Circularity as a waste management strategy for the built environment

Circular construction is an emerging business strategy that promotes the reuse and recycling of as many raw materials as possible in a bid to minimise CO2 emissions and waste to landfill. Circular construction, as an important component of sustainable development, is focused on promotion of the maximum reuse and recycling of raw materials and products to reduce waste and CO2 emissions. Reduce, reuse, recycle and recover are essential interventions for a circular construction, with a systemic shift in the culture and mind-sets of stakeholders. This section focuses on Construction and Demolition Waste (CDW) and how potential new technologies developed for other applications can be utilised to bring circularity to CDW management.

Reduced carbon production of raw materials with less imperfections and better circular construction models are at the forefront of the built environment’s agenda. However, technical issues, such as price, legal barriers and regulations that stand in the way of the solutions being rolled out more widely must be overcome. The new CDW management systems are designed to maximise the recycling of construction, demolition and excavation waste and maximise the production of high quality, high value recycled sand and aggregates which can be used as a replacement for natural resources in a range of products including concrete and asphalt production.

New digitised platforms and innovative technologies are being developed and implemented for efficient waste management practices to reach full circularity. The target is systems that could be used in waste treatment plants or machines to make collection, sorting, treatment and recovery of secondary raw materials from waste more efficient. Systems that are capable of carrying out the sorting of mixed waste using robotic technologies are paramount. Smart bins with sensors for material detection or level measurement, methods for digital image analysis and new business models are already being developed. For example, K-project: Recycling and Recovery of Waste 4.0 - ‘‘ReWaste4.0” showcases developments in projects that focus on digitalization and the use of robotic technologies in waste management. Collection and logistics, machines and waste treatment plants, business models and data tools are four important pieces of achieving circular waste management within the built environment.

Many countries have made significant progress in developing circular practices and strategies for their CDW management. For example, the nation-wide circular economy program in the Netherlands, Circular Dutch Economy by 2050 specifies that the construction industry should adopt more innovations, e.g., circular and modular construction to reduce the construction waste. Many CDW management initiatives are also emphasised in the European Union’s Action Plan for the Circular Economy, including promoting sorting systems, encouraging recycling and design improvements to contribute to circular construction across Europe. It is important to focus more on developing cutting-edge recycling technologies to have more upcycling options for construction waste into high-performing products, rather than just focusing on processing construction waste with a view to relieving the burden on their environment, for which more down-cycling options may emerge.