Tunnel formwork also for non-standard shapes
In collaboration with HSB Bouw Volendam, we have taken on an exciting challenge and are demonstrating to the construction industry that tunnel casting offers many more possibilities on the Twister and Tango project on Aziëweg in Haarlem.
The project site is located in the Schalkwijk district. Twister and Tango are two residential towers that will be situated in a beautiful rolling park being developed by the municipality of Haarlem.
The two residential towers have a very striking, round shape. The balconies are rotated by 90 degrees on each floor. The Twister residential tower has 14 floors and Tango has 11 floors. Each floor has five apartments.
It is very unique to carry out this project using tunnel formwork. We took on this challenge together with HSB Bouw. We opted for an approach that allows us to construct one floor in four pouring phases. Four tunnels, each with different dimensions, and two different table formworks are being used. The tunnels are all connected to each other, forming a single structure. The largest tunnel is located in the centre of the building.
This will be extended after day 1 for the second pouring day and then prepared again for the upper floor. Two narrow tunnels with table formwork opposite each other form a whole for the corners. Two concrete columns will be placed in the table formwork, which will be poured immediately.
Hendriks designed many components, supports and scaffolding especially for this project. In addition to the table formwork, the support structures for the prefabricated balconies were also specially tailored to this project. The balconies are rotated 90 degrees per floor. Every corner and every layer is different. Because adjustment devices have been installed at multiple positions, the balconies can always be adjusted precisely. With the necessary additions and reinforcements to the tunnels, it is possible to place the balconies on the tunnels.
For this project, we constructed a test setup of the tunnels with the prefab balcony slabs on top at the Hendriks site. Hendriks organised a day for a number of HSB Bouw employees to view the test setup. They were also given a tour of the factory and the Hendriks site.
By daring to think in terms of tunnel construction, not shying away from challenges, experienced people, a good tunnel team, knowledge and close cooperation between Hendriks and HSB Bouw, it has been proven that tunnel formwork offers a wealth of possibilities.
