Carbon-Negative Concrete: A Promising Solution to Reduce Carbon Emissions
2023-08-04
| Policy Research and Advocacy Team, Friends of the Earth (HK)
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.