This report argues that recycling concrete reduces natural resource exploitation and waste going to landfill. It asks for an ultimate goal of “zero landfill” of concrete.
The CSI hopes that raising awareness of concrete recycling will promote discussion among all relevant stakeholders and lead to an increase in recycling of concrete. Cement producers can indirectly support this through the work of subsidiaries in the concrete, aggregates and construction industry.
Concrete is the second most consumed material after water and it shapes the built environment. An estimated 25 billion tonnes of concrete are manufactured globally every year. It is a material that can last for a very long time, and most concrete waste is generated not because the concrete is worn out, but usually because the structure itself has become redundant with changing infrastructure needs and planning.
Global data on concrete waste generation is not available, but data is collected in some countries, for example in the US, Japan and Europe where approximately 900 million tonnes of construction and demolition waste (containing between 20% and 80% concrete) are generated yearly. However, different definitions and measurement methods make a comparison very difficult.
While in some countries near full recovery of concrete is achieved, in most parts of the world the potential to recover concrete is overlooked and it ends up as unnecessary waste in landfill. This is generally the result of low public concern, as the waste poses relatively low hazard risks compared to other materials.
The recovery of concrete falls between standard definitions of reuse and recycling: concrete is broken down into aggregates (granular material), generally to be used in road works, but also as aggregates in new concrete. Recovering concrete has two main advantages: it reduces the use of new virgin aggregate and the associated environmental costs of exploitation and transportation, and it reduces landfill of valuable materials.
The CSI recommends that governments and key stakeholders publicize data on construction and demolition waste and develop reliable and consistent statistics; that they develop economic incentives and legislation to allow infrastructure that promotes concrete recycling (particularly green building schemes); and that they set targets for the use of recycled concrete in both road construction and building industries.