Decarbonizing concrete, one patio at a time

Earlier this month, a 575-sf patch of concrete was poured as part of a public space known as the Paseo, inside One Boston Wharf Road, a 707,000-sf 17-story building in Boston’s Seaport district that is scheduled for completion later this year. Amazon will be the building’s sole tenant.

What makes this newsworthy, you ask? Well, for one thing, One Boston Wharf Road, developed by WS Development, will be Beantown’s largest Net Zero Carbon office building. Its goal is to reduce greenhouse gas emissions by more than 90 percent below code requirements and eliminate 5.1 million pounds of CO₂ annually. (WS Development recently announced that it had purchased renewably generated electricity for all electric power used by its Seaport portfolio.)

Also see: AGC releases decarbonization playbook to help assess, track, reduce GHG emissions

The concrete installation represents the first commercial application of low-carbon cement manufactured by Sublime Systems, a business that the Massachusetts Institute of Technology spun out as an enterprise in 2010.

Production of cement currently accounts for 8 percent of global CO₂ emissions, mostly caused by the intense temperatures required to make cement clinker from limestone, a common ingredient in concrete. Sublime Systems, which is based in Somerville, Mass., claims that its Sublime Cement, the product's marketing name, avoids traditional cement’s major emissions sources, limestone feedstock and fossil-fueled kilns, by applying electrochemistry to extract cementitious ingredients from non-carbonate materials, without degrading the properties that make concrete the most-used building material worldwide.

Sublime Systems’ technology makes ASTM C1157-compliant cement, a drop-in replacement for Portland Cement in concrete. The company, which was incorporated four years ago, has raised more than $140 million from tech investors, and cooperative agreements with several U.S. Department of Energy programs. The company’s pilot plant has a 250-ton annual production capacity, and Sublime Systems is developing a 30,000-ton capacity commercial facility that will open in Holyoke, Mass., in early 2026.

“We and Sublime share the same vision and mission,” said Yanni Tsipis, a Senior Vice President at WS Development and a lecturer at the MIT Center for Real Estate. “We have an opportunity to showcase the most forward—thinking low-carbon building technology on the planet in the public space, at the heart of the building. This partnership epitomizes the value of technology transfer from incubator to industry.”

Educating the public about lowering carbon

The floor of the Paseo, in which Sublime Cement is installed, will be marked with educational material explaining the significance of decarbonized cement in the battle against climate change. The Paseo will lead to a new 1.5-acre park called The Rocks at Harbor Way that will be the focal point of a one-third-mile promenade that connects to the water’s edge. (James Corner Field Operations came up with this concept for Harbor Way.) One Boston Wharf Road will feature 77,000 sf of retail space.

Copenhagen-based Henning Larsen designed One Boston Wharf Road in collaboration with Gensler. Turner Construction is the general contractor.

One Boston Wharf Road is adjacent to 11 Harbor Way, a 525,000-sf, 17-story office tower that WS Development completed in the spring of 2022.