Building for climate change with Firth EcoMix Low Carbon Concrete
Is it possible to build with concrete and reduce your carbon footprint?
As New Zealand’s leading concrete manufacturer Firth has been deeply engaged in the conversation about how to design for climate change with concrete, something an increasing number of designers are looking to understand. It’s often talked about but hard to define when designing a building.
Taking a whole of life approach to ensure the structure will be here for a long time is more important than ever, making concrete a logical choice. But how can we be sure?
Concrete’s benefits include:
- Long product life - with low maintenance
- Durability - perfect for foundations, retaining structures, infrastructure, and industrial floors
- Fire resistant
- Good sound attenuation
- Hardscape applications (permeable mixes are achievable with additional storm water control and water quality benefits)
- Thermal mass - the ability to store heat providing inertia against temperature fluctuations.
These benefits, combined with availability, excellent quality control and cost competitiveness make concrete construction an attractive proposition, right? However, as with all materials, there are aspects of the report card which read - ‘could do better’. For some time the focus for the concrete industry has been to find ways to reduce the carbon footprint of concrete.
What is a carbon footprint?
A carbon footprint is a colloquial term for the Global Warming Potential (GWP) of a material or product. It is expressed as a number of kilograms per CO2 equivalence (CO2e). The equivalence refers to converting the impact to global warming of a range of gases to that of carbon dioxide. For example, 1 kg of methane is approximately equivalent to 24 kg of CO2 in terms of global warming potential.
So we need to know this number. You may see claims about ‘reductions in the percentage of embodied carbon (CO2e)’ - but what does this mean? Without knowing the reference number that reduction comes from it’s impossible to know if that is the best option for reducing carbon. Instead it’s best to look for the GWP number which can be found on the product’s Environmental Product Declaration (or EPD) - a third party verified document that shows the GWP and whether it’s the right product for your project.
