CO2 and the concrete industry
If airplanes were like buildings we would still be going around in biplanes.— Bechthold, 2017.
About the industry
Concrete is the most consumed substance in the world, second only to water.
Portland Cement is a core ingredient in traditional concrete. The cement industry accounts for approximately 8% of global carbon dioxide emissions. Building our world’s living spaces and infrastructures destroy our environment and kills our chance at a future.
In 2014, around 54% of the world’s population were living in towns and cities. This number is projected to increase to nearly 70% by the middle of the century (2050) (Jessen, 2003). With urban environments on the rise, the importance of sustainable developments in cities are more crucial than ever. Society’s dependence on concrete is growing; each year 8,736 billion tons of concrete is used globally (Forty, 2012).
Society’s dependence on concrete is growing; each year 8,736 billion tons of concrete is used globally.
The world’s leading climate scientists have warned there is only a dozen years for global warming to be kept to a maximum of 1.5°C, beyond which even half a degree will significantly worsen the risks of drought, floods, extreme heat and poverty for hundreds of millions of people (IPPC, 2018).
There has never been a more important time than now to change how we make, consume and use building materials.
The future is bright, but we must all make the decision to demand more.
Current state of the art
In the concrete space there are many companies that are trying to reduce the carbon footprint and increase material efficiency, it is an exciting space for both investors and consumers.
The current state of the art can be broadly broken down into four key categories: carbon infusion, cementitious replacement, the hybrid and biological bonding (growing).
Carbon infusion
Carbon infusion or mineralisation technology has become popular in recent years with concrete manufacturers to reduce their carbon impact.
This technology is interesting for two key reasons:
The carbon mineralises with the cement and increases the strength, thus reducing the amount of cementitious material needed.
It can easily be implemented into the concrete industry and requires very little retooling.
For me, this technology misses the bigger problem which is cement. While this is a step the industry can take to almost instantly reduce the carbon footprint of their material, it isn’t at the rapid reduction (7% to max 30%) that is needed to radically and rapidly reduce our carbon footprint.
Cementitious replacement
Cementitious replacement technology relies on partially or fully replacing OPC (Ordinary Portland Cement).
This eradicates the need for carbon intensive OPC but depending on the replacement, the carbon impact varies greatly from (35% to 90%).
The technology has three key interesting facets:
No need or very small amount of cement, radically reducing emissions.
Depending on the technology, it can easily be implemented into the concrete industry and require little to no retooling.
These cements can increase strength durability and/or fire resistance.
This technology offers a wider impact for reducing concrete’s CO2 emissions but does carry the risk of introducing a material that has not been widely used in the construction industry.
The hybrid
The hybrid is a mix of the two technologies mentioned above - a carbon infusion and cementitious replacement. On the surface it seems like the perfect blend of the two technologies.
This technology has two key benefits:
No need for cement or very small amounts of cements.
Pumping CO2 into concrete, further reducing the emissions.
This technology while interesting, has shown trouble in scaling across the industry due to the material not having the legacy of the other materials mentioned above, coupled with the need for manufacturers to retrain and retool.
Biological fusion (growing)
Biological fusion refers to cements that are ‘grown’ with biology rather than chemically activated. This technology offers a way to radically reduce the carbon footprint of cement.
Two key benefits for this technology are:
Non carbon intensive process using biology.
New approach to cement that require different materials.
This technology requires the rebuilding of complete systems and ways of producing materials which is cost intensive. Also the materials have not been produced at the ready-mix scale, so it is uncertain whether this material can exist outside of the factory-controlled setting.
What needs to be done
It is simple, but yet sometimes the most complex thing to do.
Purchase, invest and champion these materials. We must all demand better of our own construction projects; be that the ones we live, work or play in.
Its always darkest before the dawn and green cement technology is at the dawn of a new construction industry that is sustainable, durable and follows the circular approach.
This technology is at the forefront of changing how we make cement and will disrupt an $37 billion industry just in the US alone.
