Amazon Web Services (AWS) has signed to use low-carbon EcoPact concrete for building work in Northern Virginia.

AWS has signed with building material provider Holcim US, and Baker Concrete Construction, to use Holcim's EcoPact concrete for the construction of several Amazon data centers. Holcim claims that the material is available in various options with carbon emissions ranging from 30 to 100 percent less than those of regular concrete.

Concrete is a major contributor to global warming, providing up to eight percent of the world's greenhouse gases, during its production and use. Efforts to reduce these emissions include using lower-carbon cement materials and switching to renewable electricity for the heat in the process. One company, CarbonCure, injects carbon into the mix to sequester it, a process that cuts emissions by around five percent.

Holcim doesn't go into great detail on how it makes EcoPact, but materials on its site suggest it substitutes other cementitious materials such as fly ash for the Portland cement used in most concrete. The basic mix produces 30 to 50 percent less GHG than conventional concrete, with other options reducing that still further. To reach 100 percent decarbonization, it uses offsets, a controversial process that is decried by campaigners such as Greenpeace as "greenwash". DCD has reached out to Holcim for more information on the techniques it uses to reduce emissions in EcoPact.

Reports say EcoPact can be poured and mixed in much the same way as conventional concrete and has similar structural properties.

Holcim says it worked with AWS to improve its standard mix to 39 percent carbon reduction compared with regular concrete, to meet a design commitment: "AWS implemented a new design standard requiring concrete with at least a 20 percent reduction in embodied carbon versus standard concrete for new US data centers. Holcim’s EcoPact mixes allow AWS to not only meet this requirement but almost double it."

Cedric Barthelemy, regional head, mid-Atlantic with Holcim US, said: “AWS and Baker Concrete Construction are known for bold thinking across business models, which extends to the companies’ respective approaches to sustainability. Our partnership pairs AWS’ experience in data warehousing and our expertise in designing low-carbon concretes to ultimately result in contributing to a more sustainable built environment.” 

Holcim has set itself a target of reducing scope 1 and 2 emissions per ton of cementitious materials by 25 percent by 2030, from a 2018 base year.

For its part, Amazon has pledged to reach net-zero emissions by 2040, said Gurmeet Sethi, AMER head of AWS data center procurement: “To help meet that commitment, AWS is focused on continuous sustainability-related innovation across our global infrastructure, and forging industry collaborations with companies like Holcim is one way we can do that. This will both allow AWS to further reduce carbon emissions associated with the building of our data centers and create new opportunities to build infrastructure more sustainably across the region.”

Last week Virginia Governor Glenn Youngkin announced that Amazon would spend $35 billion over the next 17 years expanding its data center presence in Virginia.