Interview: Redefining Concrete Sustainability with ACI’s 212 Committee’s Report on Chemical Admixtures
Over the past couple of decades, the construction industry has seen significant change. That has especially been the case when it comes to concrete sustainability. Nowadays, there is a stronger focus on green building efforts like reaching net-zero-carbon concrete by 2050 and a higher demand for sustainable building materials. At the same time, AEC professionals now have access to a wider range of effective concrete technologies.
All of which has led to an increase in commitment to environmentally friendly practices.
It’s a concept that the American Concrete Institute (ACI) values highly, having developed their committee for sustainability, ACI Committee 130, in 2008. Through it, they have helped inform the industry of changes to the best practices in sustainable concrete construction.
Their commitment to sustainability hasn’t stopped there either. Despite the challenges of the pandemic, ACI has several committees that have remained committed to including sustainable construction as part of their mandate. And while they have been meeting virtually over the last two years, this year, they will meet in person and online at ACI’s spring convention in Orlando, Florida.
Taking part in these efforts is Kryton’s CEO, Kari Yuers, who has been a member of the ACI for decades and was appointed a Fellow of the ACI in 2010. She has always kept sustainability in mind both in her work with ACI and in her business.
It’s part of her dedication to helping the industry build better, and it shows in all facets of her work. Currently, she is bringing that dedication to her latest task in leading the efforts to revise and expand the ACI 212 Report on Chemical Admixtures.
While this work is still underway, much development has gone into it already, paving the way to redefine concrete sustainability and improve building practices and use of materials. For a little more insight on what the industry can expect in this latest 212 report, Kari has joined us today for an interview on the topic.
Thank you for joining us, Kari! We know you’re currently working with other ACI members to revise the ACI 212 chemical admixtures document. Can you share what key topics the committee had in mind for the document?
That’s a good question.
So, one of the first things we did when I came in as Chair of 212 was to solicit perspectives from ACI members and the general public. We wanted to determine what new advancements in chemical admixtures we needed to recognize and whether they needed their own chapter or could be added to current chapters.
Eventually, we settled on a range of new chapters and content. Besides updating the existing chapters, we are adding new information on admixtures for 3D printing, durability, and hardening and erosion control and the impact on the sustainability of admixtures in general.
How do you see these additions helping with concrete sustainability practices?
Well, I think it’s important to first keep in mind that we weren’t seeing widespread use of admixtures in concrete until the 1950s. By 1982, at least 71% of the concrete produced in the USA had a water-reducing admixture in the mix. The use of chemical admixtures for concrete has significantly grown from there.
It’s made them a more relevant part to the discussion on sustainability. And it’s why the committee is working hard to make sure such technologies are being recognized and discussed so that the concrete community can better understand what they are and how they can help them achieve their building and sustainability goals.
Nowadays, admixtures can play a key role in the construction and attainment of sustainability in concrete construction. After all, sustainability is about reducing waste, making solutions more effective and last longer, addressing the circular economy and that materials can be recycled, and ensuring construction methods save time and money. It’s even about making construction easier, better, faster, and safer to do. These are all things that we see as adding value. Admixtures make these qualities easier to attain.
So in view of that, we’re also trying to provide more content around durability, which is another aspect of sustainability.
With that in mind, do you think this kind of document could help support a carbon reduction strategy?
I think we have to acknowledge that concrete has received a bad name because of its relationship to cement and the carbon intensity of creating cement.
But today, there are so many ways to reduce cement consumption or maximize its effectiveness or efficiency by using admixtures and designing buildings to be much more sustainable in their construction. Part of that is because admixtures can make structures more durable. But it’s also partly due to how else they benefit and impact a project with features like carbon footprint reduction. The use of limestone cement as a solution has been widespread in some jurisdictions for over a decade. However, it is just now being adopted in many others. Admixtures play an important role in this shift to greener concrete mixes.
We already see permeability-reducing admixtures that contribute to LEED Double Platinum, Platinum, and Gold certifications for projects like the TELUS Garden in Vancouver, Canada.
The document even focuses on sustainability as a whole for admixtures in a chapter dedicated to the topic. Do you think this will be a game-changer for specifiers?
I think the simple answer is yes.
But more specifically, I think it will shift the mentality around admixtures. Currently, many look to them purely for their economic benefits. This is understandable as they’re able to reduce cement, speed up construction, and increase durability. All of which help to reduce the cost of a project.
It’s not the only beneficial angle to admixtures, though. As we’ve touched on before, they also increase a project’s sustainability. And they can do so in many different ways. The document provides these solutions. Some of which can include using superabsorbent polymers to help convert returned concrete into aggregate to reduce the need for off-site aggregate, applying rheological admixtures to limit the amount of virgin sand used, or even using admixtures for extending the wear life of concrete so that it lasts longer and requires less maintenance or fewer replacements.
It all shows that there are more ways to create sustainable concrete with admixtures than most likely consider.
Of course, AEC professionals are already using admixtures and bringing them as possible solutions to an extent. But we also need the owners and clients to understand that these materials can really make a difference to their sustainability goals and should become a part of a well-balanced approach to sustainable construction.
While it’s not out yet, when the 212 report is finalized and published, how do you think it will affect the construction industry as a whole?
It will offer the industry a way to gain more knowledge and guidance on how to build sustainable construction and how to specify and use the right materials to achieve that and meet client-specific sustainability goals.
It’s also about raising awareness of how admixtures have the ability to help professionals deal with drastic changes to the industry. With water levels rising, storms getting worse, and ongoing material and labor shortages, the construction industry has had to quickly adapt to ensure they can keep building and maintain the resiliency of their structures.
These changes have made it clear that we can’t build to the durability standards of the past. We need to think about building for the future. We need concrete that will withstand the rigors of the future that we’re already seeing signs of today. Even with some of its carbon limitations, concrete is still the most durable product on the face of the earth when it comes to building compared to wood and other materials.
So I think that becomes more about how we impart that knowledge so that people are taking action to change the way they think about their concrete specifications and their designs.
ACI recognizes the importance of that. It’s why they hold committees of concrete professionals from around the world to keep the industry’s knowledge on concrete as current as possible. Documents like the ACI 212 Report on Chemical Admixtures are just one part of that.