Carbon-Negative Concrete: A Promising Solution to Reduce Carbon Emissions

The construction industry is a significant contributor to global carbon emissions, accounting for approximately 37% of the world's carbon footprint.[1]The production of concrete, the most widely used construction material in the world, is responsible for a significant portion of these emissions.[2]However, recent advances in technology have enabled the development of carbon-negative concrete, a prospective solution to reduce carbon emissions and mitigate the impact of climate change.

Buildings and construction's share of global final energy and energy-related CO2 emissions (Image Source: IEA)

Carbon Impacts of Concrete (Image Source: Carbon Smart Materials Palette)

Carbon-negative concrete can be made using carbon capture and storage (CCS) technology, which captures carbon dioxide emissions from industrial processes and uses them for concrete production.[3]In addition, instead of using traditional binding agents like Portland cement, fly ash and slag can be used as alternatives.[4]Unlike Portland cement, which requires high-temperature heating and releases significant amounts of carbon dioxide during the manufacturing process, recycled materials have a lower carbon footprint as they require less energy to produce.[5]

Production of low-carbon concrete products (Image Source: Abdulaziz Alturki)

Several companies have already begun producing carbon-negative concrete products and developed a technology that injects carbon dioxide into concrete during the mixing process.[6]The carbon dioxide reacts with the concrete, forming calcium carbonate, which permanently sequesters the carbon dioxide and strengthens the concrete.[7]Researchers at Washington State University have also recently developed a promising formula for an environmentally friendly, carbon-negative concrete that is almost as durable as conventional concrete.[8]

The biochar-infused carbon-negative concrete (Image Source: Washington State University)

Furthermore, the use of recycled materials in carbon-negative concrete can also reduce waste and support the circular economy by creating a market for recycled materials that might otherwise be sent to landfills.[9]This can also contribute to the creation of green jobs and support local economies.

The circular economy in the built environment (Image Source: RPS)

Despite the promising benefits of carbon-negative concrete, there are still challenges to its widespread adoption. Currently, the cost of producing carbon-negative concrete is higher than traditional concrete, which may deter some construction companies from adopting the technology. Additionally, there is still a need for more research and development to ensure the long-term durability and performance of carbon-negative concrete.

Carbon-negative concrete is a promising solution for reducing carbon emissions, waste, and promoting the circular economy while mitigating the impact of climate change in the construction industry. To encourage the widespread use of carbon-negative concrete, governments and industry leaders can incentivize its production and use through policies and regulations like carbon pricing and green procurement. [10]Increased investment in research and development can also help reduce production costs and improve its performance. By fostering sustainable and eco-friendly construction practices, we can contribute to creating a more sustainable future.