Case study: Reuse of hollow concrete slabs from Ikea Kållered

When the old Ikea store in Kållered outside Gothenburg was demolished, a unique opportunity arose to test the large-scale reuse of prestressed concrete elements. In close collaboration between RISE, NCC, and Framtiden Byggutveckling, around 3,000 square meters of hollow core slabs (HD/F) were dismantled, quality assured, and given new life in the Kvarteret Återbruket residential district in Gothenburg.

Hollow concrete slabs are prefabricated, prestressed concrete elements that combine high load-bearing capacity with good possibilities for both dismantling and reassembly. In the project, the geometry and reinforcement could be verified against manufacturing documentation from 1971, which provided a basis for a reliable service life assessment – in a similar indoor environment to that for which they were originally intended.

RISE methodology for quality assurance of reclaimed concrete elements

Within the framework of the Vinnova-funded Återhus project, RISE has developed a four-step methodology for quality assurance:

Documentation analysis
Site visits with non-destructive testing
Sample collection and laboratory testing
Statistical analysis and conclusions

The methodology has been tested in several demo projects and forms the basis for ongoing Swedish standardization work.

Technical assessment and service life

RISE carried out both non-destructive and destructive testing. The results showed:

Good remaining load-bearing capacity
Low durability risk
Estimated remaining service life of up to 224 years in a dry indoor environment

From demolition to assembly – logistics and production

Dismantling, ID marking, temporary storage, and assembly were carried out in the spring of 2024. Assembly went faster than planned thanks to good planning and collaboration. The project shows that logistics and storage space are crucial for cost-effective reuse.

Climate benefits and economics

The project reported climate savings of approximately 37 kg CO₂e/BTA in A1–A3 and 10 kg CO₂e/BTA in A4 compared with newly produced hollow concrete slabs. Economic analyses showed that modular design and minimized processing are key to good economics.

From practice to standard – towards the construction of the future

The experiences from Ikea Kållered and Kvarteret Återbruket have contributed to the development of a Swedish methodology for assessing the service life of prefabricated elements. This methodology forms the basis for standardization work within SIS TK 191, with the potential to cover more element types than hollow concrete slabs.