The role of cement and concrete in the circular economy
The question is: what is our role in the circular economy, and what do we realistically have to offer?
- Raw materials: Did you know that the raw materials that we use (limestone for cement and aggregates for concrete) are abundantly available in Europe? This is important, as we are not extracting and using scarce raw materials.
- The cement manufacturing process: It probably comes as no surprise to hear that we use primarily coal and petcoke in our kilns. But what you may be less aware of is the fact that we are able to replace part of these traditional fuels with fuels and biomass derived from waste. Not only does this form of energy recovery reduce our dependence on fossil fuels, we are also able to recycle the ash back within our process. Our main energy sources are : petcoke, oil are the primary fuels with which we fire up our kilns; that, you know; what is probably new to you is that the cement industry in Europe takes a pioneering role in recovering energy and recycling material from waste in an operation we call “co-processing”
- Concrete: Concrete is in fact made up of cement, water and aggregates (gravel, crushed stone, sand, recycled concrete). And guess what: concrete is 100% recyclable and can go back into concrete as a recycled aggregate or into other applications (e.g. road base). Another interesting fact is that concrete is such a durable material that structures can last for decades, or even centuries! We have all heard of the Channel Tunnel, but what you probably did not know is that the concrete used to build it is contractually guaranteed to last at least 120 years!
- According to the Commission’s figures, approximately one third of all waste in Europe comes from construction and demolition. Only one third of that amount is recycled and it’s not technical difficulties that prevent a higher recycling rate. It’s market realities. Proof of that is that recycling rates greatly differ between European Member States with a 95% recovery rate in The Netherlands, for instance, against a European average varying between 30% and 60%. We are not alone in tackling this challenge. We will call upon the other material producers in the construction industry to work together and improve the collection and sorting of demolition waste and in creating an economically viable system encouraging its use.
- Through The Concrete Initiative, we have tried to focus on each of the three pillars of sustainability and how concrete can contribute to each of them. When giving equal weight to each of these three pillars, we need to carefully assess requirements such as on minimum recycled content which has sometimes been suggested: in imposing such requirement, it is crucial to look beyond the product and assess other economic costs or environmental impacts that can be generated. By way of an example, it would not make sense to transport concrete over long distances in order for it to be reused in a building when there is an option of recycling it in a different application (e.g. road base) but do so locally.