Limestone Calcined Clay Cement (LC3) Workshop 727 367 CORA Structural

Limestone Calcined Clay Cement (LC3) Workshop

Cora Structural was a guest at a recent workshop on “Unlocking Cement Decarbonization with LC3” featuring Dr. Karen Scrivener and other top global researchers, industry experts, practitioners, and clients. The event was co-hosted by RMI and Climateworks, and included presentations and discussions on the role of Limestone Calcined Clay Cement (LC3) and calcined clays in decarbonizing the cement industry. The workshop took place at City Club of San Francisco on the week prior to the Spring ACI Convention.  Dr. Karen Scrivener of the LC3 project and Scott Shell of Climateworks wrote up a fantastic brief on LC3 and its potential for scaling up the decarbonization of the cement industry following the workshop. We think you’ll see tremendous value in the potential of LC3 in the overall movement of decarbonization. We highly recommend your read it:

The workshop was a great opportunity to connect with a range of cement industry stakeholders and provide a structural engineering perspective as both a practicing structural engineer as well as a steward of the national SE 2050 Commitment Program and its mission of achieving net-zero embodied carbon structures by 2050. One takeaway we had was on the importance of knowledge-sharing and trying to understand the perspectives of all parties. If we have any chance to meet the global CO2 targets we cannot do it in silos and this workshop completely corroborated that notion. Until we attended this event, we did not fully grasp the potential that LC3 could have on reducing the embodied carbon of concrete particularly as the availability of high quality supplemental cementitious materials (SCM) like slag and fly ash for clinker replacement level off. Being part of the conversations on the complexities of the cement and SCM supply chain, both domestically and internationally, helped us understand a bit better how things can be translated locally to current projects and when speaking with clients. As with any movement its imperative to understand the right questions to ask and we certainly heard a few we’ll be asking in our daily practice.

It was particularly wonderful to hear Dr. Karen Scrivener speak about LC3 – her expertise and drive to move the cement industry forward was inspiring. From her presentation, and others, we became educated on the scalability of LC3 by the simple fact that availability of adequate clays to create LC3 is significant globally and that calcining them can be done at a much lower rate of CO2 emissions. Its being produced in the United States, TODAY, and the potential for cement producers to produce and supply with modest upgrades to existing technology exists now.

The workshop reminded us of a great article that summarizes solutions to decarbonizing the cement industry from a global perspective. We feel this is one of the ‘go-to’ articles providing the full picture tied to the global decarbonization movement. See below.

So what to do with this information?

As structural engineers we must not only educate ourselves but educate our clients to put them in the best position to achieve their goals. The present day structural engineer must engage more on this topic, understand where opportunities exist on projects and find ways to implement all while satisfying present day project constraints. It can be done. The first step is to educate yourself and then ask your fellow colleagues some basic questions to get started:

  • To the General Contractor / Construction Manager
    • “What do you know about this low-carbon concrete movement?”
  • To the Concrete sub-contractor (on your current project if possible)
    • “Have you ever installed concrete with a portland cement replacement rate higher than 30%?”
  • To the Concrete ready-mix supplier (on your current project if possible)
    • “Have you been having any issues getting fly ash or slag?”
    • “Do you have any test data on concrete’s with portland cement replacement rates higher than 40%?”
  • To the Structural Engineer
    • “Are you comfortable specifying concrete with portland cement replacement rates higher than 30%?”

Just by asking those basic questions you’ll open up a great opportunity to learn more than you ever thought you would!

8th Grade Podcast Interview 1024 576 CORA Structural

8th Grade Podcast Interview

We had a great time being interviewed by an 8th grade student from the Newton, MA Public School system for a podcast project (things sure have changed since we were in 8th grade!).  The conversation touched on several topics with a focus on the day-to-day activities of a structural engineer. We discussed the important relationship between the architect and the structural engineer and some of the key differences. We also got to review some of the really interesting things structural engineers get to do and are responsible for and how we design the ‘skeleton’ of the building.

We were very happy to also have the opportunity to talk about what structural engineers are doing to address climate change and how the SE 2050 Commitment ( is an important commitment for firms to make. We were so very happy to hear just how knowledgeable the student was in science and the climate and pleasantly surprised at how many questions they had on the topic.

“We have made some progress that we are proud of but we need everyone, particularly young people, to really engage in this and push us to be better than we have been today.”

-Michael Gryniuk, Principal, Cora Structural

Being interviewed by an 8th grader reminded us of the obligation we have to continue to pursue the seemingly impossible task of addressing climate change and moving the structural engineering profession forward. With fantastic questions from an impressive 8th grader we sure do hope we hold up our end of the bargain!

HSS Fabrication Plant Visit 1024 768 CORA Structural
HSS Fabrication

HSS Fabrication Plant Visit

Cora Structural had the opportunity to visit the massive Atlas Tube facility in Blytheville, AR to see first hand how Hollow Structural Sections (officially HSS but you probably know them as ‘tubes’) are made.  Starting with the initial unbuckling of the huge steel coils, continuing on to the splicing of plate ends and the slowly folding to round sections and eventual rectangular sections, to the continuous seam welds, and finally to the finish cutting and stacking, it was an incredible process to witness!  And each step of the way is covered by critically important quality control measures and a highly trained staff. 

DID YOU KNOW? All square and rectangular sections start as round sections, which are then methodically shaped into sections with flat edges by way of a series of rollers while simultaneously being doused with water to keep things cool and moving smoothly.

In our humble opinion, being in facilities producing the structural elements we design and specify daily provides an invaluable perspective that ultimately makes us better structural engineers.  We are so thankful to Atlas Tube for the opportunity and for taking the time to show us around and answer all of our (many, many) questions.

Tour of Nucor-Yamato Steel Mill 1024 768 CORA Structural

Tour of Nucor-Yamato Steel Mill

Cora Structural was a special guest of the American Institute of Steel Construction’s (AISC) Sustainability Committee to participate in a behind the scenes tour of the Nucor-Yamato steel mill in Blytheville, AR. The mill produces millions of tons of rolled steel sections each year.

At the tour were representatives from the steel industry across the country including fabricators, service distribution centers, and suppliers as well as architects, engineers, contractors, and owners. The day was broken into two parts: 1. walking the steel mill and observing the process of creating steel sections starting with the initial loading of scrap steel to the electric arc furnace and continuing through to the finish rolling of wide flange sections and 2. an in depth discussion on the future of sustainable steel production which followed presentations by Nucor-Yamato, AISC, and other steel professionals.

The mill facility and its multiple buildings, roads and yards couldn’t have been any more impressive. It was incredible to watch with one’s own eyes the well-choreographed process of taking large amounts of scrap steel and converting it to new molten steel and casting large ‘blanks’ for eventual rolling to a finished product. On any given day there are specific sets of wide flange sections produced by first re-heating the blanks and then running through rollers to get the specified sizes. Standing in the facility it was hard not to ‘nerd out’ a bit and feel the awesome capacity of steel.

It’s one thing to talk about the benefits of an Electric Arc Furnace (EAF) over that of a Basic Oxygen Furnace (BOF) for steel production but its a whole other thing to stand next to one and hear the sound of (and feel the vibration of) the electric current arcing across electrodes and melting recycled scrap steel.

Michael Gyniuk, Principal, Cora Structural

At each stage of the production process were stations of employees of the mill working to ensure all systems were functioning appropriately and the highest levels of quality control. The employees were very generous with their time to explain the process and answer all of our questions.

We appreciated the candid discussion about how to achieve more sustainable steel. We reviewed the complexities of the global supply chain, the amount of scrap steel available, and how much the mill can produce in a given year (it’s a lot!). The representatives at the mill were very willing to answer all of our questions and even had some for us.

In our humble opinion, being in facilities producing the structural elements we design and specify daily provides an invaluable perspective that ultimately makes us better structural engineers.  We are so thankful to Nucor-Yamato Steel, AISC, and others for the opportunity and for taking the time to show us around and answer all of our (many, many) questions.

We learned SO much and looking forward to bringing our knowledge to future projects.

Do you know the impact of your project’s steel?

On a recent project we reviewed the source of steel for a large frame located in Boston, MA. On that project, for a large educational institution, the steel mill certificates were collected and the mill source of each member was determined. For that project and tonnage, about 800 tons, 65% of the steel was domestically sourced whereas the other 35% was from overseas mills. Using the facility-specific Environmental Product Declarations (EPD) we found that the embodied carbon impact of the domestic steel was significantly less than that of the overseas steel per ton, even to the point where the impact of the overseas steel was nearly the same as the domestic steel even at half the tonnage. There are several reasons for this and we’d be happy to discuss them with you. Have you checked your steel?

Here are some useful links to industry average EPDs and specification guidance. Note that the link to industry average EPDs also has links to facility-specific EPDs for domestic steel.

Steel Environmental Product Declarations (EPDs) from AISC – Industry Average EPDs

Specification Guidance from SE 2050 – Steel Spec Guidance

Reach out if you have questions or want to learn more!