Scientists discover unexpected byproduct that could revolutionize concrete production: 'An encouraging step'Jenny Allison
The Cool DownWed, August 27, 2025 at 1:30 AM EDT
3 min read
Scientists discover unexpected byproduct that could revolutionize concrete production: 'An encouraging step'It's so widespread that it can be easy to forget, but concrete is actually one of the most polluting materials in the world. During its production, both the energy used to fire it in a kiln — as well as the chemical reaction generated from the materials used — generates nearly one pound of carbon dioxide for every pound of cement, according to research from Princeton University.
"Until the overall emissions are cut worldwide, the environment will continue to be polluted with over 4 billion tonnes [4.4 billion U.S. tons] of carbon dioxide annually due to this industry," they shared.
Some manufacturers are turning to carbon offsets to lower their net pollution, but many others are looking into materially different production methods. And one study recently shared promising results of incorporating natural materials into cement, AZo Build reported.
The study, which was
published in the journal Nature Scientific Reports, examined the use of biochar — carbon-rich agricultural waste material — in ultra-high-performance concrete (UHPC). The team found that small amounts of biochar could actually enhance the strength of UHPC, reduce its shrinkage, and improve durability.
They tested this by replacing varying amounts of cement mixture with biochar derived from apricot shells and other sources, including one control group that contained zero biochar. Then, they cured the samples for both three and 28 days before testing them for a variety of performance factors, including slump (workability), density, compressive strength, water permeability, and more.
While high percentages of biochar led to a loss of performance, a 1% replacement actually improved multiple areas of performance for the UHPC — including increasing its compressive strength by 2.65%. Shrinkage also lessened, which researchers attributed to biochar's porous structure being able to regulate internal moisture and thereby assist in curing.
"By repurposing agricultural waste, this approach offers a more sustainable path for UHPC production without compromising performance," AZo Build explained, calling it "an encouraging step toward greener construction practices."
It's a critical area of improvement, considering just how pollutive the construction industry is and how much it contributes to global heating — 37% of all pollution comes from building and construction, according to the UNEP. This has led to a myriad of negative impacts, from severe weather patterns to agricultural losses due to heat, storms, and drought.
And concrete, in particular, is a major contributor: nearly 10% of all pollution around the world comes directly from concrete production, according to Princeton. However, if researchers can implement findings like this one, as well as continue to iterate on other green production practices, it's possible to slow the pollution generated from its production and create a more stable, safe future for generations to come.
https://www.yahoo.com/news/articles/scientists-discover-unexpected-byproduct-could-053000290.html
