Opportunities for a circular economy
Infrastructure construction is raw-material intensive and produces a significant amount of CO2 emissions. Marjo Koivulahti, from Ramboll, a global engineering, architecture and consultance company, is the project manager of UUMA4 programme, working with both the public and private sectors to promote the usage of recycled materials within earth construction in Finland. According to Koivulahti, natural rocks could be replaced with recycled materials acquired from surplus land, industrial byproducts and waste, as well as mildly contaminated soil and materials from old ground works. Koivulahti and her team are also looking into the increased usage of crushed concrete aggregate, mineral slag and ash from waste incineration.
The goal of the UUMA programmes is to reduce the environmental footprint of construction by replacing natural resources with recycled materials. The programme focuses on the promotion of sustainable material solutions and the commercialisation of recycled materials. UPM, which together with energy company Pohjolan Voimais participating in the UUMA4 programme, views ash e.g. as a construction material that could be used more than at present.
Recycled fibres can account for up to 100% of the paper produced by UPM, according to Michael Heberle, UPM’s Central European Byproducts Manager, and Heiko Hilbert, Project Manager at UPM. “From the ash that is generated we manufacture our commercial CINERIT® products, which can be used, for example, as a raw material for cement and in soil stabilisation,“ says Heberle. “Our other product, ELURIT®, can in turn replace caustic soda. At UPM we use our ELURIT® product for bleaching pulp, instead of using sodium hydroxide. The third product to use ash is ENVIROFIL®, a filler that has been able to replace a significant amount of calcium carbonate used in our paper products.”
UPM’s ash-based innovations are carbon-neutral and can reduce the need for natural resources, as well as reduce a company’s carbon footprint.
“Much of a company’s carbon footprint comes from the transportation of materials. Therefore, it usually makes sense to favour local materials. But using recycled materials to replace highly polluting cement-based soil stabilisers can reduce a company’s carbon footprint, even if they have to be brought in from further away,” says Koivulahti.
The challenges of a circular economy
The environmental benefits of recycled materials are undeniable, but there are still challenges when it comes to taking advantage of these opportunities. Hilbert points out that waste still has a bad reputation and Koivulahti agrees: “Waste-derived recycled materials are associated with misconceptions that have led to doubt in the construction industry.”
Bureaucracy also poses barriers to the use of recycled materials, as with many other innovations. “The challenges are legal restrictions on products made from waste, the excessive duration of the approval process and a myriad of regulatory differences between countries and regions. Differences in the views of decision makers and the lobbying that supports them also bring their own challenges, and then there is the simple reluctance to change familiar practices. The introduction of waste-based technology is also slowed down by a downturn in investments, especially in the paper industry,” Koivulahti continues.
Koivulahti also has experienced the challenges of infrastructure projects which arise from scheduling issues, lack of temporary storage space and long processing times for environmental permits. Fortunately, experts see several solutions to these challenges. For example, the percentage of recycled materials used per project could be regulated by law. According to Heberle, this would save raw materials and minimise both CO2 emissions and energy consumption.
Heberle believes that the EU's sustainable construction strategy could be extended to all waste-based products in addition to other building materials. Legislation plays a key role in encouraging the development of waste technologies and in demonstrating the value of investing in them.
The path to commercialisation
CINERIT®, ELURIT and ENVIROFIL® are already commercial products in Austria and Germany. According to Hilbert, it is important to show other industries how UPM's waste-based products are implemented in different mills. Production lines utilising recycled materials play a crucial role in the development of processes and new innovations.
“Up-to-date communication is essential to increase the acceptance of recycled materials in civil engineering. Their use can be significantly promoted by commercialising materials and developing construction technology, as well as design and procurement processes,” concludes Koivulahti.