Photo: Heikki Vuorinen
It is worth considering carefully whether the demolition of buildings is necessary at all. Concrete is after all an ever-lasting material. It can be found in buildings that are 2,000 years old and still standing today. And when the production of new materials accounts for a large part of carbon emissions from construction, the demolition of old buildings can seem wasteful.
There is a lot of effort going into avoiding demolition, with buildings being repurposed, refurbished and retrofitted where possible to bring them up to modern standards. But sometimes demolition is the only choice. For example, urbanization can require that buildings in cities need to be removed to make way for bigger developments that can house the increasing numbers of people moving in. And that in turn can mean there are many empty buildings left behind in the countryside.
We do recycle concrete today from some demolished buildings, but the process is not efficient. It involves crushing the old concrete, which requires a lot of energy, and only produces low-value gravel or aggregate suitable for road construction and landscaping.
So wouldn’t it be great if we could find an economically viable way to reuse actual concrete components from buildings due for demolition. If we could take those components and use them in new constructions? It would reduce both the energy used for crushing and the need to produce new materials. With the carbon footprint of reused concrete elements at just 5 percent of corresponding new elements*, the sustainability benefits would be huge.
ReCreating a way to deconstruct
At Skanska in Finland, we are helping to make reuse a reality by working with partners in ReCreate. This four-year EU-funded research project involves the deconstruction of a 1980s Skanska-owned seven-floor concrete office building in Tampere. Our site managers have led the deconstruction, which has included the careful removal of entire beams, columns and hollow core slabs. These components are now being tested and refurbished at a specialist factory, after which they will be used in a new construction project.
Our many partners in the project include Umacon, a specialist demolition and recycling company, and Consolis Parma, a precast concrete manufacturer which is ensuring the components’ compliance with structural and architectural design requirements. Tampere University is coordinating the project.
Pioneering work
This is pioneering work that is pushing towards circular construction by investigating how to create a whole new ecosystem for deconstruction and reuse. Extracting entire elements from old buildings is expensive. Reuse often requires off-site factories for refurbishment as well as the creation of an entire logistics chain and information management process to put the elements to use again. A marketplace may also be necessary to bring product providers and users together.
We are using the ReCreate project to develop new technological solutions and processes, and find a profitable business model for deconstructing and reusing concrete components that we need.
Our involvement in the ReCreate project will help us achieve our goal of achieving net-zero carbon emissions by 2045. Every country in the EU has set targets to achieve net-zero quite quickly, and this will be one way to reach those targets.
We will still need to produce new materials. But I am confident that we will find a profitable business model for reuse that will be a global game-changer when it comes to demolition. It is a very exciting project to be involved in.