In the Geneva municipality of Prégny-Chambésy, Implenia is building a new administration building in the heart of the Quartier des Nations. The "Pregny Park Center" is located just 200 meters from the WHO (World Health Organization) and 500 meters from the ILO (International Labour Organization) - in the middle of a 4,500 square metre wooded park.
"Green" is not only the surroundings, but also the piles that were used to hold the ground to construct the basement floors of the building. Implenia's specialist civil engineering department recently completed an excavation pit enclosure consisting of overlapping piles held in place by HEB and ROR steel supports. Around 1,870 cubic meters of concrete were required for the piles.
"In collaboration with our civil engineer AB Ingénieurs SA, we decided to make these piles from recycled concrete1," explains Alain Coudurier, Technical Manager and Project Manager, Civil Engineering. The recycled concrete aggregates are integrated into the concrete mixes (ECOPact+2) at our local partner Holcim Granulats et Béton SA and come from demolition concrete from Geneva construction sites. This pays off in terms of sustainability: Local recycled concrete conserves natural resources, shortens transportation routes and makes a valuable contribution to the circular economy by reusing materials.
In terms of mechanical strength, workability and durability, the piles made from recycled concrete are comparable to those made from standard concrete. "This was demonstrated by our preliminary tests and the tests we carried out throughout the project," says Alain Coudurier. In addition, around 95% of the HEB profiles and ROR pipes used for the excavation support will be reused by Implenia in future construction projects.
The "Pregny Park Center" will be completed in 2025 and will offer over 3,260 square meters of office space in a modern and bright architecture.
1 Concrete according to SN EN 206 and Code of Practice SIA 2030:2021
