Sustainable concrete: Building a greener foundation for data centres

As the data centre industry grapples with its environmental impact, the focus has typically centred on operational emissions and power consumption.

There is, however, a vital part of data centres that emit tons of CO₂ that gets often overlooked: the carbon footprint of concrete used in construction.

An open letter from hyperscale giants AWS, Google, Meta, and Microsoft states that materials widely used in data centre constructions account for 23% of global carbon emissions, with concrete alone contributing 11%.

Grant Quasha, CEO of Eco Material Technologies, suggests the amount of concrete used in construction is “massive”.

“We can't do without it, but the way we've historically made it is really emissions intensive,” Quasha explained, adding that concrete production accounts for approximately 8% of global CO₂ emissions, primarily from the manufacture of Portland cement.

Eco Material Technologies are attempting to tackle the concrete conundrum head-on by repurposing waste products, particularly fly ash from the power sector, to replace highly polluting cement in concrete mixtures.

For data centre operators facing mounting pressure to meet sustainability goals, concrete emissions present a significant challenge.

“Data centres have two big emissions problems,” Quasha said. “The first that most people recognise is power. The second big problem is embedded emissions from construction, where concrete is the number one source.”

The response from tech giants has been surprisingly detailed and hands-on. “Companies like Meta have groups that are testing all these advanced materials in different recipes to determine the optimal mix design to create their data centres,” Quasha said.

Engagement from some of the biggest firms building data centres marks a significant shift in the industry, where traditionally, developers and contractors paid little attention to the environmental impact of their concrete specifications.

Eco Material Technologies offers several solutions for data centre construction, ranging from basic emissions reductions to advanced green cement options. Their entry-level approach uses traditional SCMs to achieve a 20-25% reduction in emissions.

The firm’s more advanced product, PozzoSlag, can replace 50-60% of traditional cement, effectively doubling the emissions savings while remaining cost-neutral.

The company's impact extends beyond data centres — with Quasha highlighting their materials can be found in major infrastructure projects across the US, including Samsung's semiconductor facilities in Texas, SpaceX launch platforms, and TSMC's chip factories in Arizona.

Quasha estimates that their products are used in over half of the data centres built in the US, with notable deployments including AWS’s facility in Jackson, Mississippi, Google’s data centre in Kansas City, and Tech Data Logistics’s site in Fontana, California.

In the Northern US region alone, Eco Materials suggests it’s helped avoid 80,000 metric tons of CO₂ in data centre sites in the past year. And with the ongoing market boom, that’s a number that’s set to rise.

Looking ahead, the industry is moving toward greater transparency in emissions reporting through Environmental Product Declarations (EPDs).

“Historically, it's kind of been, 'take my word for it,'” Quasha explains. “That's changing now, at least in the US, to the point where the industry in general is creating EPDs... basically stickers like you would have a bar code on something at a supermarket that tells you what's in it.”

EPDs provide detailed verification of emissions throughout the supply chain. “It basically tells you this ton of fly ash has an embedded amount of emissions... and here's why, and scan my barcode to find out why,” Quasha adds. “It's been verified that this thing came from here, it was taken in a truck that went there, the truck emissions were this, the initial plant emissions were that.”

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