Rishi Gupta, a professor in the Civil Engineering department at UVic, is working to reduce carbon emissions by replacing cement, a key ingredient in concrete, with other sustainable binding materials. This innovative approach to concrete production is helping to reduce the CO2 emissions caused by cement and is attracting international students to UVic for research opportunities.
Eight percent of the world’s carbon dioxide (CO2) emissions come from cement, a key component in concrete, which is the most widely used construction material globally. However, what if construction materials such as concrete didn’t contain cement, leading to a lower carbon footprint? Engineer and professor Rishi Gupta from UVic’s Civil Engineering department believes this may be a solution to reduce carbon emissions.
Gupta and his team at UVic’s Facility for Innovative Materials and Infrastructure Monitoring (FIMIM) are pushing the boundaries of concrete by replacing cement with other sustainable binding materials. One of their approaches is to use precast products, such as alkali-activated concrete paver blocks, for pavements and parking lots, including those in remote and rural communities.
This work is being done in partnership with India-Canada Impacts Centres of Excellence (IC-IMPACTS), of which UVic is an affiliate partner. IC-IMPACTS develops, tests, and scales local solutions for India and Canada.
Gupta’s first project involved geopolymer concrete, which replaces cement with fly ash collected from coal-powered plants and alkali activators. This concrete can be used for various applications and doesn’t contain Portland cement, which contributes to greenhouse gas emissions. Gupta and his team took it a step further by incorporating bottom ash from coal-burning thermal power plants, making it a more sustainable option.
Geopolymer concrete requires heat during the curing period to make it stronger, but this requires energy and creates additional greenhouse gas emissions. To address this, the research team used local fly ash and bottom ash from India and Canada and cured the concrete at ambient temperature conditions. They produced paver blocks, demonstrating the use of sustainable technology in real-world applications.
Not only is Gupta’s cementless concrete better for the environment, it has also strengthened UVic’s global connections, attracting international students interested in climate action research. The team is also examining the long-term effects of CO2 sequestration, including durability and integrating green fibers to make the concrete crack-free and self-healing, ultimately reducing the overall lifetime carbon footprint.
Gupta and his students are paving the way to reducing almost four billion tonnes of CO2 emissions from cement every year, making a significant impact in combating carbon emissions. UVic is committed to advancing the United Nations’ Sustainable Development Goals and is ranked second in the world for climate action by the Times Higher Education Impact Rankings.