Construction waste is one of the biggest environmental problems today. The increase in waste generation is particularly noticeable in large cities around the world, where the construction sector continues to grow and is responsible for the movement of sizable amounts of materials or the consumption of resources, such as in new developments, renovations and eliminations of existing structures. Hence, the topic is attracting interest among research centers that recognize the need for changes in waste management, its proper disposal and sustainable use of natural resources.
Increasing attention is being paid to the reuse of waste to produce new materials that could be successfully used in the construction of houses, roads or other construction elements, proposing a number of solutions. Thanks to such measures, the amount of greenhouse gases emitted into the atmosphere is reduced, the extraction of natural resources is reduced, landfills are treated as a source of raw materials, and the amount of waste there is depleted.
main assumptions of circular economy + implementation
This concept, also known as the circular economy (GOZ), involves the reuse of properly processed (through a process of renovation, upcycling, renewal) building materials in subsequent construction projects. According to the idea of circular economy, already at the stage of construction and erection of a new building, such technologies and methods are selected so that the buildings can be dismantled rather than demolished. This is because it has been noted that the gradual dismantling of a building and the simultaneous sorting of demolition materials allows as much as 60-90% of the materials to be processed and reused. This is a solution that has been used for many years in Western European countries, the United States, Japan or Singapore. In Poland, this topic is not yet so well developed. One of the demolition materials is concrete rubble, which, after processing, can be successfully used as an ingredient in new concrete (in the Netherlands in 1995 an order was imposed that it should make up at least 20% of the material produced).
The circular economy also favors the environment. This is because huge amounts of natural resources are extracted every year (for example, in 2021 it was 100 billion tons), of which a small percentage (8.6%) is reused. The construction sector consumes about 50% of them, additionally contributing to climate change and environmental destruction by producing about 40% ofCO2 emissions and 30% of global waste. Unused reused waste is dumped in landfills, occupying more and more space, which is a problem for humans (residential buildings and accompanying infrastructure are built at a considerable distance) and biodiversity (its development is not possible amid harmful substances and lack of access to development - land, water, sun).
need for change = development opportunities for companies
In order to reduce waste, minimize greenhouse gas emissions or limit the extraction of natural resources in the coming years, companies will have to adapt to EU legislation aimed at halting climate catastrophe. It will therefore be necessary to slowly implement changes to business models that are commonly used in the construction sector and supply chains. The breakthrough on the economy will not only carry restrictions and the need to fit into a strictly defined and imposed pattern, the benefits - those environmental, social and financial - will also be visible. The circular economy is about educating the consumer to make informed purchasing choices - for example, anti-consumer behavior, or as a result of purchasing too much of a particular product, the ability to share with others. This builds good relationships and spreads cooperation. The development of the labor market from the need to adapt previously used materials is also anticipated, as evidenced by the emergence of entirely new types of establishments with specialties in refurbishing, upcycling or recycling. In the current situation, a good solution and one of the first steps towards a change for the better is, for example, to recycle construction waste in the form of rubble in those areas in Poland that are farthest from the source of obtaining and processing natural aggregates. This will save money on transporting and storing construction waste, since all of it will be carried out at the site of the construction debris. According to estimates by the European Parliament, by 2030 the closed-loop economy is expected to create 2 million new so-called "green jobs" and increase EU GDP by 0.8%. For this to happen, a lot of investment is needed in Poland, as well as the adaptation of the finance and insurance sectors in the idea of the closed-loop economy, as well as infrastructural, technological and organizational changes. For the moment, according to a report prepared by the Institute for Innovation and Responsible Development INNOWO, Norwegian strategy agency Natural State and Dutch non-profit organization Circle Economy, "Circular Restart! Polish Circularity Gap Report," Polish industry uses only 10.2% of waste, meaning that only 1 kg is recovered from 10 kg, and the greatest neglect is seen in the construction and agri-food sectors. Comparatively, in Spain and Luxembourg recycling is about 10%, in Italy and Ireland about 55%, and in Germany, Denmark and the Netherlands as much as 90%, so there are noticeable differences in waste management methods, the sources of which are to be found in social policy that builds environmental awareness of the population, owned infrastructure, level of technology or economic development.
ceramic aggregate
Photo: 652234 | © Pixabay
Alternative aggregates - an example of circular economy
Aggregate is one of the basic raw materials used by man since the beginning of civilization, now used as a basic ingredient in concrete. Originally, this loose, granular material was mined in natural or anthropogenic deposits and then mechanically processed to produce a material used in construction. However, the development of science makes it possible to make changes without further disturbance of natural deposits, proposing alternative aggregates, which include the following groups: artificial aggregates, recycled aggregates or waste (secondary) aggregates.
glass aggregate
Photo: Larisa Legzdina | © Pexels
The most interesting suggestions are:
- recycled concrete aggregate (KRB),
- aggregate from recycled brick material (KRC),
- aggregate from waste glass (KRSz),
- recycled plastic material,
- aggregate from wood waste,
- aggregate from tires,
- aggregate from electrical and electronic waste (e-waste).
Despite their potential and many favorable parameters, alternative aggregates cannot fully replace those extracted naturally due to their weaker properties: strength, frost resistance, chemical resistance (i.e., increased absorption of chlorides, sulfates and other harmful substances from outside, which cause chemical corrosion of concrete, among other things) or increased porosity and shrinkage. The above-mentioned products are still being improved, and new solutions are being developed. It is now possible to partially use/substitute them, for example, in horticulture or green roofs, where high strength is not required.
Construction waste, after cleaning and appropriate processing, can be used in the production of full-value products used in construction. The rapidly growing industrial, transportation and construction sectors require large quantities of construction aggregate. The benefits of using alternative aggregates include: reducing costs associated with transportation and extraction, stopping landscape and environmental degradation.
Dominika Grzesik
A participant in the Open Eyes Economy Young project
funded by Iceland, Liechtenstein and Norway from the EEA Funds under the Active Citizens - Regional Fund Program.
Literature/resources:
70 percent of construction waste to be reused (kierneksurowce.pl)
Aggregates magazine Elamed, Media Group, October-December, 4/2016
