to work on making this industry lower carbon for the sake of our global climate. And so curious what advice you have for people that might be interested in working in this arena who can explore more.
Alana Guzetta (41:45):
Yeah. Depending on where a person is in their education or career path, first students and internship is a great way to start, and I definitely recommend that. I was encouraged to do an internship in school and really interning anywhere in the construction business is a helpful way to start because then you start to get a feel for the industry. And having experience in one aspect of it never hurts you, whether you decide to go somewhere else within the construction industry. So concrete producers on the aggregate side, on the asphalt side all have internship opportunities and so that's a helpful way to get your hands a little bit dirty, work in the lab, and get a feel for really understanding these materials and kind of starting there. Then there are certainly a lot of industry associations that have additional events or competitions or just conferences to get involved in, so those are always a helpful way. If you're not already in the industry that you're just looking to connect and kind of learn some more, those are always helpful ways to get plugged in.
Yin Lu (42:47):
Okay, great. Well, Alana, thank you so much for spending time with us today. Oh my gosh, you should see the pages of notes that I took-
Alana Guzetta (42:55):
Oh, well, I appreciate it.
Yin Lu (42:56):
... and you sharing your knowledge.
Alana Guzetta (42:56):
Thank you so much.
Yin Lu (42:57):
All right. Take care, and thanks again for your time.
Alana Guzetta (42:59):
Thank you so much. You too.
Jason Jacobs (43:01):
Thanks again for joining us on the My Climate Journey podcast.
Cody Simms (43:05):
At MCJ Collective, we're all about powering collective innovation for climate solutions by breaking down silos and unleashing problem solving capacity.
Jason Jacobs (43:15):
If you'd like to learn more about MCJ Collective, visit us at mcjcollective.com, and if you have a guest suggestion, let us know that via Twitter @MCJPod.
Yin Lu (43:28):
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Cody Simms (43:37):
Thanks, and see you next episode.
