Concrete is the most widely used construction material in the world. It is a composite material consisting of cement, aggregate (usually sand and gravel), water, and admixtures. The concrete carbon footprint measures the number of greenhouse gases (GHGs) emitted during the manufacture, transport, and use of concrete.
Unfortunately, concrete can have a significant carbon footprint, though many testing firms, developers, and researchers are currently looking for the most sensible ways to reduce it. For engineering firms, testing labs, developers, and project owners interested in green construction initiatives, here’s what you should know about the concrete carbon footprint.
Why does the carbon footprint of concrete matter?
So, what is the carbon footprint of concrete? It depends on a few factors. The manufacture of cement is the most significant contributor to the concrete carbon footprint. Since concrete is used worldwide, it poses a widespread challenge for climate change and green business initiatives.
Greenhouse gas emissions from the cement manufacturing process include the release of carbon dioxide (CO2) from burning coal or oil and the production of nitrous oxide (N₂O) from burning natural gas.
The transportation of concrete can also contribute to the concrete carbon footprint. GHG emissions from the transport of concrete include the release of CO2 from fuel combustion and the production of emissions from trucks and other vehicles that transport the concrete.
The concrete carbon footprint varies depending on the type of cement, the aggregate, the transportation distance, and the climate. The typical carbon footprint of cement is about 0.5 kilograms of CO2 per kilogram of cement. Businesses can reduce the carbon footprint of concrete by using more efficient cement plants, using recycled materials as aggregate, and using more efficient transportation methods.
What steps are currently being taken to reduce the concrete carbon footprint?
If you’re wondering “what is the carbon footprint of concrete and how can we decrease it?” you’re not alone. There are many ways to reduce the concrete carbon footprint. One way is to use more efficient manufacturing techniques. Another way is to use alternative binders, such as fly ash, slag, or ground granulated blast furnace slag. These binders can reduce the amount of cement needed and, as a result, the amount of CO2 emitted.
Some of the many ways to reduce the concrete carbon footprint include:
- Using alternative binders such as fly ash or slag. Fly ash is a waste product from coal-fired power plants. Slag is the glassy residue that remains after metals are extracted from iron ore.
- Using recycled materials in place of aggregate. Recycled concrete can be used as aggregate but must be crushed to a minimal size.
- Using plant-based rather than fossil-fuel-based cement. Manufacturers can make cement from plant materials, such as rice husks, sugarcane bagasse, and ground-up tires.
- Preheating the limestone before calcination. This reduces the amount of energy needed to produce the cement.
- Using more efficient kilns. Newer kilns are more energy efficient than older ones.
- Capturing and sequestering the CO2 emissions from the cement manufacturing process. You can do this by planting trees or creating underground storage caverns. Some concrete mixing processes can even incorporate recycled CO2.
Another way to reduce concrete emissions from using concrete is to leverage green construction techniques. This includes using insulation, shading, and natural ventilation to reduce the amount of energy needed to cool or heat a building. It also includes using materials that are renewable or that come from sustainable sources.
Beyond that, using effective concrete testing software can help determine whether you’re implementing sustainably minded materials in your designs, structural amendments, and revisions.
Are there any drawbacks to reducing the concrete carbon footprint?
Most importantly, investing in carbon reduction initiatives is both business- and consumer-friendly, while remaining eco-conscious. However, there may be a few drawbacks for engineers, developers, and firms that don’t currently use methods that reduce the concrete carbon footprint.
For instance, finding the ideal composites for specific products and uses may take some trial and error. Beyond that, switching to carbon-friendly concrete and other sustainable building materials may represent a significant upfront cost for some brands.
Where can builders, engineers, and others turn to learn more about concrete’s carbon footprint?
When you’re ready to continue your industry education or better understand how the concrete carbon footprint can impact your projects, it’s helpful to have a working knowledge of available resources, like Build With Strength.
Build With Strength is a coalition of architects, builders, engineers, policymakers, and others, backed by the National Ready Mixed Concrete Association (NRMCA). In partnership with Build With Strength, the NRMCA’s members have reduced their emissions by 21%.
Speaking of the National Ready Mixed Concrete Association, it is the leading advocate for the ready mixed concrete industry and its members. The NRMCA provides its members with the resources they need to safely, efficiently, and profitably produce concrete. The Association also represents its members before Congress and various federal agencies, promotes ready mixed concrete as a sustainable building material, and educates the building and design communities about the benefits of concrete.
ForneyVault offers concrete testing tools to help you invest in more sustainable materials.
“What is the carbon footprint of concrete and who can help me reduce it?” For producers, project owners, developers, and managers who are ready to rethink their concrete testing processes and invest in sustainable materials, ForneyVault is here to assist you. Our platform offers robust concrete testing so you can ensure you’re using high-quality materials in each of your builds or new developments.
ForneyVault’s tools can help your researchers and team members quickly capture relevant information and create an unalterable log of your necessary test results. Reach out today to learn more about sustainable initiatives within the construction industry and how ForneyVault’s robust concrete testing software can help you automate workflows to improve your concrete performance.