Low-carbon concrete is here. Now to get people to buy it

The next step after hard-earned developments like low-emissions concrete is producing clear and believable sustainability information to back up product claims.

In the news

Concrete is the second-most-used material on the planet, trailing only water. It’s also by far the most prevalent construction material; the world uses twice as much concrete each year as all other building materials combined.

The problem is, concrete has a very high environmental impact—it’s responsible for about 7.5% of all human-created CO2 emissions. Construction’s reliance on concrete is a major cause of the sector’s push for net zero.

A big reason for concrete’s high emissions levels is cement, which—while a fundamental ingredient in concrete—is responsible for about 90% of its emissions. While alternative ingredients to cement have been identified, none can be produced at a scale that can meet the world’s appetite for concrete.

With all this in mind, it’s easy to understand the excitement around a breakthrough in which low-emission concrete can be produced at scale. Researchers at the University of Cambridge have developed a way of lowering the emissions involved in making cement by removing the need for limestone in manufacturing it. In the traditional approach, limestone is crushed and heated, along with other raw materials, to produce cement. The limestone releases large amounts of CO2 as it decarbonates to lime.

With the new approach, old concrete from demolished buildings is crushed and heated to remove the sand, stone and water from the cement. The recycled cement is then mixed with iron oxide and heated in the same electric-powered furnaces used to make steel. The resulting “slag” is used to process recycled steel and—if cooled quickly enough—creates reactivated cement that can be used in place of limestone to make concrete.

If the electric-powered furnace has no emissions (a big if—this requires it to be powered by clean electricity), this process could yield zero-emissions cement.

The construction industry is notoriously conservative where material innovation is concerned, and so are consumers. Getting people to use sustainable products is less a matter of revolutionary discoveries and more one of conveying the sustainability information in a clear, believable way.

The Cognizant take

Breakthroughs like low-emissions concrete are great news, says Philip Smith, Cognizant’s Global Head of Sustainable Business Transformation Practice. He makes note of a similarly ingenious shift, in which startup Molten Industries proposes to create graphite (a resource central to lithium-ion batteries) and hydrogen by “cracking” methane.

“But for customers to buy innovative solutions, particularly where doing so demands a premium, they need access to and belief in product sustainability claims,” Smith adds. McKinsey research “shows a clear and substantive correlation between US consumer spending and sustainability-related claims on product packaging,” he notes. The key: “clearer, reliable info on product sustainability,” Smith says.

Product sustainability information can be pulled from product lifecycle assessments, a process that helps businesses evaluate a product’s full effect on the environment over its lifecycle. With that visibility, they can assess options to reduce those impacts. LCAs can also be used to create Environmental Product Declarations (EPDs), a standardized, consumer-friendly product label. EPDs, Smith says, “are essentially just communication tools. But given the correlation between uptake and information, they’re critical ones.”

But LCAs have some intrinsic challenges. They’re labor intensive (that is, expensive) and time consuming. They also require supply chain collaboration and a granular understanding of the specific contributions of the manufacturing processes.

To increase the usefulness of LCAs, “We need to do them faster and cheaper,” Smith says. This is possible with automation. “More than 90% of footprint assessments can be automated,” Smith notes. “Through automation and by harnessing AI, time and cost can be reduced dramatically.”

Smith firmly believes that improvements in LCAs, and thus in the EPDs that flow from them, can impact consumers’ embrace of sustainable practices. “How much more of Cambridge’s clean concrete and so many other vital products would be bought if such information could be made widespread and reliable?” he asks. “We mustn’t rely solely on technology to solve the climate crisis. Success depends on coupling technology to capital, policy, business strategy and, of course, consumer behavior change.”