Low(er)-carbon concrete? It’s possible.
Construction and development company Skanska uses concrete extensively in its projects. It even has its own concrete company founded in 1887 in Sweden. Obviously, technological advancement is something that the company is keen on, so it’s been deeply involved in concrete’s various applications in construction: from concrete mix design engineering, concrete production and precast manufacturing, to self-performed structural concrete work.
In November 2019, Skanska launched the EC3 tool, which had the greatest impact on concrete than any other material, according to Senior Vice President of Sustainability Steve Clem, due to its outsized carbon impact. Specifically, the tool has helped increase transparency in the supply chain and even driven voluntary reductions in the Global Warming Potential (GWP) of many mix designs, especially in the West.
“The average mix design GWP in the Seattle area reduced by 18 percent in less than a year just by changes to sourcing as a result of one mega-project asking for EC3 data,” Clem noted.
Another company levering technology to reduce concrete’s climate impact is Concrete.ai, a startup that is the result of 10 years of research at UCLA’s Samueli School of Engineering and Applied Science.
“The diversity in concrete formulations arises from the vast options of ingredients, including types of cement, aggregates like rock and sand, as well as chemical admixtures,” explained Alex Hall, CEO of Concrete.ai.
Field testing its AI-driven software, dubbed Concrete Copilot, reduced emissions by 30 percent while cutting costs by $5 per cubic yard. The platform integrates with a producer’s existing supply chains and data, basically eliminating the need for external testing. And while the technology relies on generative AI for precision, it keeps the human experience in the driver’s seat. It uses AI to identify the optimal concrete recipes for any application and allows the producer to refine key criteria and select which recipes to use, while further training the AI to identify similar mixes in the future. Time spent on this process is cut down from weeks to minutes.
“Optimization for a carbon dioxide perspective requires reduction of cement, which generates roughly 90 percent of all concrete’s carbon dioxide emissions,” Hall said. “Reduction today is primarily achieved through substitution by Supplementary Cementitious Materials like fly ash, a byproduct of coal power stations, and slag, a byproduct of steel manufacture.” But the availability of these materials depends on proximity to source, given that every ingredient of concrete is a commodity.