Greening the production of cement

In Canada, it can seem like there are two seasons: winter and construction. Whether it’s repairing sidewalks and streets, or building new homes and apartments, much of this work uses cement – the key ingredient of concrete.

Construction comes with an environmental cost though: eight to 10 percent of total global greenhouse gas (GHG) emissions are due to the production of cement. A team from the University of Saskatchewan’s (USask) College of Engineering is exploring whether it’s possible to make cement production more environmentally friendly by substituting biochar for some of the cement that goes into making concrete.

Biochar is the fine, carbon-rich powder produced by burning plant waste (biomass) in a low-oxygen environment “We’re using the non-edible component, like flax or wheat straw,” says Ravi Patel, a PhD student at USask. “Normally, this kind of plant waste is left on the field.” Patel and his colleagues were curious what impact swapping in biochar would have on the durability of concrete. Switching from cement to biochar reduces the amount of cement required, plus it traps the carbon contained in the plant matter.

The researchers added varying amounts of biochar to the cement mix and studied each sample, first looking at how each sample stood up to the wear and tear that concrete is subjected to in real life. Then, they brought their samples to the Canadian Light Source, a national research facility of USask, to examine in ultrafine detail the inner structure of the concrete. Patel and colleagues found the samples with biochar were stronger and less porous than the ones with more cement.

Next, the team will assess how well the biochar-enhanced concrete performs over the longer term. “In our research we have studied the new formula concrete for up to 56 days,” says Patel “But we need to check this concrete strength after a year or two years, because all the structures are going to stay here for 50, 60, 70 years. We need to understand the long-term behaviour of how the biochar helps to improve the strength properties.”

The project could lead to several improvements in the construction industry: concrete production could be more environmentally friendly, using plant waste that otherwise would go to the landfill, and help concrete last longer.

“As a researcher, we want to give back to our society, our environment,” says Patel “It feels really good to get a positive result so that we can actually help address climate change.”

--

Patel, Ravi, Jarvis Stobbs, and Bishnu Acharya. "Study of biochar in cementitious materials for developing green concrete composites." Scientific Reports 15, no. 1 (2025): 22192. https://doi.org/10.1038/s41598-025-07210-3

Access images and B-roll related to this research

To arrange an interview with the researcher, contact:

Greg Basky
Communications Coordinator
Canadian Light Source
306-370-9446
greg.basky@lightsource.ca