MiniCO₂ CONCRETE reuses concrete from demolished 1960s modernist social housing
Reused concrete from Gellerupparken in Aarhus finds new life in Fredericia in the Danish apartment building project. Besides reuse, the project features innovative ways to use new concrete to lower its climate impact to below 5 kg CO₂eq/m²/year in a Danish comparative case building project.
The project explores how to minimise the climate impact of new construction only using concrete – partly through reuse – in the comparative study building MiniCO₂ Multi-Storey Building CONCRETE.
The project is initiated by Realdania By & Byg and is a collaboration with CEBRA, SØREN JENSEN, Bo Michelsen A/S, Slaatto Morsbøl, Byggeselskabet C.F. Hansen ApS, and Kingo.
The team will shed light on how to build in concrete with a low climate impact without compromising on quality and comfort. The apartment building consists of five dwellings across five floors, situated in Kanalbyen, Fredericia, Denmark.
Paving the way for a low-carbon future
Concrete is the most used building material in Denmark and globally. Therefore, it is crucial to identify and showcase how to use concrete for low-carbon construction as a stepping stone to decrease concrete production and use, innovate construction practices, and find alternatives with zero impact on the climate boundary of the planet.
Currently, the team experiments with the technique of spolia – an ancient concept referring to the reuse of fragments from earlier constructions in new buildings.
The ancient Greeks reused column fragments, statues, and gravestones as building blocks in new walls because construction materials were expensive and time-consuming to produce.
In practice, the reused fragments come from a concrete building in Gellerupparken, which Kingo is currently demolishing. A team of experts will now carry out a series of experiments with the elements to determine how the concrete should be dismantled, crushed, and cut.
These elements will be used, among other places, in the building’s foundation, creating a decorative feature.
While experimenting with reused elements, the team also works to minimise the parts constructed with new concrete, such as columns, floor slabs, load-bearing walls, and staircases. Advanced digital tools are employed here, focusing on slimmer structures and reduced material use.
The team is also investigating various options for how the new cement can be mixed.
Low-emission building designed for comparison
The project is one of three comparative study buildings made of concrete, wood, and bricks in the 'Udviklingsbyggerierne MiniCO2 etagehusene TRÆ, TEGL og BETON' project series by Realdania By & Byg.
The project series objectively assesses which material functions better and has the lowest climate impact, both as a whole and for the separate building components.
The ambition is for carbon emissions from materials to fall below 5 kg CO₂ eq/m²/year, equivalent to approximately 7.3 kg CO₂ eq/m²/year when including operational energy. This target is significantly below the Danish Building Code’s requirement of 12 kg CO₂ eq/m²/year and well beneath the average level for new multi-storey residential buildings in Denmark, which is around 9.6 kg CO₂ eq/m²/year. The buildings will achieve a DGNB Gold certification.
In the comparative study, Realdania By & Byg will focus on:
– How much CO₂ the buildings emit per square metre per year over 50 years
– How the used building materials affect the climate and environment
– How the materials function in terms of humidity, fire, and acoustics
– The impact of the building processes on the surroundings during construction
– The time it takes to construct the buildings
– The cost of constructing the building
– The indoor climate of the buildings
– How living in the homes is experienced
To ensure that any observed differences between the buildings stem from the material in question, the buildings are built from the same pre-conditions. The buildings have the same volume and height, the same geographical location, and face the same directions. They have the same budget, the same function, and approximately the same layout plan with five apartments.
Project details
Location: Kanalbyen, Fredericia, DK
Size: 600 m²
Client and initiator: Realdania By & Byg
Function: Housing
Completion (expected): 2025
Architect: CEBRA
Engineer: SØREN JENSEN A/S
Contractor: Bo Michelsen A/S
Concrete reuse experiments: Slaatto Morsbøl, Byggeselskabet C.F. Hansen ApS, and Kingo
Read more
About the concrete-based MiniCO₂ Etagehus BETON with additional info here
About the mono-material building series MiniCO₂ Etagehusene
For further information