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When you need 229,000 m2 of hollow-core it’s good to have reliable suppliers nearby

Hollow core slabs

When you have a project as large as the Karolinska University Hospital, there are plenty of requirements for the superstructure supplier. The operators chosen for the task were Benders Byggsystem (previously Skanska Stomsystem) and Contiga. We talked to the suppliers about their involvement in the NKS project.

Read the project description of Karolinska University Hospital here.

Reliable manufacturing

The Benders factory supplied the superstructure elements for the parking building, technical building, and the hospital itself. The elements ranged from hollow-core slabs, wall panels and facades to concrete columns and beams and steel structures.

In total, Benders delivered 164,000 m2 of hollow-core slabs over a two-year period from the Skanska factory conveniently situated on the outskirts of Stockholm. The factory’s hollow-core line – supplied by Elematic – has a capacity of 150,000 m2 per annum. Benders needed to be sure that everything would run as planned.

“We just kept making 380 mm slabs, and the line continued to run as expected,” applauds Thomas Axelsson, Business Director of Benders Byggsystem, who was responsible for the technical specifications of the project.

Specific precast requirements

Given the flexible design of the hospital, the floor panels needed to meet specific load and vibration requirements. The vibration requirements stemmed mostly from the functional needs of x-ray machines, while the load requirements arose from the desire to move heavy equipment flexibly over the entire lifetime of the building.

“Originally, the load requirements were set at 10 kN per m2,but they were brought down to 6 kN over the course of the project,” says Axelsson.

Giant onsite office

Valued at 700 million crowns, the superstructure deliveries of Benders were completed as planned. Axelsson is pleased to note that his team met the delivery schedules and technical specifications.

“This was by far my biggest project ever. To provide some perspective: there was a point when Skanska’s onsite office at NKS was the second largest Skanska office in the country, which is quite remarkable for a makeshift onsite construction.”

Thomas Axelsson

Thomas Axelsson
Business Director
Benders Byggsystem

Benders Byggsystem’s deliveries to NKS

  • 164,000 m2 of hollow-core slabs
  • 80,000 m2 of wall panels
  • 7,600 m2 of steel structures
  • 5,200 m2 of concrete columns and beams

Elematic’s deliveries to Benders

  • Elematic PRO hollow-core slab line (6 beds) and tilting tables with FaMe fastening method for wall panel production.

Modern solutions demand flexibility

The project was very important for Contiga as well. It was the largest project in company history and Contiga’s first hospital project with Skanska.

Contiga delivered and assembled phases 4 and 5 – the two highest buildings with the most floors. One building even had a helicopter platform, which placed high demands on the slabs.

Contiga delivered almost 30 percent of the hollow-core slabs of the whole NKS project. There were numerous special requirements for the precast concrete elements, including high loads.

“Another requirement was the extreme flexibility needed for the MRI scanners used throughout the building. MRI scanners demand floor structures capable of handling certain frequencies, and we chose our HD 380 hollow-core slabs for this purpose. The customer also had strict requirements concerning possible future changes in the apertures of the slabs,” says Project Manager Magnus Hellgren.

Time was also a factor. Every detail of the project had to be planned carefully since many agents were operating in the large work area at the same time.

“The entire project progressed as planned,” Hellgren commends.

Magnus Hellgren

Magnus Hellgren
Project Manager

Contiga’s deliveries to NKS

  • 65,000 m2 of hollow-core slabs
  • 42,000 m2 of wall panels
  • 1200 tons of steel

Elematic’s deliveries to Contiga

  • Contiga: Elematic PRO hollow-core slab line (5 beds) and molds with FaMe fastening method for wall panel production.


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