Innovative Low-Carbon Cement From Sublime Systems Used in First Project

The first usage of Sublime Systems low-to-near-zero-carbon cement on a building project was notable for how ordinary and similar the process was to a normal mud mat placement.

Photo courtesy of Sublime Systems

Sublime Systems’ low-to-no-carbon concrete was placed for the first time in a Boston-area construction project by contractor Turner and local ready-mix producer Boston Sand & Gravel.

Turner could not disclose the location of the building project where the Sublime’s concrete was specified but said it is in the greater Boston area and within ready-mix truck distance from the BS&G facilities where it was produced. 

“It’s going to be in that building for decades to come,” says Leah Ellis, Sublime Systems’ CEO and co-founder. “It really was the culmination of a lot of effort to see it not just being done for testing’s sake, but actually, replacing cement that would otherwise have been the carbon intensive variety. That’s really satisfying to see.”

The cement in Sublime’s concrete is produced through a process developed at the Massachusetts Institute of Technology and pioneered by Ellis that uses electrochemical processes to make cement powder. Instead of heating limestone and clay mixed with iron ore or fly ash in a kiln up to 2,700°F, Sublime’s cement-making technology can be fueled by renewable electricity and its processes allow electrons to break the ingredients down at room temperature. Sublime’s other co-founder, MIT Professor Yet-Ming Chiang, is a involved in a similar technology startup, the iron-air battery producer Form Energy. 

“That shift in how you define cement really lets you adopt innovative products that may not be made in a fossil-fueled kiln that gives you a certain crystalline composition,” Ellis says. 

David Robb, a Turner estimator and the preconstruction manager on the Boston-area project, said that there was nothing out of the ordinary about the concrete placement on the project and that the material provided by BS&G using Sublime’s cement was tested for temperature and slump when it arrived in ready-mix trucks just as it would have been on any other project.

“In the grand scheme of things, it was, really, very boring for construction,” Robb says. “But it’s it’s a huge step in terms of our embodied carbon reduction goals that we’re striving toward in the future here at Turner.”

He says the seven-day breaks on the mat placement came back in line with planned design strength.

Robb was looking for technologies like Sublime Systems’ cement as a part of Turner’s embodied carbon corporate commitment and heard about the company in mid-2023.

Turner has a self-perform concrete group and Robb asked local project managers to inform him of any good opportunities to pilot a product with Sublime cement. In late January, a mud mat placement on a job with Turner self-performing as  concrete contractor and Boston Sand & Gravel as the vendor came together. 

Ellis says Sublime provided its cement products to Boston Sand & Gravel who mixed it to required tolerances and sent the material out in trucks where it was pumped 200 ft.

“We had an opportunity for low-risk placement,” says Robb. “These guys were thrown into the the gauntlet on a cold day in January pumping their material.”

ENR Midwest Editor and Associate Technology Editor Jeff Yoders has been writing about design and construction innovations for 16 years. He is a two-time Jesse H. Neal award winner and multiple ASBPE winner for his tech coverage. Jeff previously launched Building Design + Construction’s building information modeling blog and wrote a geographic information systems column at CE News. He also wrote about materials prices, construction procurement and estimation for MetalMiner.com. He lives in Chicago, the birthplace of the skyscraper, where the pace of innovation never leaves him without a story to chase.