Why focus on concrete?

End-of-life (EOL) concrete accounts for some 80% of construction and demolition waste (C&DW). In turn, C&DW accounts for about one third of the controlled solid waste streams within Europe.

The recycling of EOL concrete into new concrete is therefore one of the most interesting options for reducing worldwide resource use as well as emissions associated with the building materials sector. At this time, most EOL concrete from C&DW is crushed and used in road construction. Despite this being a useful application, however, it is not sustainable in the long run. Moreover, it leaves unused a significant part of the intrinsic economic and ecological value of EOL concrete. If we could turn EOL concrete into a high-grade secondary raw material resource, it could be reused in new buildings. By creating such a sustainable parallel outlet, the price for EOL concrete would tend to increase, which would safeguard the advances made in effective dismantling and selective demolition.

The present technologies available to recycle EOL concrete are too energy intensive and are associated with high CO2 emissions, while the quality of the secondary raw material is unclear to stakeholders. The new C2CA technology aims to increase environmental performance such as a reduction in CO2 emissions and standardized online quality control.

The concept of urban mining, i.e. optimized local recycling of C&DW, may replace a substantial part of conventional mining for primary raw materials (silica, clay and limestone) by which it reduces the depletion of resources and saves valuable and ecologically vulnerable regions. Since the new C2CA technology allows for local re-use of up to 80% of the waste materials at the building demolition site, transport of building materials will be reduced significantly.