The recycling of waste materials such as plastic, cardboard, glass and metals is one of the most talked about in the world of waste management. However, there is a segment that also has great potential and which seems to have been forgotten. In this case, we are referring to waste generated within the construction and demolition sector (CDW). This waste must find a second life where it can add value and take centre stage, thus being able to maximise the benefits of a circular economy.
What is construction and demolition waste or CDW?
Construction and Demolition Waste (CDW) is waste generated in the activities and processes of construction, restoration, rehabilitation, demolition and remodelling of buildings and infrastructures. This debris, which is generated in the aforementioned construction processes, can occur in different ways and in different processes that make up the entire construction site.
According to the latest report from the National Institute of Statistics, construction and demolition waste amounted to 21,579 thousand tonnes. As early as 2008, the production and management of this waste category was regulated in Spain by Royal Decree 105/2008.
One of the aspects covered by this Royal Decree in the obligations of the producer is to include in the project the operations of reuse and recovery of this waste. What does it mean to recover waste? According to Directive 2008/98/EC it is "any operation the main result of which is that the waste serves a useful purpose by replacing other materials that would otherwise have been used to fulfil a particular function, or that the waste is prepared to fulfil that function, in the facility or in the economy in general".
The Centro de Estudios y Experimentación de Obras Públicas (CEDEX) has created a catalogue of applications of recycled construction and demolition waste that you can consult and filter with different options. As it is well known, the concept of construction and demolition refers to activities related to the construction, repair, renovation or demolition of real estate (buildings, roads, ports, airports, railways, dams, etc.). In addition, works that modify the ground or subsoil are included in this list, e.g. excavations.
Types of construction and demolition waste or CDW
The identification of the waste to be generated is coded according to the European Waste List codes (EWL) and the most common are the following:
- 01 waste from prospecting, mining and quarrying and physical and chemical treatment of minerals.
- 07 wastes from organic chemical processes.
- 08 wastes from the manufacture, formulation, distribution and use (MFSU) of coatings (paints, varnishes and vitreous enamels), adhesives, sealants, and printing inks.
- 13 waste oils and liquid fuels (except edible oils and those in chapters 05, 12 and 19).
- 14 waste organic solvents, refrigerants and propellants (except 07 and 08).
- 15 packaging wastes; absorbents, wiping cloths, wiping cloths, filter materials and protective clothing not otherwise specified.
- 16 wastes not otherwise specified in the list (Vehicles of various means of transport, Batteries and accumulators, ...).
- 17 Construction and demolition wastes (including excavated soil from contaminated sites).
- 20 municipal waste (household waste and similar waste from businesses, industries and institutions), including selectively collected fractions.
This type of industrial waste comes mostly from demolition of buildings, rejected building materials from new construction sites and from construction/refurbishment work on housing estates, also known as "rubble". And although the treatment of rubble has evolved, a large part of this waste is transported to landfills without being treated, generating a negative environmental impact and leaving aside the extraction of reusable materials. It is also necessary to monitor the evolution of the flow of CDW waste generated in order to optimise waste management. The latest figures for 2018 show that the generation of this waste increased by 105.3% compared to 2014 and the total amount of tonnes generated was 14,697,525, affirming that the trend of this category is constantly growing.
In conclusion, the generation of CDW is increasing more and more and this forces the subjects of the circular economy to manage waste in the best possible way, by converting them into recycled construction materials. As a curious fact, the homes we will occupy in the not too distant future will be designed and composed almost entirely of recoverable elements and many waste managers will have to face new challenges, optimising the reuse of waste and generating value and wealth. Thus, the importance of recycling will be increasingly.